United States v. Tanco-Baez ( 2019 )


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  •           United States Court of Appeals
    For the First Circuit
    No. 16-1322
    UNITED STATES OF AMERICA,
    Appellee,
    v.
    JUAN TANCO-BAEZ,
    Defendant, Appellant.
    No. 16-1323
    UNITED STATES OF AMERICA,
    Appellee,
    v.
    JOSÉ CEPEDA-MARTÍNEZ,
    Defendant, Appellant.
    ____________________
    No. 16-1563
    UNITED STATES OF AMERICA,
    Appellee,
    v.
    PETER ROSARIO-SERRANO,
    Defendant, Appellant.
    ____________________
    APPEALS FROM THE UNITED STATES DISTRICT COURT
    FOR THE DISTRICT OF PUERTO RICO
    [Hon. Daniel R. Domínguez, U.S. District Judge]
    Before
    Howard, Chief Judge,
    Kayatta and Barron, Circuit Judges.
    Lydia Lizarribar-Masini, for appellant Tanco-Baez.
    Eleonora C. Marranzini, Assistant Federal Public Defender,
    with whom Eric A. Vos, Federal Public Defender, and Vivianne M.
    Marrero-Torres, Assistant Federal Public Defender, Supervisor,
    Appeals Section, were on brief, for appellant Cepeda-Martínez.
    Jennie Mariel Espada, for appellant Rosario-Serrano.
    Thomas F. Klumper, Assistant United States Attorney, Senior
    Appellate Counsel, with whom Rosa Emilia Rodríguez-Vélez, United
    States Attorney, and Mariana E. Bauzá-Almonte, Assistant United
    States Attorney, Chief, Appellate Division, were on brief, for
    appellee.
    November 4, 2019
    BARRON, Circuit Judge.       Juan Tanco-Baez ("Tanco"), José
    Cepeda-Martínez ("Cepeda"), and Peter Rosario-Serrano ("Rosario")
    were indicted in the United States District Court for the District
    of Puerto Rico on three counts of federal firearms charges arising
    out of a drive-by shooting.       Cepeda and Rosario each challenge
    their conviction on one of those counts and Tanco challenges his
    conviction on two of those counts, while Tanco and Cepeda also
    challenge their sentences for their convictions on those counts.
    We   reject   all   three    co-defendants'    challenges   to   their
    convictions, except for Cepeda's challenge to his conviction on
    one of the counts, which we agree is not supported by sufficient
    evidence and must be reversed.    We affirm Tanco's sentence, but we
    vacate and remand Cepeda's sentence not only for the conviction
    that we reverse but also for the one that we affirm, as we conclude
    that our reversal of his other conviction requires that result.
    I.
    The following facts are not in dispute.      On the morning
    of March 26, 2014, Tanco, Cepeda, and Rosario participated in a
    drive-by shooting on the Román Baldorioty de Castro expressway in
    Carolina, Puerto Rico.    A witness reported seeing a high-speed car
    chase that involved a blue Toyota Yaris, a gray Toyota Yaris, and
    a wine-colored Jeep Cherokee. The chase ended when the two Toyotas
    crashed under a bridge.     The Jeep remained at a close distance.   A
    - 3 -
    witness then heard two rounds of rapid gunfire.                   Thereafter, the
    three co-defendants fled the scene in the Jeep Cherokee.
    Puerto Rico Police Department officers pursued the Jeep
    until it eventually stopped near a pedestrian bridge in the nearby
    city of San Juan.         At that point, the three defendants abandoned
    the vehicle and fled on foot across the bridge to a housing
    project.
    Cepeda    was     arrested       almost    immediately            in   the
    third-floor hallway of one of the buildings in the housing project.
    Law enforcement officers seized a pistol magazine that was found
    nearby.       Officers also found and seized a bag of marijuana hidden
    inside Cepeda's shoe.
    Tanco    and   Rosario   were     apprehended     in   an    apartment
    within Building 46 of the housing project.                     The officers then
    searched the apartment.            They found a pistol magazine under a
    table,    a    pistol    frame   inside     a   laundry   bag,    and      two    pistol
    magazines under a bed.           The slide and barrel of the pistol found
    in the laundry bag were later found on either side of Building 46.
    Officers also found two Glock pistols beside the Jeep
    Cherokee -- a model 17 and a model 27.               The latter model had been
    modified to fire as a machinegun.               Multiple shell casings from the
    scene of the shooting matched the three firearms seized in Building
    46 and near the Jeep Cherokee.
    - 4 -
    On September 17, 2014, Tanco, Cepeda, and Rosario were
    indicted in the District of Puerto Rico as co-defendants on a
    number of federal firearms charges.           Cepeda was charged with
    possession of firearms and ammunition by an unlawful user or addict
    of a controlled substance, in violation of 
    18 U.S.C. § 922
    (g)(3)
    (Count One); Tanco was charged with being a convicted felon in
    possession of firearms and ammunition, in violation of 
    18 U.S.C. § 922
    (g)(1) (Count Two); Tanco, Cepeda, and Rosario were each
    charged   with   aiding   and   abetting   each   other   in   the   illegal
    possession of a machinegun, in violation of 
    18 U.S.C. § 922
    (o)
    (Count Three).
    The three defendants proceeded to an eight-day jury
    trial in late June 2015.         At trial, an expert testified that
    Tanco's DNA was present on the steering wheel and stick shift of
    the gray Yaris and a cigarette butt found in the driver's side of
    that car.   The expert also testified that Rosario's DNA was found
    on the steering wheel of the Jeep.
    A law enforcement agent testified at the trial as well.
    He stated through an interpreter that Cepeda admitted to him in a
    post-arrest interview that he had gone into a vehicle to smoke
    marijuana that day, that he "smoked on a daily basis and that it
    had been a long time since he had started," and that he possessed
    the machinegun on the day of the events.
    - 5 -
    The government did not introduce into evidence a written
    or recorded statement by Cepeda.      Nor did the government introduce
    into evidence any notes that memorialized the law enforcement
    agent's interview with Cepeda, which had taken place over a year
    before trial.
    The jury returned guilty verdicts against each of the
    defendants on all of the counts that each faced.           Cepeda filed a
    motion for judgment of acquittal under Federal Rule of Criminal
    Procedure 29 on Counts One and Three, Tanco filed a Rule 29 motion
    on Counts Two and Three, and Rosario filed a Rule 29 motion on
    Count Three.    The government opposed each Rule 29 motion, and the
    District Court denied them all.
    On March 3, 2016, the District Court held sentencing
    hearings for both Tanco and Cepeda.           Cepeda was sentenced to 120
    months of imprisonment for his convictions on Counts One and Three,
    to be served concurrently with one another.           Tanco was sentenced
    to 120 months of imprisonment as to his convictions on Counts Two
    and Three, also to be served concurrently.
    Rosario's sentencing hearing was held on April 18, 2016.
    He   received   a   sentence   of   102   months'   imprisonment   on   his
    conviction pursuant to Count Three.             The District Court also
    imposed three-year terms of supervised release on all three co-
    defendants for their convictions.
    - 6 -
    Tanco,    Cepeda,     and   Rosario   filed       timely   notices    of
    appeal.    The consolidated appeals challenge:                 (1) the sufficiency
    of   the   evidence     as   to   Cepeda's     conviction      on   Count   One   for
    possession of firearms and ammunition by an unlawful user or addict
    of a controlled substance, in violation of 
    18 U.S.C. § 922
    (g)(3);
    (2) the sufficiency of the evidence for Tanco's conviction on Count
    Two for being a convicted felon in possession of firearms and
    ammunition,      in    violation    of   
    18 U.S.C. § 922
    (g)(1);       (3)   the
    sufficiency of the evidence for Tanco's and Rosario's convictions
    on Count Three for aiding and abetting in the illegal possession
    of a machinegun, in violation of 
    18 U.S.C. § 922
    (o); and (4) the
    procedural and substantive reasonableness of Tanco's and Cepeda's
    sentences.
    II.
    We begin by addressing the defendants' challenges to the
    denial of their Rule 29 motions, in which the defendants take aim
    at the sufficiency of the evidence supporting their convictions.
    We review de novo the District Court's denial of a Rule 29 motion
    that is based on a challenge to the sufficiency of the evidence to
    support a conviction.         United States v. Cortes-Caban, 
    691 F.3d 1
    ,
    12 (1st Cir. 2012); United States v. Perez-Melendez, 
    599 F.3d 31
    ,
    40 (1st Cir. 2010).          We undertake such review by considering the
    evidence    in   the    record     "in   the   light    most    favorable    to   the
    prosecution" and by determining whether, considered in that light,
    - 7 -
    the "body of proof, as a whole, has sufficient bite to ground a
    reasoned conclusion that the government proved each of the elements
    of the charged crime beyond a reasonable doubt."   United States v.
    Lara, 
    181 F.3d 183
    , 200 (1st Cir. 1999).
