United States v. Kilmartin ( 2019 )


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  •           United States Court of Appeals
    For the First Circuit
    No. 18-1513
    UNITED STATES OF AMERICA,
    Appellee,
    v.
    SIDNEY P. KILMARTIN,
    Defendant, Appellant.
    APPEAL FROM THE UNITED STATES DISTRICT COURT
    FOR THE DISTRICT OF MAINE
    [Hon. John A. Woodcock, Jr., U.S. District Judge]
    Before
    Barron, Selya, and Boudin,
    Circuit Judges.
    Jamesa J. Drake, with whom Drake Law LLC was on brief, for
    appellant.
    Benjamin M. Block, Assistant United States Attorney, with
    whom Halsey B. Frank, United States Attorney, was on brief, for
    appellee.
    December 6, 2019
    SELYA, Circuit Judge.      This appeal arises against the
    backdrop of a criminal scheme that was as cruel as it was cynical.
    When the scheme came to light, a federal grand jury sitting in the
    District of Maine charged defendant-appellant Sidney P. Kilmartin
    with an array of offenses.    The defendant pleaded guilty to nine
    fraud-related counts and went to trial on the remaining six counts
    of the superseding indictment (one charging mailing injurious
    articles resulting in death, see 18 U.S.C. § 1716; two charging
    wire fraud, see 
    id. § 1343;
    one charging mail fraud, see 
    id. § 1341;
    one charging witness tampering, see 
    id. § 1512;
    and one
    charging witness retaliation, see 
    id. § 1513).
      The jury found the
    defendant guilty on five of the six tried counts, acquitting him
    of witness retaliation.   The district court denied the defendant's
    post-trial motion for judgment of acquittal and/or a new trial.
    It then sentenced him to concurrent terms of immurement on the
    fourteen counts of conviction.
    In this venue, the defendant raises a golconda of issues.
    We hold that the evidence was sufficient to convict on the tried
    "mailing injurious articles" and witness tampering counts (counts
    1 and 14).   With respect to those counts and the fraud-related
    counts involving Denton (counts 5, 7, and 12), all of which were
    tried, we hold that the district court abused its discretion in
    admitting highly charged evidence having powerfully prejudicial
    effect but scant probative value.        Given the strength of the
    - 2 -
    government's evidence of guilt, this error, though egregious, was
    harmless as to most of the tried counts.                However, as to count 14
    (the witness tampering count) the error was not harmless, and we
    order   a   new   trial   on     that    count.        Finally,   we   reject   the
    defendant's claim of sentencing error.                 The tale follows.
    I. BACKGROUND
    We briefly rehearse the background and travel of the
    case,   taking     the   facts      in   the   light    most   congenial   to   the
    government, consistent with record support.                    See, e.g., United
    States v. Singh, 
    222 F.3d 6
    , 8 (1st Cir. 2000).
    In September of 2012, the defendant falsely posed as a
    commercial goldsmith to order one hundred grams (at least five
    hundred     lethal   doses)    of    ninety-eight       percent   pure   potassium
    cyanide (cyanide) from a California vendor.                The cyanide cost him
    about $127.       Because the vendor would not ship the cyanide to a
    residential address, the defendant had it sent to a UPS store in
    Augusta, Maine.       He retrieved the merchandise on the day that it
    arrived.
    The defendant's next step was to create a Gmail account,
    which allowed him to blog.           He proceeded to post, on a website for
    suicidal     people      called      "wantdeathblogspot,"         that     he   had
    industrial-grade cyanide for sale.               From around September of 2012
    until approximately May of the following year, the defendant
    exchanged cyanide-related emails with people all over the world,
    - 3 -
    including Australia, Canada, India, Nigeria, South Africa, the
    United Kingdom, and the United States.           A subsequent search of the
    defendant's Gmail account revealed 484 email strings from about
    274 unique email addresses.     In these emails, the defendant agreed
    to sell cyanide to several persons from whom he received payments
    ranging from $150 to $250.          But there was a rub:           instead of
    mailing cyanide to these purchasers, the defendant sent them Epsom
    salts (which he represented to be cyanide).
    One of the defendant's duped customers was Andrew Denton
    of Hull, England. According to his niece, Denton "was just adamant
    that he wanted to commit suicide."          Denton ordered cyanide from
    the defendant, who mailed Epsom salts to him on November 16, 2012.
    The parcel arrived at the end of November, and Denton ingested the
    substance in an effort to kill himself.            The attempt failed, and
    an irate Denton complained to the FBI Internet Crime Complaint
    Center (IC3).
    In his complaint, Denton described his dealings with the
    defendant, noting that what he received could not have been cyanide
    since "[i]t did not work." Denton also advised the defendant about
    the IC3 complaint.     On December 8, 2012, the defendant emailed
    Denton,   mentioned   the   possibility     of    a   second   shipment,   and
    described   how   Denton    could   order   cyanide     directly    from   the
    California vendor "if all else fails."           The following day, Denton
    updated his IC3 complaint, stating that his issue had been resolved
    - 4 -
    and he did not wish to pursue his complaint.         Two days later, the
    defendant mailed a second parcel to Denton.
    The second parcel, which actually contained cyanide,
    arrived on December 20.         That same day, the defendant emailed
    Denton asking if Denton could "do something" with his hard drive
    "before [his] event."         Expressing concern about the FBI being
    "aware of [his] goings on," the defendant stated that "the last
    thing" he needed was "to give [the FBI] more fodder."              Denton
    replied   that   he   would    delete   their   emails,    explained   his
    understanding that the IC3 complaint would remain open but inactive
    for three months, and expressed his hope that the cyanide would
    "work[] this time."    Denton's niece found him dead on December 31.
    Subsequent toxicological examination disclosed lethal levels of
    cyanide in his blood.
    Notwithstanding       Denton's    effort    to    retract    his
    complaint, the FBI continued its investigation. This probe ripened
    into an indictment and — in December of 2015 — the grand jury
    returned a superseding indictment.         Count 1 limned the "mailing
    injurious articles" charge; counts 2 through 13 charged wire and
    mail fraud offenses (based on a scheme to defraud suicidal people
    and to obtain money by false pretenses, specifically, by pretending
    to sell cyanide but sending Epsom salts instead);1 count 14 charged
    1 Three of these fraud counts related to the defendant's
    initial transaction with Denton.  The remainder related to the
    - 5 -
    the defendant with witness tampering, that is, with killing Denton
    knowingly, intending to prevent his testimony in an official
    proceeding    and    to    prevent   him   from   communicating   information
    related to the possible commission of a federal offense to a law
    enforcement officer; and count 15 charged the defendant with
    witness retaliation, that is, killing Denton to retaliate for
    Denton's supplying of information to IC3 regarding the commission
    of a federal offense.
    The defendant's trial was scheduled to start on October
    3, 2016.     That morning, the defendant entered guilty pleas to the
    nine non-Denton counts.         The trial went forward on the remaining
    six counts.     Four of the defendant's fraud victims testified for
    the government (including one as to whom the defendant's fraud had
    not been charged).         A victim's grandmother also testified at the
    government's behest about the uncharged fraud perpetrated against
    her minor granddaughter.           In addition, the government introduced
    testimony from a British detective about yet another victim.
    When    the   trial     concluded,   the   jury   convicted   the
    defendant on all the tried counts, save for count 15 (witness
    retaliation).       In post-trial proceedings, the defendant moved for
    defendant's communication with, receipt of payment from, and
    mailing Epsom salts to four other victims of the scheme.  We
    sometimes refer to the counts involving these four victims,
    collectively, as the non-Denton counts and to victims of the
    scheme, other than Denton, as non-Denton victims.
    - 6 -
    judgments   of   acquittal   on   counts    1   and    14    due   to    allegedly
    insufficient evidence.       See Fed. R. Crim. P. 29(c).            In the same
    motion, he sought a new trial on all of the tried counts of
    conviction based on claimed evidentiary error.                 See 
    id. R. 33.
    The district court denied the motion in all its aspects.                   It then
    sentenced the defendant to twenty years of incarceration (the
    statutory maximum) on each fraud-related count and twenty-five
    years of incarceration on counts 1 and 14, stipulating that all of
    the sentences were to run concurrently.                  This timely appeal
    followed.
    II. ANALYSIS
    The defendant's asseverational array contains three main
    parts.   First, he argues that the district court erred in refusing
    to order judgments of acquittal on counts 1 and 14.                     Second, he
    argues   that    the   district   court   should      have   excluded      certain
    evidence and that the failure to do so unfairly prejudiced the
    jury against him, necessitating a new trial on all the tried counts
    that resulted in convictions.       Third, he alleges sentencing error
    as to the sentences imposed on the fraud-related counts.                        We
    address these arguments below.
    Before undertaking our analysis, we pause to confirm
    that we review the district court's denial of a motion for judgment
    of acquittal de novo.      See United States v. Gomez, 
    255 F.3d 31
    , 35
    (1st Cir. 2001).       Where, as here, the defendant challenges the
    - 7 -
    sufficiency of the evidence, all of the proof "must be perused
    from the government's perspective."         
