United States v. Kenneth Sadler ( 2022 )


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    Pursuant to Sixth Circuit I.O.P. 32.1(b)
    File Name: 22a0012p.06
    UNITED STATES COURT OF APPEALS
    FOR THE SIXTH CIRCUIT
    ┐
    UNITED STATES OF AMERICA,
    │
    Plaintiff-Appellee,      │
    >        Nos. 19-2217/2221/20-1177
    │
    v.                                                    │
    │
    KENNETH SADLER (19-2217/2221); DEMARCO TEMPO                │
    (20-1177),                                                  │
    Defendants-Appellants.            │
    ┘
    Appeal from the United States District Court for the Eastern District of Michigan at Detroit.
    Nos. 2:16-cr-20414; 2:18-cr-20221—Sean F. Cox, District Judge.
    Argued: October 26, 2021
    Decided and Filed: January 21, 2022
    Before: DAUGHTREY, COLE, and CLAY, Circuit Judges.
    _________________
    COUNSEL
    ARGUED: David M. Burgess, Dearborn, Michigan, for Appellant Kenneth Sadler. Phillip D.
    Comorski, Detroit, Michigan, for Appellant Demarco Tempo. Daniel R. Hurley, UNITED
    STATES ATTORNEY’S OFFICE, Detroit, Michigan, for Appellee. ON BRIEF: David M.
    Burgess, Dearborn, Michigan, for Appellant Kenneth Sadler. Phillip D. Comorski, Detroit,
    Michigan, for Appellant Demarco Tempo. Amanda Jawad, UNITED STATES ATTORNEY’S
    OFFICE, Detroit, Michigan, for Appellee.
    _________________
    OPINION
    _________________
    CLAY, Circuit Judge. Defendants Demarco Tempo and Kenneth Sadler challenge the
    judgments in their criminal cases after a jury convicted them on various drug, gun, and
    Nos. 19-2217/2221/20-1177                United States v. Sadler, et al.                             Page 2
    obstruction of justice charges. Defendant Demarco Tempo appeals his convictions and sentence
    on a drug conspiracy charge under 
    21 U.S.C. §§ 841
    (b)(1)(A)–(C), 846; drug possession and
    distribution charges under § 841(a)(1), (b)(1)(C); and a drug possession and distribution near a
    school charge under §§ 841, 860. Defendant Kenneth Sadler challenges his convictions and
    sentence on a drug conspiracy charge under 
    21 U.S.C. §§ 841
    (b)(1)(A)–(C), 846; a drug
    possession and distribution near a school charge under §§ 841, 860; a felon in possession of a
    firearm charge under 
    18 U.S.C. § 922
    (g)(1); a conspiracy to obstruct justice charge under
    § 1512(k); and witness tampering charges under § 1512(a)(2)(A). For the reasons discussed
    below, we AFFIRM Tempo’s convictions and sentence, AFFIRM Sadler’s convictions, but
    VACATE Sadler’s sentence, and REMAND for a new trial on the sole question of whether
    Sadler was within the chain of distribution as required before imposing an enhanced sentence
    under 
    21 U.S.C. § 841
    (b)(1)(C).
    I. BACKGROUND
    A. The “Polo” Operation
    Between 2012 and 2016, people in east Detroit could buy heroin and crack cocaine at all
    hours of the day and night by calling one of two different phone numbers and going to a set
    location where they would meet someone to buy drugs. Those who used this drug dealing
    system called it “Polo.” (See Jamie Dabish Trial Test., R. 705, Page ID #3943, #3959; Marko
    Tomic Trial Test., R. 721, Page ID #5662; David Grzywacz Trial Test., R. 722, Page ID
    #5855).1
    The Warren City Police Department—in conjunction with the Drug Enforcement
    Administration (“DEA”) and the Federal Bureau of Investigation (“FBI”)—began investigating
    “Polo” in 2016. The investigation led to a large takedown operation. Law enforcement arrested
    thirteen “Polo” members, and the government charged them with multiple drug trafficking
    1This  appeal arises from two separate cases in the Eastern District of Michigan, Nos. 2:16-cr-20414 and
    2:18-cr-20221. The cases were joined for trial. Unless otherwise noted, citations to the record refer to the
    consolidated docket for all Defendants in Case No. 2:16-cr-20414. There are a small number of citations to the
    record in the separate, but related, case against only Kenneth Sadler, Case No. 2:18-cr-20221. Citations to that
    record will provide the case number.
    Nos. 19-2217/2221/20-1177         United States v. Sadler, et al.                     Page 3
    offenses. Most Defendants pleaded guilty. Only Tempo and Sadler proceeded to trial. The trial
    lasted nineteen days, and the witnesses included “Polo” customers, law enforcement officers,
    paramedics, acquaintances, medical and forensic experts, and one of the alleged co-conspirators
    (and co-Defendants). The government also introduced physical evidence from surveillance
    operations and property searches. This evidence tells the story of a sophisticated and well-
    organized drug trafficking scheme called “Polo.” The government alleges that Tempo led this
    operation and that Sadler—Tempo’s half-brother—participated.
    1. Customer Testimony
    Ten “Polo” customers testified at Defendants’ trial. Each bought drugs from “Polo”
    many times—some hundreds of times, and often multiple times a day. They each described
    buying drugs from “Polo” in the same way. First, customers called one of two phone numbers:
    one ending in x3399, the other ending in x5598. Customers “could call th[ose] phone[s] . . .
    24/7,” and they were “always available.” (Olivia Palazzola Trial Test., R. 715, Page ID #5369).
    Many customers said that the same person “[u]sually, but not always” answered the phone.
    (Jennifer Pointer Trial Test., R. 717, Page ID #5533; see also Dan Magda Trial Test., R. 722,
    Page ID #5898 (stating the same person answered “[m]ost of the time”); Hannah Fenn Trial
    Test., R. 715, Page ID #5275 (stating “it sounded like the same person” who answered, and that
    “maybe once or twice somebody else had answered”)). However, a few believed that different
    people answered the phones. Some customers called and asked for “Polo” or called the person
    who answered “Polo.” But the person answering did not identify himself, and customers never
    met anyone who introduced himself as “Polo.” Even so, customers understood “Polo” to mean
    “one person.” (Pointer Test., R. 717, Page ID #5530).
    On this first call, the person who answered the phone directed the customer to a meeting
    spot, usually one of five locations in east Detroit:     Hamburg Street, Dresden Street, the
    intersection of Bradford Avenue and Bringard Drive, the intersection of Seven Mile Road and
    Gratiot Avenue, or the intersection of Eight Mile Road and Hoover Road. At the meeting spots,
    cars often “lined up” waiting to buy drugs. (Tomic Test., R. 721, Page ID #5665). Once the
    customer arrived, a “runner” would approach her. (Christina Yako Trial Test., R. 723, Page ID
    ##5990–91). Runners were people who “went around and sold the drugs for whoever was in
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 4
    charge.” (Pointer Test., R. 721, Page ID #5603; see also Yako Test., R. 723, Page ID #5990
    (describing a “runner” as the one who “comes out and gives the drugs real quick, and just . . .
    goes back in”)). Customers met different runners depending on when and where they bought
    drugs. Sometimes the runner had the drugs on him, but sometimes he went “around the corner of
    a [vacant] house . . . and then [he] would come ba[ck] with the drugs.” (Grzywacz Test., R. 722,
    Page ID #5860). Runners were usually alone and often on foot. Occasionally, however, the
    runner would be in a van or car when approaching the customer. If the runner was in a car, he
    was usually with two or three other people.
    After a runner approached the customer, the customer placed an order. If the customer
    wanted heroin, she asked for “boy,” and if she wanted crack cocaine, she asked for “girl.”
    (Palazzolo Test., R. 715, Page ID #5345; Dabish Test., R. 705, Page ID #3958). The drugs were
    packaged in small plastic bags about 0.5 to 1.5 inches in size, and each small bag cost $20.
    Sometimes the runner took the small bag of drugs out of a larger “sandwich bag that had . . .
    little bags in it.” (Pointer Test., R. 717, Page ID #5537). After serving a customer, the runner
    “would walk up to the next car or walk back where they came from.” (Palazzolo Test., R. 715,
    Page ID #5351).
    One runner, Amacio Alexander, testified at Defendants’ trial. In May or June 2016, a
    man known as “Mr. Howard” recruited Alexander to sell drugs. (Amacio Alexander Trial Test.,
    R. 705, Page ID ##4032–35). Alexander’s job was to stand on Hamburg Street and “[s]ell a little
    product.” (Id. at Page ID #4040). On a typical day, he sold drugs to about 50 customers.
    Mr. Howard gave him the drugs to sell in a sandwich bag with about 50 small, prepackaged bags
    of drugs. Alexander usually sold three or four sandwich bags—roughly 150 to 200 small,
    individual bags—each day. He sold each bag for $20, and, when he ran out, Mr. Howard found
    him, took the money from earlier sales, left, and returned with a replenished bag of drugs.
    2. Undercover Purchases
    As early as 2013, the FBI began investigating drug trafficking activity on the east side of
    Detroit in connection with the name “Polo.” As part of this investigation, the FBI set up two
    undercover purchases using a confidential informant. On January 29, 2013, the informant called
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                       Page 5
    the x3399 phone number and was directed to Gratiot Avenue and Whittier Street. He bought
    three bags—0.175 grams—of heroin for $55. On November 1, 2013, the informant called the
    x3399 number again and was directed to a house on Hamburg Street. The informant bought two
    small bags—0.14 grams—of heroin for $40.
    Between April 19, 2016, and June 14, 2016, Officer David Villerot with the Warren City
    Police Department carried out eighteen more undercover purchases. He bought drugs from
    “Polo” in the same way as all the other “Polo” customers. Officer Villerot or his informant
    called the x3399 number; met runners at different places including Hamburg Street and the
    intersection of Bringard and Bradford; asked for certain drugs—for example, “two boy;” and
    paid $20 for each small plastic bag of drugs. (David Villerot Trial Test., R. 709, Page ID #4529,
    #4539, ##4545–46, #4572, #4582).
    3. Nature of the Substances
    “Polo” sold both heroin and crack cocaine. In early 2016, customers started noticing a
    change in “Polo’s” heroin. Until then, the heroin was “brownish,” (Randy Odish Trial Test., R.
    717, Page ID #5429), or “light gray,” (Tomic Test., R. 721, Page ID #5668). But in early 2016,
    the heroin changed color; it was lighter—“like a light beige . . . [or] an off-white color.”
    (Palazzola Test., R. 715, Page ID #5359). Customers also noticed that the texture changed; the
    heroin was now more “powder[y],” (Fenn Test., R. 715, Page ID #5279), or “crystally,” (Tomic
    Test., R. 721, Page ID #5677), when it previously came as a “chunk” and was more rock-like,
    (Grzywacz Test., R. 722, Page ID #5862; Haggart Test., R. 722, Page ID #5785). One customer
    was so confused by the sudden change in the heroin’s appearance that he called the x3399 “Polo”
    number back and said, “I wanted heroin, not crack,” to which the person answering said, “This is
    heroin.” (Odish Test., R. 717, Page ID ##5437–38, #5440). “Polo” customers and street-level
    dealers called this lighter drug “White China,” (Dabish Test., R. 705, Page ID #3969), “kill shit,”
    (Villerot Test., R. 709, Page ID #4554; Fenn Test., R. 715, Page ID #5279), or “Russian white,”
    (Yako Test., R. 723, Page ID #5978).
    This lighter, powdery heroin was more potent.           Noticing the change in potency,
    customers were no longer “sure how much [they] could do or how much [they] would need for
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 6
    the day.” (Palazzola Test., R. 715, Page ID #5353). One customer reacted differently to this
    heroin; she became ill and vomited after using it. Some suspected that this lighter heroin
    contained fentanyl. One “Polo” runner told a customer that this heroin was “good stuff” because
    it was cut with fentanyl. (Magda Test., R. 722, Page ID #5910).
    As part of the ongoing investigation, police ran several laboratory tests on “Polo” drugs.
    These tests showed that sometimes “Polo” sold pure heroin.             In sixteen out of eighteen
    undercover purchases, Officer Villerot bought pure heroin from “Polo.” But sometimes “Polo’s”
    heroin was cut with fentanyl. On April 19, 2016, Officer Villerot bought 0.23 grams of a
    substance containing “detectable amounts of heroin and fentanyl,” (Villerot Test., R. 709, Page
    ID #4548), and on March 17, 2016, a customer bought drugs from “Polo” that contained
    “detectable amounts of fentanyl and heroin,” (Pointer Test., R. 721, Page ID #5583). Sometimes
    “Polo” sold pure fentanyl. On May 30, 2016, Officer Villerot bought 0.28 grams of pure
    fentanyl from “Polo.” On March 30, 2016, police seized 0.028 grams of pure fentanyl from a
    “Polo” customer. And on March 29, 2016, police seized 0.107 grams of pure fentanyl from a
    “Polo” customer.
    4. Overdoses
    Around the same time that customers noticed a difference in “Polo’s” heroin, law
    enforcement officers and paramedics noticed an uptick in opioid overdoses in Warren, Michigan.
    Many of the witnesses had overdosed—or saw friends overdose—on “Polo’s” drugs. Some
    overdosed on the lighter, more potent heroin. The charges against Tempo and Sadler involve
    five overdoses by four different victims.
    a) Christina Yako
    Christina Yako overdosed on February 20, 2016. Randy Odish testified that he was with
    Yako that night and that they called the x3399 number to buy heroin. Phone records confirmed
    that Odish called the x3399 number that night. The heroin they bought was lighter in color and
    “look[ed] different.” (Yako Test., R. 723, Page ID #5976; Odish Test., R. 717, Page ID #5438).
    They went back to Odish’s house and used the drugs. Yako did not mix her drugs with anything,
    but she had used Xanax earlier that day. Odish used the drugs first, and he warned Yako not to
    Nos. 19-2217/2221/20-1177                   United States v. Sadler, et al.                                   Page 7
    do too much because they were very strong. Immediately after Yako injected the drugs, she
    “passed out;” she “could hardly breathe,” “[h]er lips [turned] bluish-purple,” and “she [began]
    bleeding from her mouth.” (Odish Test., R. 717, Page ID ##5443–44). Odish then called the
    police.
    When the paramedics arrived, they found Yako face-down in a pool of vomit. Her
    fingertips and lips were blue, and she was taking only four to six breaths per minute—a rate
    which is not life-sustaining. The paramedics administered Narcan2 intranasally, at which point
    Yako began breathing more rapidly, her vitals improved, and the paramedics transported her to
    the hospital.       At the hospital, doctors administered a second dose of Narcan—this time
    intravenously—and Yako became fully alert. The hospital did not give her a urinalysis or blood
    toxicology test. The government’s expert witness, Dr. Mills, testified that Yako’s medical
    condition was consistent with an opioid overdose—either on heroin or fentanyl—and that,
    without medical attention, she would have died.
    b) David Grzywacz
    David Grzywacz overdosed on February 26, 2016. He said he bought the drugs from
    “Polo.” Phone records showed that he called the x5598 “Polo” number eight times that day. The
    only time Grzywacz noticed a difference in “Polo’s” heroin was on the day he overdosed when
    the drug appeared powdery and lighter. He used the heroin immediately after purchasing it, and
    the next thing he remembers is waking up in an ambulance.
    The paramedics found him in the passenger seat of a car at a gas station. When they
    arrived, they suspected an opioid overdose. At that time, Grzywacz was taking only four breaths
    per minute.         The paramedics moved him into the ambulance and administered Narcan
    intravenously. Grzywacz responded well to the Narcan; his breathing returned to normal, and
    the paramedics transported him to the hospital. The hospital did not give him a urinalysis or
    blood toxicology test. Dr. Mills testified that Grzywacz’s medical condition was consistent with
    an opioid overdose and that he likely would have died without medical intervention.
    2Narcan is like an anti-venom for opioids. It reverses the effects of opioid poisoning. The government’s
    expert witness, Dr. Kirk Mills, testified that a positive response to Narcan is “basically confirmation” that the patient
    had overdosed on an opioid. (Kirk Mills Trial Test., R. 703, Page ID #3865).
    Nos. 19-2217/2221/20-1177                United States v. Sadler, et al.                              Page 8
    c) Jennifer Pointer
    Jennifer Pointer overdosed twice, first on March 17, 2016, and again on March 30, 2016.
    Before either of her own overdoses, Pointer saw her friend, Dawn Boose, overdose on heroin
    from “Polo.”3 On February 19, 2016, Pointer bought heroin from “Polo” for her boyfriend,
    Boose, and herself. The heroin she bought looked lighter than usual. After snorting an entire
    $20 bag of heroin, Boose’s lips began turning blue, and her skin turned a gray color. Police and
    paramedics arrived, revived Boose, seized the remaining heroin that the group had not used, and
    arrested Pointer. Lab tests showed that the drugs had a detectable amount of both heroin and
    fentanyl.
    On March 17, 2016—St. Patrick’s Day—Pointer called the x3399 number and bought
    heroin from “Polo.” The evidence did not contain Pointer’s phone records from that day, but she
    remembered buying drugs at the intersection of Bradford and Bringard. She said she did not buy
    drugs from any other dealer or use any other drugs that day. The heroin she bought was lighter
    than usual and “looked the same” as it did on February 19, 2016—when Boose overdosed.
    (Pointer Test., R. 721, Page ID #5588). She snorted an entire $20 bag of heroin with her
    boyfriend.
    She woke up “violently ill” with paramedics surrounding her. (Id. at Page ID #5590).
    When the paramedics arrived, she was unresponsive and barely breathing with paraphernalia
    around her.       Paramedics administered two doses of Narcan—one intranasally and one
    intravenously. She became responsive after the second dose, walked to the ambulance herself,
    and was lucid when the paramedics transported her to the hospital. At the hospital, her doctors
    gave her a urine drug screen, which was positive for opiates and cocaine. But Dr. Mills testified
    that Narcan would have worked only if Pointer overdosed on opiates; it would not reverse a
    cocaine overdose. Dr. Mills concluded that this overdose was consistent with a heroin or
    fentanyl overdose and that, without medical treatment, it was “[m]ore likely than not [that] she
    would have died.” (Mills Test., R. 703, Page ID #3873).
    3The charges against Defendants do not involve Boose’s overdose, but the facts of this incident provide
    useful background for Pointer’s later overdoses.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                      Page 9
    Pointer overdosed again on March 30, 2016. This time she used Boose’s phone to call
    the x3399 “Polo” number because she did not have a phone at that time. Boose’s phone records
    showed three calls to the x3399 number that day. The drugs she bought this time were “light, but
    not white” like they were when Boose overdosed. (Pointer Test., R. 721, Page ID #5594). She
    and Boose used the drugs in a parking lot before driving to a nearby pain center. Boose snorted
    an entire $20 bag, while Pointer snorted one-half of a $20 bag. While Pointer was driving,
    Boose began to moan, and her lips turned blue. Pointer turned into the pain center parking lot
    and called 9-1-1.
    When police arrived, they searched Pointer and found “the other half of [her] bag of
    heroin” that she bought that day. (Id. at Page ID #5597). Officer Steiber—one of the police
    officers who responded to the scene—testified that, when he searched Pointer, he found “a small
    fold paper, which is consistent with the packaging for heroin.” (Jeffrey Steiber Trial Test., R.
