United States Court of Appeals
                        For the First Circuit


Nos. 23-1132, 23-1134

                           UNITED STATES,

                              Appellee,

                                 v.

                   LUIS JAVIER MATTA-QUIÑONES,

                        Defendant, Appellant.


         APPEALS FROM THE UNITED STATES DISTRICT COURT
                FOR THE DISTRICT OF PUERTO RICO

        [Hon. Francisco A. Besosa, U.S. District Judge]


                               Before

       Montecalvo, Thompson, and Aframe, Circuit Judges.


     Jose David Rodriguez-Gonzalez, with whom Rachel Brill,
Federal Public Defender, and Franco L. Pérez-Redondo, Assistant
Federal Public Defender, Supervisor, Appeals Section, were on
brief, for appellant.
     Julia M. Meconiates, with whom W. Stephen Muldrow, United
States Attorney, and Mariana E. Bauzá-Almonte, Assistant United
States Attorney, Chief, Appellate Division, were on brief, for
appellee.



                            June 9, 2025
             THOMPSON, Circuit Judge.          Luis Javier Matta Quiñones

("Matta") appeals his convictions for possession of firearms and

ammunition as a prohibited person and possession of a machinegun.

At trial, Matta claimed that he was simply in the wrong place at

the wrong time and that police officers looking for a success story

pinned nearby contraband on him.       To boost his claim, he attempted

to cast doubt on police officers' testimony that he threw a feed

sack containing guns and ammunition, among other items, onto the

roof of a building as he fled. On appeal, Matta argues the district

court prevented him from effectively advancing his defense case in

myriad     ways.   Because   we   agree     the   district   court   erred   in

permitting the government's case agent to be a participating

presence during jury deliberations, we vacate Matta's convictions

and remand for a new trial.            And because his revocation of

supervised release sentence was based on those convictions, we

also vacate that sentence and remand for re-sentencing.

                                  BACKGROUND

I.   Matta's Arrest

             Based on the record, the following events led to Matta's

arrest.1    In the spring of 2021, police officers were patrolling a



     1 Matta's appeal raises multiple issues, which require us to
view the trial evidence through different lenses. Because "the
precise manner in which we chronicle the backstory has no impact
on our decision," our upfront account of Matta's arrest presents
the evidence in a neutral and balanced fashion as it came in at



                                    - 2 -
neighborhood in rural Loíza, Puerto Rico, as part of a planned

operation.   Hacienda Taino was a local farm in that area and Matta

worked there while he served out a supervised release term on a

years-old drug conviction.         While patrolling a suspected "drug

point" in the area in the early evening of April 27, 2021 (a few

days before the end of the planned operation), four police officers

encountered Matta outside Hacienda Taino.            The meet up ended with

Matta's arrest and at trial, three police officers recounted the

circumstances leading to his apprehension.             Officer Angel Cruz-

Soto   ("Cruz")    testified     that   he    "saw    several      individuals,

including [Matta], start moving around the place" when the officers

first arrived.     On the other hand, according to Officers Eduardo

Vidal-Santiago ("Vidal") and Ivan Marrero-Lopez ("Marrero"), Matta

was alone and they saw no one else in the area.               Officers Vidal

and Cruz recalled that they could not see if Matta was holding

anything in his hands as they approached, but Officer Marrero

testified that Matta was holding a black purse.

          All     officers     testified     that    when   they     identified

themselves as police, Matta fled. The officers pursued him, taking

different routes partly to maneuver around the many rooster cages

and other obstacles.     During the chase, Officers Vidal and Cruz


trial. United States v. Zimny, 

, 460 n.2 (1st Cir.
2017). When we discuss Matta's challenge to the sufficiency of
the evidence, however, we will take that evidence in the light
most favorable to the jury's verdict. 

                                   - 3 -
saw Matta was holding a plastic sack for animal feed, which he

threw onto the roof of a structure used to house roosters, but

Officer Marrero testified that he never observed Matta holding a

feed sack.    Eventually, officers caught up to Matta and arrested

him.    After the arrest, Vidal retrieved the feed sack from the

roof.    When he returned to Matta and his fellow officers, Vidal

opened the sack in front of Matta who denied ownership of its

contents.    The officers could see through the plastic that the

sacks contained ammunition.         The officers brought Matta and the

feed sack to their station and processed the evidence.           The sack

contained (1) more than 300 rounds of ammunition split across 8

plastic bags, and (2) a black purse which in turn held two cell

phones, two pistols, and multiple loaded magazines for those

pistols.    Matta was eventually indicted on two gun-related charges

and in due course trial got underway.          Aspects of what happened

there lead us here.