    Id. A reviewing
    court must
    determine     whether    that   evidence,    including       the   plausible
    inferences therefrom, "enables a rational factfinder to conclude
    beyond a reasonable doubt that the defendant committed the charged
    crime." 
    Id. (quoting United
    States v. Noah, 
    130 F.3d 490
    , 494 (1st
    Cir. 1997)).    The court need not be convinced that the verdict is
    correct; it need only be satisfied that the verdict is supported
    by the record.    See 
    id. Although the
    defendant's motion for judgment of acquittal
    targets both count 1 and count 14, the circumstances attendant to
    this appeal counsel in favor of bifurcating our inquiry.            Thus, we
    treat separately each of the targeted counts.
    A. Judgment of Acquittal:        Count 1.
    It is not possible to address the motion for judgment of
    acquittal on count 1 in a vacuum.            First, we must resolve a
    threshold issue.        Only then can we turn to the merits of the
    request for an acquittal.         Specifically, we must resolve an
    apparent discrepancy between the indictment and the proof at trial.
    1. Constructive Amendment.      As stated in the superseding
    indictment, count 1 charged the defendant with a misdemeanor
    (mailing nonmailable poison), together with an enhancement for
    "death resulting."      The indictment itself did not allude to a mens
    rea requirement.     At trial, though, the parties and the district
    - 8 -
    court approached count 1 as if it charged a felony under a
    different paragraph of the "mailing injurious articles" statute.
    That paragraph requires the government to show that the defendant
    had mailed an injurious article with the intent to kill or injure
    another.   The government labored to prove this intent at trial,
    both parties requested that the district court instruct the jury
    on this intent element, and the district court obliged.                  As
    explained below, this series of events added up to a constructive
    amendment of count 1.
    "A constructive amendment occurs when the charging terms
    of an indictment are altered, either literally or in effect, by
    prosecution or court after the grand jury has last passed upon
    them." United States v. McIvery, 
    806 F.3d 645
    , 652 (1st Cir. 2015)
    (quoting United States v. Brandao, 
    539 F.3d 44
    , 57 (1st Cir.
    2008)).    Constructive amendments have Fifth and Sixth Amendment
    implications.    See 
    id. These implications
    typically arise from "a
    mismatch   between   the   indictment's   description   of   the    charged
    offense and some other variable," such as the evidence offered,
    the jury instructions given, or the sentence imposed.         
    Id. In this
    instance, the statute of conviction provides in
    relevant part:
    (1) Whoever knowingly deposits for
    mailing or delivery . . . anything declared
    nonmailable by this section, unless in
    accordance with the rules and regulations
    authorized to be prescribed by the Postal
    - 9 -
    Service, shall be fined under this title or
    imprisoned not more than one year, or both.
    (2) Whoever knowingly deposits for
    mailing or delivery . . . anything declared
    nonmailable by this section, whether or not
    transmitted in accordance with the rules and
    regulations authorized to be prescribed by the
    Postal Service, with intent to kill or injure
    another . . . shall be fined under this title
    or imprisoned not more than twenty years, or
    both.
    (3) Whoever is convicted of any crime
    prohibited by this section, which has resulted
    in the death of any person, shall be subject
    also to the death penalty or to imprisonment
    for life.
    18 U.S.C. § 1716(j).      Count 1 of the superseding indictment, by its
    terms,   charged    the     defendant    with   the   misdemeanor   offense
    described    in    (j)(1)    along    with    the   sentencing   enhancement
    described in (j)(3):
    [T]he defendant . . . knowingly deposited for
    mailing and delivery something declared
    nonmailable . . . not in accordance with rules
    and regulations prescribed by the United
    States Postal Service, in other words,
    potassium cyanide, a poison, which resulted in
    the death of a person . . . . All in violation
    of 18 U.S.C. § 1716(j)(3).
    At trial, however, the parties and the district court treated count
    1 as if the offense was charged under (j)(2) and (j)(3), not (j)(1)
    and (j)(3).2      During its preliminary instructions, the district
    court told the jurors that in order to find the defendant guilty
    2 Although the record is tenebrous as to the reason for this
    shift in focus, we note that the original indictment (later
    superseded) clearly charged the defendant with violating paragraph
    (j)(2).
    - 10 -
    under count 1, they had to find, among other things, that the
    defendant acted "with the intent to kill or injure another."    The
    jury instructions proposed by both the government and the defendant
    included this "intent to kill or injure another" element.        Not
    surprisingly, then, the district court mirrored this language in
    defining the elements of count 1 when it charged the jury.
    Although the constructive amendment of an indictment may
    constitute grounds for reversal of a conviction, see United States
    v. Bucci, 
    525 F.3d 116
    , 131 (1st Cir. 2008); cf. 
    McIvery, 806 F.3d at 651
    (reviewing unpreserved claim of constructive amendment for
    plain error), the defendant has not raised this issue on appeal
    (or, for that matter, in the district court).        Except in rare
    instances — and this is not one of them — we have no duty to raise
    arguments for a party who has not seen fit to raise those arguments
    himself.   See, e.g., United States v. Flete-Garcia, 
    925 F.3d 17
    ,
    38 (1st Cir.), cert. denied, No. 19-5757, 
    2019 WL 5150648
    (U.S.
    Oct. 15, 2019); cf. United States v. Mercado-Flores, 
    872 F.3d 25
    ,
    28 (1st Cir. 2017) (noting appellate court's obligation to raise
    jurisdictional issues sua sponte).     At any rate, the constructive
    amendment did not prejudice the defendant in any respect because
    it had the effect of adding another element that the government
    was required to prove beyond a reasonable doubt.       We therefore
    conclude that count 1 was constructively amended with the implied
    consent of the parties.   We proceed accordingly.
    - 11 -
    2. The Merits.     Having ironed out this wrinkle, we now
    reach the question of whether the evidence was sufficient to
    support the defendant's conviction on count 1 (as constructively
    amended).      To begin, it is important to note that the defendant
    challenges the sufficiency of the evidence only with respect to
    the "death resulting" element of the offense.              He contends that
    his conduct was neither the actual nor the proximate cause3 of
    Denton's death because Denton voluntarily took his own life.
    The defendant's conduct is an actual, but-for cause of
    harm when that harm would not have occurred without it. See United
    States v. Ortiz-Carrasco, 
    863 F.3d 1
    , 5 (1st Cir. 2017) (concluding
    that defendant's conduct was but-for cause of victim's drowning
    where defendant embarked on voyage on overcrowded yola, traveled
    in rough seas in the dark, and had no safety equipment aboard).
    But-for causation is often regarded as "the minimum requirement
    for a finding of causation."        
    Id. (emphasis in
    original) (quoting
    Burrage   v.    United   States,   134   S.   Ct.   881,   888   (2014)).   A
    defendant's conduct can be a but-for cause of harm even when it
    3 The defendant's briefing on this point is confusing. For
    instance, his reply brief indicates that this "case is about actual
    causation, not . . . proximate causation." Yet his opening brief
    contends at some length that Denton's own conduct "was an
    intervening and superseding cause" of Denton's death. In fairness
    to the defendant, we think that this latter argument remains in
    the case — and it is steeped in the language of proximate cause.
    See, e.g., 1 Wayne R. LaFave, Substantive Criminal Law § 6.4(c)
    (3d ed. 2018).
    - 12 -
    combines with other independent causes.           See 
    Burrage, 134 S. Ct. at 888
    .    As Justice Scalia explained:        "if poison is administered
    to a man debilitated by multiple diseases, it is a but-for cause
    of his death even if those diseases played a part in his demise,
    so long as, without the incremental effect of the poison, he would
    have lived."    
    Id. Appraising the
    evidence in the light most favorable to
    the government, it was more than sufficient to ground a finding
    that the defendant's conduct was a but-for cause of Denton's
    demise.    The jury saw the empty beaker and the mailer with the
    defendant's return address recovered from Denton's home, and it
    heard evidence of test results indicating that the residue in the
    mailer was cyanide. So, too, the jury heard evidence that a lethal
    quantity   of   cyanide    had   been    discovered   in   Denton's   blood.
    Finally, the jury heard testimony from investigators who had
    determined Denton's death to be a suicide and had ruled out other
    causes of death.       If the defendant had not sent Denton a deadly
    dose of cyanide, the defendant could not have ingested it and died.
    No more was exigible to ground a finding that the defendant's
    conduct was a but-for cause of Denton's death.
    The defendant rejoins that this conception of the chain
    of causation is too "literal" and that Denton's actions in mixing
    and ingesting the poison were intervening events that broke the
    but-for    causal     connection.       This   rejoinder   blinks   reality.
    - 13 -
    Although Denton's desire to end his life surely played a part in
    his   suicide,   he   would   not    have   been   successful   but   for   the
    defendant's provision of cyanide.             Viewing the evidence in the
    requisite light, a rational factfinder could conclude — as this
    jury did — that the defendant actually caused Denton's death.
    In an effort to change the trajectory of the debate, the
    defendant tries to invoke the rule of lenity.                   Marshaling a
    sampling of cases in which defendants were charged with mailing
    explosives under 18 U.S.C. § 1716, see, e.g., United States v.