    717, Page ID ##5504–06). Officer Steiber seized the substance, and test results concluded that it
    was 0.028 grams of pure fentanyl, which is “nine to ten times the lethal dose of fentanyl to your
    average adult.” (Mills Test., R. 703, Page ID #3877). Steiber handcuffed Pointer and put her in
    the back of the squad car. He walked away from the car momentarily, and, when he returned, he
    found Pointer unconscious with shallow breathing. The paramedics administered two doses of
    Narcan—one intranasally and one intravenously. After the second dose, “she became responsive
    almost immediately.” (Steiber Test., R. 717, Page ID ##5510–11).
    Pointer was taking Suboxone and Adderall at the time of both overdoses. At the hospital,
    Pointer’s urinalysis drug screen tested positive for amphetamines, cannabinoids, and cocaine—
    but not opiates. Even so, Dr. Mills said that Pointer’s responsiveness to Narcan indicated that
    she overdosed on opioids and that, unlike heroin, fentanyl “is not detected by that particular
    [urinalysis] drug screen.” (Mills Test., R. 703, Page ID ##3874–75, ##3877–78). He said that
    the cocaine and amphetamines (Adderall) “played no role” in her overdose. (Id. at Page ID
    #3878). Dr. Mills did not offer an opinion on whether Suboxone contributed to either overdose,
    but he did say that Suboxone would not appear on a urine drug test. Dr. Mills concluded that
    Pointer’s second overdose was “consistent with an opioid poisoning” and that, without medical
    attention, “she could have died.” (Id. at Page ID #3875, #3878).
    Nos. 19-2217/2221/20-1177                United States v. Sadler, et al.                              Page 10
    d) Anoosh Baghdassarian
    Anoosh Baghdassarian died on March 30, 2016, at 19 years of age. Baghdassarian’s
    friend, Marko Tomic, said that he and Baghdassarian bought heroin from “Polo” the day before
    she died.4 Tomic testified that he drove to Baghdassarian’s house, she came outside and got into
    his car, they called “Polo,” and then they went to buy heroin near Six Mile Road in Detroit.
    They then returned to Baghdassarian’s house.                 Tomic used the drugs in his car outside
    Baghdassarian’s house, but Baghdassarian did not use her drugs immediately; rather, she took
    them inside with her. After Tomic used the drugs, he fell asleep in front of Baghdassarian’s
    house. When he awoke, he began driving home. The police stopped him and arrested him for
    possession of a controlled substance. They seized the drugs that Tomic bought earlier that day
    with Baghdassarian, and lab results showed that they were pure fentanyl.
    At trial, Baghdassarian’s mother, Yvonne Baghdassarian, remembered that day somewhat
    differently. She recalled Marko Tomic—whom she called “Markos”—coming to their home
    around 4:30 p.m. (Yvonne Baghdassarian Trial Test., R. 721, Page ID #5648). But she said that,
    when he pulled up, she and Baghdassarian were in their car about to leave to take
    Baghdassarian’s brother to work. When Tomic arrived, Baghdassarian asked her mother to “just
    give [her] a minute.” (Id.) Baghdassarian walked to Tomic’s car, got inside, and “la[id] down
    under his window talking to him.” (Id.) After a few minutes, she got back in the car with her
    mother. In an earlier statement to police, Yvonne said that Tomic arrived at their home around
    3:30 p.m. and that Baghdassarian left with him for roughly one hour between 3:30 and 4:30 p.m.
    4The  phone records do not show any calls to the x5598 or the x3399 number from either Baghdassarian’s
    or Tomic’s phone on March 29, 2016. Between March 31, 2015, and March 6, 2016, phone records revealed 903
    contacts between Tomic’s number and the x5598 and x3399 numbers. But there were no contacts between Tomic
    and those numbers after March 6, 2016. Baghdassarian had two different phone numbers during the relevant period.
    Between September 8, 2015, and February 14, 2016, there were 259 contacts between her two phones and the two
    “Polo” phones. But neither of Baghdassarian’s phone numbers had any contacts with the “Polo” phones after
    February 14, 2016.
    But these “contacts” showed only phone calls and text messages, (Robert Witt Trial Test., R. 791, Page ID
    #8000), and one of Baghdassarian’s friends testified that Baghdassarian sometimes used an application on her phone
    to make phone calls. The phone data that investigators collected would not reflect any communication between
    Baghdassarian and the target phones that was conducted over a phone application—such as WhatsApp, GroupMe, or
    Facebook Messenger—rather than through a direct telephone call or text message.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                    Page 11
    However, at trial, Yvonne denied ever making that statement and said that Baghdassarian never
    left with Tomic.
    After Tomic left, Baghdassarian left with her mother. They dropped off her brother and
    picked up food from a McDonald’s restaurant before returning home around 9:00 p.m. Shortly
    thereafter, she told her mother that she was not feeling well and went to bed. Her mother stayed
    awake until 3:00 a.m. and twice saw Baghdassarian come out of her room to get water. Her
    mother left around 7:00 a.m. the next morning to pick up Baghdassarian’s brother from work.
    Around 9:00 a.m., Yvonne saw Baghdassarian in the kitchen eating leftover food from
    McDonald’s. But Baghdassarian subsequently went back to bed. When Yvonne went to check
    on Baghdassarian around 1:00 p.m., she found Baghdassarian face down on the floor and called
    9-1-1.    Between 9:00 p.m. on March 29 and 1:00 p.m. on March 30, Yvonne never saw
    Baghdassarian leave the house, never saw anyone come to the house, never saw Baghdassarian
    meeting anyone, and never saw anyone giving her anything.
    Officer Accivetti responded to the 9-1-1 call and found Baghdassarian in a cluttered
    bedroom and believed, upon seeing her, that she was already dead. He saw “a syringe near the
    deceased body on the floor, as well as a cigarette pack containing a bottle cap and some residue
    inside of it.” (Michael Accivetti Trial Test., R. 721, Page ID #5721). He said that these items
    are “commonly used to mix narcotics in, to inject inside the needle.” (Id. at Page ID #5722).
    These items were not taken into evidence or tested because Officer Accivetti did not collect
    them, believing that an evidence technician would do so.
    When paramedics arrived, they found Baghdassarian pulseless and breathless. They
    attempted to revive her with Narcan, but they were unsuccessful, and doctors declared her dead
    when she arrived at the hospital.     The medical examiner’s blood toxicology report found
    11 nanograms of fentanyl per milliliter of blood and 15 nanograms of alprazolam (Xanax) per
    milliliter of blood. Three nanograms of fentanyl per milliliter is considered a fatal dose. The
    medical examiner testified that Baghdassarian’s Xanax levels were “less than therapeutic”—or
    less than a safe prescription dosage—and concluded that she died of a fentanyl overdose.
    (Bernardine Pacris Trial Test., R. 723, Page ID #6047).
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                     Page 12
    5. Demarco Tempo’s Involvement with “Polo”
    Tempo was widely known by the nickname “Polo.” It started as “Marco Polo” but
    became just “Polo” over the years. (William Dennis, Sr. Trial Test., R. 713, Page ID #5179). As
    early as 2009, William Dennis, Sr.—the father of Tempo’s half-brother—saw Tempo cut up
    heroin, place it in small plastic bags, bundle those small bags together, and package them “into a
    sandwich bag for sale.” (Id. at Page ID ##5134–35, ##5140–41). Dennis also saw Tempo
    selling crack cocaine as early as 2013. Indeed, Dennis used to cook crack cocaine with Tempo,
    which Tempo later sold.
    Amacio Alexander—a “Polo” runner—identified Tempo in open court as the man to
    whom his boss, Mr. Howard, answered. Alexander interacted with Tempo a few times while
    selling drugs on Hamburg Street. The first time, Tempo turned to Alexander and told him that
    selling drugs “is grown-men business.” (Alexander Test., R. 705, Page ID #4038). The second
    time, Alexander handed the money from his drug sales directly to Tempo. Finally, Tempo gave
    Alexander a phone to use while selling drugs, and Tempo called that phone to tell Alexander
    when customers were coming.
    Other witnesses saw Tempo when they bought drugs from “Polo.”                During three
    undercover purchases in 2016, Officer Villerot saw Tempo driving the car as a passenger made
    the drug sales. Once, Officer Villerot saw the passenger hand Tempo the money from the sale.
    Phone tracking data put Tempo at the location of this deal at that time. Officer Villerot also
    identified Tempo’s voice in recorded calls from the FBI’s 2013 undercover purchases and his
    2016 undercover purchases.
    As early as 2009, Tempo listed his personal phone number as the x5598 “Polo” number.
    Tempo often carried two phones in his hands, and geolocation data showed that the x5598 phone
    and the x3399 phone were always together. Using geolocation data, police officers located the
    phones and used that information to pull Tempo over as he was driving home from a trip to
    Chicago. When Tempo got back from Chicago, officers tracked the phones as they stopped at
    each suspected “Polo” stash house “like clockwork.” (Craig Bankowski Trial Test., R. 708, Page
    ID #4427).
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 13
    Witnesses said Tempo’s phone was always ringing, with calls coming in every minute.
    After taking a call, he would “tell one of the other guys around to go meet somebody
    somewhere.” (Dennis Test., R. 713, Page ID #5158). Tempo occasionally entrusted the phones
    to “certain people,” but he was selective about who he trusted for this task. (Id. at Page ID
    #5163). When officers arrested Tempo on June 14, 2016, they found both the x3399 and the
    x5598 phones in the center console of his car.         The phones “wouldn’t stop ringing” and
    “consistently rang” until an officer turned them off. (Villerot Test., R. 710, Page ID ##4683–
    84).
    On June 14, 2016, officers searched various properties that had ties to “Polo” drug deals
    and to Tempo personally.
    15431 Spring Garden. Tempo bought this property from William Dennis. The DEA
    searched it and found a digital scale with white residue, large and small plastic bags, razor blades
    with white residue, and “other drug packaging material.” (Kevin Dailey Trial Test., R. 711, Page
    ID ##4859–61).
    19504 Strasburg. This house was seemingly vacant; no utilities ran to it, and it had a “for
    rent” sign out front. (Bankowski Test., R. 708, Page ID #4410). It is located within 1000 feet of
    a school. In 2014 and again in early 2016, Tempo paid Dennis to do some repairs on the
    property. While working, Dennis often saw Tempo in the house with other people. At times,
    Dennis saw large quantities of drugs and people packaging drugs into small plastic bags. Once,
    when Tempo was at the house, Dennis saw someone put a substance into his mouth, taste it, and
    then spit it out, saying: “That’s that fentanyl, I don’t want none of that shit.” (Dennis Test., R.
    713, Page ID #5171).       Tempo responded by saying: “That’s that strong[;] [t]hat’s what
    everybody want.” (Id.)
    Investigators said the house was a “Polo” “stash location” that operated “almost like a
    dispatch center.” (Bankowski Test., R. 708, Page ID #4352, #4357). Surveillance showed
    Tempo at the property “at least once a day.” (Id. at Page ID #4413). “Polo” members and
    runners—those involved in “hand-to-hand drug transactions,” (id. at Page ID #4363)—frequently
    came and went from the property. When officers searched it, they found: 16.7 grams of cocaine
    Nos. 19-2217/2221/20-1177            United States v. Sadler, et al.                      Page 14
    in a nickel-sized plastic bag, 138.3 grams of crack cocaine on a plate, a digital scale, razor
    blades, and plastic bags with white powder residue.
    24343 Flower. On May 23, 2016, during a traffic stop, Tempo told police that he resided
    at this home with a woman named Tachelle Harris. When officers searched the house on June
    14, 2016, they found 379.8 grams of cocaine in a plastic bag with Tempo’s fingerprints on it.
    The bag was in a shoebox under the bed in the master bedroom. Officers also found two digital
    scales in a cabinet and court documents with Tempo’s name on them.
    12634 Hamburg. “Polo” often sold drugs on Hamburg Street. A police informant bought
    drugs there as early as November 1, 2013, and Officer Villerot bought drugs there as late as May
    30, 2016. When customers went to Hamburg, they were sometimes told to park in front of, or
    even go inside, a blue house to buy drugs. On one occasion, “one of the people in the [“Polo”]
    organization” told a “Polo” customer, who was experiencing withdrawal symptoms, that she
    could go inside the house to use the heroin she bought. (Palazzola Test., R. 715, Page ID
    #5357). That customer used drugs in the house many times between late 2015 and early 2016,
    and she said that the house was vacant. When officers searched the property on June 14, 2016,
    they found digital scales, drug packaging materials, clear plastic bags, multiple dishes with
    suspected drug residue, and razor blades.
    6. Kenneth Sadler’s Involvement with “Polo”
    Sadler’s involvement with the drug scene traces back to 2009, when William Dennis saw
    Sadler with Tempo as Tempo cut heroin. Between 2009 and 2010, and again in 2015, Sadler
    told Dennis that “he could give [Dennis] the good heroin.” (Dennis Test., R. 713, Page ID
    #5146). In 2012, an informant working with the Sterling Heights Police Department set up two
    undercover purchases and bought $120 worth of heroin from Sadler. Sadler met the informant in
    a Meijer parking lot in Sterling Heights. He showed up in a car driven by a woman with children
    in the back seat. The police arrested Sadler for these sales. The Sterling Heights investigation
    was a “short term investigation;” it was not a part of a larger “Polo” investigation, and the officer
    did not know what phone number had been called to set up the deal. (Jason Modrzejewski Trial
    Test., R. 706, Page ID ##4279–81).
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                    Page 15
    Alexander never saw Sadler involved with “Polo” deals or with Alexander’s drug sales
    on Hamburg Street. When Dennis saw Tempo send runners to meet customers, Tempo never
    sent Sadler. Sometime in 2009 or 2010, Dennis saw Sadler arguing with Tempo for control of
    the “Polo” phones and customer base. Dennis also saw Sadler get angry when Tempo entrusted
    other people, but not Sadler, with more responsibility within “Polo” operations.
    On June 14, 2016, police arrested Tempo and found both phones. But one day later, the
    police received an “updated GPS ping” on the x3399 phone, showing that the phone tied to that
    number was no longer in the police station but was now at 15652 Eastburn. (Villerot Test.,
    R. 711, Page ID ##4932–34). Officer Villerot called the x3399 number, trying to set up another
    undercover purchase. A person answered the phone and directed him to a location. But when
    Officer Villerot called the x3399 number after he arrived, the person directed him to a different
    location.    After repeating this process two or three times, Officer Villerot abandoned the
    operation.
    While Officer Villerot was trying to set up a purchase, other officers were surveilling the
    15652 Eastburn house. They saw a man leave the house and get into a black Escalade. Police
    stopped that vehicle and found Sadler driving. Geolocation data put the x3399 number at the
    same location during the traffic stop. Officer Villerot called the x3399 number and saw the
    phone in the center console of the car ringing with Officer Villerot’s phone number displayed as
    the caller. The same process identified the x5598 phone in the center console. Officers then
    arrested Sadler.
    Earlier surveillance of “Polo” operations saw the same black Escalade—identified by its
    VIN and license plate number—near various “Polo” drug deals. When police searched the
    15652 Eastburn house, they found a digital scale—which is “commonly used for the weighing or
    separating of narcotics for prepackaged sales,” (Nicholas Lienemann Trial Test., R. 713, Page ID
    #5088)—a large bag with drug residue, sandwich bags, Noscapine—which is a popular heroin
    cutting agent—and a firearm and ammunition. Forensic testing found Sadler’s DNA on the
    firearm. Sadler’s children lived in this house with their mother, and officers found documents
    and other evidence indicating that Sadler resided there.
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 16
    B. Witness Tampering
    Two days after Sadler’s arrest on June 15, 2016, the court released him on bond. On June
    19, 2016, Sadler approached Alexander while Alexander was at his aunt’s house. Sadler drove
    up to the house in a black truck and, without getting out of the vehicle, approached Alexander
    and said, “Take back what you said. Don’t go to court or your family going to see your face on a
    T-shirt.”   (Alexander Test., R. 705, Page ID #4064).        Alexander believed this referred to
    “memorial T-shirt[s]” and believed it was a death threat. (Id.) The geolocation data on Sadler’s
    phone confirmed that he was near Alexander’s aunt’s house around the time of this incident.
    On March 23, 2018, Sadler’s attorney—Doraid Elder—gave Sadler the witness list in this
    case and reviewed grand jury testimony with him, including testimony from William Dennis.
    Around that time, Francine Leatherwood, Dennis’ mother, got a phone call from Sadler and his
    mother, Sheila Frill. Leatherwood knew them both well and recognized their voices. During the
    call, Sadler and Frill told Leatherwood that Dennis agreed to testify against Tempo and Sadler.
    They did not ask her to do anything, and they did not threaten her. After four to five minutes,
    Leatherwood ended the conversation by telling Sadler and Frill that she could not control her son
    and there was nothing she could do if Dennis wanted to testify. “[R]ight after” that phone call
    ended, Leatherwood got another call from a person whose voice she did not recognize.
    (Francine Leatherwood Trial Test., R. 791, Page ID ##7875–76). When she answered, the caller
    said, “Tell William to shut up or one of y’all are going to go missing.” (Id. at Page ID #7875).
    The caller then immediately hung up.
    Within a few days of this call, Sadler sent Andrea Leatherwood, Dennis’ sister, a
    Facebook message stating: “That’s crazy how your brother are main witness, but we telling on
    him. Little bro turn in his grave, that’s how shit . . . .” (Andrea Leatherwood Trial Test., R. 791,
    Page ID ##7883–84, ##7890–91).          She discussed the incident with her mother, Francine
    Leatherwood, and they realized that the Facebook message and phone call came just days apart.
    At that point, they notified the police about the messages and calls.
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 17
    C. Procedural Background
    A grand jury indicted Sadler and Tempo—along with several other co-Defendants—on
    drug and firearm-related offenses. Based on Sadler’s conduct while released on bond, the
    government brought additional charges against him for witness tampering and obstruction of
    justice. Sadler and Tempo proceeded to trial on all counts. Before trial, the district court denied
    Sadler’s motion to exclude the testimony of his former attorney, Doraid Elder. At trial, the court
    overruled Sadler’s objections concerning evidence of two drug sales to an undercover Sterling
    Heights police officer in 2012.
    At the close of the government’s evidence, both Defendants moved for judgments of
    acquittal under Federal Rule of Criminal Procedure 29. The district court reserved ruling on the
    motions until after trial, and ultimately denied both motions.
    The jury convicted Tempo on seven counts:           one count of drug conspiracy under
    