    A.
    We first consider Cepeda's challenge to the sufficiency
    of the evidence for his conviction on Count One for violating 
    18 U.S.C. § 922
    (g)(3), which makes it "unlawful for any person . . .
    who is an unlawful user of or addicted to any controlled substance
    . . . to . . . possess in or affecting commerce, any firearm or
    ammunition."   To establish the "unlawful user" element of this
    offense, the government must prove beyond a reasonable doubt that
    (1) the defendant used controlled substances regularly, (2) that
    the use took place over a long period of time, and (3) that the
    use was proximate to or contemporaneous with his possession of a
    firearm.   See United States v. Caparotta, 
    676 F.3d 213
    , 216 (1st
    Cir. 2012) (defining "unlawful user" under § 922(g)(3)); United
    States v. Marceau, 
    554 F.3d 24
    , 30 (1st Cir. 2009) (same).
    Cepeda does not dispute that he possessed a firearm.   He
    contends only that the evidence was insufficient to support a
    finding that he was "an unlawful user of . . . any controlled
    substance" within the meaning of § 922(g).    He alleges that the
    only evidence in the record that could suffice to support that
    finding is the testimony from the law enforcement officer who
    - 8 -
    interviewed him that he admitted during that interview that he had
    been a regular, long-term drug user.      Cepeda further contends that
    this evidence cannot suffice to establish that he was an "unlawful
    user," however, because, in his view, that admission was not
    corroborated.
    The government agrees that the admission is necessary to
    prove Cepeda's regular, long-term drug use and thus that he was an
    "unlawful user."   The government further agrees that the admission
    must be corroborated in order for it to be able to provide the
    requisite   evidentiary   support   for   a   finding   that   he   was    an
    "unlawful user," such that his conviction then could survive
    Cepeda's    sufficiency-of-the-evidence       challenge.       But,       the
    government contends, his challenge still lacks merit.
    The government asserts, first, that Cepeda failed to
    contend in his Rule 29 motion that the admission concerning the
    nature and duration of his drug use was not corroborated.             Thus,
    the government contends, he has waived that ground for reversing
    his conviction for lack of sufficient evidentiary support, or, at
    least, he has forfeited that argument and cannot meet the demanding
    plain error standard that applies in consequence.
    We do not agree.    In his written Rule 29 motion, in
    addition to advancing various specific arguments, Cepeda made a
    general sufficiency-of-the-evidence challenge, claiming that "the
    government presented insufficient evidence at trial to support the
    - 9 -
    elements of the offenses of which he was convicted."                         See United
    States v. Foley, 
    783 F.3d 7
    , 12 (1st Cir. 2015) ("[A] general
    sufficiency-of-the-evidence            objection      preserves        all     possible
    sufficiency arguments."); United States v. Marston, 
    694 F.3d 131
    ,
    135 (1st Cir. 2012) ("There is good reason in case of doubt to
    treat an ambiguous [Rule 29] motion . . . as 'general' in the sense
    that it preserves all grounds.").            In that written motion, Cepeda
    also   called     the   District      Court's   attention         to   the     lack    of
    sufficient evidence to establish Cepeda's status as an unlawful
    user, while stating that "Officer Concepcion's testimony that Mr.
    Cepeda stated he had smoked marijuana 'for a long time' . . .
    without more . . . could not have persuaded a rational trier of
    fact   that    Mr.   Cepeda    was    an   unlawful    []    user      of    controlled
    substances at the time of the charged offense."                        We know, too,
    that the government asserted, in response to this motion, that the
    evidence was sufficient to sustain the conviction, in part because
    Cepeda's      "confession     was    corroborated     by    the   testimonial         and
    ballistic evidence presented on trial."                    We therefore conclude
    that this issue was not forfeited below.                    See United States v.
    Valenzuela, 
    849 F.3d 477
    , 487 (1st Cir. 2017) ("Because this
    argument was included in the defendant's original Rule 29 motion,
    we undertake de novo review.").
    Alternatively, the government contends that even if
    Cepeda preserved this challenge below, it lacks merit because the
    - 10 -
    admission concerning his long-term drug use was corroborated.
    But, here, too, we disagree.         To explain why, though, we need to
    provide some background about the relevant legal precedents on the
    weight     that   federal   courts    may   give   to    certain    types      of
    incriminating statements by criminal defendants in assessing their
    evidentiary sufficiency challenges to their convictions.             We begin
    by describing those precedents.        We then explain why, in light of
    them, the admission that is at issue was not corroborated and thus
    cannot suffice to support the "unlawful user" element of the
    offense for which Cepeda was convicted.
    1.
    "It is a settled principle of the administration of
    criminal justice in the federal courts that a conviction must rest
    upon firmer ground than the uncorroborated admission or confession
    of the accused."     Wong Sun v. United States, 
    371 U.S. 471
    , 488-89
    (1963).      This "corroboration rule" initially was intended to
    mitigate    the   risk   that   a   false   confession   would     lead   to   a
    conviction for a crime that not only had not been committed by the
    defendant but also that had not been committed by anyone else.
    See Smith v. United States, 
    348 U.S. 147
    , 153–54 (1954).
    That risk was evident from early English and American
    cases.    Defendants in some of them had been sentenced to death for
    homicide solely on the basis of their confessions of guilt, but
    the supposed victims had then appeared, post-sentencing, "very
    - 11 -
    much alive."     David A. Moran, In Defense of the Corpus Delicti
    Rule, 
    64 Ohio St. L.J. 817
    , 826–31 (2003).
    Courts thus began, in cases involving an offense that,
    like homicide, involved physical damage or injury, to demand
    evidence independent of the defendant's confession of what is known
    as the corpus delicti -- encompassing both an injury and a criminal
    cause for that injury.       Only with such evidence could a confession
    to that offense be considered corroborated.          And thus, only with
    such evidence could a conviction be deemed adequately supported by
    the evidence if the sufficiency of the proof depended upon the
    confession.
    In this way, courts ensured that there would at least be
    independent proof of a crime in place before the accused could be
    convicted of committing it, even if there were no proof apart from
    the defendant's confession of the defendant's culpability for that
    crime.    So,    for   example,    under   this   corroboration    rule,   a
    defendant's     confession    to   a   homicide   could   not   ground   the
    conviction for that offense unless the government also put forth
    adequate "tangible evidence of the death of the supposed victim."
    Wong Sun, 
    371 U.S. at
    489 n.15.
    But, while the corroboration rule initially served this
    important but "extremely limited function," Smith, 
    348 U.S. at 153
    , the Supreme Court expanded on it in a trio of cases decided
    on the same day in 1954.      See Smith, 
    348 U.S. 147
    ;     Opper v. United
    - 12 -
    States, 
    348 U.S. 84
     (1954); United States v. Calderon, 
    348 U.S. 160
        (1954).      In   so    elaborating      the    rule's    scope,    the   Court
    broadened it in various ways, some of which have direct bearing on
    the issues that are before us in this appeal.
    First, the Court explained in this trio of cases that,
    although the corroboration rule was aimed at ensuring that a
    defendant could not be convicted of committing a crime based simply
    on his confession when no independent evidence indicated that a
    crime had been committed at all, the rule also reflected broader
    concerns    about    the      reliability      of   certain     statements    by   the
    accused.    Specifically, the Court described the rule as reflecting
    the fact that confessions may be unreliable because they are
    coerced or induced or because, even if not involuntarily made,
    they    might    "reflect       the   strain    and    confusion      attending    [an
    accused's] predicament rather than a clear reflection of his past."
    Smith, 348 U.S. at 153.               The Court further explained that the
    requirement that a conviction for a crime like homicide must rest
    on more than an uncorroborated confession by the accused reflects
    the fact that the average juror is not familiar with the criminal
    justice system's long history of false confessions.                    Id.
    These observations provided background for the Court's
    clarification       in   this    trio   of     cases   that     the   scope   of   the
    corroboration rule was not limited to "confessions."                      To be sure,
    the Court explained, a confession is a "complete and conscious
    - 13 -
    admission of guilt," Opper, 
    348 U.S. at 91
    , and the corroboration
    rule historically had been applied to such confessions by the
    accused. But, the Court held in these cases that the corroboration
    rule was no less applicable to certain admissions by the accused,
    even   though    such    statements       by    the    accused   are      not    like   a
    confession because they fail to "admit[] to all the elements of
    the offense," Smith, 
    348 U.S. at 154
    , and may merely "explain
    actions rather than admit guilt," Opper, 
    348 U.S. at 91
    .
    The Court described the types of admissions to which the
    corroboration rule applied as "statements of the accused out of
    court that show essential elements of the crime . . . necessary to
    supplement      an    otherwise      inadequate       basis    for   a    verdict       of
    conviction."         Opper, 
    348 U.S. at 91
    .                 After all, the Court
    elaborated, these "admissions have the same possibilities for
    error as confessions."             