    Caraway, 
    534 F.3d 1290
    , 1292-93 (10th Cir. 2008), the defendant
    baldly asserts that Congress did not intend the statute to cover
    cases of assisted suicide.          This assertion is belied by the broad
    sweep of the language that Congress employed.                   Arraying the
    evidence favorably to the government — as we must — the defendant's
    actions fall squarely within the four corners of the conduct that
    the text of the statute proscribes.
    Undaunted, the defendant claims that the rule of lenity
    requires construing the statute, notwithstanding its text, to
    exclude the conduct with which he was charged.             This is wishful
    thinking.    The rule of lenity only requires reading a criminal
    statute in the accused's favor when that statute is so unclear
    that courts are left to guess what Congress intended.             See United
    States v. Ahlers, 
    305 F.3d 54
    , 62 (1st Cir. 2002).              To engage the
    gears of the rule, the lack of clarity must be genuine:            "a statute
    - 14 -
    is not ambiguous simply because litigants . . . question its
    interpretation."        
    Id. The defendant
    argues that section 1716 is ambiguous
    because (in his view) it is meant to cover things like bombs (which
    are mailed to unwitting victims and kill immediately), not things
    like the cyanide (which he mailed to a person who specifically
    requested it and which kills only after some further act, such as
    ingestion).       The text of the statute of conviction does not give
    this argument as much as a shred of support.                   As written, the
    statute has a plain and plausible meaning.                 It unambiguously
    prohibits mailing not only things like bombs but also poisons,
    insects, and scabs (which do not necessarily kill immediately).
    The    sentencing      enhancement   applies   whenever   mailing     such   an
    injurious article "result[s] in the death" of a person.                   That
    enhancement, read in context, is not ambiguous and does not permit
    the distinction that the defendant attempts to insinuate into it.
    In    short,    both   the    superseding   indictment   (as    constructively
    amended) and the government's proof bring count 1 comfortably
    within the statute's well-defined reach.            And because we discern
    no relevant ambiguity, we find no basis for resorting to the rule
    of lenity.      See 
    id. As a
    fallback, the defendant attempts to argue that the
    proper measure of causation was proximate cause (a more rigorous
    standard).      See, e.g., Paroline v. United States, 
    134 S. Ct. 1710
    ,
    - 15 -
    1719 (2014).      This argument, though, is foregone.                 During the
    charge   conference,    a   protracted     discussion        ensued   about    the
    propriety of a but-for causation instruction as the appropriate
    means of establishing the "death resulting" element under count 1.
    Defense counsel told the court that he could not "argue that it
    isn't the law."    The district court proceeded to instruct on but-
    for causation, and the defendant neither interposed an objection
    nor asked for a proximate cause instruction.            Cf. Fed. R. Crim. P.
    30 (providing that parties may request specific instructions at or
    before close of evidence and must object to instructions given
    before jury retires to deliberate).
    "We have made it luminously clear that '[a] party waives
    a right when he intentionally relinquishes or abandons it.'"
    United   States   v.   Orsini,   
    907 F.3d 115
    ,    119    (1st    Cir.    2018)
    (alteration in original) (quoting United States v. Rodriguez, 
    311 F.3d 435
    , 437 (1st Cir. 2002)).          As a general rule, waived claims
    are unreviewable on appeal.             See 
    id. In this
    instance, the
    defendant waived any entitlement to a proximate cause instruction.
    What happened here falls comfortably within the general rule of
    unreviewability, not within the long-odds exception to that rule.
    See   
    id. at 120-21.
           By     explicitly     acquiescing       in    the
    appropriateness of a but-for causation standard, eschewing any
    objection to the district court's but-for causation instruction,
    and failing to request a proximate cause instruction, the defendant
    - 16 -
    waived any claim that the offense of conviction required a finding
    of proximate cause.
    If more were needed — and we doubt that it is — "[i]t is
    settled that, when a cause is submitted to the jury under an
    instruction, not patently incorrect or internally inconsistent, to
    which no timely objection has been lodged, the instruction becomes
    the law of the case."    United States v. Gomes, 
    969 F.2d 1290
    , 1294
    (1st Cir. 1992); see United States v. Zanghi, 
    189 F.3d 71
    , 77-80
    (1st Cir. 1999) (concluding that jury instruction increasing level
    of intent required to convict was "patently erroneous" and did not
    become the law of the case). That is precisely the situation here:
    the district court's treatment of causation in its charge to the
    jury was neither patently incorrect nor internally inconsistent.
    The court instructed on but-for causation, consistent with case
    law interpreting similarly worded "results" elements in other
    criminal statutes.      See, e.g., United States v. Webb, 
    655 F.3d 1238
    , 1250, 1255-56 (11th Cir. 2011) (18 U.S.C. § 1347(a) and 21
    U.S.C. § 841(b)(1)(C)); United States v. De La Cruz, 
    514 F.3d 121
    ,
    137-38 (1st Cir. 2008) (21 U.S.C. § 841(b)(1)(A)); cf. United
    States v. Pacheco, 
    489 F.3d 40
    , 46-47 (1st Cir. 2007) (interpreting
    USSG §5K2.2's authorization of upward departure when significant
    physical   injury     resulted   from     commission     of   offense   of
    conviction).   Thus, all roads lead to Rome:           whether we examine
    the defendant's proximate cause argument in terms of waiver or
    - 17 -
    law-of-the-case doctrine, a conviction on count 1 required the
    government to prove no more than but-for causation.
    The final piece of the puzzle falls easily into place.
    As we already have elaborated, the jury had ample evidence from
    which to find that the defendant's conduct was the but-for cause
    of Denton's death.    Consequently, the district court did not err
    in denying the defendant's motion for judgment of acquittal with
    respect to count 1.
    B. Judgment of Acquittal:       Count 14.
    The defendant also challenges the denial of his motion
    for judgment of acquittal with respect to count 14 (the witness
    tampering count).     In his view, the evidence on this count was
    insufficient   for   two   reasons.   First,    he   contends    that   the
    government's proof was inadequate because it did not show that his
    conduct actually or proximately caused Denton's death.          Second, he
    contends that the evidence was inadequate to show that he "killed"
    Denton within the purview of the statute of conviction. We address
    each contention in turn.
    The statute of conviction provides in relevant part:
    (a)(1) Whoever kills or attempts to kill
    another person, with intent to —
    (A) prevent the attendance or
    testimony of any person in an official
    proceeding; [or]
    . . .
    (C) prevent the communication by any
    person to a law enforcement officer or
    judge of the United States of information
    - 18 -
    relating to the commission or possible
    commission of a Federal offense . . .
    shall be punished as provided [by law].
    18 U.S.C. § 1512.   In order to convict the defendant under section
    1512(a)(1)(C), the government had to prove a killing aimed at
    preventing a communication to a federal law enforcement officer
    about the commission or possible commission of a federal crime.
    See Fowler v. United States, 
    563 U.S. 668
    , 672 (2011).             The
    defendant's initial complaint about evidentiary insufficiency is
    narrowly focused.   He says that the government failed to prove the
    requisite causation.    We already have rejected the defendant's
    argument that no reasonable jury could have found that his conduct
    was a but-for cause of Denton's death, 
    see supra
    Part II(A)(2),
    and no useful purpose would be served by repastinating that ground.
    The   remaining   pieces   of   the   defendant's   causation
    argument — that proof of proximate cause was required to sustain
    a conviction under 18 U.S.C. § 1512(a)(1) and that such proof was
    lacking here — fare no better.       Importantly, the district court
    did not give any specific instruction on causation (nor was it
    asked to do so).     Instead, the court charged the jury that to
    convict on count 14, it simply had to find "[f]irst, that . . .
    [the defendant] knowingly killed [Denton]; and second, that [the
    defendant] did so with the intent to prevent a communication about
    the commission of a federal offense to a federal law enforcement
    - 19 -
    officer."     Inasmuch as the defendant did not object to this
    instruction, his claim of error is forfeited, and our review is
    for plain error.4    See United States v. Duarte, 
    246 F.3d 56
    , 60
    (1st Cir. 2001).    Such review requires four showings:        "(1) that
    an error occurred (2) which was clear or obvious and which not
    only (3) affected the defendant's substantial rights, but also
    (4) seriously    impaired   the    fairness,     integrity,   or   public
    reputation of judicial proceedings."       
    Id. The proponent
    of plain
    error (here, the defendant) must carry the devoir of persuasion as
    to each of these four components.     See United States v. Brown, 
    235 F.3d 2
    , 4 (1st Cir. 2000).
    When a crime specifies both conduct and result elements,
    a defendant ordinarily may not be convicted unless his conduct is
    both the but-for and the proximate cause of the result.              See
    
    Burrage, 134 S. Ct. at 887
    (citing 1 Wayne R. LaFave, Substantive
    Criminal Law § 6.4(a) (2d ed. 2003); Model Penal Code § 2.03 (Am.