    21 U.S.C. §§ 841
    (b)(1)(A)–(C), 846; five counts of drug possession and distribution under
    § 841(a)(1), (b)(1)(C); and one count of drug possession and distribution near a school under
    §§ 841, 860. The court sentenced him to 30 years of imprisonment. The jury convicted Sadler
    on six counts: one count of drug conspiracy under 
    21 U.S.C. §§ 841
    (b)(1)(A)–(C), 846; one
    count of drug possession and distribution near a school under §§ 841, 860; one count of
    possessing a firearm as a convicted felon under 
    18 U.S.C. § 922
    (g)(1); one count of conspiracy
    to obstruct justice under 
    18 U.S.C. § 1512
    (k); and two counts of tampering with witnesses under
    
    18 U.S.C. § 1512
    (a)(2)(A). The court sentenced him to 20 years of imprisonment for the drug
    conspiracy and distribution offenses, 10 years of imprisonment for the firearm offense, and
    5 years of imprisonment for the obstruction of justice charges.
    On both Defendants’ conspiracy charges, the jury found that the crimes “resulted in the
    death . . . [and] serious bodily injury of another person.” (Def. Tempo Jury Verdict, R. 665, Page
    ID #3629; Def. Sadler Jury Verdict, R. 667, Page ID #3643). On Tempo’s drug distribution
    charges, the jury found that one count “resulted in . . . death” and four counts “resulted in . . .
    serious bodily injury.” (Def. Tempo Jury Verdict, R. 665, Page ID ##3629–31).
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 18
    Several months later, both Defendants filed motions for a new trial, which the district
    court denied. Both Defendants filed timely notices of appeal to this Court.
    II. DISCUSSION
    Defendants raise multiple challenges to their convictions and sentences. First, both argue
    that their convictions were not supported by sufficient evidence. Second, Sadler raises two
    evidentiary challenges. Third, both Defendants claim that the district court gave erroneous jury
    instructions. Finally, Tempo argues that he was sentenced under an unconstitutionally vague
    sentencing provision.
    A. Sufficiency of the Evidence
    In challenges under Federal Rule of Criminal Procedure 29, we review “de novo the
    sufficiency of the evidence to sustain a conviction.” United States v. Emmons, 
    8 F.4th 454
    , 477
    (6th Cir. 2021) (quoting United States v. Gunter, 
    551 F.3d 472
    , 482 (6th Cir. 2009)). When a
    defendant also argues that he was entitled to a new trial under Federal Rule of Criminal
    Procedure 33, the district court’s decision “is reviewed for abuse of discretion and granted only
    ‘in the extraordinary circumstances where the evidence preponderates heavily against the
    verdict.’” United States v. LaVictor, 
    848 F.3d 428
    , 455–56 (6th Cir. 2017) (quoting United
    States v. Hughes, 
    505 F.3d 578
    , 593 (6th Cir. 2007)).
    Under Rule 29, notwithstanding the jury verdict, “the court on the defendant’s motion
    must enter a judgment of acquittal of any offense for which the evidence is insufficient to sustain
    a conviction.” Fed. R. Crim. P. 29(a). “[A] defendant claiming insufficiency of the evidence
    bears a very heavy burden.” Emmons, 8 F.4th at 478 (quoting United States v. Abboud, 
    438 F.3d 554
    , 589 (6th Cir. 2006)). “In reviewing the sufficiency of the evidence, the relevant inquiry is
    whether, after reviewing the evidence in the light most favorable to the prosecution, any rational
    trier of fact could have found the essential elements of the crime beyond a reasonable doubt.”
    
    Id.
     at 477–78 (quoting United States v. Wallace, 
    597 F.3d 794
    , 800 (6th Cir. 2010)).
    “All reasonable inferences must be made to support the jury verdict.” LaVictor, 848 F.3d at 456
    (citing United States v. Wettstain, 
    618 F.3d 577
    , 583 (6th Cir. 2010)). “Circumstantial evidence
    alone is sufficient to sustain a conviction and such evidence need not remove every reasonable
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 19
    hypothesis except that of guilt.” 
    Id.
     (quoting United States v. Spearman, 
    186 F.3d 743
    , 746 (6th
    Cir. 1999)).   When considering the sufficiency of the evidence, we cannot “reweigh the
    evidence, reevaluate the credibility of witnesses, or substitute [our] judgment for that of the
    jury.” Emmons, 8 F.4th at 478 (quoting United States v. Callahan, 
    801 F.3d 606
    , 616 (6th Cir.
    2015)). Defendants challenge each of their convictions.
    1. Drug Conspiracy
    Both Defendants argue that their conspiracy convictions under 
    21 U.S.C. §§ 841
     and 846
    were not supported by sufficient evidence. Those sections prohibit conspiracies to distribute a
    controlled substance or possess a controlled substance with the intent to distribute. §§ 841(a)(1),
    846. “[T]o sustain a conviction for drug conspiracy under section 846, the government must
    prove beyond a reasonable doubt: (1) an agreement to violate drug laws; (2) knowledge of and
    intent to join the conspiracy; and (3) participation in the conspiracy.” United States v. Williams,
    
    998 F.3d 716
    , 728 (6th Cir. 2021) (quoting United States v. Gardner, 
    488 F.3d 700
    , 710 (6th Cir.
    2007)). “An agreement can be tacit, not formal, and the ‘government may meet its burden of
    proof through circumstantial evidence.’” 
    Id.
     (quoting United States v. Layne, 
    192 F.3d 556
    , 567
    (6th Cir. 1999)). In § 846 conspiracy cases, “circumstantial evidence that may establish that ‘a
    drug sale is part of a larger drug conspiracy’ includes advance planning, ongoing purchases or
    arrangements, large quantities of drugs, standardized transactions, an established method of
    payment, and trust between the buyer and seller.” Id. (quoting United States v. Deitz, 
    577 F.3d 672
    , 680–81 (6th Cir. 2009)).
    For starters, the jury could have found beyond a reasonable doubt that each “Polo” drug
    deal was “part of a larger drug conspiracy.” Williams, 998 F.3d at 728. “Polo” drug deals
    required significant advance planning.     Drugs were individually packaged and prepared in
    advance so that runners could make multiple sales before needing to replenish their stock. When
    customers called either “Polo” phone, they were directed to a specific location where a runner
    was nearby or waiting for them. “Polo” continuously sold drugs for many years. Customers
    often bought drugs from “Polo” hundreds of times over the course of three to four years. The
    sales were standardized. Indeed, customers used nearly identical procedures to buy drugs from
    “Polo.” “Polo” also handled large quantities of drugs. A single “Polo” runner would sell
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 20
    between 150 and 200 individual bags of drugs each day. The method of payment was consistent;
    each individual plastic bag of heroin consistently cost $20, and customers paid the runner in cash
    each time.   Finally, customers found “Polo” to be a reliable system, and both the person
    answering the “Polo” phones and the runners came to recognize loyal customers.
    Even though the evidence sufficiently showed that the “Polo” conspiracy existed, the
    government still had to prove that each Defendant joined that conspiracy. “[O]nce the existence
    [of] a conspiracy is shown, the evidence linking an individual defendant to that conspiracy need
    only be slight.” United States v. Caver, 
    470 F.3d 220
    , 233 (6th Cir. 2006) (citing United States v.
    Henley, 
    360 F.3d 509
    , 514 (6th Cir. 2004)). We address each Defendant in turn.
    a) Demarco Tempo
    The evidence sufficiently showed that Tempo was a member of the “Polo” conspiracy.
    Tempo went by the nickname “Polo,” and two insider witnesses testified that Tempo led all
    “Polo” operations. Dennis saw Tempo package and prepare drugs for sale. Tempo controlled
    the “Polo” phones. Records tie him to the x5598 “Polo” number as early as 2009. Geolocation
    data puts the x5598 phone, the x3399 phone, and Tempo in the same place on multiple
    occasions, and police found both of those phones in Tempo’s car when they arrested him. The
    only way that customers could buy drugs from “Polo” was by calling one of those two phones.
    Dennis saw Tempo answer his phones and immediately send runners to meet customers. While
    some customers said that multiple people answered the “Polo” phones, many said the same
    person answered most of the time. The same person answered each time Officer Villerot called
    to set up an undercover buy, and Villerot later identified that speaker as Tempo. The jury could
    have weighed this evidence and concluded that Tempo personally controlled those phones, the
    key to “Polo’s” success.
    Witnesses also saw Tempo at the scene during some sales. One saw a runner hand
    money from a drug deal directly to Tempo. Alexander said that he did that himself. Tempo
    oversaw runners in other ways too. Tempo gave Alexander a phone to use for drug deals and
    told him that selling drugs was “grown-men business.” (Alexander Test., R. 705, Page ID
    #4038). Even if Tempo never engaged in the hand-to-hand drug deals himself, the evidence
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                     Page 21
    sufficiently supports a finding that Tempo agreed with others—including runners and
    customers—to violate drug laws and that he knew about and participated in the “Polo”
    conspiracy. Tempo makes three specific arguments challenging this finding. Each is meritless.
    First, he argues that the government’s evidence “showed the existence of multiple
    conspiracies, not a single conspiracy as charged in the indictment.” (Def. Tempo Br. at 25). He
    argues that this mismatch between the indictment and the evidence was a prejudicial variance.
    Because Tempo did not raise this argument at trial, we review this allegation of a variance for
    plain error. Caver, 
    470 F.3d at 235
    . “A variance to the indictment occurs when the charging
    terms of the indictment are unchanged, but the evidence at trial proves facts materially different
    from those alleged in the indictment.” 
    Id.
     “Within the context of a conspiracy, a variance
    constitutes reversible error only if a defendant demonstrates that he was prejudiced by the
    variance and that the ‘indictment allege[d] one conspiracy, but the evidence can reasonably be
    construed only as supporting a finding of multiple conspiracies.’” 
    Id.
     at 235–36 (alteration in
    original) (quoting United States v. Warner, 
    690 F.2d 545
    , 548 (6th Cir. 1982)). “We ‘review the
    evidence as to the number of conspiracies in the light most favorable to the government,
    considering ‘the existence of a common goal, the nature of the scheme, and the overlapping of
    the participants in various dealings.’” Williams, 998 F.3d at 730 (quoting United States v.
    Williamson, 656 F. App’x 175, 183 (6th Cir. 2016)).
    Tempo asks us to focus on the relationship between him and the customers. He argues
    that this case presents a “rimless” wheel-and-spoke conspiracy “in which various defendants
    enter into separate agreements with a common defendant, but where the defendants have no
    connection with one another, other than the common defendant’s involvement in each
    transaction.” (Def. Tempo Br. at 26–27 (quoting Dickson v. Microsoft Corp., 
    309 F.3d 193
    , 203
    (4th Cir. 2002))). But “[a] single conspiracy does not become multiple conspiracies simply
    because each member of the conspiracy did not know every other member, or because each
    member did not know of or become involved in all of the activities in furtherance of the
    conspiracy.” Caver, 
    470 F.3d at 236
     (quoting Warner, 
    690 F.2d at 549
    ). Tempo’s argument
    ignores middlemen and runners like Mr. Howard and Alexander—with whom Tempo
    coordinated. Even if each “Polo” member did not know every other member or participate in
    Nos. 19-2217/2221/20-1177             United States v. Sadler, et al.                  Page 22
    every aspect of the conspiracy, the evidence sufficiently shows that “Polo” operations were
    interdependent and relied on a steady customer base, runners and middlemen, and higher-ups to
    answer the “Polo” phones, ensure runners had sufficient supplies, and choose the locations for
    deals. Thus, the jury could have found, beyond a reasonable doubt, that there was a single
    conspiracy to distribute and sell controlled substances based on evidence of “a regular pattern of
    distribution for a large quantity of drugs.” Caver, 
    470 F.3d at 236
    .
    Second, Tempo argues that he never conspired to distribute fentanyl in particular. But
    this proposition is both factually and legally flawed. Legally, “knowledge and intent to join the
    conspiracy includes that the defendant ‘was aware of the object of the conspiracy and that he
    voluntarily associated himself with it to further its objectives.” Williams, 998 F.3d at 729
    (quoting United Sates v. Hodges, 
    935 F.2d 766
    , 772 (6th Cir. 1991)). “[T]he government need
    not prove mens rea as to the type and quantity of the drugs in order to establish a violation of
    §§ 841 and 846.” Id. (internal quotation marks omitted) (quoting United States v. Villarce,
    