    Id.
       Thus, the Court explained, when an
    accused's "admission is made after the fact to an official charged
    with   investigating         the    possibility        of    wrongdoing,        and   the
    statement embraces an element vital to the Government's case," it
    must be corroborated, just as a confession must be, to provide the
    necessary evidentiary support to permit a conviction to survive a
    sufficiency-of-the-evidence challenge.                 Smith, 348 U.S. at 155.
    The Court emphasized, moreover, that a statement by the
    accused of the sort just described is subject to the corroboration
    rule   even    when    the   admission     is    not    to    "one   of   the     formal
    - 14 -
    'elements' of the crime" but instead only to "a fact subsidiary to
    the proof of these 'elements,'" Smith, 
    348 U.S. at 155
    , that is
    "essential" to the proof of an element, Opper, 
    348 U.S. at 90
    .
    "It is the practical relation of the statement to the Government's
    case which is crucial," the Court explained, "not its theoretical
    relation to the definition of the offense."    Smith, 
    348 U.S. at 155
    .
    In light of this precedent, Cepeda's statement in his
    interview with the law enforcement agent about the length and
    nature of his drug use must be corroborated if it is to be relied
    upon to support his conviction against the sufficiency-of-the-
    evidence challenge that he brings.   For while that admission was
    not a strict confession, it was made "after the fact to an official
    charged with investigating the possibility of wrongdoing, and the
    statement embrace[d] an element vital to the Government's case,"
    
    id.,
     given that the statement admits to a fact that is vital to
    the government's effort to prove an element of the offense for
    which he was convicted -- namely, the "unlawful user" element.
    Second, the Court in this trio of 1954 cases clarified
    the corroboration rule in another respect that bears on Cepeda's
    sufficiency-of-the-evidence   challenge.      This   clarification
    concerned the types of offenses to which the corroboration rule
    applied.
    - 15 -
    The Court recognized that the corpus delicti for some
    offenses -- unlike the corpus delicti for, say, homicide -- is not
    "tangible."   Smith, 348 U.S. at 154.     For example, according to
    the Court, tax evasion is an offense that lacks a "tangible" corpus
    delicti, id., because the offense results in no "physical damage
    to person or property," Wong Sun, 
    371 U.S. at
    489 n.15.     The Court
    then explained that, for offenses of that sort, evidence that would
    tend to establish the corpus delicti "must implicate the accused,"
    even though evidence that would tend to establish the corpus
    delicti of offenses that result in physical damage or injury --
    such as evidence of the murdered body in a homicide case -- need
    not.   Smith, 
    348 U.S. at 154
    .
    The Court thus confronted a choice about whether to apply
    the corroboration rule to this class of offenses.        As the Court
    described that choice, it could either "apply[] the corroboration
    rule to [these] offense[s] and accord[] the accused even greater
    protection than the rule affords to a defendant in a homicide
    prosecution, or . . . find[] the rule wholly inapplicable because
    of the nature of the offense."   
    Id.
     (internal citations omitted).
    In the end, the Court chose the former path.     
    Id.
       And,
    it did so even though it recognized that it was thereby necessarily
    providing a "broader guarantee" to defendants in cases of crimes
    lacking a "tangible corpus delicti" than had been granted to
    defendants accused of crimes that had one.         
    Id.
         The Court
    - 16 -
    explained that this "broader guarantee" resulted precisely because
    the substantial independent evidence needed in such cases to
    corroborate the admission or confession -- and thus to ensure that
    a crime had been committed at all -- necessarily would also be
    evidence "implicat[ing] the accused."     
    Id.
    The Court eventually summarized the corroboration rule
    as it had been elaborated in this trio of 1954 cases in dicta as
    follows: "[w]here the crime involves physical damage to person or
    property, the prosecution must generally show that the injury for
    which the accused confesses responsibility did in fact occur, and
    that some person was criminally culpable."      Wong Sun, 
    371 U.S. at
    489 n.15.   And, "in such a case," the Court went on, "[t]here need
    . . . be no link, outside the confession, between the injury and
    the accused who admits having inflicted it."     Id.; see also Smith,
    
    348 U.S. at 153-54
     (recognizing that for crimes producing physical
    injuries, "[o]nce the existence of the crime was established . . .
    the guilt of the accused could be based on his own otherwise
    uncorroborated confession").
    But, by contrast, the Court further explained in that
    dicta, "where the crime involves no tangible corpus delicti," then
    "the corroborative evidence must implicate the accused in order to
    show that a crime has been committed."    Wong Sun, 
    371 U.S. at
    489
    n.15 (second quotation quoting Smith, 
    348 U.S. at 154
    ).      For, in
    a case of that type, the only evidence that could corroborate the
    - 17 -
    fact that a crime was committed at all -- according to the Court
    -- is evidence that tends to prove that the defendant committed
    it.     Smith, 
    348 U.S. at 154
    .       And so, the Court has made clear
    that, at least in cases of that type, "[a]ll elements of the
    offense    must     be   established     by     independent     evidence   or
    corroborated admissions."        
    Id. at 156
    .
    The Court's guidance in the trio of 1954 cases about the
    scope of the offenses to which the corroboration rule applies is
    of direct relevance to Cepeda's sufficiency-based challenge to his
    conviction.      That is so because the conviction that he challenges
    under the corroboration rule is for a status-based, firearms
    possession offense.      Thus, like the crime of tax evasion at issue
    in Smith, it is a crime that has no "tangible corpus delicti."
    Wong Sun, 
    371 U.S. at
    489 n.15 (emphasis added) (citing Smith, 
    348 U.S. at 154
    ).     In consequence, even though any evidence that would
    tend to establish the corpus delicti for that offense "must
    implicate" Cepeda in its commission, Smith, 
    348 U.S. at 154
    , the
    government must corroborate the admission that he made about the
    nature and duration of his drug use if it wishes to rely on that
    admission to support the "unlawful user" element of the status-
    based firearms possession offense of which he was convicted, see
    
    id. at 154-56
    .
    Finally, the Court in this trio of cases addressed one
    other    issue    that   bears   on   Cepeda's    evidentiary    sufficiency
    - 18 -
    challenge to his conviction. That issue concerns the means through
    which the government may corroborate an admission in a case in
    which there is no tangible corpus delicti for the underlying
    offense.
    Notably, the Court made clear in the trio of 1954 cases
    that "the corroborative evidence [for the admission] need not be
    sufficient, independent of the statements, to establish the corpus
    delicti."     Opper, 348 U.S. at 93.       Thus, there is no requirement
    for the government to put forth "substantial evidence . . . which
    tends to establish the whole of the corpus delicti" directly.              Id.
    (emphasis added).       For example, corroboration may be shown even if
    the "direct corroborative evidence . . . tends to establish . . .
    one element of the offense" and the other elements are proven
    "entirely by independent evidence," so long as the evidence as a
    whole, including any corroborated admissions, is "sufficient to
    find guilt beyond a reasonable doubt."              Id. at 93-94 (emphasis
    added).
    The Court also made clear that, while there must be
    "substantial    independent     evidence     that   the   offense   has   been
    committed," that substantial independent evidence may include
    evidence that "merely fortifies the truth of the confession" or
    admission.     Smith, 
    348 U.S. at 156
    .          Thus, evidence that would
    not,   absent     the     confession    or      admission,   "independently
    establish[] the crime charged," may nonetheless corroborate the
    - 19 -
    admission or confession.          
    Id.
        For that reason, the independent
    evidence      that     corroborates   the   essential   fact   that   has   been
    admitted may take the form of evidence that "bolster[s] the
    [admission] itself and thereby prove[s] the offense 'through' the
    statements of the accused."           
    Id.
     (emphasis added).
    The Court had no occasion in Opper, Smith, and Calderon
    to address in full, however, the types of independent evidence
    that could be relied upon to bolster such an admission, such that
    the offense may be proved through that corroborated admission.
    The Court was asked in each of those cases to find the admission
    or confession at issue corroborated only based on evidence that
    tended to show that the content of the relevant portions of the
    admission or confessions was actually true, or that the alleged
    crime had actually occurred.            Smith, 348 U.S. at 157-59; Opper,
    
    348 U.S. at 93-94
    ; Calderon, 
    348 U.S. at 164-168
    .               The Court had
    no need, therefore, to address when or whether independent evidence
    that directly tended to confirm only admitted facts other than the
    "vital" fact in dispute could render trustworthy the admission of
    that       essential     fact,   notwithstanding    the    absence     of    any
    independent evidence that directly tended to establish it.1
    1In Smith, for instance, the government successfully
    corroborated admissions of the defendant's net worth -- a key fact
    in his prosecution for tax evasion -- both by "substantiating [his]
    opening net worth directly" and by presenting "independent
    evidence . . . which tends to establish the crime of tax evasion."