    Law Inst. 1985)).    As to count 14, the statute of conviction is
    silent regarding the nature of the requisite causal nexus.         See 18
    4  While the defendant neither objected to the court's
    instruction nor requested a proximate cause instruction with
    respect to count 14, these circumstances differ from those
    surrounding count 1.    With respect to the latter count, the
    defendant expressly agreed that but-for causation sufficed to
    convict. Yet he made no such representation with respect to count
    14. The absence of such an express representation explains why we
    treat his argument vis-à-vis count 14 as forfeited, not waived.
    See 
    Rodriguez, 311 F.3d at 437
    (explicating distinction between
    forfeited claims and waived claims).
    - 20 -
    U.S.C. § 1512(a)(1).           We are cognizant, though, that the Supreme
    Court on several occasions has found a proximate cause requirement
    built    into   a    statute    that    did   not   explicitly    impose     such   a
    requirement.        See 
    Paroline, 134 S. Ct. at 1720
    (collecting cases).
    Proximate causation sets a higher bar than but-for causation,
    demanding "some direct relation between the injury asserted and
    the injurious conduct alleged."           
    Id. at 1719
    (quoting CSX Transp.,
    Inc.    v.    McBride,   
    564 U.S. 685
    ,     707   (2011)    (Roberts,    C.J.,
    dissenting)).
    It is an interesting question whether section 1512(a)(1)
    demands proof of proximate causation as opposed to some lesser
    strain   of     causation.       But    courts   should   not    rush   to   answer
    unsettled questions, see Privitera v. Curran (In re Curran), 
    855 F.3d 19
    , 22 (1st Cir. 2017), and this question is one that we need
    not answer.      Even assuming (as the government concedes) that the
    statute of conviction requires a showing of proximate cause, it is
    neither clear nor obvious that the evidence in this case is
    insufficient to sustain the conviction on count 14.                     We explain
    briefly.
    Viewing the evidence in the light most hospitable to the
    government, a rational jury could find that the defendant's conduct
    proximately caused Denton's death.               After all, the evidence was
    sufficient to support findings that the defendant, the second time
    around, sent real cyanide to Denton, knowing that the cyanide was
    - 21 -
    lethal and that Denton intended to ingest it; that Denton received
    the cyanide; that Denton swallowed it; and that he died as a
    result.   Proximate cause is commonly understood as a function of
    the foreseeability of the harm.        See, e.g., United States v.
    Chiaradio, 
    684 F.3d 265
    , 284 (1st Cir. 2012) ("The evidence must
    show that the defendant's conduct created a reasonably foreseeable
    risk of harm to the victim, notwithstanding that others may also
    have contributed to that harm.").   Intervening causes normally do
    not break the causal chain if they are foreseeable.   See 
    Paroline, 134 S. Ct. at 1719
    (explaining that purpose of proximate cause
    requirement is to preclude liability where link between conduct
    and result is merely fortuitous).
    Here, Denton's death was entirely foreseeable.     Among
    other things, the defendant posted his cyanide advertisement on a
    suicide blog, and his avowed purpose in sending Denton genuine
    cyanide the second time around was to facilitate Denton's demise.
    On this record, we are satisfied that a rational jury could
    conclude that the defendant proximately caused Denton's death by
    mailing him cyanide with which to commit suicide.
    The defendant has a fallback position as to count 14.
    This position hinges on the meaning of "kill" as that word is used
    in the statute of conviction.   The defendant would have us read
    "kill" in that context as synonymous with "murder." But this "kill
    is tantamount to murder" argument is presented only in connection
    - 22 -
    with his assertion that the statute of conviction requires proof
    of some direct causal link between the charged conduct and Denton's
    death.     That assertion goes nowhere:            as we previously have
    explained, the evidence was sufficient to ground a finding that a
    causal relationship existed between the defendant's conduct and
    Denton's death.5     See 
    text supra
    .      No more is exigible.
    Even though the defendant eschews a mens rea attack, his
    comments   about    the   meaning    of   "kill"   might   theoretically   be
    directed to the mens rea that a defendant must possess in relation
    to his victim's death.       See Schad v. Arizona, 
    501 U.S. 624
    , 640
    (1991) (plurality opinion) ("At common law, murder was defined as
    the   unlawful     killing   of     another   human   being   with   'malice
    aforethought.'").     The statute of conviction does not define the
    word "kill."       And during the charge conference, neither party
    requested an instruction elucidating the meaning of the word.
    Following the parties' lead, the district court did not expound on
    the meaning in its jury instructions, and neither party objected.
    5To like effect, the defendant contends that "resulted in,"
    as used in the statute of conviction for count 1 (18 U.S.C.
    § 1716), requires the same causation as murder.      The ordinary
    meaning of the phrase forecloses this argument. See 
    Burrage, 134 S. Ct. at 887
    (explaining that "[a] thing 'results' when it
    '[a]rise[s] as an effect, issue, or outcome from some action,
    process or design'" (second and third alterations and emphasis in
    original) (quoting 2 The New Shorter Oxford English Dictionary
    2570 (1993))); see also De La 
    Cruz, 514 F.3d at 137-38
    (interpreting similarly worded "result" element in 21 U.S.C.
    § 841(b)(1)(A) as requiring only but-for causation).
    - 23 -
    Subsequent to the verdict, the defendant shifted gears and argued
    for the first time that, under the statutory regime, the word
    "kill" must be construed as synonymous with murder.               Building on
    this foundation, he submitted that he merely supplied the means
    that Denton used to kill himself and did not participate in the
    final act.        Thus, he did not "kill" Denton but, rather, merely
    assisted Denton's suicide.
    In    litigation    as    in   life,   timing   is    critically
    important.        So it is here:      the defendant did not develop his
    statutory "kill is tantamount to murder" argument until he filed
    his post-conviction motion for judgment of acquittal under Federal
    Rule of Criminal Procedure 29(c).           Even then, he did not direct it
    at the mens rea element.        Because he did not seasonably raise this
    mens rea argument at any time prior to the jury's verdict, his
    post-conviction motion cannot give it a new lease on life.                See
    United States v. Alberico, 
    559 F.3d 24
    , 27 (1st Cir. 2009).                In
    light of this conspicuous procedural default, the most that the
    defendant can expect is for us to review his late-blooming argument
    for plain error.6
    6 Given the defendant's decision not to brief a mens rea
    theory, this aspect of his argument is likely waived, see United
    States v. Zannino, 
    895 F.2d 1
    , 17 (1st Cir. 1990) ("[I]ssues
    adverted to in a perfunctory manner, unaccompanied by some effort
    at developed argumentation, are deemed waived."), and, thus,
    either unreviewable or reviewable only for "clear and gross
    injustice," United States v. Valenzuela, 
    849 F.3d 477
    , 484 (1st
    Cir. 2017) (quoting United States v. Cheung, 
    836 F.2d 729
    , 730 n.1
    - 24 -
    We need not tarry.           As we have said, the defendant's
    argument rests on the premise that "kill," as used in 18 U.S.C.
    § 1512(a)(1), means "murder."             To support this argument, the
    defendant points to cases in which courts have used "murder"
    interchangeably with "kill" in discussing the witness tampering
    statute.        See, e.g., 
    Fowler, 563 U.S. at 679-80
    (Scalia, J.,
    concurring in the judgment) (using "murder" hypothetical); United
    States v. Burgos-Montes, 
    786 F.3d 92
    , 111-12 (1st Cir. 2015)
    (stating that defendant faced charges for "murdering" victim to
    prevent communication with law enforcement); United States v.
    Tyler, 
    732 F.3d 241
    , 245 (3d Cir. 2013) (similar).             But judicial
    dicta    often    include    imprecise    shorthands.   This    is    such    an
    instance.        Because none of the quoted statements concerns the
    "kill" element, those cases are of scant assistance here.
    The defendant also points to section 1512's penalty
    provisions and specifically notes that killing a witness shall be
    punished as provided in 18 U.S.C. §§ 1111 and 1112.            See 18 U.S.C.
    § 1512(a)(3)(A).       Those sections, in turn, set out the penalties
    for     first    degree     murder,   second   degree   murder,      voluntary
    manslaughter, and involuntary manslaughter — penalties that range
    from a term of years all the way to capital punishment.                      The
    (1st Cir. 1988) (per curiam)). Here, however, nothing turns on
    these distinctions, so we assume, favorably to the defendant, that
    review for plain error is available.
    - 25 -
    defendant argues that punishing violations of section 1512(a) on
    the level of manslaughter might make sense but that his conduct
    did not even meet the elements of manslaughter, as he merely
    "suppl[ied] the means of death" rather than murdered or killed
    Denton.
    Even if "kill," as used in section 1512(a), means murder
    or manslaughter — a matter on which we express no opinion — it is
    neither clear nor obvious that the defendant's conduct amounted to
    something less than murder.        "Murder is the unlawful killing of a
    human being with malice aforethought."               
    Id. § 1111(a).
          The
    elements of murder require that a defendant engage in some conduct,
    such as an affirmative act; that he act with a malicious mens rea,
    such as an intent to kill; and that his conduct cause death.             See
    2 Wayne R. LaFave, Substantive Criminal Law § 14.1(f) (3d ed.
    2018).    Here, it is neither clear nor obvious that a rational jury
    could not conclude that the defendant acted with the intent to
    kill when he shipped a lethal dose of cyanide to a man whom he
    knew to be suicidal.