II.    Jury Deliberations

            During        closing    arguments,     Matta      emphasized

inconsistencies      in   the   officers'   testimony,   the   absence   of

photographs depicting items inside the feed sack or black handbag

as officers claimed to have observed and recovered them, and the

fact that none of the officers could describe when and how Matta

had acquired the feed sack.         A key part of Matta's case was his

assertion that he lacked the physical ability to throw the feed


                                    - 4 -
sack, with all its contents, up onto the roof of a building ——

which was tall enough that Vidal had to climb a ladder to retrieve

the   sack ——    while     fleeing    the    police.      As    part   of   its

deliberations, Matta urged the jury to recreate the weight of the

feed sack by placing all the objects allegedly recovered from the

feed sack into the sack and testing its weight for themselves.

            On the second day of deliberations, the jury sent a note

with several questions to the district judge, including a request

to have "all the physical evidence be brought to the deliberating

room."   The district court shared the note with the parties and

announced       its      intent      to     have   "all        the     physical

evidence . . . brought to the deliberating room except for the

weapons and the ammunition."          As to the guns and ammunition, the

court determined the jurors could "come to the courtroom and take

a look at it in the presence of the agent" (more on the "agent" or

the "case agent" in a bit).

            Multiple times during this conference, Matta requested

that the district court modify the in-court procedure it had

settled upon regarding the jurors' viewing of the firearms and

ammunition.     First, the defense asked that the jury be allowed to

"carry the ammunition in the presence, obviously, of the agent or

of the CSO."          (The abbreviation "CSO," which we'll also use

throughout this opinion, stands for the court security officer).

In response to this request, the district court drafted and shared


                                     - 5 -
with counsel a proposed note which informed jurors that they could

"view and handle the firearms and the ammunition in the courtroom

with    the    case   agent    present."      After    hearing        the   revised

instruction, Matta objected, saying that "our request would be for

the firearms and ammunition also to be brought to the deliberating

room."       The district court denied the request, saying "the case

agent has to be present when they view and handle the firearms.

The case agent cannot say a word."             The district court further

clarified that only the CSO, a United States marshal, and the case

agent would be allowed in the courtroom while the jury examined

the firearm and ammunition.

              Although   the   conference     turned      to   the    other   juror

questions, Matta continued to return discussion to the viewing of

the guns and ammunition.         He asked the court to consider allowing

the jurors to bring the feed sack into the courtroom, "since they

are only allowed to see the ammunition and firearms here in the

courtroom in the presence of the case agent," so the jurors could

put    the    firearms   and   ammunition    into   the    sack      as   Matta   had

suggested during his closing argument.          The district court said if

the jury asked for the feed sack to be brought into the courtroom,

the district court would allow it, but refused to preemptively

respond to a request the jury had not expressly made in its note.

              After the court and parties concluded discussion of the

jury's remaining requests, the prosecution asked if the district


                                     - 6 -
court had "any specific instruction" to give the case agent.    The

district court responded that the case agent should "keep his mouth

shut."   It then elaborated that the jury should be permitted to

handle the firearm, and that the case agent should not "explain

what the firearm is" or "point to any part of the firearm."      At

that point, Matta proposed that the case agent sit in the first

bench of the courtroom instead of at the table where the jurors

would handle the evidence, because the defense did not "want the

jury to feel uncomfortable."     The district court responded that

"[t]he agent is going to have to give the weapon to the jury and

will have to stand near the weapon while it's being handled."

            Under the district court's direction, the jury, during

its ongoing deliberations, examined the firearms and ammunition

inside the courtroom with the case agent, CSO, and marshal present.

A brief aside:   the "case agent" was an FBI special agent who had

been introduced to the jury at the start of the trial, sat at the

government's counsel table throughout the trial, and assisted the

government attorneys with the handling and publication of an

exhibit (one of the firearms).     Presumably, pursuant to a local

rule, the case agent retained possession of the firearms throughout

the course of the trial, even after they had been submitted into

evidence.    D.P.R. Loc. R. 123. During the presentation of the

government's case, the judge once reprimanded the case agent for




                               - 7 -
pointing to a specific part of the firearm that the agent was

displaying to the jury.