    - 20 -
    In Massei v. United States, however, we rejected the
    notion that, under the corroboration rule as developed in the trio
    of 1954 cases, the government could corroborate an admission
    concerning such a vital fact merely through independent evidence
    that corroborates a different fact that the accused had admitted,
    regardless of the relation between that corroborated fact and the
    vital one that was disputed.    
    241 F.2d 895
    , 904 (1st Cir. 1957),
    aff'd, 
    355 U.S. 595
     (1958).    Massei was a case about tax evasion,
    and we held there that the defendant's admission that he had taken
    in graft (which was alleged to be the source of his potentially
    reportable income) was not sufficiently corroborated by "the fact
    that [the defendant] was proved to have been a police officer as
    stated in his admissions."    
    Id.
       We explained that the independent
    348 U.S. at 157-59. The government thus did not attempt to argue
    that -- and, in consequence, the Court had no occasion to consider
    whether -- the net worth admission was trustworthy because, for
    example, other of his financial disclosures were shown to be
    accurate.    Stating that corroboration can "prove the offense
    'through' the statements of the accused," Smith, 348 U.S. at 156,
    the Court cited by "cf." and without explanation to Parker v.
    State, 
    88 N.E.2d 556
     (Ind. 1949), reh'g denied, 
    89 N.E.2d 442
     (Ind.
    1950), in which the Indiana Supreme Court held that "the
    corroboration required is not of incidental facts stated in the
    confession but that the offense charged had been committed."
    Parker, 88 N.E.2d at 558. In other words, the corroboration could
    not merely tend to support the credibility of the confession if it
    did not also tend to show the existence of a crime. Id. at 559-
    60.
    - 21 -
    evidence that tended to establish the police officer aspect of the
    defendant's admission "f[ell] short of . . . corroboration" of the
    admission that concerned his taking in graft, as there was no
    "evidence of actual graft taking or opportunity for such."   Id.2
    Nor do we understand our most recent decision in United
    States v. Singleterry to require us to take a contrary approach to
    the corroboration rule than the one Massei took.   See 
    29 F.3d 733
    (1st Cir. 1994).     In Singleterry, we considered a sufficiency
    challenge by a defendant who had admitted to, and been convicted
    of, carrying a gun in connection with a drug trafficking offense.
    
    Id. at 735-36
    .   Without mentioning Massei, we stated in a footnote
    that, "in the absence of independent evidence of the corpus
    delicti," an admission may be corroborated by "other evidence
    typically used to bolster the credibility and reliability of an
    out-of-court statement."    
    Id.
     at 737 n.3.   We further concluded
    -- in dicta in a separate footnote -- that corroborated evidence
    of the defendant's admitted drug trafficking was "strong evidence"
    2 Upon appeal, the Supreme Court rejected our contention that
    what the graft admission was introduced to demonstrate -- the
    "likely source" of the defendant's increased net worth -- was an
    "indispensable element" of the crime of tax evasion under the net
    worth method of proving evasion, as the government could
    alternatively demonstrate that no possible source of nontaxable
    income existed. United States v. Massei, 
    355 U.S. 595
    , 595 (1958).
    Nevertheless, the Court affirmed without disagreeing with our
    discussion of what would be required to corroborate that admission.
    
    Id.
    - 22 -
    of the trustworthiness of the defendant's further admission that
    he had used a firearm that had been found in connection with the
    trafficking.      
    Id.
     at 738 n.5.
    But, we do not understand that conclusion concerning two
    types of conduct that have long been thought to be associated with
    one another -- drug trafficking and firearms usage in furtherance
    of the trafficking        -- to suggest that Massei erred in declining
    to   treat    a   corroborated      admission     as    necessarily   rendering
    trustworthy an unrelated one not otherwise corroborated.                      The
    Court has noted that questions of corroboration are necessarily
    fact-dependent,     see    Opper,    
    348 U.S. at 93
    ,   and,   given   the
    particular facts at issue in Singleterry, and the oft-remarked-
    upon connection between firearms and drug trafficking, see, e.g.,
    United States v. Bianco, 
    922 F.2d 910
    , 912 (1st Cir. 1991) ("[W]e
    often observe that firearms are common tools of the drug trade
    . . . ."), we do not read the dicta in Singleterry to hold that
    independent evidence that tends to establish a fact that has been
    admitted renders trustworthy all other facts admitted by the
    accused, no matter how unrelated to each other they may be, even
    though no independent evidence tends to establish those facts
    directly.     See also United States v. Deville, 
    278 F.3d 500
    , 506-
    07 (5th Cir. 2002) (finding a defendant's admission to carrying a
    gun in connection with drug trafficking corroborated by extensive
    evidence that the defendant engaged in drug trafficking); cf.
    - 23 -
    United States v. Brown, 
    617 F.3d 857
    , 863 (6th Cir. 2010) (deeming
    a defendant's admission to committing a burglary and possessing a
    gun stolen in that burglary corroborated by independent evidence
    that the gun was stolen in that burglary).
    Indeed, we note that, in accord with Massei, other
    circuits have declined to apply the corroboration rule in such a
    mechanical fashion, whereby independent evidence that tends to
    establish    a   fact    in   an   accused's       admission    may   suffice    to
    corroborate an otherwise unrelated vital fact that the admission
    also contains on the theory that the defendant's corroborated
    admissions permit the conclusion that he is generally reliable.
    See United States v. Stephens, 
    482 F.3d 669
    , 673 (4th Cir. 2007)
    (finding a defendant's confession uncorroborated despite testimony
    demonstrating that a person described in the confession existed
    and owned the car described by the defendant); United States v.
    Calhoun, No. 92-2001, 
    1993 WL 280324
     at *3 (6th Cir. July 26, 1993)
    (per curiam) ("Nor do we believe that the fact the other crimes
    admitted to in the confession are corroborated permits the use of
    the confession to prove an uncorroborated crime."); United States
    v. Lopez-Alvarez, 
    970 F.2d 583
    , 595 (9th Cir. 1992) (holding that
    a defendant's admission that he helped a murderer avoid capture at
    an airport was uncorroborated where "[t]he only elements of [it]
    that have been independently verified are those relating to his
    presence    at   the    airport"    and    rejecting    as     insufficient     the
    - 24 -
    government's     evidence        that   other      unrelated   admissions     of   the
    defendant "appear[ed] trustworthy").
    This guidance about the means by which admissions may be
    corroborated         directly    bears       on    Cepeda's    case,    because    the
    government does not contend that substantial independent evidence
    directly corroborates all parts of his admission.                      The government
    does argue that we may treat the evidence in the record of Cepeda's
    recent drug possession -- namely, the drugs found in his shoe on
    the day of his arrest -- as corroborative of his admission of his
    recent   drug    use,        although   we    note    that    the   caselaw   is   not
    consistent      in     its    treatment       of    whether    such    evidence    can
    corroborate such an admission.               Compare United States v. Sperling,
    
    400 F. App'x 765
    , 768 (4th Cir. 2010) (concluding that a canine
    alert may have provided some evidence of drug possession but did
    not sufficiently corroborate a defendant's admission that he was
    an unlawful user), with United States v. Mashore, 
    346 F. App'x 934
    , 935 (4th Cir. 2009) (per curiam) ("[T]he strong odor of
    marijuana that [a police officer] observed while standing outside
    [the defendant's] vehicle . . . was sufficient to justify an
    inference by the fact-finder that [his] confession about his
    marijuana use was true.").3
    3 We do not endorse Sperling's suggestion that evidence of
    drug possession "is quite irrelevant to the issue of drug use."
    400 F. App'x at 768.
    - 25 -
    But, the government does not argue that there is any
    independent evidence in the record that in and of itself tends to
    establish that he was a long-term drug user, as the government has
    sometimes offered in other cases in which courts have found
    admissions that pertain to the "unlawful user" element to have
    been corroborated.      See, e.g., United States v. Dalhouse, 
    534 F.3d 803
    , 807 (7th Cir. 2008) (finding an "unlawful user" admission
    corroborated by witness testimony that the defendant was a long-
    term user).      But see United States v. Soltani, 
    360 F. App'x 694
    ,
    696 (8th Cir. 2010) (concluding, without significant explanation,
    that evidence relating only to recent use corroborated a confession
    to being a regular, long-term user); Mashore, 346 F. App'x at 935-
    36 (similar).        Notably, for example, the government conceded at
    oral argument that the marijuana found on Cepeda did not directly
    tend to establish the length of his drug use.