    Similarly,   it   is   neither   clear    nor   obvious   that   a
    rational jury could not find that the defendant's conduct amounted
    to manslaughter (which, after all, is a lesser included offense of
    murder under federal law, see 18 U.S.C. § 1112(a) ("Manslaughter
    is the unlawful killing of a human being without malice."); United
    States v. Lincoln, 
    630 F.2d 1313
    , 1320 (8th Cir. 1980)).              And for
    - 26 -
    what it may be worth, many states treat assisted suicide as a
    species of manslaughter.          See, e.g., Alaska Stat. § 11.41.120;
    Ariz. Rev. Stat. Ann. § 13-1103; Ark. Code Ann. § 5-10-104; Colo.
    Rev. Stat. § 18-3-104; Conn. Gen. Stat. § 53a-56; Fla. Stat.
    § 782.08; Mo. Rev. Stat. § 565.023; N.Y. Penal Law § 125.15; Or.
    Rev. Stat. § 163.125; see also LaFave, supra, § 15.6(c).
    No more need be said.         For these reasons, we hold that
    the district court committed no reversible error in denying the
    defendant's motion for judgment of acquittal with respect to count
    14.
    C. Admission of Evidence.
    We proceed next to the defendant's contention that some
    evidence was improperly admitted.          He contends that his objections
    should have been sustained to certain testimony from or about the
    non-Denton victims, as well as to Exhibit 16 — a 113-page chart
    containing the contents of 484 email strings, which memorialize
    the defendant's correspondence with persons who replied to his
    cyanide advertisement (including both purchasers and potential
    purchasers).      For ease in exposition, we refer to all of this body
    of    evidence,    in   the   aggregate,    as   the   "anecdotal   background
    evidence."        In the defendant's view, the anecdotal background
    evidence was either wholly or partially inadmissible under Federal
    Rule of Evidence 403.
    - 27 -
    By means of a pretrial filing, the defendant indicated
    that he intended to object generally to the anecdotal background
    evidence (specifically, to any evidence that he had swindled any
    victims other than those identified in the various fraud counts of
    the superseding indictment and, in addition, to any testimony about
    non-Denton victims' mental health histories).              On the morning that
    trial began, the district court indicated that the objections —
    which the defendant tied so tightly at sidebar to Rule 403 that
    the court described this as his "real objection" — should be raised
    during trial.         The court stated that it would make a "formal[]
    rul[ing]" at that time, and defense counsel would have a continuing
    objection from that point forward, without needing to object
    thereafter. The trial got underway. The first time the government
    sought      to    introduce   any    specific   evidence       about    non-Denton
    victims, the defendant — in furtherance of the praxis prescribed
    by   the    district     court   —   objected   to   Exhibit    10     (a   document
    concerning a non-Denton victim not named in the indictment).                    The
    court      nonetheless    admitted    the   evidence   and     gave    a    limiting
    instruction, based on Federal Rule of Evidence 404(b), about the
    purposes for which the jury could consider it.
    Before any more evidence about non-Denton victims was
    admitted (including anecdotal background evidence), the defendant
    sought clarification as to whether the court had provided a
    "definitive ruling" because he did not want to continue "being
    - 28 -
    overruled" in front of the jury and "interrupt[ing] the trial."
    The court replied in the affirmative and asked only that the
    defendant   request   a     further    limiting    instruction       whenever   he
    deemed it necessary.
    From then on, the parties appear to have treated the
    defendant's   Rule    403    objection     to     the    anecdotal    background
    evidence as subject to a continuing objection (which we sometimes
    call a "blanket objection").          Reinforcing this blanket objection,
    the defendant objected from time to time to the admission of
    specific pieces of non-Denton evidence (including Exhibit 16).
    Our case law has long permitted the use of blanket
    objections at or before trial as an efficacious means of preserving
    issues for appellate review.          See United States v. Ladd, 
    885 F.2d 954
    , 958 (1st Cir. 1989).              In determining whether a blanket
    objection sufficiently preserves a particular claim of evidentiary
    error,   courts   typically     consider       whether    the   trier   had     the
    opportunity to address the issue, see United States v. Simms, 
    757 F.3d 728
    , 733-34 (8th Cir. 2014); whether "[t]he substance of the
    objection . . . was thoroughly explored," Palmerin v. City of
    Riverside, 
    794 F.2d 1409
    , 1413 (9th Cir. 1986); whether the
    objecting party was entitled to rely on the trier's grant of the
    blanket objection, see United States v. Sanchez-Hernandez, 
    507 F.3d 826
    , 831 (5th Cir. 2007); and whether testimony admitted
    without specific objection after a blanket objection "presented
    - 29 -
    substantially the same type of information" as testimony admitted
    over a specific objection, 
    id. In this
    instance, each of these considerations counsel
    in favor of concluding that the defendant's blanket objection
    adequately preserved his Rule 403 objection for appellate review.
    To begin, the district court had ample opportunity to address the
    objection before trial, as the defendant initially raised it weeks
    in advance.       Moreover, the court explored the relevance and
    admissibility of the anecdotal background evidence at several
    points, confirmed that the defendant's objection was based on Rule
    403, and explicitly declared that the Rule 403 balance weighed in
    favor of admitting the anecdotal background evidence.     So, too,
    the defendant appears to have relied on the blanket objection;
    even when he lodged specific objections to particular pieces of
    anecdotal background evidence, he stated that he was making his
    "usual" objection.     Finally, when the defendant did not lodge a
    specific objection to a specific piece of anecdotal background
    evidence, the information presented was substantially similar to
    Exhibit 16 (to which he expressly objected).    Given the district
    court's repeated assurance both before and during trial that the
    defendant need not object to each reference to the anecdotal
    background evidence, the defendant's reliance on this assurance
    was reasonable.
    - 30 -
    We add a note of caution.      Although blanket objections
    are sometimes a useful mechanism, see United States v. Cianci, 
    378 F.3d 71
    , 105 (1st Cir. 2004) (noting that "stop-and-go evidentiary
    evaluations" can cause delay and prejudice), trial courts should
    not    dispense    them   indiscriminately,     see   United    States    v.
    Fortenberry, 
    919 F.2d 923
    , 924 (5th Cir. 1990); cf. 
    Cianci, 378 F.3d at 104-05
    (noting that ambiguous blanket objection may fail
    to preserve point for appeal).        Here, however, it seems fair to
    the parties and the district court to give force to the blanket
    objection.     After all, the defendant clearly stated the grounds
    for his objection, the government knew exactly where it stood, and
    the district court acted sensibly in preferring this mechanism to
    a steady stream of specific objections.         We conclude, therefore,
    that   the   blanket   objection   adequately    preserved     the   claimed
    evidentiary errors.       See United States v. Thompson, 
    976 F.2d 666
    ,
    669-70 n.2 (11th Cir. 1992); 
    Ladd, 885 F.2d at 958
    ; see also 3B
    Charles Alan Wright & Peter J. Henning, Federal Practice and
    Procedure § 842 (4th ed. 2013) ("If the problem has been brought
    to the attention of the court, and the court has indicated in no
    uncertain terms what its views are, to require an objection would
    exalt form over substance.").
    With the issue preserved for review, we turn to its
    particulars.      Notwithstanding the district court's grant of the
    blanket objection and the spate of follow-up objections, the court
    - 31 -
    allowed the government to call four non-Denton victims (Walter
    Cottle, Stacy Williams, Cynthia Kirschling, and Autumn Roland) in
    its case in chief.7     The court also permitted the government to
    call two other witnesses (Detective Stuart Daniel Quinn and Edith
    Collins) to testify about the travails of particular non-Denton
    victims.    Detective Quinn testified concerning Derek Jorgensen, a
    victim named in counts 6 and 11, and Collins testified concerning
    her minor granddaughter, a victim not named in the indictment.
    All in all, this testimony went into excruciating detail
    about the non-Denton victims' personal lives, medical issues,
    histories    of   depression,   earlier   suicide   attempts,   suicidal
    motivations, and the like.        It was augmented, and its effect
    exponentially increased, by the government's introduction, over
    specific objection, of Exhibit 16.
    Where, as here, objections to evidentiary rulings are
    preserved, review is for abuse of discretion.        See United States
    v. Sabean, 
    885 F.3d 27
    , 35 (1st Cir. 2018). Although this standard
    of review is deferential, it "does not render trial court decisions
    impervious to scrutiny."        Ruiz-Troche v. Pepsi Cola of P.R.
    Bottling Co., 
    161 F.3d 77
    , 83 (1st Cir. 1998). As we have observed,
    abuse of discretion "sounds worse than it really is."       Schubert v.
    7 The defendant pleaded guilty to wire and mail fraud counts
    involving three of these victims. The defendant was never charged
    with any crimes related to his communications or transactions with
    the fourth victim (Roland).