    323 F.3d 435
    , 439 & n.1 (6th Cir. 2003)). Therefore, even if Tempo was not personally aware
    that “Polo” was selling fentanyl, or cutting heroin with fentanyl, evidence showed that he
    “conspired to violate drug laws,” even if he did not conspire to distribute fentanyl specifically.
    See Williams, 998 F.3d at 728–29. Factually, the evidence showed that Tempo did know that
    “Polo” sold fentanyl. Dennis testified that—while doing repairs for Tempo at a suspected stash
    house—someone put a substance in his mouth and spit it out, saying, “That’s that fentanyl,
    I don’t want none of that shit.” (Dennis Test., R. 713, Page ID #5171). Tempo responded by
    saying, “That’s that strong[;] [t]hat’s what everybody want.” (Id.) We will not reweigh the
    weight and credibility of Dennis’ testimony, see Emmons, 8 F.4th at 478, and a rational jury
    could have relied on his testimony to conclude that Tempo was aware that “Polo” laced heroin
    with fentanyl or sold pure fentanyl.
    Finally, at base, Tempo asks us to reweigh the evidence and reevaluate the witnesses’
    credibility. Tempo highlights that Dennis and Alexander only testified to get lesser sentences in
    their own criminal cases and that “the rewards for these individuals were so substantial that they
    could not help but conform their testimony to the government’s theory of the case.” (Def.
    Tempo Br. at 29). He further suggests that Officer Villerot’s voice-identification testimony—
    Nos. 19-2217/2221/20-1177            United States v. Sadler, et al.                    Page 23
    identifying Tempo as the person answering the x3399 number during eighteen controlled
    purchases in 2016 and two controlled purchases in 2013—was not reliable because Officer
    Villerot had “only two brief contacts with Mr. Tempo and no expertise in voice identification.”
    (Id. at 28). But “determining the credibility of witnesses is a task for the jury, not this court.”
    United States v. Beverly, 
    369 F.3d 516
    , 532 (6th Cir. 2004) (citing United States v. Hilliard,
    
    11 F.3d 618
    , 620 (6th Cir. 1993)); see also United States v. Eaton, 
    784 F.3d 298
    , 305 (6th Cir.
    2015) (refusing to entertain the defendant’s argument that the jury should not have relied on
    inconsistent testimony from two “admitted perjurers” because “[t]he jury was entitled to believe
    the trial testimony of the two [witnesses]”).
    b) Kenneth Sadler
    Although a closer call, sufficient evidence also supported Sadler’s conspiracy conviction.
    Sadler argues that no rational jury could have found beyond a reasonable doubt that he knew
    about and intended to join the “Polo” conspiracy or that he participated in that conspiracy.
    “Knowledge and participation can be inferred from the defendant’s conduct, but mere
    association with members of the conspiracy is not enough to support such an inference.” United
    States v. Martinez, 
    430 F.3d 317
    , 334 (6th Cir. 2005) (citing United States v. Pearce, 
    912 F.2d 159
    , 162 (6th Cir. 1990)). “To be sure, knowledge and intent to join the conspiracy includes that
    the defendant ‘was aware of the object of the conspiracy and that he voluntarily associated
    himself with it to further its objectives.’” Williams, 998 F.3d at 729 (quoting Hodges, 
    935 F.2d at 772
    ). The defendant must be aware of the conspiracy’s “ultimate purpose.” 
    Id.
     (quoting
    United States v. Sliwo, 
    620 F.3d 630
    , 633 (6th Cir. 2010)). In a sprawling drug conspiracy like
    “Polo,” “it is enough to show that each member of the conspiracy realized that he was
    participating in a joint venture, even if he did not know the identities of every other member, or
    was not involved in all the activities in furtherance of the conspiracy.” Martinez, 
    430 F.3d at
    332–33.
    As discussed above, there is sufficient evidence demonstrating the existence of a “Polo”
    conspiracy. The question as to Sadler is whether there was even a “slight” connection tying him
    to that conspiracy. See Caver, 
    470 F.3d at 233
     (“[O]nce the existence [of] a conspiracy is
    shown, the evidence linking an individual defendant to that conspiracy need only be slight.”
    Nos. 19-2217/2221/20-1177                  United States v. Sadler, et al.                               Page 24
    (citing Henley, 
    360 F.3d at 514
    )). A rational jury could have found that Sadler knew the
    “ultimate purpose” of the conspiracy—to sell controlled substances—and that he intended to join
    and participated in the conspiracy.              As early as 2009—before the start of the alleged
    conspiracy—Dennis saw Sadler with Tempo as Tempo cut up heroin and packaged it for sale.
    Evidence also showed that Sadler wanted to be involved with “Polo.” At times, Sadler got angry
    when Tempo entrusted other people, but not Sadler, with more responsibility within “Polo”
    operations, and Sadler fought with Tempo over control of the “Polo” phones and customer base.
    This evidence shows Sadler’s agreement with “Polo” members and his intent to join the
    conspiracy.
    Evidence also showed that Sadler actually participated in the conspiracy. After police
    arrested Tempo on June 14, 2016, geolocation data showed that the x3399 “Polo” number moved
    to 15652 Eastburn, an address that Sadler often visited (and possibly where he resided), and
    where his children lived with their mother. When Officer Villerot called the x3399 number
    trying to set up another undercover purchase on June 15, 2016, a man answered the phone and
    directed Officer Villerot to a location. Ultimately, Officer Villerot abandoned this undercover
    purchase. Around the same time, officers saw Sadler leave the Eastburn house in a black
    Escalade that officers had previously seen near “Polo” drug sales. Officers pulled Sadler over
    and found both “Polo” phones in the car. When police searched the 15652 Eastburn residence,
    they found a digital scale, a large bag with drug residue, sandwich bags, Noscapine—which is a
    popular heroin cutting agent—documents with Sadler’s name on them, and a firearm and
    ammunition. The jury heard evidence that these objects are commonly associated with drug
    trafficking.5    While these facts may not be enough, standing alone, to support the jury’s
    conviction, together, this evidence shows that Sadler sought out more involvement and
    leadership within “Polo” and that he attempted to take over “Polo” operations after many “Polo”
    5The  government also points to evidence from two undercover drug purchases involving Sadler in 2012.
    During a “short term investigation,” an informant with the Sterling Heights Police Department bought $120 worth of
    heroin from Sadler. (Modrzejewski Test., R. 706, Page ID #4279, #4286). Sadler argues that this evidence was
    inadmissible. As discussed below, the district court abused its discretion by admitting this evidence. See infra Part
    II.B.1. Ultimately, however, there was sufficient evidence of Sadler’s involvement in the conspiracy even absent
    this fact.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                     Page 25
    members were arrested on June 14, 2016.         Combined, this amounts to sufficient evidence
    supporting the jury’s verdict.
    Sadler’s arguments do not undermine these key facts. Sadler points out that Alexander
    never saw Sadler involved with any “Polo” deals, and Tempo never used Sadler as a runner. But
    this evidence does not mean that Sadler could not have knowingly and intentionally joined the
    “Polo” conspiracy, nor does it preclude his involvement in other ways. See Martinez, 
    430 F.3d at
    332–33. The combination of Sadler’s desire for leadership within “Polo,” his possession of
    drug trafficking paraphernalia, and his possession of the “Polo” phones provided sufficient
    evidence for the jury to conclude beyond a reasonable doubt that Sadler was a co-conspirator.
    2. Drug Distribution Causing Serious Bodily Injury or Death
    Tempo next argues that there was insufficient evidence to support his five charges under
    
    21 U.S.C. § 841
    (a)(1), (b)(1)(C). He raises two issues in this regard: (1) whether he can be held
    liable for every “Polo” drug distribution under § 841(a), and (2) whether “Polo” drugs caused the
    death and injuries of the four overdose victims as required under § 841(b)(1)(C).
    a) Distribution
    Section 841(a)(1) prohibits the knowing or intentional distribution, or possession with the
    intent to distribute, of a controlled substance. 
    21 U.S.C. § 841
    (a)(1). There is no dispute that
    heroin, fentanyl, and crack cocaine are controlled substances. See § 812. As the district court
    instructed, there were three ways the government could have proven that Tempo was guilty of
    this crime:
    The first is by convincing [the jury] that [Tempo] committed or participated in
    this crime. The second is by showing that [Tempo] aided and abetted the
    commission of the charged offense. The third is based on the legal rule that all
    members of a conspiracy are responsible for acts committed by the other
    members, as long as those acts are committed to help advance the conspiracy, and
    are within the reasonably foreseeable scope of the agreement. This is often called
    “Pinkerton Liability.”
    (Jury Instrs., R. 662, Page ID #3580). Sufficient evidence would allow a jury to conclude,
    beyond a reasonable doubt, that Tempo was liable under any of these three theories.
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 26
    First, the facts show that Tempo acted as a principal—meaning a jury could have found
    him personally liable for distributing “Polo” drugs. The applicable statute defines “distribute” as
    “to deliver,” which in turn “mean[s] the actual, constructive, or attempted transfer of a controlled
    substance . . . , whether or not there exists an agency relationship.” 
    21 U.S.C. § 802
    (8), (11).
    “Although distribution may involve the actual or constructive possession of a controlled
    substance, ‘distribution’ includes other acts perpetrated in furtherance of a transfer or sale, such
    as arranging or supervising the delivery, or negotiating for or receiving the purchase price.”
    United States v. Colon, 
    268 F.3d 367
    , 377 (6th Cir. 2001). “Although it may be unusual for a
    person to distribute a controlled substance without at least momentarily possessing the controlled
    substance, it is not impossible.” 
    Id.
     (quoting United States v. Jackson, 
    213 F.3d 1269
    , 1296–97
    (10th Cir. 2000)); see also United States v. Waller, 
    503 F.2d 1014
    , 1015–16 (7th Cir. 1974)
    (finding constructive transfer when a mother told her daughter to hand the drugs to the buyer).
    Under this theory, the jury could have found that Tempo constructively distributed all of
    the drugs “Polo” sold because he planned and coordinated “Polo” drug deals. Tempo answered
    the “Polo” phones to set up buys; Tempo told runners to go meet customers; witnesses identified
    Tempo as the head of the “Polo” operation; and Tempo gave runners phones to use while selling
    drugs. This evidence sufficiently shows that Tempo led “Polo” operations and constructively
    participated in all “Polo” sales. Moreover, distribution accounts for the actions of agents. See
    
    21 U.S.C. § 801
    (8). Thus, a jury could have found Tempo directly responsible for drug sales that
    “Polo” members conducted on Tempo’s behalf or at his behest.
    Second, the jury could have found Tempo liable for aiding and abetting “Polo” drug
    sales. “To prove that [a defendant] aided and abetted drug transactions . . . the government must
    establish that [he] participated in the venture as something [] he wished to bring about and sought
    to make succeed.” Williams, 998 F.3d at 735 (quoting United States v. Ward, 
    190 F.3d 483
    , 487
    (6th Cir. 1999)). For the same reasons listed above, the jury could have found, beyond a
    reasonable doubt, that Tempo aided and abetted each “Polo” sale, including sales to the overdose
    victims.
    Finally, the jury could have concluded that Tempo was liable as a co-conspirator under
    Pinkerton v. United States, 
    328 U.S. 640
     (1946). “The Pinkerton doctrine permits conviction of
    Nos. 19-2217/2221/20-1177                  United States v. Sadler, et al.                               Page 27
    a conspirator for the substantive offenses of other conspirators committed during and in
    furtherance of the conspiracy.” United States v. Martin, 
    920 F.2d 345
    , 348 (6th Cir. 1990). “The
    doctrine holds that a member of a conspiracy is liable for ‘substantive offense[s]’ committed by
    his co-conspirators, even if he did not participate in them, as long as: (1) the offenses are ‘done
    in furtherance of the conspiracy,’ (2) they ‘fall within the scope of the unlawful project,’ and
    (3) they are reasonably foreseeable ‘consequence[s] of the unlawful agreement.’” United States
    v. Hamm, 
    952 F.3d 728
    , 744 (6th Cir. 2020) (quoting Pinkerton, 
    328 U.S. at
    647–48). Certainly,
    “Polo” drug sales meet these requirements; the entire point of “Polo” was to sell drugs. As
    discussed above, the jury’s conclusion that Tempo was a member of the “Polo” conspiracy was
    also supported by sufficient evidence. Therefore, under each of these three theories, a rational
    jury could have found beyond a reasonable doubt that Tempo was liable for each “Polo” sale—
    including the sales to the overdose victims.
    b) Resulting in Death or Serious Bodily Injury
    While § 841(a)(1) states the offense, § 841(b)(1)(C) imposes an enhanced sentence.
    Section 841(b)(1)(C) imposes a 20-year mandatory minimum sentence if a defendant violates
    § 841(a)(1) and “death or serious bodily injury results from the use of [the distributed]
    substance.” § 841(b)(1)(C). The death-or-injury-results enhancement “is an element that must
    be submitted to the jury and found beyond a reasonable doubt.” Burrage v. United States,
    
    571 U.S. 204
    , 210 (2014) (citing Alleyne v. United States, 
    570 U.S. 99
    , 115–16 (2013)). In
    Burrage, the Supreme Court held that, “at least where use of the drug distributed by the
    defendant is not an independently sufficient cause of the victim’s death or serious bodily injury,
    a defendant cannot be liable under the penalty enhancement provision of 
    21 U.S.C. § 841
    (b)(1)(C) unless such use is a but-for cause of the death or injury.”6 
    Id.
     at 218–19. “[B]ut-
    for causation exists where use of the controlled substance ‘combines with other factors to
    6“An   independently sufficient cause is not quite the same thing as a but-for cause.” Hamm, 952 F.3d at
    738 n.3 (citing Antony Honoré & John Gardner, Causation in the Law, Stanford Encyclopedia of Philosophy
    (Winter 2010 ed.), https://plato.stanford.edu/archives/win2010/entries/causation-law/). Although suggesting that an
    independently sufficient cause would satisfy the “results from” requirement, the Supreme Court in Burrage did not
    address that question. See Burrage, 571 U.S. at 210. Here, there is likely sufficient evidence that heroin and/or
    fentanyl were sufficient independent causes of the victims’ overdoses. Even so, there is also sufficient evidence that
    those substances were the but-for cause of the victims’ overdoses. Thus, we need not reach the issue of independent
    sufficient cause at this time. See Hamm, 952 F.3d at 738 n.3.
    Nos. 19-2217/2221/20-1177                 United States v. Sadler, et al.                               Page 28
    produce’ death [or serious bodily injury], and death [or serious bodily injury] would not have
    occurred ‘without the incremental effect’ of the controlled substance.” United States v. Volkman,
    