           That afternoon, the jury returned a unanimous guilty

verdict on both charges.

III. Post-Trial Motion and Appeal

           After the trial ended, Matta moved for a judgment of

acquittal based on insufficiency of the evidence, and for a new

trial, contending that allowing the case agent to present the

firearms and ammunition to the jury, outside the presence of the

defendant and counsel, deprived him his right to a fair and

impartial trial under the Sixth and Fourteenth Amendments.           The

district court denied both motions in a combined order.      As to the

motion for a new trial, the district court first reasoned that

Matta had only objected to the location where the firearm and

ammunition could be viewed (i.e., in the courtroom) and had waived

any objection to the presence of the case agent.          Further, the

district court decided that Matta's juror contact claim failed on

the merits because (1) the case agent's contact was "brief and de

minimis," (2) "the presence of the CSO and the Marshal mitigated

the risk of any unauthorized communication," and (3) the procedure

was "a transparent accommodation to ensure jury safety" to which

the   defense   consented.   Separately,   the   court   concluded   the

evidence was sufficient to support Matta's convictions.         Having

resolved the post-trial motions, the district court sentenced


                                - 8 -
Matta to 96 months' imprisonment, and revoked his supervised

release and gave an additional 18 months' immurement for the

revocation to be served consecutively.

                                DISCUSSION

           On appeal, Matta offers various reasons why we should

vacate his convictions and associated prison sentences.                In our

view, Matta's sufficiency argument is not a winner. But his

argument   about   the   case   agent's     presence    during   the   jury’s

examination of the physical evidence is.        Because we conclude that

Matta made out a colorable claim of juror misconduct which the

district court did not investigate, we vacate Matta's convictions

and sentence and remand for a new trial.               We also address two

evidentiary   rulings    by   the   district   court,    because   disputes

regarding the same evidence would likely recur at a new trial.             We

do not reach Matta's remaining claims of error.2

I.   Sufficiency of the Evidence

           We start with Matta's claim that the evidence introduced

at trial was insufficient to support his two convictions for

possession of a firearm as a prohibited person, 

(g),

and for possession of a machinegun, 

 § 922(o).            We begin here

because if Matta is successful, our ruling would not only overturn



     2 Those remaining arguments go to the appearance of bias by
the district court, cumulative error, and improper consideration
of the facts at sentencing.


                                    - 9 -
his convictions, but also bar the government from re-trying him on

those charges under the Double Jeopardy Clause of the Fifth

Amendment, rendering his remaining claims of error moot.                            See

United States v. Gonzalez-Sanchez, 

, 588 n.56 (1st

Cir. 1987) ("Even if the appellate court finds alternative grounds

for reversal, it must consider the defendant's challenge to [the]

sufficiency of the evidence to ensure that the prohibition against

double jeopardy is upheld."); see also United States v. Szpyt, 

 (1st Cir. 2015) ("'[O]nce [a] reviewing court has found

the     evidence       legally       insufficient,'       a     second     trial     is

'preclude[d]'" (second and third alteration in original) (citation

omitted)).

            Because Matta preserved this challenge, we apply de novo

review.    United States v. Soler-Montalvo, 

, 7 (1st Cir.

2022).    Our goal is to "determine whether 'any reasonable jury

could    find    all   the      elements    of   the    crime   [proven]    beyond   a

reasonable doubt.'"             

 (quoting United States v. Seary-Colón,

 (1st Cir. 2021)).             We make that determination taking

the record "in the light most favorable to the verdict," giving

"the    prosecution       the     benefit   of    all   sensible      inferences    and

credibility choices."             

 (citations omitted).          Matta claims

that the government failed to prove that he possessed the modified

pistols    and     that      he    had   knowledge      that    the    pistols     were

machineguns.       We address each argument separately.