    - 32 -
    Nissan Motor Corp. in U.S.A., 
    148 F.3d 25
    , 30 (1st Cir. 1998)
    (quoting In re Josephson, 
    218 F.2d 174
    , 182 (1st Cir. 1954)).                   It
    simply means that "when judicial action is taken in a discretionary
    matter, such action cannot be set aside by a reviewing court unless
    it   has   a    definite    and   firm    conviction     that   the   court   below
    committed a clear error of judgment in the conclusion it reached
    upon a weighing of the relevant factors."              
    Id. (quoting Josephson,
    218 F.2d at 182).
    Evidence is relevant as long as it has some tendency to
    make a fact of consequence more or less probable.                     See Fed. R.
    Evid. 401.        In a criminal case, the government is generally
    "entitled to prove its case by evidence of its own choice."                     Old
    Chief v. United States, 
    519 U.S. 172
    , 186 (1997).                        But this
    entitlement is hedged with exceptions.              For instance, a lack of
    dispute or concession of a central allegation may significantly
    reduce the probative value of particular evidence and, thus, call
    its admissibility into question.             See United States v. Ford, 
    839 F.3d 94
    , 109 (1st Cir. 2016).
    To ameliorate these competing concerns, a trial court
    "may   exclude      relevant      evidence    if   its    probative     value    is
    substantially outweighed by a danger of . . . unfair prejudice."
    Fed. R. Evid. 403.         This balance is sometimes difficult to strike.
    As a practical matter, nearly all evidence is offered for the
    purpose of prejudicing the factfinder's views, and Rule 403 is
    - 33 -
    meant to stand as a sentinel, which can be alerted to screen out
    unfair prejudice.     See 
    Sabean, 885 F.3d at 38
    ; United States v.
    Rodriguez-Estrada, 
    877 F.2d 153
    , 155-56 (1st Cir. 1989).         Evidence
    presents a risk of unfair prejudice when it has "the capacity
    . . . to lure the factfinder into declaring guilt on a ground
    different from proof specific to the offense charged."       Old 
    Chief, 519 U.S. at 180
    .     Put another way, unfair prejudice ensues when
    particular evidence "serves only to evoke an improper emotional
    response"    and   distracts   "from   careful   consideration    of   the
    relevant issues."     United States v. Fulmer, 
    108 F.3d 1486
    , 1498
    (1st Cir. 1997).    Although there is no blanket prohibition against
    the admission of such evidence, a trial court faced with an
    objection to its introduction must strike a delicate balance
    between the government's need for the evidence (that is, its
    probative value) and the risk that the evidence will inflame the
    jurors' passions (that is, its unfairly prejudicial effect).           See
    
    id. at 1497-98;
    see also Fed. R. Evid. 403.
    Assessing the totality of the relevant circumstances, we
    conclude that the district court abused its discretion in failing
    to exclude the anecdotal background evidence under Rule 403.
    Though marginally relevant, it had "the capacity . . . to lure the
    factfinder into declaring guilt on a ground different from proof
    specific to the offense charged."      Old 
    Chief, 519 U.S. at 180
    .      A
    - 34 -
    few examples help to illustrate why much of this evidence was
    unfairly prejudicial:
       On direct examination, Cottle testified that he was
    so overwhelmed that he "didn't want to see [his]
    wife" and "didn't want to see [his] child."                       He
    "was crying probably twenty, twenty-five times a
    day for no reason."
       Williams testified about a myriad of factors that
    rendered her suicidal (including going through a
    "terrible"      second     divorce,      experiencing           great
    financial pressure, watching her neighbor shoot her
    dog, and undergoing a horrible car accident).                    She
    also described why she was looking for cyanide:                    "I
    knew that I didn't have the courage to shoot myself,
    and . . . I knew I didn't have the courage to cut
    myself."
       Kirschling testified that she "suffered from major
    depression," was lonely, "couldn't do [her] job,"
    and was "just in constant pain."
       Roland testified that "severe distress" led her to
    look   for    cyanide     after   she    was        diagnosed    with
    schizophrenia,      was    unable       to    work,     and     found
    herself      homeless.      She   was        also    having     "side
    effects from psychological medications that were
    - 35 -
    affecting [her] motor skills to the point where it
    became excruciatingly hard just to turn over in
    bed."
    There    was    more.   Called   as   a   government   witness,
    Detective Quinn, testifying about Jorgensen, stated in part:
    Twenty years ago, [Jorgensen] entered a public
    house, a bar, where people were drinking and
    identified four males that had bullied him
    while he was at childhood school and continued
    to bully him into young . . . adulthood. And
    Mr. Jorgensen was armed with a shotgun. He
    walked into the public house and discharged
    the shotgun at the people who had bullied him,
    fortunately, missing all of them. He then ran
    out of the public house, placed a shotgun into
    his mouth, and discharged it.     Fortunately,
    the cartridge of the firearm left the right
    cheek of his face and didn't go up into the
    brain. He required extensive facial surgery
    . . . .
    In addition, Detective Quinn told the jury about several of
    Jorgensen's botched suicide attempts.       These included sitting in
    a tree with a noose, willing himself to jump, and swimming out to
    sea, waiting for "tiredness" to get "the better of him."
    So, too, Collins testified that her minor granddaughter
    lived with the granddaughter's father after her mother's death.
    That arrangement, though, "didn't work out."          She then moved in
    with her maternal grandparents but "grandma died."         She was sent
    "to a girls' home and ended up with" Collins, who soon discovered
    that her granddaughter, then a young teenager, "ha[d] posted a
    - 36 -
    picture of herself with a scarf around her neck like she was
    hanging herself."
    This barrage of emotionally laden testimony was merely
    the tip of the iceberg.         Through the medium of Exhibit 16, the
    government displayed to the jury a mountain of emails to and from
    the defendant pertaining to cyanide-related transactions.                   Some
    authors wrote paragraphs explaining how their lives had fallen
    apart.       Others   emailed   repeatedly,      begging    the    defendant   to
    respond.     Taken collectively, these lachrymose emails were likely
    to   evoke    an    emotional   response    in    even     the    most   hardened
    individuals. Once again, a few examples suffice to make the point:
       "[I] have been suffering an infection since birth
    . . . [I] don[']t want to continue my life . . .
    [I] need some potassium cyanide . . . tell me the
    price."
       "I need enough C to make me go fast and painlessly
    . . . I keep trying to kill myself but won't die.
    . . . How much will I need how long will it take to
    make me sleep forever."
       "I am ready to die and this seemed like the best
    method."
       "[H]ow much can [I] get it for [I'm] sick of this
    shit world."
    - 37 -
       "I don't know what to expect from this email but
    the darkness has overtaken me and my friend."
       "Rumour has it you can hook me up with sweet
    release.     How much, how quickly?"
    This evidence permeated the record:             it was as copious
    as it was emotionally charged.         And it had virtually no probative
    value.
    In an effort to dredge up some semblance of probative
    value, the government notes that it had the burden to prove the
    existence of the fraudulent scheme.            That is true as far as it
    goes — but it does not take the government very far.             The existence
    and dimensions of the scheme were amply demonstrated by proof of
    the   defendant's     advertisement,    the    number     of   victims,   their
    initial contacts, and the defendant's responses.                 Although the
    anecdotal background evidence may have had a scintilla of probative
    value with respect to the existence of the fraudulent scheme, it
    was wholly cumulative and, thus, gratuitous.               See Fed. R. Evid.
    403; 
    Sabean, 885 F.3d at 40
    .
    The short of it is that the extensive evidence as to the
    circumstances    of    the   defendant's      customers    and   the   thought
    processes that led them to the brink of suicide added virtually
    nothing of legitimate value to the government's case.                     This
    evidence was not needed to prove the existence of the scheme, nor
    did it assist the government in proving, say, the defendant's
    - 38 -
    identity or motive.          Just because evidence may have a smidgen of
    probative value, that bare fact does not give the government free
    rein     to     capitalize       upon   its      emotionally    laden     content,
    particularly where, as here, the government can easily prove its
    case without fanning the flames of unfair prejudice.
    The prosecution — which has available to it the immense
    resources of the federal government — possesses a significant
    advantage in criminal cases, and there seldom is a good reason for
    a prosecutor to push the envelope of that advantage.                    Mindful of
    this imbalance, we consistently have "warn[ed] the government"
    about "the folly of . . . overkill." United States v. Frankhauser,
    
    80 F.3d 641
    , 650 (1st Cir. 1996) (quoting United States v. Arias-
    Montoya, 
    967 F.2d 708
    , 714 (1st Cir. 1992)).                We echo this warning
    today.
    For these reasons, we hold that the anecdotal background
    evidence unfairly prejudiced the defendant because it dwelled upon
    the desperation of severely depressed individuals in what amounted
    to a blatant attempt to engage and inflame the jurors' passions.
    In   our      view,   such   unfair     prejudice     substantially     outweighed
    whatever scant probative value the anecdotal background evidence
    may have had.         We are left with a definite and firm conviction
    that the district court committed a manifest error of judgment in
    working       the   Rule   403   calculus.       As   a   result,   admitting   the
    anecdotal background evidence was an abuse of discretion.