    Instead, the government seeks to fortify the reliability
    of Cepeda's statement concerning the nature and duration of his
    past   drug    use   solely    by    pointing    to   evidence   that   provides
    independent support for finding the content of other statements
    that   Cepeda    offered      in    the   same   twenty-to-twenty-five-minute
    interview to be true.         In addition to his admission to drug use on
    the day of the offense, Cepeda stated that he was present in the
    gray Yaris during the shootout, that his escape was into the Jeep,
    and that he possessed an automatic weapon and concealed a pistol
    - 26 -
    magazine.    The government asserts -- and Cepeda does not dispute
    -- that substantial independent evidence does tend to establish,
    in and of itself, each of those statements.                The government then
    further asserts that, in consequence, we may treat his admission
    concerning the regular and long-term nature of his drug use as
    reliable, given that the reliability of his other statements has
    been adequately demonstrated even though it does not argue that
    any of the evidence that corroborates those admissions constitutes
    evidence that in and of itself tends to establish that Cepeda was
    a long-term user of drugs.
    Thus,   we      now   consider      the    record      evidence      of
    corroboration and the government's case that it suffices here.                  In
    doing so, we emphasize that the need for there to be substantial
    independent evidence to corroborate Cepeda's admission bearing on
    his status as an "unlawful user" is particularly clear, because
    the   circumstances    in   which    Cepeda   is   said     to   have   made    the
    admission bear strong "indicia of unreliability."                Smith, 348 U.S.
    at 159.
    Cepeda's     statement    pertained       to   the   most   disputed
    element of the crime, the length of time he had used drugs.                    That
    element is also one that is unusually difficult to prove absent an
    admission, as it requires evidence of regular illegal activity
    over a long period of time. In addition, the interview with Cepeda
    in which he made the admission was not videotaped or recorded.
    - 27 -
    Nor were any supporting notes of the interview submitted. Instead,
    one of his interviewers, Homeland Security Investigations Task
    Force Agent Carlos Concepcíon-Ramos ("Concepcíon"), testified at
    trial based solely on his memory of Cepeda's statements. Moreover,
    while Concepcíon testified that he understood Cepeda to have
    admitted to being an unlawful user, his testimony revealed that
    Cepeda's actual words -- "hacía tiempo" -- are susceptible to
    multiple understandings, some of which would not clearly establish
    the length of Cepeda's drug usage.       See Calderon, 
    348 U.S. at 164
    (carefully scrutinizing an admission for corroboration where the
    meaning of an "oral statement" at issue was "certainly not clear").
    2.
    We begin with the independent evidence in this case that
    corroborates Cepeda's admissions concerning the vehicles he was in
    during the shootout.    We do not see how this independent evidence
    concerning the day of his arrest suffices to corroborate Cepeda's
    admission that he regularly used drugs over a long period of time.
    There is too little relationship between the admitted fact that is
    directly confirmed by independent evidence and the admitted fact
    for which there is none. And, the absence of any such relationship
    is   especially    problematic    given       the   strong    indicia    of
    unreliability present here.
    For     similar   reasons,     we    conclude   that     Cepeda's
    admissions   concerning     firearms    do    not   require   a   different
    - 28 -
    conclusion.        For while those admissions are also confirmed by
    independent evidence, as Cepeda himself accepts, his connection to
    firearms bears no relationship to any past, regular drug use on
    his part.    Nor does the government contend otherwise.                   This is not
    a case, for example, like Singleterry in which the admissions --
    corroborated and uncorroborated, respectively -- concern conduct
    that has a well-known relationship.                  For while a corroborated
    admission    of    being   a   drug      trafficker       may   suffice       to   render
    trustworthy an uncorroborated admission of using a firearm to carry
    out   that   unlawful      trade,     there   is     no    similarly      established
    connection    between      regular       long-term    drug      use     and    firearms
    possession.       Nor does the government argue otherwise.
    Of course, Cepeda did also admit to recent drug use, as
    he admitted to using marijuana on the day of his arrest.                             But,
    even if we were to treat that admission concerning recent drug use
    as if it were corroborated by the evidence of his recent drug
    possession, as would seem plausible, but see Sperling, 400 F. App'x
    at 768 (finding that evidence of current possession does not
    corroborate       an   admission    of    recent     use),      there    is    still   a
    substantial temporal gap between the conduct admitted to in his
    statement about his recent use of drugs and the conduct admitted
    to in his statement about whether he was a regular, long-term user,
    cf. Calderon, 
    348 U.S. at 164
     (holding that evidence that the
    defendant was poor at one point in time was "too remote" to
    - 29 -
    corroborate an admission relating to his wealth a decade later).
    Without purporting to identify precisely how long such drug use
    must have occurred to qualify, we note that the government points
    us to authority finding a defendant to have been an "unlawful user"
    only on the basis of evidence that he had used drugs for at least
    a year.     See United States v. Burchard, 
    580 F.3d 341
    , 352-54 (6th
    Cir.   2009)      (affirming    a   conviction      under      § 922(g)(3)    where
    evidence showed the defendant had used cocaine over a one-year
    period).
    Moreover, we emphasize, the government conceded at oral
    argument that it is not contending that the evidence of Cepeda's
    recent drug use in and of itself tends to establish that he used
    drugs over the extended period of time required by the statute.
    Rather, the government argues only that the evidence corroborating
    that admission about recent drug use, along with the evidence
    corroborating Cepeda's other admissions unrelated to his admission
    concerning     his   past    drug     use,   suffices     to    corroborate       that
    admission    by    revealing    him    to    be   generally     reliable     in   his
    admissions.       See United States v. Jones, 
    232 F. Supp. 2d 618
    , 622
    (E.D. Va. 2002) (finding a defendant's admission to being an
    "unlawful      user"        uncorroborated        where        the   government's
    corroboration merely verified "peripheral facts unrelated to the
    crime in prosecution").
    - 30 -
    Nor do we see how the fact that independent evidence
    corroborates   each   of   these   various    admissions    --   concerning,
    respectively, the cars that Cepeda was in during the shootout, the
    firearms that he possessed during it, and his recent drug use
    -- requires a different conclusion.           The government provides us
    with no argument as to why the confirmation of any of these
    admissions   is   particularly     probative    of   the   key   unconfirmed
    admission to being a regular, long-term user.              Thus, even when
    considered together, the government advances no argument as to why
    there is more than a remote relationship between these corroborated
    facts and the "essential" fact that is in dispute: whether Cepeda
    was a long-term, regular drug user, given that such conduct
    necessarily had to occur well before the shootout.                 Yet, the
    precedent is clear that each essential fact that is admitted must
    be corroborated in order for the offense to be proved through the
    admission of such a fact.
    We emphasize, again, that the interview in which the
    defendant made the critical admission was not documented at all in
    the two years prior to trial and the admission itself was unusually
    ambiguous as to a key element of the offense.          The jury therefore
    had no basis to make an independent assessment of the conditions
    and context under which Cepeda admitted to being a regular, long-
    term drug user and therefore no basis to conclude that Cepeda's
    admission was untainted by pressure or coercion.                 If Cepeda's
    - 31 -
    admission had fewer indicia of unreliability, then the jury might
    have had a greater ability to assess the admission's credibility.
    There thus might in such circumstances be a correspondingly lesser
    amount of corroboration required on sufficiency review.
    Thus, mindful of these indicia of reliability and that
    "[e]ach case has its own facts admitted and its own corroborative
    evidence,"        Opper, 348 U.S. at 93; see also Smith, 
    348 U.S. at 156
    (recognizing "differing views on the substantiality of specific
    independent evidence"), we conclude that the evidence that the
    government        identified   as   sufficient     to   corroborate   Cepeda's
    statement that he had used drugs over a long period of time is not
    adequate     to    do   so.    Accordingly,   we    conclude   that   Cepeda's
    conviction on Count One rested on an uncorroborated admission and
    thus must be reversed because it is not supported by sufficient
    evidence.4
    B.
    We next consider Tanco's challenge to his § 922(g)(1)
    conviction.        Under 
    18 U.S.C. § 922
    (g)(1), it is "unlawful for any
    person . . . who has been convicted in any court of, a crime
    4 Cepeda also asserts that the government's evidence, even if
    sufficiently corroborated, does not establish that his drug use
    took place over a long period of time. Because we resolve the
    first argument in his favor, we need not address the second.
    - 32 -
    punishable by imprisonment for a term exceeding one year . . . to
    . . . possess in or affecting commerce, any firearm or ammunition."
    Tanco stipulated that he was a felon.              He challenges
    only the possession element of the offense.            "Possession can be
    either actual or constructive, sole or joint."              United States v.
    Wight,   
    968 F.2d 1393
    ,   1397   (1st   Cir.   1992).      "Constructive
    possession of a firearm may be established when a person 'knowingly
    has the power and intention at a given time of exercising dominion
    and control over [it] either directly or through others.'"            United
    States v. Ridolfi, 
    768 F.3d 57
    , 61-62 (1st Cir. 2014) (quoting
    United States v. McLean, 
    409 F.3d 492
    , 501 (1st Cir. 2005)).
    Constructive possession can be inferred, moreover, from
    circumstances "such as a defendant's control over the area where
    the contraband is found (e.g., defendant's home or automobile)."