    797 F.3d 377
    , 392 (6th Cir. 2015) (quoting Burrage, 571 U.S. at 211). The government does not
    need to prove that the defendant directly delivered the drug to the injured or deceased person or
    even that a co-conspirator handed the drug to that person. United States v. Davis, 
    970 F.3d 650
    ,
    656 (6th Cir. 2020). Rather, “[t]he statute requires the government to prove only that the specific
    drug underlying a defendant’s violation of § 841(a) is the same drug that was the but-for cause of
    the victim’s death.” Id. The causation inquiry thus has two parts for each victim: (1) did the
    victim use “Polo” drugs, and (2) were those drugs the but-for cause of the victim’s overdose.
    Before turning to these victim-specific questions, Tempo argues that the government
    cannot establish causation without a blood test identifying the substances in the victim’s body at
    the time of the overdose. Of the four overdose victims involved here, only one—Anoosh
    Baghdassarian—received a blood toxicology test,7 and only one received a urine toxicology test.
    The district court rejected this argument and concluded that “there is no legal requirement that
    blood tests be admitted to establish that a serious bodily injury or death resulted from the use of a
    substance distributed by Tempo.” United States v. Tempo, No. 16-cr-20414, 
    2019 WL 5896138
    ,
    at *2 (E.D. Mich. Nov. 12, 2019) (citing Cockrell v. United States, No. 14-cv-175, 
    2017 WL 1088339
    , at *3 (E.D. Tex. Mar. 22, 2017)). We likewise decline to adopt a bright-line rule that
    but-for causation under § 841(b)(1)(C) requires evidence from blood toxicology tests. This is a
    matter of first impression before us, but our sister circuits have found but-for causation in
    overdose cases even without blood tests. See United States v. Harris, 
    966 F.3d 755
    , 759, 762
    (8th Cir. 2020) (finding but-for causation based on victims’ testimony and recollection); United
    States v. Lewis, 
    895 F.3d 1004
    , 1006–07, 1009 (8th Cir. 2018) (finding but-for causation based
    on medical expert testimony and lab-tested paraphernalia found at the scene). Only the Fifth
    Circuit has directly addressed this question. United States v. Cockrell, 769 F. App’x 116, 118
    (5th Cir. 2019). In Cockrell, the Fifth Circuit found that, even despite “the lack of medical
    testing of the victims,” the victims’ positive reactions to Narcan showed that they overdosed on
    7The  hospital ran a blood test on Jennifer Pointer, but it was not a blood toxicology test. Her doctors ran
    standard blood tests because she had pneumonia at the time. Dr. Mills relied on Pointer’s urinalysis tests—not the
    blood tests—to determine what drugs were in her system.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                    Page 29
    opioids. 
    Id.
     We agree with this conclusion. The absence of blood tests here does not undermine
    the jury’s finding that “Polo” drugs caused the victims’ overdoses. We must therefore determine
    whether sufficient evidence showed that each victim used “Polo” drugs and that those drugs
    caused the victim’s overdose. We have already presented many of the relevant facts. See supra
    Part I.A.4.
    i. Count 3: Christina Yako
    Sufficient evidence supported the jury’s conclusion that Yako overdosed on drugs she
    bought from “Polo.” She and her friend, Randy Odish, both testified that they bought heroin
    from “Polo” on February 20, 2016, shortly before Yako overdosed. Phone records showed that
    Odish called the x3399 number that evening. Immediately after using those drugs, Yako “passed
    out,” “[h]er lips [turned] bluish-purple,” and “she [began] bleeding from her mouth.” (Odish
    Test., R. 717, Page ID ##5443–44). When the paramedics arrived, she was taking only six
    breaths per minute, which is not life-sustaining. The paramedics and the doctors at the hospital
    administered two doses of Narcan, at which point Yako became fully alert. Dr. Mills testified
    that her medical condition was consistent with an opioid overdose—either heroin or fentanyl—
    and, without medical attention, she would have died.
    In arguing that this evidence is insufficient, Tempo highlights that Odish’s memory was
    clouded by past drug use, that he was a convicted felon, and that he had previously lied to law
    enforcement. He also highlighted inconsistencies in Yako’s testimony about whether she or
    Odish called the “Polo” phone. But these arguments amount to “non-reviewable credibility
    questions.” United States v. Whyte, 795 F. App’x 353, 363–64 (6th Cir. 2019). Tempo also
    argues that there were no phone records produced for either Odish’s phone or Yako’s phone that
    evening. This is simply incorrect. Evidence showed that Odish’s phone had “seven contacts”
    with the x3399 “Polo” number on February 20, 2016. (Witt Test., R. 726, Page ID #6393).
    Finally, Tempo argues that “because Yako injected Xanax all day long on February 20,
    2016, that drug could have independently caused” her overdose. (Def. Tempo Br. at 31). Yako
    admitted that she used Xanax that day, but the jury was entitled to credit Dr. Mills’ conclusion
    that Yako’s positive reaction to Narcan “shows that it was an opioid intoxication,” and that
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                     Page 30
    “[t]here was no other explanation for [her reaction to Narcan].” (Mills Test., R. 703, Page ID
    #3865). The jury could have concluded that this evidence established but-for causation despite
    Yako’s Xanax use. See United States v. Smith, 656 F. App’x 70, 74 (6th Cir. 2016) (finding
    sufficient evidence of but-for causation when victim had “numerous substances in her body,
    including a lethal dose of oxycodone,” which was the drug the defendant allegedly distributed).
    ii. Count 4: David Grzywacz
    Sufficient evidence supported the jury’s conclusion that Grzywacz overdosed on drugs
    he bought from “Polo.” Grzywacz called the x5598 “Polo” number eight times on the day he
    overdosed. He used the drugs right away, and the next thing he remembers is waking up in the
    ambulance. When the paramedics arrived, he was taking only four breaths per minute, which is
    not life-sustaining. Paramedics administered Narcan, and Grzywacz’s breathing immediately
    improved. Dr. Mills testified that his medical condition was consistent with an opioid overdose
    and that he likely would have died without medical intervention.
    Again, Tempo asks us to discredit Grzywacz’s testimony because he is “a twice
    convicted felon,” he is a “daily heroin user,” and he seemingly received a lesser sentence in his
    own criminal case after he cooperated against Tempo. (Def. Tempo Br. at 31). Again, we do not
    entertain such credibility arguments. See Emmons, F.4th at 616. Tempo also highlights that
    Grzywacz “us[ed] the same syringe for over a month” to inject drugs. (Def. Tempo Br. at 32).
    He thus argues that “[t]here was no way to determine if residue of prior uses of other drugs
    remained in the syringe barrel or needle, and if they contributed to [Grzywacz’s] overdose.”
    (Id.) We generally reject these kinds of arguments as mere “speculative possibilities already
    rejected by the jury.” United States v. Assfy, — F. App’x —, No. 20-1630, 
    2021 WL 2935359
    ,
    at *6 (6th Cir. July 13, 2021) (quoting United States v. Simer, 835 F. App’x 60, 65–66 (6th Cir.
    2020)). But, even if residue from other drugs got mixed up in the needle, that finding does not
    preclude but-for causation, which is met “where use of the controlled substance ‘combines with
    other factors to produce’” the overdose. Volkman, 797 F.3d at 392 (quoting Burrage, 571 U.S. at
    211).
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 31
    iii. Counts 5 & 7: Jennifer Pointer
    A rational jury could similarly conclude beyond a reasonable doubt that Pointer
    overdosed on drugs she bought from “Polo” on both March 17 and March 30, 2016. Pointer
    testified that she bought heroin from “Polo” at the intersection of Bradford Avenue and Bringard
    Drive on the day of her first overdose—March 17, 2016. She went home and snorted an entire
    $20 bag of heroin with her boyfriend. She testified that she did not buy drugs from any other
    dealer that day, and she did not use any other drugs.
    Paramedics arrived and found Pointer unresponsive and barely breathing with drug
    paraphernalia around her.     They administered two doses of Narcan, and Pointer became
    responsive after the second dose. At the hospital, doctors administered a urine drug screen,
    which was positive for opiates and cocaine. Dr. Mills testified that Narcan would only have been
    effective if Pointer had overdosed on opiates; it would not have reversed a cocaine overdose.
    Dr. Mills concluded that Pointer’s March 17, 2016, overdose was consistent with a heroin or
    fentanyl overdose and that, without medical treatment, it was “[m]ore likely than not [that] she
    would have died.” (Mills Test., R. 703, Page ID #3873). Tempo argues that Pointer was also
    taking Adderall and Suboxone at the time, which “alone could have caused her overdose.” (Def.
    Tempo Br. at 32–33). He further argues that Pointer’s urinalysis drug test was “not reliable.”
    (Id. at 33). But—for the same reasons as discussed above with Yako and Grzywacz—a rational
    jury could find that the urinalysis results, along with Dr. Mills’ testimony, demonstrated that the
    “Polo” drugs were the but-for cause of Pointer’s overdose. See Volkman, 797 F.3d at 392.
    On March 30, 2016, Pointer reported using Boose’s phone to call the x3399 “Polo”
    number. Phone records confirm that Boose’s phone called the x3399 number three times that
    day. Initially, police and paramedics arrived to treat Boose for an overdose. When police
    arrived, Pointer was still conscious. Police searched Pointer and found “a small fold paper,
    which is consistent with the packaging for heroin.” (Steiber Test., R. 717, Page ID ##5504–06).
    Officer Steiber seized the substance, and test results concluded that it was 0.028 grams of pure
    fentanyl, which is “nine to ten times the lethal dose of fentanyl to your average adult.” (Mills
    Test., R. 703, Page ID #3877). After Steiber handcuffed Pointer and put her in the back seat of
    the squad car, she fell unconscious. Paramedics administered two doses of Narcan, and after the
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 32
    second dose, Pointer became responsive. Pointer’s urinalysis tested positive for amphetamine,
    cannabinoids, and cocaine—but not opiates.          Even so, Dr. Mills testified that Pointer’s
    responsiveness to Narcan indicated that she had overdosed on opioids and that, unlike heroin,
    fentanyl “is not detected by that particular [urinalysis] drug screen.” (Mills Test., R. 703, Page
    ID ##3874–75, ##3877–78). He testified that the cocaine and amphetamines “played no role” in
    her overdose. (Id. at Page ID #3878). He said that her medical condition was “consistent with
    an opioid poisoning” and that, without medical attention, “she could have died.” (Id. at Page ID
    #3875, #3878).
    Tempo points to the physical evidence to prove that Pointer’s second overdose did not
    involve drugs from “Polo.” He alleges that, because Pointer’s drugs were in a folded piece of
    paper, and not a small plastic bag like those used in all “Polo” sales, the drugs likely came from
    another source. But Pointer testified that she bought the heroin from “Polo” in a small plastic
    bag. She then took it out of the bag, placed it into a piece of paper, crushed it up, and snorted it
    out of the piece of paper. While Pointer did make some inconsistent statements about her
    practice of repacking her drugs into paper folds, the jury was justified in crediting her testimony
    that she bought drugs from “Polo” and repackaged them into a paper fold. For the same reasons
    as discussed above, Pointer’s positive drug test for cocaine does not preclude but-for causation.
    See Volkman, 797 F.3d at 392. Indeed, Dr. Mills testified that the cocaine and amphetamines
    “played no role” in her overdose. (Mills Test., R. 703, Page ID #3878).
    iv. Count 6: Anoosh Baghdassarian
    Finally, sufficient evidence supported the jury’s conclusion that “Polo” drugs caused
    Baghdassarian’s death. Baghdassarian died on March 30, 2016. The medical examiner who
    conducted the autopsy concluded that Baghdassarian died of a fentanyl overdose. Paramedics
    found Baghdassarian in her room at her mother’s house with drug paraphernalia around her.
    Paramedics attempted to revive her with Narcan, but they were unsuccessful, and the doctors
    declared her dead when she arrived at the hospital. The blood toxicology report showed eleven
    nanograms of fentanyl per milliliter and fifteen nanograms of alprazolam (Xanax) per milliliter.
    The Xanax dosage was at a safe, therapeutic level, whereas Baghdassarian’s fentanyl levels were
    three times higher than a fatal dose of three nanograms.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                     Page 33
    There is also sufficient evidence for a jury to conclude that Baghdassarian overdosed on
    fentanyl from “Polo.”        Tomic testified that, on March 29, 2016—the evening before
    Baghdassarian died—he drove to Baghdassarian’s house, she came outside and got into Tomic’s
    car, they called “Polo,” and they bought drugs somewhere near Six Mile Road. Baghdassarian
    took her share of the drugs inside her house without using any while in Tomic’s car. That was
    around 3:30 or 4:30 p.m. on March 29.          Baghdassarian’s mother testified that she saw
    Baghdassarian meet with Tomic in his car and that, for the rest of that evening and the following
    morning, she never saw Baghdassarian leave the house or meet with anyone else. Later that
    night, police stopped Tomic and arrested him for drug possession. The police seized the drugs
    that Tomic bought with Baghdassarian, and lab results showed that they were pure fentanyl.
    Even though Tomic thought they bought heroin, “Polo” occasionally sold pure fentanyl to
    unknowing customers. Based on these facts, a rational jury could have concluded that Tomic
    and Baghdassarian purchased drugs from “Polo” and that those drugs caused Baghdassarian’s
    overdose the next morning.
    Tempo argues that the government “failed to show that [Baghdassarian] obtained the
    heroin from the Polo group.” (Def. Tempo Br. at 33). First, he notes that Baghdassarian’s last
    contact with a “Polo” phone was on February 14, 2016, and Tomic’s last contact was on March
    6, 2016.   However, sometimes Baghdassarian used a phone application (“app”) to contact
    “Polo,” and contacts through an app would not appear on the phone records. The jury could
    have inferred that the significant history of phone contacts between Baghdassarian, Tomic, and
    the “Polo” phones—amounting to over 1000 contacts—showed a pattern of using “Polo” to
    obtain drugs and indicated that the two bought drugs from “Polo” on March 29, just as Tomic
    said they did. Furthermore, while there are discrepancies between Tomic’s and Baghdassarian’s
    mother’s testimony as to when Tomic bought the drugs and whether Baghdassarian went with
    him, the jury could have weighed the evidence and concluded beyond a reasonable doubt that
    Baghdassarian died after overdosing on drugs that she and Tomic bought from “Polo.”
    3. Drug Possession with Intent to Distribute Near a School
    Both Defendants argue that there was insufficient evidence to support their drug
    possession convictions under 
    21 U.S.C. §§ 841
     and 860. Section 860 doubles the penalties for
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                    Page 34
    certain drug crimes that occur within 1000 feet of a school. § 860(a). Defendants were charged
    with possessing cocaine and heroin at 19504 Strasburg. On June 14, 2016, officers searched that
    property and found 16.7 grams of cocaine, 138.3 grams of crack cocaine, razor blades, a digital
    scale, and plastic bags with a white powder residue. Neither Defendant contests that 19504
    Strasburg is within 1000 feet of a school. Therefore, the question is whether each Defendant
    committed the underlying drug crime—possessing a controlled substance with intent to
    distribute—while at this property.
    The underlying offense requires proof that the defendant: “(1) knowingly, (2) possessed
    a controlled substance, (3) with intent to distribute it.” United States v. Russell, 
    595 F.3d 633
    ,
    645 (6th Cir. 2010) (quoting United States v. Coffee, 
    434 F.3d 887
    , 897 (6th Cir. 2006)). “[T]he
    government need not have provided evidence of actual possession; proof of constructive
    possession suffices.” United States v. Welch, 
    97 F.3d 142
    , 150 (6th Cir. 1996) (citing United
    States v. White, 
    932 F.2d 588
    , 589 (6th Cir. 1991)). “Constructive possession requires that a
    person knowingly have power and intention to exercise control over an object.” United States v.
    Critton, 
    43 F.3d 1089
    , 1096 (6th Cir. 1995) (citing United States v. Craven, 
    478 F.2d 1329
    , 1333
    (6th Cir. 1973)). Control over the substance can be “either directly or through others.” Welch,
    
    97 F.3d at 150
     (quoting United States v. Reeves, 
    794 F.2d 1101
    , 1105 (6th Cir. 1986)).
    However, “proof of the ‘mere presence’ of the defendant in proximity to the controlled
    substance, by itself, is insufficient evidence to establish possession with intent to distribute
    beyond a reasonable doubt.” 
    Id.
     (quoting White, 
    932 F.2d at
    589–90).
    a) Demarco Tempo
    A rational jury could have found beyond a reasonable doubt that Tempo possessed these
    drugs with the intent to distribute. This case is similar to Welch, where we upheld a distribution
    conviction because “[t]here was extensive evidence of [the defendant’s] involvement in a
    conspiracy to distribute cocaine and specifically his having sold cocaine from a [specific] crack
    house.” 
    97 F.3d at 150
    . Here, 19504 Strasburg was a suspected “stash location” for “Polo”
    operations, and it operated “almost like a dispatch center.” (Bankowski Test., R. 708, Page ID
    #4357). Although 19504 Strasburg appeared to be vacant, Tempo exerted some control over the
    property. He hired William Dennis to do repairs on the house. While working there, Dennis saw
    Nos. 19-2217/2221/20-1177                 United States v. Sadler, et al.                              Page 35
    people cutting up drugs, measuring them, and placing them in small plastic bags. Several
    witnesses saw Tempo at the property with other known “Polo” members and large quantities of
    drugs. While at the property, Tempo answered his phone and told runners to go meet customers.
    This evidence sufficiently shows that Tempo constructively possessed the substances
    found at 19504 Strasburg. See United States v. Sheppard, 
    149 F.3d 458
    , 462 (6th Cir. 1998)
    (upholding conviction under constructive possession theory when, among other facts, the
    defendant “was seen several times at the house in which the drugs were found” and “a large
    number of people were seen coming and going from the house”); United States v. Hill, 
    142 F.3d 305
    , 311–12 (6th Cir. 1998) (finding constructive possession with intent to distribute when drugs
    were found in large quantities along with items like scales, razor blades, packaging materials,
    and the defendant’s own possessions); Wettstain, 
    618 F.3d at 586
     (finding possession with intent
    to distribute when the defendant “receive[d] a phone call” and directed another person to retrieve
    the drugs to make a sale).8
    b) Kenneth Sadler
    The government’s only argument in support of the jury’s guilty verdict against Sadler is
    that Sadler is liable as a co-conspirator under Pinkerton. “The doctrine holds that a member of a
    conspiracy is liable for ‘substantive offense[s]’ committed by his co-conspirators, even if he did
    not participate in them, as long as: (1) the offenses are ‘done in furtherance of the conspiracy,’
    (2) they ‘fall within the scope of the unlawful project,’ and (3) they are reasonably foreseeable
    ‘consequence[s] of the unlawful agreement.’” Hamm, 952 F.3d at 744 (quoting Pinkerton,
    