    - 39 -
    The government has a fallback position.             It says that
    even if the district court abused its discretion in admitting the
    anecdotal    background   evidence,   the    error      was   harmless.     The
    question reduces to whether admission of this evidence "results in
    actual prejudice because it had a substantial and injurious effect
    or influence in determining the jury's verdict."              
    Ruiz-Troche, 161 F.3d at 87
    (quoting United States v. Shay, 
    57 F.3d 126
    , 134 (1st
    Cir. 1995)).
    "An error will be treated as harmless only if it is
    'highly   probable'   that   the   error    did   not    contribute    to   the
    verdict."     
    Fulmer, 108 F.3d at 1498
    (quoting United States v.
    Melvin, 
    27 F.3d 703
    , 708 (1st Cir. 1994)).                    "To sustain the
    verdict, the reviewing court must be able to say with a fair degree
    of assurance that the erroneous ruling did not substantially sway
    the jury."     
    Ruiz-Troche, 161 F.3d at 87
    .
    [A] harmlessness determination demands a
    panoramic, case-specific inquiry considering,
    among other things, the centrality of the
    tainted   material,    its   uniqueness,   its
    prejudicial impact, the uses to which it was
    put during the trial, the relative strengths
    of the parties' cases, and any telltales that
    furnish clues to the likelihood that the error
    affected the factfinder's resolution of a
    material issue.
    United States v. Piper, 
    298 F.3d 47
    , 57 (1st Cir. 2002) (quoting
    United States v. Sepulveda, 
    15 F.3d 1161
    , 1182 (1st Cir. 1993)).
    For criminal cases, the strength or weakness of the government's
    - 40 -
    evidence of guilt is normally the most important integer in the
    harmlessness equation.         Practically speaking, a reviewing court
    may find an error harmless when the properly admitted evidence, in
    and of itself, furnished overwhelming proof of the defendant's
    guilt.    See 
    Ford, 839 F.3d at 110
    ; see United States v. Eads, 
    729 F.3d 769
    , 778 (7th Cir. 2013); Clark v. Moran, 
    942 F.2d 24
    , 27
    (1st Cir. 1991).       Here, we hold that the error in admitting the
    anecdotal background evidence was harmless as to counts 1, 5, 7,
    and 12 but not as to count 14.
    At the outset of the trial but before the jury was in
    the courtroom, defense counsel acknowledged that the government
    would not "hear much" from him as to counts 5, 7, and 12 (the
    Denton fraud counts).        He explained that the defendant already had
    pleaded guilty to the non-Denton fraud counts and, thus, had
    admitted the existence of the fraudulent scheme.           Consistent with
    these    statements,   the    defense   focused   at   trial   primarily   on
    attacking the elements of counts 1 and 14 rather than attempting
    to present a full-throated defense to the fraud counts. And during
    his summation, defense counsel stated outright that Denton was a
    victim of the fraudulent scheme and that counsel could "not deny
    that the [g]overnment" proved that scheme.
    These admissions did not come out of the blue.           During
    the trial, the government presented copious — and uncontradicted
    — evidence of the scheme.        In addition, the government introduced
    - 41 -
    documentary evidence of Denton's payment to the defendant, their
    email correspondence, tracking information for the first package
    the defendant sent to Denton, and Denton's IC3 complaint (which
    pointed out that the first package did not contain cyanide).
    On whole-record review, we are confident that the guilty
    verdicts on the fraud counts were mandated by the properly admitted
    evidence.    This evidence, standing alone, supplied overwhelming
    proof of the defendant's guilt.         Thus, even though the error in
    admitting the anecdotal background evidence was egregious, we do
    not think that the jury verdicts on the fraud counts were tainted
    by that evidence.
    We reach the same conclusion as to count 1 (mailing
    injurious articles resulting in death).              With respect to this
    charge,   the   evidence   of   guilt   was   very   strong.   After   the
    constructive amendment, 
    see supra
    Part II(A)(1), the government
    had to prove that the defendant "knowingly deposit[ed] for mailing
    . . . anything declared nonmailable . . . with intent to kill or
    injure another . . . [and that such mailing] resulted in the death
    of any person."     18 U.S.C. § 1716(j).       The government made that
    showing — and it did so without reference to the improperly
    admitted evidence.    Although the defendant made a feeble effort to
    suggest that he was not the source of the cyanide that killed
    Denton, the government presented plentiful evidence, properly
    admitted, confirming the existence of each element required by the
    - 42 -
    statute of conviction.        For instance, there were postal records
    tracking the defendant's second shipment to Denton; the envelope
    discovered      near   Denton's   body   contained     cyanide     residue    and
    identified the defendant as its sender; records detailing the
    defendant's receipt of cyanide from California and his payment for
    it were admitted into evidence; and the jury reviewed emails
    between Denton and the defendant discussing the former's desire to
    end his life and the latter's willingness to send cyanide to
    assist.    There was, moreover, ample proof that the defendant's
    actions resulted in Denton's death.            
    See supra
    Part II(A)(2).
    Given the strength of the government's case on count 1, we have a
    high degree of assurance that the anecdotal background evidence,
    though improperly admitted, did not tarnish the verdict.                      It
    follows that as to count 1, the error was harmless.              See 
    Ford, 839 F.3d at 108
    ; 
    Piper, 298 F.3d at 58
    .
    This leaves count 14 (the witness tampering count). That
    count required proof of the defendant's intent to "prevent the
    communication by [Denton] to a law enforcement officer . . . of
    information relating to the commission . . . of a Federal offense."
    18 U.S.C. § 1512(a)(1)(C).          Intent is inherently difficult to
    demonstrate, see United States v. Whiffen, 
    121 F.3d 18
    , 21 (1st
    Cir. 1997), and in this instance we discern no overwhelming
    evidence   of    the   culpable   intent    required    by   the    statute    of
    conviction.
    - 43 -
    To be sure, there was some circumstantial evidence of
    this intent.        For instance, there was evidence that Denton had
    complained to IC3, that the defendant knew about this complaint
    when he shipped the cyanide, and that the defendant was concerned
    about the FBI's awareness of his "goings on."              But the defendant
    might have sent the cyanide, the second time around, for any number
    of reasons apart from trying to prevent Denton from communicating
    with law enforcement.            As his counsel implied at trial, the
    defendant simply may have wanted to assist Denton's suicide. Given
    the inherent difficulty of proving the necessary intent and the
    peculiarities of this case, we cannot conclude with the requisite
    degree of assurance that the anecdotal background evidence did not
    influence the verdict on count 14.
    This conclusion is fortified by the other considerations
    revealed        through     a   panoramic   inquiry     into   the    relevant
    circumstances.          It strains credulity to imagine that the poignant
    nature     of     the     anecdotal   background   evidence     was    somehow
    overshadowed by properly admitted evidence of the defendant's
    guilt on count 14, especially since the properly admitted evidence
    on this count lacked emotional valence.               Common sense and human
    experience suggest that raw testimony about severe depression,
    failed suicide attempts, and the like would substantially sway a
    jury, whereas drier documentary evidence such as UPS records and
    purchase invoices would have considerably less impact.
    - 44 -
    The government's actual use of the anecdotal background
    evidence is telling.    In his opening statement, the prosecutor
    alluded to the anecdotal background evidence — mentioning Cottle's
    difficulties at work as well as Williams's divorce, car accident,
    and dead dog.   A full quarter of the government's witnesses (seven
    out of twenty-eight) provided anecdotal background evidence.   Last
    but not least, the prosecutor's summation made abundant use of the
    anecdotal background evidence, first recounting contents from some
    of the Exhibit 16 emails and then discussing in detail how the
    defendant "toyed" with Roland.
    When a panoramic inquiry into the relevant circumstances
    has been carried out, we are left without fair assurance that the
    erroneous admission of the anecdotal background evidence did not
    materially influence the jury's verdict on count 14. The anecdotal
    background evidence was central to the government's presentation
    of its count 14 case; it was unique; its emotional content was
    highly charged and its potential for prejudice was correspondingly
    great; and the government made powerful use of it at critical
    stages of the trial.      These factors tilt the balance of the
    harmlessness equation against the government as to this count.
    In an attempt to snatch victory from the jaws of defeat,
    the government makes two additional arguments.   First, it submits
    that the acquittal on count 15 (witness retaliation) is a telltale
    clue that the jury dispassionately considered the proof as to count
    - 45 -
    14,    notwithstanding        the    force       of    the    anecdotal      background
    evidence.    We do not agree.            Simply because a jury acts rationally
    in acquitting on one charge while convicting on others does not
    relegate improperly admitted evidence to the scrap heap of harmless
    error.     See United States v. Litvak, 
    889 F.3d 56
    , 71-72 (2d Cir.
    2018).     This is such a case:            the strongly provocative nature of
    the anecdotal background evidence, improvidently admitted, created
    too high a likelihood that such evidence influenced the jury's
    consideration of count 14.