                                         - 10 -
      A.      Possession

              Matta claims the government did not prove his possession

of   the   contraband      on   either    count,   because   "[t]he    [police]

officers'       testimonies        were     fatally     contradictory       and

inconsistent."        But the evidence viewed favorably to the verdict

is sufficient.        Officers Cruz and Vidal testified that as Matta

fled from police, he threw the feed sack he was holding onto the

roof.     And Vidal further testified that he retrieved the feed sack

from the roof.     At the scene, officers could see the sack contained

ammunition, and they ultimately recovered the guns, ammo, and a

cell phone belonging to Matta inside.3 A rational jury was entitled

to   credit    this    testimony    and   conclude    that   Matta    literally

possessed the feed sack and its contents and sought to discard the

sack to avoid being caught with contraband.                  This would be a

sufficient basis for finding he possessed the prohibited items.

See United States v. Pena, 

 (1st Cir. 2009)

(concluding that a rational jury could have convicted the defendant

for possession of cocaine where a witness testified to seeing him

discard objects while fleeing from police and the police then

recovered his cell phone, a gun bearing his fingerprint, and a

plastic bag of cocaine along the flight path).


      3Matta stipulated that one of the two cell phones submitted
into evidence belongs to him, but as we'll discuss in more detail,
disputes that police seized his cell phone from within the feed
sack.


                                     - 11 -
            Matta resists this conclusion by highlighting portions

of the police officers' testimonies that were inconsistent.                But

"[e]vidence does not become legally insufficient merely because of

some inconsistencies in witnesses' testimony."              United States v.

Ayala-García, 

 (1st Cir. 2009) (citation omitted)

(explaining      that    arguments    based     on   "discrepancies   in   the

testimony   of    the    government's     witnesses"     are   "unavailing").

Rather, "we must assume that the jury credited those witnesses

whose testimony lent support to the verdict" and cannot "second-

guess the jury's credibility calls."            Soler-Montalvo, 44 F.4th at

8 (citations and quotation marks omitted).              Nor do we think the

absence of any photographs of "the rounded-up evidence" (that is,

photographs showing the firearms and ammunition within the black

purse and feed sack) renders the evidence insufficient, despite

Matta's urging to the contrary.           Matta was free to argue to the

jury that the absence of such evidence was significant —— and in

fact he did just that.4          On appeal, however, "[t]he fact that the

government did not present certain kinds of evidence does not

[necessarily]     mean    that    there   was   insufficient    evidence   for


     4 The record reveals that the jury heard and considered his
argument —— going so far as to ask the district judge if any
"report and/or photos of the evidence recollected in the police
precinct [were] available" (which they weren't) —— but found
against him despite that absence. See United States v. O'Shea,

 (1st Cir. 2005) (explaining that a note sent by
the jury indicated that "the jury was doing its job" and that the
jury "considered [defendant's] theory . . . but rejected it").


                                     - 12 -
conviction."      United States v. Forty-Febres, 

(1st Cir. 2020) (second alteration in original) (citation omitted)

(concluding that the lack of DNA or fingerprint evidence placing

the   appellant    at   the   scene     of   the   crime     did    not   amount    to

insufficient      evidence    because    the    jury      could    have   rationally

convicted based on victims' testimony); see also United States v.

Rivera-Rodríguez, 

 (1st Cir. 2010) (concluding

that the jury could have convicted on the drug conspiracy charge

based on witness testimony, even where there was no audio, video,

or photograph of        the appellant committing             the crime nor any

contraband seized in his presence).

           In his reply brief, Matta attempts to fit this case into

the "'extremely narrow' exception" our Court has carved out for

cases where a witness's material testimony "is so inherently

implausible that it could not be believed by a reasonable juror."

United   States    v.   Garcia,   

    (1st    Cir.   1992)

(citation omitted).      But there is nothing inherently impossible or

incredible about Vidal's and Cruz's accounts that they saw Matta

running with the feed sack and throw it onto the roof of a

structure, or about Vidal's testimony that he later retrieved the

feed sack from the rooftop.           Indeed Cruz's and Vidal's accounts




                                      - 13 -
largely corroborate each other.5             See United States v. Rivera-

Donate,   

    (1st    Cir.   2012)   (concluding   that

witnesses' accounts were not "facially incredible" where they

corroborated each other).           Matta theorizes that the officers'

accounts are facially incredible because they "cannot all be

accurate" and "[t]he differences are simply too great."                    But

viewing the evidence in the light most favorable to the verdict as

we must, some of the inconsistencies in the witnesses' testimonies

could be chalked up to faulty memory or poor visibility.                  More

importantly     though,   Matta     cites   no   authority   supporting    the



     5  We reach this conclusion over Matta's argument that
consistent portions of Vidal's and Cruz's accounts were rendered
facially incredible by the fact that they testified inconsistently
as to the presence of unknown individuals at the scene. Although
the inconsistency might go to the officers' credibility and to the
weight afforded it as Matta argued unsuccessfully to the jury, we
see no reason why uncertainty as to the number of people present
would have so undermined the rest of the officers' accounts as to
render them implausible.    See United States v. Washington, 