    Id. at 62 (quoting McLean, 
    409 F.3d at 501
    ).           Thus, constructive
    possession may be proven "through the use of either direct or
    circumstantial evidence; however, mere presence or association
    with another who possessed the contraband is insufficient to
    establish constructive possession."         Wight, 
    968 F.2d at 1397
    .     Put
    otherwise, "there must be some action, some word, or some conduct
    that links the individual to the contraband and indicates that he
    had some stake in it, some power over it."            McLean, 
    409 F.3d at 501
     (alterations and internal quotations omitted).
    - 33 -
    Tanco contends that there was insufficient evidence of
    either his actual or his constructive possession of a firearm.           We
    disagree.
    The evidence supportably shows that Tanco was involved
    in a drive-by shooting and that, during it, he was driving the
    gray Yaris that was involved in that shooting.         The evidence also
    supportably shows both that he was in an apartment where officers
    found a pistol in a laundry bag and a pistol magazine under the
    table and that two other firearms were found near the Jeep from
    which he and his co-defendants exited during the police chase.
    Furthermore, the evidence suffices to show that shell casings from
    each of these three firearms were found at the site of the
    shooting.
    Viewing the evidence in the light most favorable to the
    verdict, a jury could reasonably find that all three firearms were
    used during the shooting.         The evidence concerning the shell
    casings,    when   considered   with    other   evidence   just   reviewed,
    suffices to establish as much.           Given that the evidence also
    supportably shows that Tanco participated in the entirety of the
    drive-by shooting and police chase along with the other two co-
    defendants, the evidence suffices to permit a reasonable jury to
    find that he had or could have exercised control over at least one
    of the three firearms during the course of those events.                See
    Wight, 
    968 F.2d at 1398
     (finding that "it could be inferred from
    - 34 -
    [the] fact" that the defendant was in the vehicle for the purpose
    of committing a crime that "he, as a convicted felon, exercised
    joint dominion or control over the vehicle and its contents,
    including the firearm").       Therefore, we affirm Tanco's conviction
    on Count Two.
    C.
    We next turn to Tanco's and Rosario's challenges to their
    § 922(o) convictions of aiding and abetting in the possession of
    a machinegun.    On appeal, Cepeda does not contest his conviction
    as to Count Three.     Therefore, we affirm.
    Under 
    18 U.S.C. § 922
    (o), it is "unlawful for any person
    to   transfer   or   possess   a   machinegun,"   setting   aside   certain
    enumerated exceptions that do not apply here.               To establish a
    violation of § 922(o), "the government must prove that 1) the
    defendant possessed or transferred a machinegun 2) with knowledge
    that the weapon had the characteristics to bring it within the
    statutory definition of a machinegun."         United States v. Olofson,
    
    563 F.3d 652
    , 659 (7th Cir. 2009).        "A machine gun is defined as
    'any weapon which shoots, is designed to shoot, or can be readily
    restored to shoot, automatically more than one shot, without manual
    reloading, by a single function of the trigger.'"            United States
    v. Nieves-Castano, 
    480 F.3d 597
    , 599 (1st Cir. 2007) (quoting 
    26 U.S.C. § 5845
    (b)).
    - 35 -
    With regard to the knowledge requirement, the government
    must prove that "the defendant had knowledge of the characteristics
    that brought the gun within the statutory definition, and not that
    []he had knowledge that the gun was in fact considered a machine
    gun under law."         
    Id.
        "The requisite mens rea may be established
    by circumstantial evidence," which includes "external indications
    signaling the nature of the weapon."               
    Id. at 601
     (quoting Staples
    v. United States, 
    511 U.S. 600
    , 615 n.11 (1994)).
    At trial, the District Court instructed the jury, with
    respect to this offense, about aiding and abetting liability.
    "Aiding    and     abetting      requires     that    'the     defendant    [have]
    associated himself with the venture, participated in it as in
    something he wished to bring about, and sought by his actions to
    make it succeed.'"            United States v. Luciano-Mosquera, 
    63 F.3d 1142
    , 1149–50 (1st Cir. 1995) (alteration in original) (quoting
    United    States   v.    Alvarez, 
    987 F.2d 77
    ,   83   (1st   Cir.), cert.
    denied, 
    510 U.S. 849
        (1993)).      "Mere       association   with     the
    principal, or mere presence at the scene of a crime, even when
    combined with knowledge that a crime will be committed, is not
    sufficient to establish aiding and abetting liability."                    
    Id. at 1150
    .
    The Supreme Court has held that aiding and abetting
    liability requires the government to show that the defendant had
    "advance knowledge" of the elements of the offense.                   Rosemond v.
    - 36 -
    United States, 
    572 U.S. 65
    , 78 (2014).    Advance knowledge "means
    knowledge at a time the accomplice can do something with it --
    most notably, opt to walk away."      Id.; see United States v.
    Rodríguez-Martinez, 
    778 F.3d 367
    , 371 (1st Cir. 2015).
    The government contends that the evidence sufficed to
    show that Tanco and Rosario aided and abetted Cepeda's possession
    of the machinegun, given the evidence that showed their joint
    involvement in the drive-by shooting and Cepeda's admission that
    he possessed the machinegun during that incident.        Tanco and
    Rosario, however, argue that the government failed to prove that
    they had advance knowledge of the characteristics of the machinegun
    and thus that the evidence did not suffice to establish that they
    aided and abetted Cepeda in the possession of the machinegun.   We
    are not persuaded.
    It is true that the government presented no evidence
    that Tanco and Rosario knew of the pistol's machinegun capabilities
    until the point at which Cepeda began firing.   But, the government
    did introduce evidence from which a jury could reasonably find
    that Tanco and Rosario were with Cepeda during the drive-by
    shooting and that they each heard a rapid round of shots being
    fired that was consistent with the firing of a machinegun.   Taking
    the evidence of the rapid firing of the machinegun in the light
    most favorable to the verdict, a jury could reasonably find beyond
    a reasonable doubt that Tanco and Rosario knew that the pistol
    - 37 -
    that was being fired was a machinegun.         See Staples, 
    511 U.S. at
    615   n.11    ("[K]nowledge    can   be   inferred    from   circumstantial
    evidence, including any external indications signaling the nature
    of the weapon.    And firing a fully automatic weapon would make the
    regulated characteristics of the weapon immediately apparent to
    its owner.").
    Thus, the only question is whether Tanco and Rosario had
    a "realistic opportunity to quit the crime" after the point at
    which the jury could reasonably find that they knew the pistol was
    a machinegun.     United States v. Manso-Cepeda, 
    810 F.3d 846
    , 849
    (1st Cir. 2016) (internal quotations omitted).            For, if they did
    not have such an opportunity, then         "the defendant has not shown
    the requisite intent to assist a crime involving a gun."                
    Id.
    (internal quotations omitted).
    The Supreme Court has made clear that "if a defendant
    continues to participate in a crime after a gun was displayed or
    used by a confederate, the jury can permissibly infer from his
    failure to object or withdraw that he had such knowledge.           In any
    criminal case, after all, the factfinder can draw inferences about
    a defendant's intent based on all the facts and circumstances of
    a crime's commission."        Rosemond, 572 U.S. at 78 n.9.      Tanco and
    Rosario "do[] not adequately explain why it was too late to
    withdraw."     Manso-Cepeda, 810 F.3d at 851.        Thus, they have failed
    - 38 -
    to provide a basis for overturning their convictions for violating
    § 922(o) on sufficiency grounds.5
    III.
    Finally, we address the reasonableness of Cepeda's and
    Tanco's challenges to their sentences.           Cepeda and Tanco both
    challenge the procedural and substantive reasonableness of their
    sentences.
    Our first task is to determine whether the District Court
    made any procedural errors "such as failing to calculate (or
    improperly     calculating)   the   Guidelines   range,   treating   the
    Guidelines as mandatory, failing to consider the [18 U.S.C.]
    § 3553(a) factors, selecting a sentence based on clearly erroneous
    5 Rosario also argues for the first time on appeal that the
    jury instructions related to illegal possession were erroneous
    because they "failed to require that Rosario[] knew in advance
    that one of his codefendants would be armed."      The government
    argues that any such argument is waived because Rosario neither
    raised an objection to the instructions below nor adequately
    developed his argument on appeal. See United States v. Soto, 
    799 F.3d 68
    , 96 (1st Cir. 2015); United States v. Zannino, 
    895 F.2d 1
    ,
    17 (1st Cir. 1990). In any event, Rosario's argument has no merit,
    because the jury instructions specifically required "that the
    charged defendants consciously shared advance knowledge of the
    person's possession of the machine gun and advance knowledge of
    the characteristic that made the weapon a machine gun, intended to
    help each other, and took part in the endeavor seeking to make it
    succeed." (Emphasis added); see Rosemond v. United States, 
    572 U.S. 65
    , 78 (2014) (holding that "advance knowledge" is "knowledge
    that enables [the defendant] to make the relevant legal (and
    indeed, moral) choice," including to "withdraw from the
    enterprise").