    Second,     the     government         suggests      that    because      the
    district court instructed the jury on several occasions that the
    use of certain exhibits, including Exhibit 16, must be restricted
    to    purposes     delineated       in    Rule   404(b)      (motive,     opportunity,
    intent,     preparation,       plan,       knowledge,        identity,      absence    of
    mistake, or lack of accident), the admission of the anecdotal
    background evidence was harmless.                  The flaws in this suggestion
    are   at   least    twofold.         First,      the   court    did   not    give     this
    instruction relative to any anecdotal background evidence, save
    for Exhibit 16.        Second — and more fundamentally — the limiting
    instruction did nothing to insulate the jurors from the emotional
    clout of the challenged evidence.
    That ends this aspect of the matter.                  We find the error
    in admitting the anecdotal background evidence harmless as to most
    counts.     Count 14, though, requires a different calculus.                        As to
    - 46 -
    that count, the error was not harmless, and the verdict cannot
    stand.
    D. Sentencing.
    This brings us to the defendant's claim of sentencing
    error.   The defendant attempts to argue that the court erred in
    calculating his base offense level with respect to count 1 by
    analogizing that conviction to first degree murder.     We deem this
    argument waived:   the appellant's brief mentions it only in a
    cursory manner, without citation to any relevant authority.     See
    
    Zannino, 895 F.2d at 17
    .
    The defendant also contends that the concurrent twenty-
    year sentences on the wire and mail fraud counts (counts 2 through
    13) are unconstitutional.      Because this claim relates only to
    sentences imposed on the fraud counts, it is unaffected by our
    vacation of the jury verdict on count 14.
    The defendant's claim rests on the Eighth Amendment's
    proscription against "cruel and unusual punishments."    U.S. Const.
    amend. VIII.    As relevant here, this proscription applies to
    criminal sentences that are "grossly disproportionate" to the
    underlying offenses.      Solem v. Helm, 
    463 U.S. 277
    , 288 (1983).
    When — as in this case — capital punishment is not implicated,
    "the Eighth Amendment 'does not require a precise calibration of
    crime and punishment.'"    United States v. Rivera-Ruperto, 
    852 F.3d 1
    , 17 (1st Cir. 2017) (quoting United States v. Graciani, 61 F.3d
    - 47 -
    70, 76 (1st Cir. 1995)), cert. denied, 
    139 S. Ct. 1258
    (2019).
    Given this latitude, it is not surprising that, in non-capital
    cases, "successful challenges to the proportionality of particular
    sentences have been exceedingly rare."               Rummel v. Estelle, 
    445 U.S. 263
    , 272 (1980); see United States v. Polk, 
    546 F.3d 74
    , 76
    (1st Cir. 2008) (describing such cases as "hen's-teeth rare").
    Here,    the    defendant     complains      that    his    concurrent
    twenty-year sentences on the wire and mail fraud counts were
    grossly disproportionate to the offenses of conviction.                     Because
    the defendant proffers this plaint for the first time on appeal,
    our review is for plain error.           See United States v. Blodgett, 
    872 F.3d 66
    , 71 (1st Cir. 2017); 
    Duarte, 246 F.3d at 60
    .
    As   a   general      rule,    defining      federal       crimes   and
    establishing appropriate penalties are matters within Congress's
    exclusive domain.      See 
    Polk, 546 F.3d at 76-77
    .              Congress has made
    the reasoned judgment that a fraud offense can, under certain
    circumstances, be so blameworthy as to warrant a twenty-year term
    of    immurement.      See    18   U.S.C.   §§    1341,    1343.        Courts   owe
    substantial deference to such legislative judgments; they cannot
    sit    as   "'superlegislature[s]'         to    second-guess"      congressional
    wisdom.     Ewing v. California, 
    538 U.S. 11
    , 28 (2003) (plurality
    opinion); see 
    Rivera-Ruperto, 852 F.3d at 17-18
    .
    In this instance, the challenged sentences were within
    — though at the apex of — the penalties that Congress established
    - 48 -
    for the offenses of conviction.                Those offenses included seven
    wire fraud counts and five mail fraud counts.                  At sentencing, the
    district court explained that the defendant's crimes were much
    "more egregious than . . . common fraud." After all, the defendant
    sought out and preyed upon vulnerable, suicidal victims, offering
    to sell them cyanide but instead sending them Epsom salts.                       The
    court appropriately identified the defendant's chosen targets, his
    use    of   the    internet   to   enlarge       the   reach     of   his   criminal
    activities, and the protracted duration of the scheme (roughly
    thirteen months).         Moreover, the court acknowledged that the
    defendant had gone from bad to worse and had taken drastic measures
    to conceal his fraud by sending real cyanide to the one victim
    whom   he   knew    had   dared    to   blow     the   whistle    and   report   the
    defendant's       chicanery   to   federal       authorities.         Against    this
    backdrop, the sentencing judge — an experienced hand — concluded
    that the offenses of conviction were "among the most heinous" that
    he had ever seen.         This depravity was all the more opprobrious
    because the defendant operated in an "appalling moral vacuum."
    Given the sentencing court's supportable findings, we think that
    the twenty-year sentences, though severe, scarcely can be seen as
    grossly disproportionate to the defendant's conduct.
    The defendant demurs.         In his repast, he trivializes the
    scope of his cruel and cynical scheme by pointing to his relatively
    few victims (nine) and the relatively meager revenues ($2,732.55)
    - 49 -
    garnered through his scheme.     Similarly, he tries to minimize the
    gravity of his conduct by noting that "there is no evidence" that
    any of the victims besides Denton actually "attempted suicide with
    the Epsom salts." Finally, he argues that the guideline sentencing
    range for fraud offenses suggests sentences much more modest than
    the sentences that he received.
    These arguments lack force.        They ignore not only the
    fragility of the defendant's victims but also the broad scope and
    breathtaking cruelty of the defendant's scheme. By the same token,
    they ignore the sordid fact that no fewer than 274 desperate
    individuals, all of whom were contemplating suicide, reached out
    to the defendant in response to his ads.          Considering all of the
    relevant circumstances, there is no principled way for us to say
    that the sentences imposed were grossly disproportionate to the
    conduct surrounding the offenses of conviction.
    The sentencing guidelines do not lead us to a different
    conclusion.   Although the guideline sentencing range for a garden-
    variety fraud case is well below twenty years, the guidelines are
    designed for cases that fall within the "heartland" of a given
    offense.    Kimbrough v. United States, 
    552 U.S. 85
    , 109 (2007)
    (quoting Rita v. United States, 
    551 U.S. 338
    , 351 (2007)).             The
    case at hand is well outside the heartland of fraud offenses:         the
    defendant's conduct and his subsequent coverup were far more
    egregious   than   that   entailed   in   a   run-of-the-mill   fraudulent
    - 50 -
    scheme.      The     guidelines    account    for   atypical   cases   through
    departures and variances, see 
    Rita, 551 U.S. at 344
    , and thus, the
    guideline sentencing range for a particular offense bears very
    little relation to the question of whether a particular sentence
    in an out-of-the-ordinary case violates the Eighth Amendment, see,
    e.g., United States v. Bowers, 
    811 F.3d 412
    , 432-33 (11th Cir.
    2016) (holding sentence that exceeded top of guideline range by
    more than 150 years not grossly disproportionate).
    If more were needed — and we doubt that it is — the
    Supreme Court has repeatedly upheld lengthy sentences against
    Eighth Amendment challenges for offenses less grievous than the
    offenses of conviction.           See, e.g., 
    Ewing, 538 U.S. at 28-31
    (affirming lengthy sentence based on recidivist statute for theft
    conviction); Harmelin v. Michigan, 
    501 U.S. 957
    , 961, 996 (1991)
    (affirming    sentence     of     life   imprisonment    for   possession   of
    cocaine); 
    Rummel, 445 U.S. at 265-66
    , 284-85 (upholding life
    sentence     under    recidivist     statute    when    triggering     offenses
    involved small amounts of money).            So, too, the courts of appeals
    have rejected Eighth Amendment challenges to lengthy sentences in
    fraud cases which, like this one, are embedded in an array of
    aggravating circumstances.         See, e.g., United States v. Neba, 
    901 F.3d 260
    , 264-65 (5th Cir. 2018) (affirming seventy-five-year
    sentence for healthcare fraud), cert. denied, 
    139 S. Ct. 1322
    (2019); United States v. Hebert, 
    813 F.3d 551
    , 565-66 (5th Cir.
    - 51 -
    2015)   (affirming   ninety-two-year   sentence   for   bank   fraud   and
    related offenses); United States v. Tolliver, 
    730 F.3d 1216
    , 1231-
    32 (10th Cir. 2013) (affirming consecutive ten- and twenty-year
    sentences for two counts of using fire to commit mail fraud).
    To say more would be to paint the lily. We hold, without
    serious question, that the concurrent twenty-year sentences on
    counts 2 through 13 are not grossly disproportionate to the
    offenses of conviction.       Thus, they do not offend the Eighth
    Amendment.     Plain error is plainly absent.
    III. CONCLUSION
    We need go no further. For the reasons elucidated above,
    the sentences imposed on counts 1 through 13 are affirmed.             The
    judgment on count 14 is vacated and that count is remanded for
    further proceedings consistent with this opinion.
    Affirmed in part, vacated in part, and remanded.
    - 52 -