 (1st Cir. 2006) (affirming conviction where "minor
consistencies" fell "far short of rendering the testimony facially
incredible").
     Matta also emphasizes that Vidal's testimony about retrieving
the feed sack from the roof of a farm building was uncorroborated.
But we have held that uncorroborated testimony from a single
witness can sustain a conviction, unless the testimony is
inherently improbable. See Foxworth v. St. Amand, 

 (1st Cir. 2009) (explaining in context of habeas petition that
"a criminal conviction can rest on the testimony of a single
eyewitness" even if "the eyewitness's testimony is uncorroborated
and comes from an individual of dubious veracity"). Nothing about
Vidal's account of retrieving the feed sack was inherently
improbable. Nor is there anything remarkable about the fact that
no other witnesses could corroborate an act Vidal performed alone.


                                    - 14 -
proposition   that   we   can   overturn   a   conviction   because     the

witnesses' testimony was too "different," as opposed to inherently

improbable.   See Seary-Colón, 

 (concluding that

witness accounts of robbery were not "inherently improbable" even

though one witness could not remember what defendant said and

portions of second witness's testimony were inconsistent with both

prior statements to law enforcement and physical evidence at the

scene (citation omitted)).        Faced with competing stories about

what Matta had in his hands on the evening of the arrest, the jury

did not need to envision a universe in which all three officers'

accounts   were    comprehensive,    completely   accurate,    and    100%

consistent; it was free to credit portions of the officers'

accounts   while   discrediting     others.     See   United   States    v.

Nishnianidze, 

 (1st Cir. 2003) (recognizing that the

jury "may accept or reject, in whole or in part, any testimony").

           Accordingly, we hold there was sufficient evidence for

a rational jury to conclude that Matta possessed the firearms.

     B.    Knowledge of Machinegun Characteristics

           Second, Matta claims that the government did not prove

he knew that the pistols in the black purse, retrieved from the

tossed sack, were machineguns.       To prove illegal possession of a

machinegun under 

(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


                                  - 15 -
within the statutory definition of a machinegun."            United States

v. Torres-Pérez, 

 (1st Cir. 2021) (quoting United

States v. Tanco-Baez, 

 (1st Cir. 2019)).          To clarify,

the government does not need to prove that Matta knew "that the

gun was in fact considered a machine gun under federal law," only

that the gun had "characteristics that brought [it] within the

statutory definition." 

 at 33 (quoting United States v. Nieves-

Castaño, 

, 599 (1st Cir. 2007)).          The relevant statute

defines a machinegun 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." Id. at 32 (quoting Nieves-Castaño, 480 F.3d at 599);

see 

(a)(4) (defining machinegun with reference to

(b)).6       The government may prove Matta's knowledge

with       circumstantial   evidence,   including   "external   indications

signaling the nature of the weapon."         

    The extent to which the

defendant handled the weapon, the defendant's familiarity with

firearms, the presence of accessories that would be used with an

automatic weapon, and the defendant's efforts to avoid discovery



       This definition captures fully automatic weapons which fire
       6

multiple bullets with one trigger pull, but not semi-automatic
weapons, which fire one bullet per trigger pull. Nieves-Castaño,
480 F.3d at 600 (citing Staples v. United States, 

,
602 & n.1 (1994)).        When we refer to a weapon firing
"automatically" in this opinion, we refer to fully automatic
weapons, rather than semi-automatic weapons.


                                   - 16 -
may also be relevant considerations.                    See, e.g., United States v.

Pérez-Greaux, 

 (1st Cir. 2023); Torres-Pérez, 

; see also United States v. Shaw, 

(1st Cir. 2012) (applying similar analysis to determine whether

defendant        had    knowledge       that        a     sawed-off      shotgun    had

characteristics        falling     within   the         statutory   definition     of   a

firearm under 

(a)(2)).