    328 U.S. at
    647–48).
    As discussed above, Sadler was a co-conspirator in the “Polo” operation. See supra Part
    II.A.1.b.     Sadler also had ties to the Strasburg property; police surveillance showed
    Sadler coming and going from the house between May and June 2016. Based on Sadler’s status
    8As  each of Tempo’s Rule 29 challenges fails, his argument that the district court erred in denying his
    motion for a new trial under Rule 33 also fails. Federal Rule of Criminal Procedure 33 provides that, “[u]pon the
    defendant’s motion, the [district] court may vacate any judgment or grant a new trial if the interest of justice so
    requires.” Fed. R. Crim. P. 33. Here, Tempo’s Rule 33 motion presented the same arguments as his Rule 29
    motion. Because his Rule 29 arguments fail, so to do his Rule 33 arguments, even under Rule 33’s different
    standard. See United States v. Bowens, 
    938 F.3d 790
    , 796 (6th Cir. 2019).
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 36
    as a co-conspirator, his presence at the Strasburg property on multiple occasions, and the
    evidence discussed above about drug activity at the house, there was sufficient evidence for the
    jury to conclude that possession with the intent to distribute at 19504 Strasburg was a foreseeable
    crime within the scope of and in furtherance of the conspiracy. Thus, Sadler is liable for this
    substantive offense under Pinkerton. See Martin, 
    920 F.2d at
    348–49.
    4. Felon in Possession
    Sufficient evidence supports Sadler’s conviction under 
    18 U.S.C. § 922
    (g)(1) for being a
    felon in possession of a firearm. “The elements of the crime of being a felon in possession of a
    firearm are: 1) a prior felony conviction; 2) knowing possession of a firearm; and 3) the firearm
    must have traveled in interstate commerce.” United States v. Mayberry, 
    540 F.3d 506
    , 514 (6th
    Cir. 2008) (citing 
    18 U.S.C. § 922
    (g)(1)). Sadler does not dispute that he is a convicted felon or
    that the gun he allegedly possessed travelled in interstate commerce. Thus, if a reasonable jury
    could find, beyond a reasonable doubt, that Sadler possessed the firearm at issue, his conviction
    will stand.
    “Possession may be ‘either actual or constructive and it need not be exclusive but may be
    joint.’” United States v. Paige, 
    470 F.3d 603
    , 610 (6th Cir. 2006) (quoting United States v.
    Covert, 
    117 F.3d 940
    , 948 (6th Cir. 1997)). “Constructive possession may be proved by direct or
    circumstantial evidence and it is not necessary that such evidence remove every reasonable
    hypothesis except that of guilt.” Coffee, 
    434 F.3d at
    895–96 (citing Craven, 
    478 F.2d at 1333
    ).
    “Proof that ‘the person has dominion over the premises where the firearm is located’ is sufficient
    to establish constructive possession.” Id. at 896 (quoting United States v. Kincaide, 
    145 F.3d 771
    , 782 (6th Cir. 1998)). “However, presence where a firearm was found, without more, is
    insufficient to establish ‘knowledge, power, or intention to exercise control’ over the firearm.”
    
    Id.
     (quoting United States v. Arnold, 
    434 F.3d 396
    , 403 (6th Cir. 1993)).
    The government charged Sadler with possession of a .40 caliber Smith & Wesson
    handgun found on June 15, 2016, during a search of 15652 Eastburn. Police saw Sadler leaving
    that house earlier that day. Sadler’s children lived at the home with their mother, and police
    found some of Sadler’s belongings in the house. Police found the firearm on the top shelf of a
    Nos. 19-2217/2221/20-1177                 United States v. Sadler, et al.                Page 37
    kitchen cabinet. A forensic scientist identified Sadler’s DNA on the firearm. After his arrest,
    Sadler told police that “he was taking full responsibility for the firearm . . . that w[as] found in
    the residence on Eastburn Street.” (John Pickett Trial Test., R. 706, Page ID #4208). Even
    without unequivocal evidence that Sadler owned or resided at the Eastburn property full-time,
    this evidence is sufficient to establish constructive joint possession. See Coffee, 
    434 F.3d at
    896–
    97 (finding constructive possession despite conflicting testimony about the defendant’s primary
    residence at the time of the search).
    5. Conspiracy to Obstruct Justice
    Sufficient evidence supported Sadler’s conviction for conspiring to obstruct justice.
    Under 
    18 U.S.C. § 1512
    , it is a crime to conspire to use “the threat of physical force against any
    person . . . with intent to . . . influence, delay, or prevent the testimony of any person in an
    official proceeding.” § 1512(a)(2)(A), (k). The government charged Sadler with conspiring to
    threaten William Dennis. To sustain this conviction, Sadler must have agreed with another
    person to threaten Dennis in hopes of preventing or influencing his testimony at trial. Although
    the government’s evidence on this charge is circumstantial, that does not preclude the jury from
    finding Sadler guilty beyond a reasonable doubt. See United States v. Ledbetter, 
    929 F.3d 338
    ,
    355 (6th Cir. 2019) (upholding conviction for conspiracy to obstruct justice based on
    circumstantial evidence alone). There are three key pieces of evidence here: Sadler found out
    who would be testifying against him at trial;9 Sadler and his mother then called Dennis’
    mother—Francine Leatherwood—and discussed Dennis’ future testimony; and immediately after
    that call, an unknown person called Dennis’ mother and said, “Tell William to shut up or one of
    y’all are going to go missing.” (Francine Leatherwood Test., R. 791, Page ID #7875).
    Sadler argues that “there was absolutely no testimony from any witness, including
    William Dennis Sr., that Mr. Sadler ever threatened [Dennis] or directed anyone to threaten
    him.” (Def. Sadler 19-2221 Br. at 14). “But that misses the point at this stage, where all
    inferences must be made in favor of the prosecution and the evidence need not ‘exclude every
    reasonable hypothesis except that of guilt.’” Ledbetter, 929 F.3d at 355 (quoting Johnson v.
    9As   discussed below, this evidence was admissible. See infra Part II.B.2.
    Nos. 19-2217/2221/20-1177                United States v. Sadler, et al.                              Page 38
    Coyle, 
    200 F.3d 987
    , 992 (6th Cir. 2000)). A jury could infer intent based on the timing of the
    calls in relation to Sadler’s discovery that Dennis would testify. It could further infer an
    agreement to threaten Leatherwood with physical force by the back-to-back calls from Sadler
    and the threatening caller. The timing of these events could have led the jury to conclude,
    beyond a reasonable doubt, that Sadler had agreed with the unknown caller to threaten
    Leatherwood with the use of physical force.
    6. Witness Tampering
    A person commits a substantive offense under § 1512 when he or she “uses . . . the threat
    of physical force against any person, or attempts to do so, with intent to . . . influence, delay, or
    prevent the testimony of any person in an official proceeding.” 
    18 U.S.C. § 1512
    (a)(2)(A). The
    jury found Sadler guilty of tampering with two witnesses: Dennis and Alexander.
    a) William Dennis Sr.
    Sufficient evidence showed that Sadler used threats of physical force with the intent to
    influence or prevent Dennis’ testimony in this trial. After learning that Dennis would testify in
    this case, Sadler and his mother called Dennis’ mother, asking whether she knew that her son
    was testifying and commenting on his decision to testify. An unknown caller immediately called
    Leatherwood back and said: “Tell William to shut up or one of y’all are going to go missing.”
    (Francine Leatherwood Test, R. 791, Page ID #7875).10 Around the same time, Sadler sent a
    Facebook message to Dennis’ sister—Andrea Leatherwood—saying, “That’s crazy how your
    brother are main witness, but we telling on him. Little bro turn in his grave, that’s how
    shit . . . .” (Andrea Leatherwood Test., R. 791, Page ID ##7890–91).
    Sadler argues that his statements were not threats and that, even if they were, there was
    no evidence indicating that Dennis found out about the threats. First, his statements that Dennis
    would “turn in his grave” and that, if Dennis did not “shut up . . . [,] one of y’all are going to go
    missing” satisfy the threats-of-physical-force requirement.               See United States v. Thompson,
    10Having   concluded that this statement was made as part of a conspiracy, see supra Part II.A.5, Sadler
    would be liable for this substantive offense committed by a co-conspirator under the Pinkerton doctrine, see supra
    Part II.A.3.b.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                     Page 39
    758 F. App’x 398, 411–12 (6th Cir. 2018) (defendant’s statement that “I’m going to get her,”
    when referring to the witness, satisfied “threat” requirement). Second, for purposes of § 1512
    liability, it does not matter that Sadler made the threats to Dennis’ family members, or that
    Dennis may not have heard about them. The statute encompasses threats “against any person,”
    id., even if not made directly to the witness and the witness never learned of the threat, see
    United States v. England, 
    507 F.3d 581
    , 589 (7th Cir. 2007) (upholding conviction when the
    defendant threatened the witness’s father even though the witness never heard about the threat).
    b) Amacio Alexander
    There is also sufficient evidence supporting the jury’s finding that Sadler threatened
    Alexander. On June 19, 2016, Sadler approached Alexander while Alexander was at his aunt’s
    house. Sadler drove up to the house in a black truck and, without getting out of the vehicle,
    approached Alexander and said, “Take back what you said. Don’t go to court or your family
    going to see your face on a T-shirt.” (Alexander Test., R. 705, Page ID #4064). Alexander
    believed this was a reference to “memorial T-shirt[s]” and believed it was a death threat. (Id.)
    The geolocation data on Sadler’s phone confirmed that he was near Alexander’s aunt’s house
    around the time of this incident. Based on this evidence, a rational jury could have found that
    Sadler threatened Alexander with the intent to prevent him from testifying.
    B. Evidentiary Objections
    Sadler challenges the district court’s decision to admit two pieces of evidence against
    him: (1) evidence of two incidents where he sold heroin to an undercover police officer in 2012,
    and (2) his former attorney’s testimony discussing when Sadler learned about the witnesses in
    this case.
    1. Sadler’s 2012 Heroin Sales
    We “generally review the district court’s admission or exclusion of evidence for abuse of
    discretion.” Emmons, 8 F.4th at 473 (quoting United States v. Bell, 
    516 F.3d 432
    , 440 (6th Cir.
    2008)). “A district court has abused its discretion when its decision rests on the wrong legal
    standard, a misapplication of the correct standard, or on clearly erroneous facts.” United States
    v. Gibbs, 
    797 F.3d 416
    , 422 (6th Cir. 2015). “If evidence was erroneously admitted, we ask
    Nos. 19-2217/2221/20-1177                United States v. Sadler, et al.                            Page 40
    whether the admission was harmless error or requires reversal of a conviction.” United States v.
    Churn, 
    800 F.3d 768
    , 775 (6th Cir. 2015) (citing United States v. Martinez, 
    588 F.3d 301
    , 312
    (6th Cir. 2009)). This standard applies when reviewing a district court’s determination that
    Federal Rule of Evidence 404(b) is inapplicable because the evidence is intrinsic or res gestae.
    Id. at 774, 779. Here, the district court abused its discretion by admitting evidence of two
    instances where Sadler sold drugs in 2012. But, ultimately, the error is harmless.
    Under Rule 404(b)(1), “[e]vidence of any other crime, wrong, or act is not admissible to
    prove a person’s character in order to show that on a particular occasion the person acted in
    accordance with the character.” Fed. R. Evid. 404(b)(1). “The purpose of Rule 404(b) is to
    prevent a jury from ‘convict[ing] a “bad man” who deserves to be punished not because he is
    guilty of the crime charged but because of his prior or subsequent misdeeds’ and from
    ‘infer[ring] that because the accused committed other crimes, he probably committed the crime
    charged.’” Emmons, 8 F.4th at 473 (quoting United States v. Phillips, 
    599 F.2d 134
    , 136 (6th
    Cir. 1979)).
    However, Rule 404(b) does not apply when the prior bad act forms the basis of the
    charges for which a defendant is being tried. See United States v. Adams, 
    722 F.3d 788
    , 822 (6th
    Cir. 2013) (Rule 404(b) “is not implicated when the other crimes or wrongs evidence is part of a
    continuing pattern of illegal activity” (quoting United States v. Barnes, 
    49 F.3d 1144
    , 1149 (6th
    Cir. 1995))). That is, if evidence is “intrinsic,” Rule 404(b) will not apply as long as the
    acts “are part of a single criminal episode.” 
    Id.
     (quoting Barnes, 
    49 F.3d at 1149
    ). “Intrinsic
    acts are those that are . . . a part of the criminal activity[,] as opposed to extrinsic acts, which are
    those that occurred at different times under different circumstances from the offense charged.”
    Churn, 800 F.3d at 779 (quoting United States v. Stafford, 
    198 F.3d 248
     (Table), 
    1999 WL 1111519
    , at *4 (6th Cir. 2012)). A similar but distinct doctrine involves an exception to Rule
    404(b) for res gestae, or background, evidence. See Adams, 722 F.3d at 810 (citing United
    States v. Clay, 
    667 F.3d 689
    , 697 (6th Cir. 2012)). Such evidence “consists of those other acts
    that are inextricably intertwined with the charged offense.”11 United States v. Hardy, 228 F.3d
    11We    have not always been clear when distinguishing between res gestae and intrinsic evidence. Adams
    indicates that these concepts are different. See 722 F.3d at 810, 822. However, later cases have merged the two.
    Nos. 19-2217/2221/20-1177                   United States v. Sadler, et al.                                Page 41
    745, 748 (6th Cir. 2000). “Typically, such evidence is a prelude to the charged offense, is
    directly probative of the charged offense, arises from the same events as the charged offense,
    forms an integral part of a witness’s testimony, or completes the story of the charged offense.”
    Id. “Concerned with the potential for abuse of background evidence as a means to circumvent
    Rule 404(b),” we have recognized “severe limitations as to ‘temporal proximity, causal
    relationship, or spatial connections’ among the other acts and the charged offense.” Adams,
    722 F.3d at 810 (quoting Clay, 
    667 F.3d at 698
    ). We must be careful not to allow res gestae
    evidence as a “‘backdoor to circumvent [the] goals’ of Rule 404(b).” Gibbs, 797 F.3d at 423
    (quoting Clay, 
    667 F.3d at 698
    ).
    Sadler believes the district court improperly admitted evidence relating to his 2012 heroin
    sales—which he does not dispute happened—as intrinsic evidence. The government alleges that
    these sales were evidence of the “Polo” conspiracy.                     The district court overruled Sadler’s
    objection to this evidence and found that it was “relevant because it’s certain acts alleged[ly] by
    the defendant . . . during the time frame of the conspiracy relating to the overall charge.” (Trial
    Tr., R. 706, Page ID #4127). The district court did not consider whether the testimony was
    admissible under any exception to Rule 404(b), such as proof of motive, opportunity, intent,
    plan, knowledge, or lack of accident. See Fed. R. Evid. 404(b)(2).
    The parties’ dispute boils down to the degree of relatedness between Sadler’s 2012 heroin
    sales and the broader “Polo” conspiracy between 2010 and 2016. The government argues that
    the jury could reasonably infer that these sales were part of the “Polo” conspiracy. It relies on
    the following threads to tie Sadler’s 2012 sales to the broader “Polo” conspiracy: Sadler sold
    heroin; “Polo” sold heroin; Sadler sold heroin in small plastic bags; “Polo” sold heroin in small
    plastic bags; Sadler sold those bags for roughly $20; “Polo” sold bags for $20; Sadler used a
    phone to set up drug deals; “Polo” used phones to coordinate drug deals; Sadler’s sales were in
    2012; “Polo” allegedly operated in 2012. But, as Sadler notes, “[t]he similarities that the
    See Churn, 800 F.3d at 779 (“Res gestae is sometimes also known as ‘intrinsic evidence.’”). As we have
    recognized, “the distinctions among res gestae, inextricably intertwined evidence, intrinsic evidence, and
    background evidence [are] far from clear.” Id. (quoting Adams, 722 F.3d at 822 n.26). Ultimately, we do not need
    to split hairs deciding whether this is “intrinsic” or “res gestae” evidence because under either theory, the outcome is
    the same.
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 42
    government claims are unique, are actually so generic that [we] . . . give them no credence
    whatsoever.” (Def. Sadler Reply Br. at 3).
    The government’s comparisons are flawed for several reasons. First, they do not indicate
    that the 2012 sales were intrinsic evidence that was “part of a single criminal episode.” Adams,
    722 F.3d at 822 (quoting Barnes, 
    49 F.3d at 1149
    ). The evidence does not show that Sadler’s
    sales were “Polo” sales. There is no evidence that Sadler set up the sales using either “Polo”
    phone, he did not use a runner, and the sales were in a different part of town than “Polo” sales.
    Sadler pulled up to the undercover officer in a car, driven by the mother of his children, with a
    child in the backseat. Officers did not see other cars waiting or other drug deals happening at the
    same time. Sadler’s 2012 drug sales are thus not intrinsic evidence because they have no bearing
    on whether he agreed, knowingly joined, and participated in the conspiracy. See Williams,
    998 F.3d at 728 (listing elements of conspiracy); United States v. Peete, 781 F. App’x 427, 434
    (6th Cir. 2019) (noting that evidence is intrinsic if it “tends to logically prove an element of the
    crime charged” (emphasis added) (quoting United States v. Till, 
    434 F.3d 880
    , 883 (6th Cir.
    2006))). Indeed, in a similar drug conspiracy case, we found evidence of the defendant’s past
    drug sales inadmissible extrinsic evidence when the parties involved in those deals were not the
    alleged co-conspirators, and the prior sales did not “tend to establish the charged conspiracy
    itself.” United States v. Hardy, 
    228 F.3d 745
    , 749–50 (6th Cir. 2000). Without some connection
    to the conspiracy itself, prior bad acts are not intrinsic to the alleged conspiracy even if the bad
    act is of the same kind alleged in the conspiracy charge. See 
    id.
    Second, the 2012 sales are not res gestae or background evidence. Although courts can
    admit such evidence even when the prior acts are not “identical” to those charged, the facts must
    be “closely related.” Churn, 800 F.3d at 779 (quoting United States v. Vincent, 
    681 F.2d 462
    ,
    465 (6th Cir. 1982)). Here, Sadler’s 2012 drug deals are not “closely related” to the “Polo”
    conspiracy. The spatial and temporal connections between “Polo” and Sadler’s 2012 sales are
    tenuous at best. Most of the evidence at trial concerned “Polo” deals between 2015 and 2016.
    But even in the earlier “Polo” sales, the evidence showed a clear pattern of “Polo” using the
    same two phones and the same handful of locations. Although Sterling Heights is a suburb just
    east of Detroit, it is roughly ten miles away from the small area where “Polo” operated. The
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                       Page 43
    2012 deals did not happen at a “Polo” stash house or other identifiable “Polo” hotspot like
    Hamburg Street or the intersection of Bringard and Bradford. Rather, they were in a Meijer
    parking lot ten miles away.
    We require a much stronger connection between the prior act and the conduct charged to
    support a finding that the past act was intrinsic or res gestae evidence. See Churn, 800 F.3d at
    779 (admitting evidence of a non-charged fraudulent transaction because that transaction was
    with the same victim and the fraudulent deals were set up around the same time, and thus it was
    evidence of “the very scheme alleged in the indictment”); United States v. Hughes, 562 F. App’x
    393, 396 (6th Cir. 2014) (admitting “intrinsic” evidence showing that the defendant—who was
    charged with carjacking a Pontiac Sunfire—used a Sunfire to commit several robberies within
    three hours of the alleged carjacking). The district court thus abused its discretion by admitting
    this evidence as intrinsic or res gestae evidence. Because the 2012 sales are not relevant to the
    charged offense and do not provide any necessary background, the only inference that can be
    drawn from them is that Sadler’s prior drug-dealing activity makes it more likely that he would
    join a conspiracy involving those types of crimes. This is precisely the kind of inference that
    Rule 404(b) seeks to avoid. See Fed. R. Evid. 404(b); see also United States v. English, 
    785 F.3d 1052
    , 1059 (6th Cir. 2015) (Clay, J., concurring) (noting that defendant’s prior fraudulent
    conduct was not res gestae because it involved “discrete instances of fraudulent conduct
    constituting only gratuitous evidence of [the defendant’s] propensity to commit fraud”).
    After seemingly concluding that Rule 404(b) was not implicated, the district court did not
    consider whether any exceptions to Rule 404(b) applied. But we do not need to remand on this
    issue because the error in admitting evidence of Sadler’s 2012 drug deals was harmless. “[A]n
    error is harmless unless one can say, with fair assurance[,] that the error materially affected the
    defendant’s substantial rights—that the judgment was substantially swayed by the error.” Gibbs,
    797 F.3d at 425–26 (quoting Clay, 
    667 F.3d at 700
    ). As discussed above, a rational jury could
    have found beyond a reasonable doubt that Sadler was guilty of conspiracy under § 846 even
    without considering the 2012 drug sales. See supra Part II.A.1.b.
    Nos. 19-2217/2221/20-1177             United States v. Sadler, et al.                      Page 44
    2. Prior Attorney’s Testimony
    Sadler next argues that the district court erred by allowing his former attorney—Doraid
    Elder—to testify at trial because that testimony violated the attorney-client privilege.
    “[W]hether the attorney-client privilege applies is a mixed question of law and fact, subject to de
    novo review.” Automated Sols. Corp. v. Paragon Data Sys., Inc., 
    756 F.3d 504
    , 517 (6th Cir.
    2014) (quoting Reg’l Airport Auth. of Louisville v. LFG, LLC, 
    460 F.3d 697
    , 712 (6th Cir.
    2006)). “The purpose of attorney-client privilege is to ensure free and open communications
    between a client and his attorney.” 
    Id.
     (quoting In re Grand Jury Subpoenas, 
    454 F.3d 511
    , 519
    (6th Cir. 2006)). “The burden of establishing the existence of the privilege rests with the person
    asserting it.” United States v. Dakota, 
    197 F.3d 821
    , 825 (6th Cir. 1999). In deciding whether a
    communication is privileged, we have held that: “(1) [w]here legal advice of any kind is sought
    (2) from a professional legal adviser in his capacity as such, (3) the communications relating to
    that purpose, (4) made in confidence (5) by the client, (6) are at his instance permanently
    protected (7) from disclosure by himself or by the legal adviser, (8) unless the protection is
    waived.” Reed v. Baxter, 
    134 F.3d 351
    , 355–56 (6th Cir. 1998). While this definition seemingly
    only applies to the client’s statements, courts generally agree that an attorney’s statements to a
    client can also fall within the privilege if that communication would reveal client confidences or
    legal advice. See In re Grand Jury Procs., 
    616 F.3d 1172
    , 1182 (10th Cir. 2010). However,
    those communications are not protected “when an attorney conveys to his client facts acquired
    from other persons or sources.” 
    Id.
     (quoting In re Sealed Case, 
    737 F.2d 94
    , 99 (D.C. Cir.
    1984)).
    Elder testified that he gave Sadler the witness list in this case shortly before Sadler made
    threatening calls to Francine Leatherwood (Dennis’ mother) and sent threatening messages to
    Andrea Leatherwood (Dennis’ sister). The government sought to admit this evidence because
    the temporal proximity of these events circumstantially showed that Sadler intended to
    “influence, delay, or prevent the testimony of any person in an official proceeding” as required to
    prove witness tampering.        The district court allowed Elder to testify, but limited Elder’s
    testimony to the following issues: (1) whether Elder had conversations with Sadler between
    March 19 and 23, 2018; (2) whether Elder and Sadler met on March 23, 2018; (3) whether Elder
    Nos. 19-2217/2221/20-1177            United States v. Sadler, et al.                      Page 45
    gave Sadler a witness list and the grand jury testimony transcript on that day; and (4) whether
    those materials identified cooperating witnesses. Whether these types of communications are
    privileged is a matter of first impression. We agree with the district court that the Seventh
    Circuit’s decision in United States v. Defazio, 
    899 F.2d 626
     (7th Cir. 1990), is instructive here.
    In Defazio, the defendant was charged with tax fraud. During the course of the
    IRS’s pre-indictment investigation, the defendant’s attorney met with IRS agents
    to discuss his audit. [899 F.2d] at 634. The agents told the attorney that the IRS
    “had completed their investigation and are ready to refer the case [for
    prosecution] and that if you have any defenses you would like to present, he
    would be glad to listen to them.” 
    Id.
     Later, the attorney met with the defendant to
    discuss his meeting with the IRS, and the fact that criminal prosecution was
    likely. 
    Id.
     After this discussion, the defendant transferred assets, for nominal
    consideration, to a newly created corporation. 
    Id.
    The Government sought to prove that the transfers were part of the defendant’s
    willful attempt to evade income taxes by calling the attorney to testify “only to
    what the IRS agent said to him, and that he later relayed those statements to [the
    defendant].” 
    Id. at 635
    . The trial court allowed the attorney to testify to this
    effect, and the defendant appealed. The Seventh Circuit upheld the trial court’s
    decision, concluding that “the content of [the attorney’s] testimony is
    unprivileged because it did not reveal, either directly or implicitly, legal advice
    given [to the defendant] or any client confidences.” 
    Id.
     Accordingly, allowing
    the attorney to testify as to what the IRS agent told him, and that he later relayed
    the IRS agent’s statements to the defendant, did not violate attorney-client
    privilege.
    (Dist. Ct. Order, R. 653 at 5–6). As the district court noted, Elder’s testimony did not disclose
    the contents of any meetings or conversations with Sadler beyond those facts that the
    government relayed to Elder. “Like the IRS statements in Defazio, this information did not
    reveal either directly or implicitly, legal advice or any client confidence.” (Id. at 6). Elder’s
    testimony merely indicated when Sadler received specific types of information from the
    government—vis-à-vis his attorney—about the case. In this context, the communications are not
    protected by the attorney-client privilege.
    C. Jury Instructions
    Both Defendants argue that the district court made multiple errors in its jury instructions
    concerning 
    21 U.S.C. § 841
    (b)(1)(C)’s death-or-injury-results provision. That provision imposes
    an enhanced sentence if a defendant is found guilty of distributing, or conspiring to distribute, a
    Nos. 19-2217/2221/20-1177            United States v. Sadler, et al.                      Page 46
    controlled substance and “death or serious bodily injury results from the use of such substance.”
    § 841(b)(1)(C). Whether death or serious bodily injury results from a particular substance is a
    question for the jury. Burrage, 571 U.S. at 210.
    We generally “review the legal accuracy of jury instructions de novo.” United States v.
    Pritchard, 
    964 F.3d 513
    , 522 (6th Cir. 2020) (citing United States v. Roth, 
    628 F.3d 827
    , 833
    (6th Cir. 2011)). However, “a district court’s refusal to give an instruction requested by the
    defendant must amount to abuse of discretion in order for [us] to vacate a judgment.” 
    Id.
     (citing
    Roth, 
    628 F.3d at 833
    ). If the defendant failed to request a specific instruction from the district
    court, we review that omission for plain error. United States v. Semrau, 
    693 F.3d 510
    , 527 (6th
    Cir. 2012) (citing United States v. Carmichael, 
    232 F.3d 510
    , 523 (6th Cir. 2000)). Even if the
    district court plainly erred, the error must have “affected substantial rights,” meaning that we will
    not reverse or vacate a decision unless the error “affected the outcome of the district court
    proceedings.” United States v. Castano, 
    543 F.3d 826
    , 833 (6th Cir. 2008) (quoting United
    States v. Olano, 
    507 U.S. 725
    , 734 (1993)).
    Neither Defendant raised the precise objections that they now raise on appeal.
    Arguments challenging the district court’s jury instructions are properly preserved when the
    defendant “objected to [the] jury instructions on [the same] ground in the trial.” United States v.
    Blackwell, 
    459 F.3d 739
    , 764 (6th Cir. 2006) (internal citation omitted) (citing Carmichael,
    