    - 39 -
    facts, or failing to adequately explain the chosen sentence --
    including an explanation for any deviation from the Guidelines
    range." Gall v. United States, 
    552 U.S. 38
    , 51 (2007). Generally,
    procedural errors in sentencing are reviewed for an abuse of
    discretion.   United States v. Dávila-González, 
    595 F.3d 42
    , 47
    (1st Cir. 2010). If there are no procedural errors, we then review
    the substantive reasonableness of the sentence for an abuse of
    discretion.   United States v. Pantojas-Cruz, 
    800 F.3d 54
    , 58-59
    (1st Cir. 2015).6
    A.
    We begin by reviewing what happened at sentencing.    We
    start by reviewing the pre-sentence reports ("PSRs") that the
    United States Probation Officer prepared for Tanco and Cepeda's
    cases.
    Tanco's and Cepeda's PSRs highlighted that, on the date
    of the events in question, gunfire was heard by witnesses and the
    two defendants "were seen leaving the scene in a wine Jeep Cherokee
    where the body of Juan R. Delgado-Rodríguez was found."    Because
    6 The government asserts that because Tanco did not argue that
    the 120-month prison sentence was substantively unreasonable after
    it was imposed, we should review on plain error. However, "the
    applicable standard of review for an unpreserved, substantive
    reasonableness challenge is murky." United States v. Arsenault,
    
    833 F.3d 24
    , 29 (1st Cir. 2016)(internal quotations omitted).
    Thus, we will apply the more defendant-friendly abuse of discretion
    standard of review.
    - 40 -
    the PSRs concluded that Cepeda and Tanco had committed their
    firearms crimes in connection with the murder of Delgado, the PSRs
    recommended a base offense level ("BOL") of 43 for first degree
    murder     under    U.S.S.G.    § 2A1.1,     as    U.S.S.G.     § 2K2.1(c)(1)(B)
    requires the application of the most analogous homicide cross-
    reference if firearms or ammunition were used or possessed in
    connection with a death.
    Cepeda had a Criminal History Category ("CHC") of I and
    Tanco had a CHC of II.         The PSRs accordingly calculated that the
    guidelines    would       recommend   a    sentence     of   life   imprisonment.
    However, 
    18 U.S.C. §§ 922
    (g)(1), 922(g)(3), and 922(o) do not carry
    life sentences.       See 
    18 U.S.C. § 924
    (a)(2).             The PSRs therefore
    recommended a guidelines range of the statutory maximum prison
    sentence: 120 months', or 10 years', imprisonment as to both Tanco
    and Cepeda.
    Cepeda and Tanco objected to the PSRs' application of
    the murder cross-reference.           The defendants each pointed to an
    alleged lack of evidence to support its application.                  After all,
    they noted, the District Court expressly prohibited any discussion
    of   the   murder    of    Delgado,   as    it    was   being   handled   in   the
    Commonwealth's local courts.
    Absent the application of the murder cross-reference,
    Cepeda and Tanco argued, the proper BOL for each of them under
    U.S.S.G. § 2K2.1(a)(4)(B) was 20, because their offenses involved
    - 41 -
    a machinegun and because, according to the jury verdict, they were
    prohibited persons at the time of the offense under § 922(g)(3)
    and § 922(g)(1), respectively.7              Tanco argued that, with a BOL of
    20 and a CHC of II, his sentencing range should be 37-to-46 months’
    imprisonment.         Cepeda argued that with a CHC of I and a BOL of 20,
    his guidelines range was 33-to-41 months’ imprisonment.
    At the sentencing proceeding, the District Court made a
    number of findings regarding Cepeda and Tanco's participation in
    the murder of Delgado.               The District Court correctly determined
    that it needed only to find by a preponderance of the evidence
    that they had participated in that murder in order to apply the
    murder cross-reference.              See United States v. Rodriguez-Reyes, 
    714 F.3d 1
    , 11-14 (1st Cir. 2013).               Nevertheless, the District Court
    declined to apply the murder cross-reference and the BOL of 43
    that would have applied in consequence.
    Instead, the District Court agreed with Tanco and Cepeda
    that       a   BOL   of   20   was   appropriate.    The   Court's   calculation
    reflected not only the fact that Cepeda and Tanco were convicted
    of offenses involving a machinegun, which would have resulted in
    only a BOL of 18 under U.S.S.G. § 2K2.1(a)(5), but also that they
    were both determined to be prohibited persons, which increased
    7
    The guidelines define "prohibited person" for the purposes
    of U.S.S.G. § 2K2.1 as "any person described in 
    18 U.S.C. § 922
    (g)
    or § 922(n)." U.S.S.G. § 2K2.1 cmt. n.3.
    - 42 -
    their BOLs to 20 under U.S.S.G. § 2K2.1(a)(4)(B).       The Court then
    proceeded to apply an additional two-level enhancement pursuant to
    U.S.S.G. § 2K2.1(b)(1)(A), because their offenses involved three
    or more firearms, for a total offense level ("TOL") of 22. Because
    neither Cepeda's nor Tanco's requested guidelines calculations
    reflected this enhancement for multiple firearms, the District
    Court arrived at higher guidelines ranges than those argued for by
    the defendants: 41-to-51 months' imprisonment for Cepeda and 46-
    to-57 months' imprisonment for Tanco.
    The   District   Court   first    sentenced   Cepeda.     It
    considered a variety of sentencing factors, including his age,
    education, and use of marijuana.    Regarding Cepeda's participation
    in the shooting, the District Court concluded that Cepeda had been
    in the car that had been following the victim and that shots were
    fired by someone in that car.        The District Court could not
    determine, however, that Cepeda himself had used a firearm, as it
    could have been Tanco who fired the shots.
    After reviewing the § 3553(a) factors, including the
    "need for the sentence imposed . . . to protect the public from
    further crimes of the defendant," see 
    18 U.S.C. § 3553
    (a)(2)(C),
    the District Court imposed a sentence of 120 months of imprisonment
    each for Counts One and Three -- an upward variance from the
    guidelines range to the maximum sentence allowed under the statute
    -- to be served concurrently.      In support of the variance, the
    - 43 -
    District Court noted its finding that Cepeda had participated in
    the killing of Delgado.       The Court found that the killing was
    preplanned because the high-speed chase appeared to be highly
    orchestrated and involved two people -- Cepeda and Tanco -- in the
    gray Yaris, as well as a third person in the Jeep.             The District
    Court also took note of a cell phone seized near the abandoned
    Jeep that contained a text message describing someone as being
    "alone," wearing a black sweater, and having a "spider web tattoo
    on his hand."
    The government suggested that the message supported an
    inference that the shooting was preplanned because the description
    in the text message matched Delgado's appearance on the day of the
    shooting.    Although it was unclear to whom the phone belonged or
    whether Cepeda or Tanco had sent or received the message, the
    District Court, after considering the § 3553(a) factors, stated
    that the text message did provide support as to the co-defendants'
    premeditation to kill the victim, as the message identifying
    Delgado   and   claiming   that   he    was     alone   suggested   that   the
    defendants were implementing a plan to commit a murder that had
    been arranged in advance.
    Cepeda objected to the sentence as procedurally and
    substantively unreasonable.       He emphasized that it was more than
    two times greater than the highest end of the guidelines range and
    that there was a lack of evidence to establish premeditation or
    - 44 -
    mens rea.    The District Court disagreed and noted that Cepeda was
    one of the three people who exited the Jeep after the police chase
    and that he was found with a loaded magazine nearby.
    The District Court next sentenced Tanco.           After hearing
    about and considering his education level, his upbringing in a
    dangerous area, and his obligations to his wife and his young
    children, the Court then decided to apply the same upward variance
    for Tanco that it had applied for Cepeda because the use of the
    weapons for which Tanco was being charged resulted in a death.             In
    arriving at that conclusion, the District Court made similar
    findings as it did in Cepeda's case, noting as well that Tanco's
    DNA had been found in the Yaris and that Tanco was eventually found
    in an apartment where part of a firearm was seized.
    B.
    With that background in place, we first address Tanco's
    sentencing    challenge.     Tanco   argues      that   the   District   Court
    committed    procedural    error   by     "circumventing      the   applicable
    guidelines range and fail[ing] to justify the extent of [its]
    upward variance."      Specifically, he contends that the District
    Court erred in relying on a determination that he was involved in
    Delgado's murder for the upward variance, that his sentence was
    imposed   without   the    protections     afforded     by    the   sentencing
    guidelines, and that the District Court failed to consider his
    - 45 -
    mitigating      factors.         He       also   challenges    the     substantive
    reasonableness of the sentence.
    1.
    With     respect   to    Tanco's     challenge    to    the    District
    Court's consideration of his role in the Delgado murder, the
    District Court did not find that Tanco committed it. Rather, based
    on the evidence presented at trial and at sentencing, the District
    Court found by a preponderance of the evidence that the firearms
    underlying Tanco and his co-defendants' federal charges were used
    to kill Delgado, that Tanco was at least associated with the
    murder, and that the killing was preplanned.