               We acknowledge this may be a close call, but viewing the

evidence in the light most favorable to the government, we conclude

there was sufficient evidence to sustain the conviction.                        Because

Matta's personal cell phone was found alongside the pistols in the

black purse, the jury could have inferred that Matta had been

inside the purse and was familiar with its other contents.                          See

Torres-Pérez, 

 (concluding that the jury could infer

that       defendant   possessed    a   machinegun            because   the   government

presented evidence "connecting [defendant] to the truck" where the

machinegun       was   recovered,    such      as       his   wallet,   identification

cards, and cell phone).             The modifications to the pistols were

externally visible,7 and the jury had the opportunity to view the

firearms up close and gauge whether Matta would have noticed the


       The trial evidence showed that a small piece of metal stuck
       7

out from the plastic plate which covers the back of each pistol's
slide. The plastic plate on one pistol was also modified with a
skull illustration.    The government's firearm expert testified
that the metal piece on each pistol allowed the pistols to fire
automatically.


                                        - 17 -
modifications and understood their purpose.      See Pérez-Greaux, 

.      And the storage of high-capacity magazines in the

same container as the pistols supports an inference that Matta was

aware of the pistols' ability to fire a large number of bullets in

an extremely short period of time.8      

 (concluding that the jury

rationally inferred defendant's knowledge of the automatic firing

capabilities of gun which he "stored . . . in the same bag as a

thirty-round magazine"); Torres-Pérez, 

 (concluding

that the jury could infer defendant's knowledge that modified

pistol could fire automatically in part because the pistol "had an

extended magazine to accommodate additional ammunition").        This

evidence distinguishes the present case from Nieves-Castaño, cited

by Matta, where the only evidence that the defendant had ever been

inside a golf bag from which a modified firearm was seized was her

statement to an investigator that she had once "looked in" the

bag.       See 480 F.3d at 599, 601 (explaining that "there was no



       8Matta claims that the extended magazines were found in the
feed sack and the pistols were found in the black purse. Therefore,
he argues, "the presence of the extended magazines reveals nothing
about Mr. Matta's knowledge about the firearms in a separate bag."
As an initial matter, we note that Officer Vidal testified on
direct examination that the magazines were recovered from the black
purse, and we are required to take the evidence in the light most
favorable to the guilty verdict.      Moreover, even if we credit
Vidal's later testimony that the magazines were actually found in
the feed sack, we are not persuaded that because the pistols were
found instead in the black purse, the jury's inference was
irrational.   After all, the black purse itself was in the feed
sack.


                                - 18 -
evidence that one would see, simply by looking into the golf bag,

a small mark on the weapon between the fire and safety settings").

           Matta claims the visibility of the pistols' structural

modifications was not enough to infer knowledge, because only an

individual with "years of training and experience," like the

government's firearms expert, would have been able to tell from

merely seeing the small metal part that the pistols were capable

of automatic firing.         But the government is not required to

"present evidence that a layperson (rather than an expert) could

draw the conclusion, simply by looking at the firearm, that it had

been modified to a machinegun," where other evidence reasonably

permits an inference that the defendant understood the purpose of

the modification.      See Pérez-Greaux, 

.         Certainly

Matta has a point that there is no direct evidence that Matta ever

handled   the   pistols,   nor   any   evidence    about   Matta's   overall

familiarity     with   firearms.       We   are   also   skeptical   of   the

government's argument that the requisite knowledge can be inferred

from Matta's flight in this case given that Matta had previously

been convicted of a felony and was thus prohibited from possessing

any form of firearm.9      However, a defendant's knowledge frequently


     9 As a prohibited person, Matta would have faced criminal
consequences for possessing any type of firearm, regardless of
whether it was a machinegun.   18 U.S.C. 922(g).   And thus his
flight does little to establish his knowledge of the pistols'
automatic firing capability. See Nieves-Castaño, 480 F.3d at 601



                                   - 19 -
cannot be proven by direct evidence.               United States v. Agosto-

Vega, 

 (1st Cir. 2010); see Staples, 

 n.11 (explaining that "knowledge [of machinegun capabilities]

can    be    inferred     from   circumstantial     evidence").         Here,   the

visibility of the modifications and proximity of Matta's cell phone

to the altered weapon and extended magazines permit the inference

that Matta was sufficiently familiar with the pistols to know they

were     capable     of   automatic      fire.     And    the    fact   that    the

circumstantial evidence does not "compel a finding of [guilty]

knowledge" is no reason to reverse the conviction for insufficient

evidence.      United States v. Kilcullen, 

 (1st Cir.