    232 F.3d at 523
    ). Before the district court, Tempo objected to two jury instructions concerning
    causation and Pinkerton liability related to the death-or-injury results enhancement. However,
    he did not ask for the specific instructions that he now alleges the district court improperly
    omitted. Sadler similarly argues that the death-or-injury results instruction used the wrong
    causation standard and omitted an element of that enhancement. Sadler claims that “[t]his was
    objected to in a timely manner by . . . his attorney.” (Def. Sadler 19-2217 Br. at 43). But he
    does not cite any part of the record showing that his attorney lodged these objections, and we
    have found none.      Thus, neither Defendant properly preserved these objections.          Because
    Defendants argue that the district court improperly omitted necessary instructions, but neither
    Defendant requested those specific instructions at trial, we review the instructions for plain error.
    See Semrau, 693 F.3d at 527 (citing Carmichael, 
    232 F.3d at 523
    ).
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 47
    1. Causation Instruction
    The jury instructions correctly stated the causation standard under § 841(b)(1)(C). Both
    Defendants argue that the “results from” language requires a showing of proximate causation,
    which includes a foreseeability requirement. See United States v. Jeffries, 
    958 F.3d 517
    , 520
    (6th Cir. 2020). Defendants thus argue that the district court erred by giving the following jury
    instruction:
    In determining whether the serious bodily injury or death of these individuals
    resulted from the use of Heroin of Fentanyl that was distributed, the government
    is not required to prove that the defendant or defendants knew ahead of time that
    the Distribution of a Controlled Substance would or could result in a serious
    bodily injury, or in the death of, these individuals. In other words, the
    government need not prove that the serious bodily injury or death was foreseeable
    to the defendant or defendants. . . .
    If you find that one or more of the defendants is guilty of the charged [offenses],
    you may find that the controlled substance so distributed caused a serious bodily
    injury or death if he or she would not have suffered that serious bodily injury or
    death if he or she not used that Substance. Along those lines, if you find that the
    substance distributed combined with other drugs or factors to produce his or her
    serious bodily injury or death, you may find that the substance caused the serious
    bodily injury or death of the victim if the victim would have avoided that serious
    bodily injury or lived but for his or her use of that substance. That is, you may
    find the substance distributed by the defendant caused a victim’s serious bodily
    injury or death if, so to speak, this substance was the straw that broke the camel’s
    back. But the government must prove beyond a reasonable doubt that the serious
    bodily injury or death would not have occurred had the substance distributed by
    the defendant not been ingested by the individual.
    (Jury Instrs., R. 662, Page ID #3588–89 (emphasis added)). At trial, Tempo asked for an
    additional “superseding cause instruction.” (Tempo Mot. for Jury Instr., R. 345, Page ID #1803).
    Sadler raises the argument for the first time on appeal. Because neither defendant specifically
    requested a proximate-cause instruction, we review this instruction for plain error.          See
    Pritchard, 964 F.3d at 522 (citing Roth, 
    628 F.3d at 833
    ).
    There is no dispute that § 841(b)(1)(C) requires but-for causation. Burrage, 571 U.S. at
    218–19.    At the time of the trial, this circuit had not addressed whether the sentencing
    enhancement also required proximate causation. But we recently took up this question and
    decided that § 841(b)(1)(C) does not require a showing of proximate causation, including
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 48
    foreseeability. Jeffries, 958 F.3d at 520, 524; see also United States v. Daniels, 
    653 F.3d 399
    ,
    409 (6th Cir. 2011) (noting that the inquiry is whether the error was plain at the time of appellate
    review, not at the time of trial). Thus, the district court properly instructed the jury on the
    applicable causation standard under § 841(b)(1)(C).
    2. Chain of Distribution
    Even if “Polo” drugs were the but-for cause of the victims’ overdoses, Defendants argue
    that the jury was also required to find that they were personally linked to these drug sales in
    order to impose an enhanced sentence under 
    21 U.S.C. § 841
    (b)(1)(C). The death-or-injury-
    results enhancement applies only if the defendant violated a substantive provision of § 841—that
    is, there must be an underlying crime. See § 841(b)(1)(C). When a defendant’s underlying
    crime relies on a conspiracy theory of liability, then the district court cannot impose the
    enhanced sentence unless the jury finds that the defendant was part of the distribution chain that
    led to the victim’s overdose. Hamm, 952 F.3d at 745. This rule emerged through two cases:
    United States v. Swiney, 
    203 F.3d 397
     (6th Cir. 2000) and United States v. Hamm, 
    952 F.3d 728
    (6th Cir. 2020).
    In Swiney, nine co-defendants were convicted of conspiring to distribute heroin under
    § 846. 
    203 F.3d at 400
    . One unindicted co-conspirator sold heroin to a man who later overdosed
    on that heroin. 
    Id.
     at 400–01. The district court refused to apply the death-or-injury-results
    enhancement to the conspiracy defendants because there was “no proof linking the heroin which
    caused” the overdose to other co-conspirators, and we affirmed. 
    Id. at 401
    . We concluded that
    “before any of the [d]efendants can be subject to the sentence enhancement of 
    21 U.S.C. § 841
    (b)(1)(C)” the jury must find that the defendants were “part of the distribution chain.” 
    Id. at 406
    . We vacated the defendants’ sentences and remanded the case for the district court to
    make this factual determination. See 
    id.
    In Hamm, we reiterated that “to apply the § 841(b)(1)(C) sentencing enhancement” to any
    underlying conspiracy crime, “the jury need[s] to find beyond a reasonable doubt that [the
    defendant] w[as] part of the distribution chain.” 952 F.3d at 747. But Hamm also extended
    Swiney, applying the chain-of-distribution requirement when the underlying crime is a
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                     Page 49
    substantive offense under § 841 that is based solely on a conspiracy theory, even if the
    underlying crime is not conspiracy under § 846. 952 F.3d at 746–47. Specifically, Hamm held
    that a defendant who did not personally commit the underlying crime, but who is nevertheless
    liable as a co-conspirator, cannot be sentenced under the death-or-injury-results enhancement
    unless he was part of the chain of distribution. Id. Such co-conspirator liability, known as
    “Pinkerton liability,” “is a way of holding members of a conspiracy liable ‘for acts committed by
    other members.’” Id. at 744 (quoting Kumar Katyal, Conspiracy Theory, 
    112 Yale L.J. 1307
    ,
    1336 (2003)).
    In Hamm, the defendants were convicted of distribution charges under § 841. Hamm,
    952 F.3d at 746–47. The two defendants worked together with another woman, Tracey Myers,
    to buy carfentanil in Cincinnati and bring it back to Kentucky. See id. at 748. But, once in
    Kentucky, Myers and the two defendants each used or sold their carfentanil on their own terms.
    See id. At some point, Myers gave carfentanil to her cellmates while in jail, and her cellmates
    overdosed on the drugs. Id. The defendants were convicted of distributing carfentanil, and each
    received a 20-year sentence because the carfentanil caused Myers’ cellmates’ overdoses. See id.
    at 746–47. We concluded that, without the Pinkerton doctrine imposing liability onto co-
    conspirators, the defendants could not have been convicted under § 841(a). See id. at 747 (“No
    one is alleging that [the defendants] actually sold carfentanil to [the overdose victims]; they are
    only liable for the distribution to [the overdose victims] as . . . Myers’ co-conspirators.”).
    Because the defendants were only liable as co-conspirators, “it ma[de] little sense to say that
    Swiney [wa]s a conspiracy case but this one [wa]s not.” Id. at 747. We thus held that the district
    court could not have imposed the sentence enhancement unless the jury found that the defendants
    were in the chain of distribution. Id. at 747; see also Williams, 998 F.3d at 734 (“To prove that
    [the defendant] was liable for the death of others, moreover, the government cannot rely on
    Pinkerton liability, and must show that [the defendant] was in the chain of distribution that
    caused the victim’s death or injury.”). But the jury was not instructed on this element. See
    Hamm, 952 F.3d at 747. By failing to give a chain-of-distribution instruction, the district court
    “misstated the law.” Id.; see also United States v. Nelson, 
    27 F.3d 199
    , 200, 202 (6th Cir. 1994)
    (finding plain error when district court failed to instruct the jury on a critical element under a
    similar sentencing enhancement provision—
    18 U.S.C. § 924
    (c)(1)(A)). The district court here
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 50
    did not give a chain-of-distribution instruction for either Tempo or Sadler.         Because their
    underlying crimes were different, and the effects of any error differ, they require separate
    discussions.
    a) Kenneth Sadler: § 846 Conspiracy
    The district court plainly erred by omitting a chain-of-distribution instruction as part of
    the jury instructions for Sadler’s § 846 conspiracy count. The district court instructed the jury
    that:
    If you find that the defendant is guilty of the conspiracy charged in Count One,
    and that the distribution of Heroin or Fentanyl causing the serious bodily injury or
    death was in furtherance of the conspiracy and was committed by or reasonably
    foreseeable to him, you may find that the Heroin or Fentanyl so distributed caused
    a serious bodily injury or death if he or she would not have suffered a serious
    bodily injury or died had he or she not used that substance.
    (Jury Instrs., R. 662, Page ID ##3574 (emphasis added)). Sadler did not object to this instruction
    or request a chain-of-distribution instruction before the district court. We therefore review this
    instruction for plain error. See Castano, 
    543 F.3d at 833
    .
    The jury found that Sadler conspired to distribute controlled substances, that the
    substances distributed as part of that conspiracy resulted in death and serious bodily harm, and
    that those distributions were in furtherance of the conspiracy and reasonably foreseeable to
    Sadler. But the jury did not receive a chain-of-distribution instruction and, thus, did not decide
    whether Sadler was “part of the distribution chain” as required under Hamm and Swiney. Hamm,
    952 F.3d at 745 (quoting Swiney, 
    203 F.3d at 406
    ). Because the district court sentenced Sadler
    under the death-or-injury-results provision without the necessary factual findings by the jury, the
    district court plainly erred. See Nelson, 
    27 F.3d at 200, 202
    .
    This error substantially affected Sadler’s rights because, “taken as a whole, the jury
    instructions were so clearly erroneous as to likely produce a grave miscarriage of justice.”
    Castano, 
    543 F.3d at 833
    . An erroneous jury instruction affects a defendant’s substantial rights
    when it “could have led the jury to convict the defendant under a lower standard.” 
    Id. at 836
    .
    Here, the jury found that Sadler was part of the “Polo” conspiracy, but the jury did not consider
    Nos. 19-2217/2221/20-1177             United States v. Sadler, et al.                    Page 51
    whether Sadler was “part of the chain of distribution” of the drugs that killed or injured the
    victims. Therefore, the district court improperly imposed the 20-year minimum sentence under
    § 841(b)(1)(C). See Hamm, 952 F.3d at 745; see also United States v. Donovan, 539 F. App’x
    648, 653 (6th Cir. 2013) (vacating defendant’s sentence because “[a] defendant may not be
    sentenced under the statutory penalties for a cocaine conspiracy following a general jury verdict
    on a conspiracy to distribute both cocaine and marijuana as the jury may have found only a
    marijuana conspiracy”). The chain-of-distribution instruction could have monumental effects for
    Sadler. Without the 20-year enhancement, Sadler’s sentence would have been five years shorter.
    He is entitled to have a jury decide whether he was in the chain of distribution. Therefore, we
    vacate his sentence and remand on this question.
    b) Demarco Tempo: Pinkerton Liability
    Tempo similarly argues that the district court improperly omitted a chain-of-distribution
    instruction. However, he believes that this instruction was necessary because the jury convicted
    him of substantive offenses under § 841 solely under a Pinkerton conspiracy theory. In its jury
    instructions, the district court explained that:
    There are multiple ways that the government can prove a defendant guilty
    [distribution under § 841]. The first is by convincing [the jury] that the defendant
    personally committed or participated in this crime. The second is by showing that
    the defendant aided and abetted the commission of the charged offense. The third
    is based on the legal rule that all members of a conspiracy are responsible for acts
    committed by the other members, as long as those acts are committed to help
    advance the conspiracy, and are within the reasonably foreseeable scope of the
    agreement. This is often called “Pinkerton Liability.”
    (Jury Instrs., R. 662, Page ID #3580). As to the death-or-injury-results enhancement on the
    substantive distribution counts, the court instructed that:
    [T]he government need not prove that the serious bodily injury or death was
    foreseeable to the defendant or defendants. Rather, the government must prove
    beyond a reasonable doubt that:
    (A) The defendant is guilty of the charged Distribution of a Controlled
    Substance under at least one of the theories of liability described
    above;
    (B) That the victim . . . used the Heroin of Fentanyl so distributed . . .;
    Nos. 19-2217/2221/20-1177            United States v. Sadler, et al.                        Page 52
    (C) That he or she suffered a serious bodily injury or died; and
    (D) That he or she would not have suffered a serious bodily injury or died
    but for the use of the Heroin or Fentanyl.
    (Id. at Page ID ##3588–89 (emphasis added)).
    At trial, Tempo objected to the Pinkerton instruction, but he did not ask for a chain-of-
    distribution instruction. Rather, he argued that the Pinkerton instruction was erroneous because
    “no conspiracy ha[d] been established” that involved Tempo. (Trial Tr., R. 727, Page ID #6626).
    The district court overruled that objection. Because Tempo lodged his objection to Pinkerton on
    different grounds than he now presents, we review the district court’s omission of a chain-of-
    distribution instruction for plain error. See Castano, 
    543 F.3d at 833
    .
    As Hamm made clear, the death-or-injury-results enhancement cannot apply if the
    defendant is convicted on a Pinkerton theory unless the jury also finds that the defendant was in
    the chain of distribution. Hamm, 952 F.3d at 745. Here, the district court gave a Pinkerton
    instruction but not a chain-of-distribution instruction on Tempo’s substantive charges. Because
    the district court failed to instruct the jury that, if it found Tempo liable under a Pinkerton theory,
    it must also determine whether he was in the chain of distribution, the district court plainly erred.
    Although Tempo argues that this error alone necessitates vacation and remand, such a
    remedy is warranted only if the error “affect[ed] substantial rights,” meaning it “affected the
    outcome of the district court proceedings.” Castano, 
    543 F.3d at 833
     (quoting Olano, 
    507 U.S. at 734
    ). Unlike Sadler’s conspiracy conviction—and unlike the defendants in Hamm who could
    be found liable only on a Pinkerton theory—a rational jury could have found, beyond a
    reasonable doubt, that Tempo was a principal in the crime and/or an aider and abettor. See supra
    Part II.A.1.a. In this context, omitting a chain-of-distribution instruction did not substantially
    affect Tempo’s rights because he “is not being held responsible for someone else’s actions based
    on his status as a co-conspirator, but is being punished for his own actions.” Davis, 970 F.3d at
    657 (quoting United States v. Atkins, 289 F. App’x 872, 877 (6th Cir. 2008) (refusing to require a
    Swiney/Hamm instruction because the defendant was liable as a principal)). Thus, even though
    the district court plainly erred by omitting a chain-of-distribution instruction with the Pinkerton
    instruction, that error does not warrant remand. See Castano, 
    543 F.3d at 833
    .
    Nos. 19-2217/2221/20-1177           United States v. Sadler, et al.                      Page 53
    D. Vagueness
    Finally, Tempo argues that the death-or-injury-results enhancement is unconstitutionally
    vague. In whole, this provision provides that if a defendant violates § 841(a) by distributing
    schedule I or II controlled substances:
    if death or serious bodily injury results from the use of such substance [then the
    defendant] shall be sentenced to a term of imprisonment of not less than twenty
    years or more than life, a fine . . . , or both.
    