    The District Court did not err in doing so.                        Prior
    criminal conduct is part of the history and characteristics of the
    defendant that may be considered at sentencing, see 
    18 U.S.C. §§ 3553
    (a)(1), 3661, and may be relevant in particular cases to
    the   factors       enumerated       in    § 3553(a)(2).        In     making       its
    determination about the sentence to be imposed, moreover, "[a]
    sentencing court is entitled to rely on circumstantial evidence
    and   draw   plausible     inferences        therefrom."      United       States   v.
    Marceau, 
    554 F.3d 24
    , 32 (1st Cir. 2009) (internal citations
    omitted).       The    phone    found     next   to   the   Jeep,    for   instance,
    identified someone resembling the victim, thereby giving rise to
    the inference that the defendants -- who had recently abandoned
    that same Jeep -- planned and executed the murder.                         Thus, the
    - 46 -
    District Court acted permissibly in giving weight to the evidence
    concerning the Delgado murder, see United States v. Overstreet,
    
    713 F.3d 627
    , 638 (11th Cir. 2013) (affirming an above-guideline
    sentence because the District Court found that the defendant had
    committed a murder connected to the offense), even though it did
    not apply the murder cross-reference.
    In addition, because the District Court expressly made
    its findings with respect to Tanco's relationship to that murder
    under a preponderance of the evidence standard, Tanco's argument
    that he was sentenced without the procedural protections of the
    guidelines has no merit.8         See United States v. Damon, 
    595 F.3d 395
    , 399 (1st Cir. 2010) (holding the government "must show the
    facts       supporting   an   enhancement   by   a   preponderance   of   the
    evidence").
    Finally, contrary to Tanco's contention, the District
    Court did address his mitigating factors.            Although Tanco may not
    agree with the District Court's weighing of the § 3553(a) factors,
    "[w]eighing of those factors is left largely within a sentencing
    court's discretion."          United States v. Gonzalez-Rodriguez, 
    859 F.3d 134
    , 140 (1st Cir. 2017).        And while a sentencing court must
    consider the applicable § 3553(a) factors, it "is not required to
    8
    The government asserts that this argument is waived for lack
    of development. See United States v. Zannino, 
    895 F.2d 1
    , 17 (1st
    Cir. 1990).
    - 47 -
    address frontally every argument advanced by the parties, nor need
    it dissect every factor made relevant by . . . § 3553 'one by one,
    in some sort of rote incantation, when explicating its sentencing
    decision.'"   United States v. Turbides-Leonardo, 
    468 F.3d 34
    , 40-
    41 (1st Cir. 2006) (quoting United States v. Dixon, 
    449 F.3d 149
    ,
    205 (1st Cir. 2006)).   Nor is there a "requirement that a district
    court afford each of the section 3553(a) factors equal prominence."
    Dixon, 449 F.3d at 205.
    2.
    We turn, then, to Tanco's challenges to the substantive
    reasonableness of his sentence.    He asserts that his sentence was
    too harsh given his personal characteristics.     "But the fact that
    the court chose to attach less significance to certain mitigating
    circumstances than [he] thinks they deserved does not make his
    sentence substantively unreasonable."      United States v. Mangual-
    Rosado, 
    907 F.3d 107
    , 111 (1st Cir. 2018) (internal alternations
    and quotations omitted).    "Rather, a sentence is substantively
    reasonable so long as it rests on a plausible sentencing rationale
    and exemplifies a defensible result."      
    Id.
     (internal alterations
    and quotations omitted).    And that is the case here, given the
    unique features of the case that the District Court highlighted.
    Therefore, we reject Tanco's substantive reasonableness challenge
    to his sentence.
    - 48 -
    C.
    That brings us to Cepeda's challenge to his sentence.
    Because we have reversed his conviction on Count One, all that
    remains is his challenge to his sentence on Count Three.     Cepeda
    makes the same arguments that Tanco made regarding the procedural
    and substantive reasonableness of his sentence.    We have already
    considered these arguments and found them wanting in rejecting
    Tanco's sentencing challenge.    Nevertheless, we vacate and remand
    Cepeda's sentence on Count Three, in which he was convicted of
    illegal possession of a machinegun in violation of 
    18 U.S.C. § 922
    (o).
    As we have noted, the District Court determined that
    Cepeda's BOL under the guidelines was 20, based in part on a
    finding that he was a prohibited person at the time that he
    committed the offense in consequence of his Count One conviction.
    See U.S.S.G. § 2K2.1(a)(4)(B).    With a two-level enhancement for
    the use of three or more firearms, the District Court found that
    his TOL was 22, and his guidelines range was therefore 41-to-51
    months' imprisonment.
    But, as we reverse Cepeda's conviction on Count One for
    violating § 922(g)(3), that conviction cannot support the District
    Court's prohibited person finding.     Nor did the District Court
    separately find by a preponderance of the evidence that Cepeda was
    - 49 -
    such a person, assuming that the record would support such a
    finding.
    Thus, the record does not contain findings that could
    support the District Court's determination that Cepeda's BOL was
    20 -- and thus that his TOL was 22 rather than 20, due to the two-
    level multiple firearms enhancement.                  Accordingly, the record
    lacks   the    findings    that    could     support    the   District   Court's
    determination that his guidelines range for his conviction on Count
    Three is for a sentence of 41-to-51 months' imprisonment rather
    than, as Cepeda contends, for 33-to-41 months' imprisonment, as
    would be the case if his TOL were only 20 rather than 22.
    The question, then, is whether we must vacate and remand
    Cepeda's sentence.        It is possible the District Court might have
    arrived at the same 120-month sentence even under the reduced
    guidelines     range.     The     District    Court    clearly   intended   that
    Cepeda's sentence reflect his ties to the Delgado murder, and it
    stated both that it was "perform[ing] a variance upward to the
    highest end of . . . the statute," and that it was going to "make
    a variant because there's a murder," even if the TOL was only 20.
    We also recognize that, on remand, the District Court potentially
    could, under the less demanding "preponderance of the evidence"
    standard, make an independent determination that Cepeda is an
    unlawful user and therefore a prohibited person, and still arrive
    at the same TOL of 22.          After all, we are aware of no authority
    - 50 -
    -- and Cepeda supplies none -- that would indicate that, because
    the corroboration rule precludes his admission about the nature
    and duration of his drug use from supporting a jury finding that
    he was a regular, long-term drug user beyond a reasonable doubt,
    that admission -- considered in the context of the record as a
    whole -- could not support a finding at sentencing to that effect
    under the less onerous preponderance of the evidence standard.
    But, the Court relied solely on Cepeda's conviction on
    Count One in deeming him a prohibited person and thus did not
    independently make any such finding on that score.   Moreover, the
    record as to whether he is such a person is too uncertain for us
    to conclude that the District Court's reliance on the now-reversed
    conviction to calculate the guidelines range was harmless.
    Nor can we say it is sufficiently clear that the District
    Court would have imposed the same upward variance even if the
    guidelines range were premised on the lower TOL that would apply
    in the event the District Court did not find Cepeda to be a
    prohibited person on remand.   Even under the more stringent plain
    error standard, "[w]hen a defendant is sentenced under an incorrect
    Guidelines range . . . the error . . . most often will[] be
    sufficient to show a reasonable probability of a different outcome
    absent the error."   Molina-Martinez v. United States, 
    136 S. Ct. 1338
    , 1345 (2016).
    - 51 -
    Here,   the    District       Court   began    its    analysis     by
    calculating the guidelines range. And, while it ultimately imposed
    a sentence outside that range, the record does not indicate that
    the guidelines played no role in its decision, or that the District
    Court would have made the exact same upward variance regardless of
    the sentencing range set forth in the guidelines.                For while the
    District Court stated that it would impose "a variant" sentence in
    light of the evidence showing Cepeda's relationship to Delgado's
    murder, the District Court was not clear in stating that the extent
    of that variance would necessarily be to the statutory maximum
    sentence even if the defendant's TOL was lower than the District
    Court had determined that it was.           Accordingly, our reading of the
    record is that, as is ordinarily the case, the error here was not
    harmless,   as    the   "judge   use[d]     the   sentencing     range   as   the
    beginning point to explain [his] decision to deviate from it," and
    the guidelines were "in a real sense the basis for the sentence."
    Molina-Martinez, 
    136 S. Ct. at 1345
     (emphasis omitted) (quoting
    Peugh v. United States, 
    569 U.S. 530
    , 542 (2013)).
    IV.
    For   the   above    stated    reasons,   we   affirm   all   three
    defendants' convictions on Count Three and Tanco's conviction on
    Count Two. We reverse Cepeda's conviction on Count One. We affirm
    Tanco's sentence and vacate and remand Cepeda's sentence.
    - 52 -