1976).      Accordingly, the evidence was sufficient to support both

Matta's convictions.         Onto Matta's next appellate challenge.

II.    Jury Contact

              Before turning to the substance of Matta's claim that

the district court erred by allowing the case agent to present the

firearms and ammunition to the jury during its deliberations, we

first consider whether Matta properly preserved this claim for

appeal.      A litigant forfeits the right to complain on appeal about

"an improper occurrence in the course of trial or an erroneous

ruling by the trial judge" unless he "object[s] then and there."

United      States   v.   Taylor,   

   (1st   Cir.   1995).


("[K]nowledge that one is guilty of some crime is not the same as
knowledge that one is guilty of the crime charged.").


                                      - 20 -
Forfeited issues can only be reviewed on appeal for plain error,

a   somewhat   "difficult-to-meet"   standard,   United   States   v.

Kinsella, 

 (1st Cir. 2010), that permits reversal

of only "blockbuster errors and not ordinary backfires," United

States v. Chen, 

 (1st Cir. 2021) (quoting United

States v. Salley, 

 (1st Cir. 2011)).     If a party

not only fails to object, but purposefully abandons its claim of

error, it waives the issue and generally cannot challenge the issue

on appeal, even for plain error.        Id. at 6.   To avoid these

pitfalls, litigants in district court must object proactively if

they want to preserve their future appellate arguments.      Taylor,

.    This requirement is not imposed simply to set

"judicial trap[s]"in the path of "the unwary litigant," United

States v. Griffin, 

 (1st Cir. 1987), but to dissuade

sandbagging and to ensure that district courts have a complete

picture of the issues in dispute,10 see Danco, Inc. v. Wal-Mart

Stores, Inc., 

 (1st Cir. 1999) ("The basis for [the

preservation] requirement is obvious:    the judge must largely rely

upon the parties to research and raise issues, and giving the judge



     10Sandbagging in this context refers to a party's "tactical
decision to refrain from objecting, and subsequently, should the
case turn sour, assigning error" to the district court's ruling on
appeal, or, in a more egregious case, "planting an error and
nurturing the seed as insurance against an infelicitous result."
Taylor, 

; see also United States v. Franklin, 

 (1st Cir. 2022).


                              - 21 -
the wrong reason for a request is usually equivalent to giving the

judge no reason at all."); Griffin, 

 (explaining

that the purpose of the objection requirement is to "give[] both

the court and the party's opponent fair warning and a timely

opportunity to acknowledge bevues and correct them so that cases

can be decided squarely on merit").     Thus, we treat arguments as

preserved only if litigants "said enough to alert the [district]

court to the theory now being propounded" on appeal.          Bryant v.

Consol. Rail Corp., 

 (1st Cir. 1982) (explaining

that an objection for "relevancy" did not preserve a party's

argument that the evidence was inadmissible character evidence);

see United States v. Perez-Delgado, 

 (1st Cir. 2024)

(explaining in procedural sentencing appeal that "a defendant's

objection need not be framed with exquisite precision" and need

only "put[] the district court on notice of the error" (citations

and quotation marks omitted)).

          The   government   argues   that   Matta   "never   made   any

objection that could be interpreted as an improper contact claim"

at the time the district court ruled that the jury must view the

weapons and ammunition in the presence of the case agent.         We've

already described in detail the conference between the parties and

the district court regarding the jury's request to have the

physical evidence brought to the jury room, so rather than go

through another play-by-play, we'll simply highlight the most


                               - 22 -
salient moments in our analysis here.            In our view, the defense

made two objections regarding the case agent's proximity to the

deliberating jurors, which in combination and in context, were

sufficient to preserve the issue now on appeal.