    21 U.S.C. § 841
    (b)(1)(C). The district court found that this provision was not unconstitutionally
    vague, and we review that decision de novo. United States v. Hart, 
    635 F.3d 850
    , 856 (6th Cir.
    2011) (citing United States v. Suarez, 
    263 F.3d 468
    , 476 (6th Cir. 2001)). “Vagueness may
    invalidate a criminal statute if it either (1) fails ‘to provide the kind of notice that will enable
    ordinary people to understand what conduct it prohibits’ or (2) authorizes or encourages
    ‘arbitrary and discriminatory enforcement.’” United States v. Bowker, 
    372 F.3d 365
    , 380 (6th
    Cir. 2004) (quoting City of Chicago v. Morales, 
    527 U.S. 41
    , 56 (1999), vacated on other
    grounds, 
    543 U.S. 1182
     (2005)).
    Tempo first argues that § 841(b)(1)(C) is unconstitutionally vague because it “fails to
    specify” both an actus reus and a mens rea. (Def. Tempo Br. at 40). However, the actus reus is
    clear: the sentencing enhancement applies to violations of § 841(a), which in turn proscribes
    possessing or distributing controlled substances. See § 841(a)(1). And we have held that the
    mens rea carries over from the underlying offense: the enhancement applies only when a
    defendant “knowingly and intentionally” violates § 841(a)(1). Jeffries, 958 F.3d at 522–23. The
    only circuit to address this question found that § 841(b)(1)(C) is not vague for lack of a mens
    rea. United States v. Waldrip, 
    859 F.3d 446
    , 451 (7th Cir. 2017); see also United States v.
    Patterson, 
    38 F.3d 139
    , 145 (4th Cir. 1994) (noting, without addressing vagueness, that
    § 841(b)(1)(C) “puts drug dealers and users on clear notice that their sentences will be enhanced
    if people die from using the drugs they distribute”). Therefore, the statute is not vague for lack
    of a mens rea or actus reus requirement.
    Nos. 19-2217/2221/20-1177                  United States v. Sadler, et al.                                Page 54
    Tempo next argues that the “or both” language—indicating that a defendant may face
    imprisonment, a fine, or both—is unconstitutionally vague. On the one hand, the provision
    instructs that, if the drugs cause death or serious bodily injury, the defendant “shall be sentenced
    to a term of imprisonment of not less than twenty years.” § 841(b)(1)(C) (emphasis added). On
    the other hand, it allows courts to impose imprisonment, a fine, “or both.” Id. (emphasis added).
    The word “or” would seemingly allow a court to bypass the mandatory minimum and apply only
    a fine. Tempo argues that this “language is directly contradictory, and this lack of clarity . . .
    constitutes a notice deficiency, raising serious due process concerns.” (Def. Tempo Br. at 41).
    But the Supreme Court has already addressed this discrepancy:
    Although this language, read literally, suggests that courts may impose a fine or a
    prison term, it is undisputed here that the “death results” provision mandates a
    prison sentence. Courts of Appeals have concluded, in effect, that the “or” is a
    scrivener’s error. The best evidence of that is the concluding sentence of
    § 841(b)(1)(C), which states that a court “shall not place on probation or suspend
    the sentence of any person sentenced under the provisions of this subparagraph
    which provide for a mandatory term of imprisonment if death or serious bodily
    injury results.”
    Burrage, 571 U.S. at 209 n.2 (internal citations omitted) (citing United States v. Musser,
    
    856 F.2d 1484
    , 1486 (11th Cir. 1988) (per curiam)). Any ambiguity in the “or both” language
    has thus been sufficiently clarified to put people on notice of the mandatory minimum. See
    United States v. Lanier, 
    520 U.S. 259
    , 267 (1997) (stating that the touchstone of notice is
    whether the statute is clear or whether courts have made clear that the statute prohibits the
    defendant’s conduct). Section 841(b)(1)(C) is not void for vagueness.12
    12Tempo    also argues that the death-or-injury-results enhancement is “facially overbroad,” (Def. Tempo Br.
    at 41), but his argument is essentially a recitation of his vagueness arguments. He argues that “[t]he statute on its
    face continues to leave our courts guessing as to what Congress intended, so surely it cannot be held to provide fair
    notice to a person of ordinary intelligence.” (Id.) However, “for a statute to be found unconstitutional on its face on
    overbreadth grounds, there must be a realistic danger that the statute itself will significantly compromise recognized
    First Amendment protections of parties not before the court.” Hart, 
    635 F.3d at 857
     (quoting Leonardson v. City of
    E. Lansing, 
    896 F.2d 190
    , 195 (6th Cir. 1990)). Tempo has not identified any protected conduct or otherwise
    indicated that the law cannot be applied constitutionally. Thus, this argument lacks merit.
    Nos. 19-2217/2221/20-1177          United States v. Sadler, et al.                    Page 55
    III. CONCLUSION
    For these reasons, we AFFIRM Defendant Tempo’s convictions and sentence, AFFIRM
    Defendant Sadler’s convictions, but VACATE Defendant Sadler’s sentence, and REMAND for
    a new trial on the sole question of whether Defendant Sadler was within the chain of distribution
    as required before imposing an enhanced sentence under 
    21 U.S.C. § 841
    (b)(1)(C).