              First, early in the conference, defense counsel lodged

an objection and requested that "the firearms and ammunition

also . . . be brought to the deliberating room" alongside the

other evidence, instead of to the courtroom for a separate showing

in the presence of the case agent.            The government views this as

a request to allow the jury to test the combined weight of the

items in the feed bag, rather than to the case agent's presence.

But we think it fair to characterize Matta's request, at least in

part, as an attempt to prevent contact between the case agent and

the jurors given the background rule that, to ensure the secrecy

and privacy of deliberations, non-jurors are not permitted in "the

deliberating room."          See United States v. Olano, 

 (1993) (discussing the presence of alternate jurors in the

deliberating room and recognizing the "cardinal principle that the

deliberations of the jury shall remain private and secret" to

"protect      the   jury's   deliberations    from   improper      influence");

Little   v.    United   States,   

   (10th    Cir.   1934)

(reversing conviction where the district court sent a stenographer

into the jury room to read aloud the jury charge and explaining

that "no one should be with a jury while it is engaged in its


                                    - 23 -
deliberations"); see also Peña-Rodriguez v. Colorado, 

 (2017) (Alito, J., dissenting) ("To protect that right

[to trial by a jury of peers], the door to the jury room has been

locked, and the confidentiality of jury deliberations has been

closely guarded.").    The district court's response to the request

shows that it was, in fact, operating under the assumption that

the case agent could not have remained with the evidence had it

been sent to the jury room. Specifically, the district court said,

"Denied.   No, no.    No way.    No way, because the case agent has to

be present when [the jurors] view and handle the firearms.            The

case agent cannot say a word."

           The district court's order that the agent remain silent

shows us a key piece of the context surrounding Matta's objections.

Namely, the court apparently recognized and tried to address the

risk that the case agent could improperly influence the jury. This

was not some obscure, improbable event that the district court had

never considered.      After all, the district court had already

reprimanded the case agent once during the trial for pointing to

one of the pistols (i.e., improperly testifying).          The risk was

apparently so self-evident that, at the end of the conference, the

government   asked    if   the   district   court   had   any   "specific

instruction" for the case agent.       The district court issued even

broader instructions seemingly in response to the risk of improper

influence:   it told the agent to "keep his mouth shut" and forbade


                                  - 24 -
the agent from "explain[ing] what the firearm is" or "point[ing]

to any part of the firearm."        Immediately following the delivery

of these instructions, defense counsel made a second and final

attempt to separate the case agent from the jury, requesting that

"the agent sit in the first bench instead of at the table right

where [the jurors] are going to handle the evidence," because "[w]e

don't want the jury to feel uncomfortable."          Given the nature of

the case-agent instructions the court had just announced, we

believe Matta's request fairly captured his disagreement with the

proximity of the case agent to the jury and his concern that this

court-sanctioned closeness would adversely impact the jurors in

their deliberations.       See Cohen v. Brown Univ., 

(1st Cir. 2021) (concluding that an argument was preserved where

"we have no reason to doubt that the district court grasped the

gist of the [party's] argument" even though it was not made "with

lapidary precision"); see also Perez-Delgado, 

(concluding    that      the   defendant's   sentencing       challenge   was

preserved even though "defense counsel could have offered some

greater specificity in his objection" where "the broader context

of   this   particular    sentencing   hearing   makes   it    'contextually

clear' that defense counsel's objection . . . put the district

court sufficiently on notice" of the basis for the objection

(citation omitted)); United States v. Meises, 

 (1st

Cir. 2011) (reviewing "the full context of counsel's colloquy with


                                   - 25 -
the   court   in   determining     whether    a   [Confrontation    Clause]

challenge was preserved").

            We acknowledge that defense counsel could have pressed

more forcefully at this point for the case agent not to be present

at all.    But in our view, the district court, having heard Matta's

requests and having decided on a different outcome, "made it

perfectly clear that [it] d[id] not wish to hear what [his]

lawyer[s] ha[d] to say."     United States v. Toribio-Lugo, 

 (1st Cir. 2004).     The district court was seemingly adamant

from the beginning of the conference, presumably in conformity

with its local rule, D.P.R. Loc. R. 123, that the case agent be

present.    In such an environment, defense counsel was not required

to "persist stubbornly" and risk the judge's ire.         

 ("To do her

job, a lawyer must be forceful, but she also must handle her

relationship with the presiding judge with care."); see United

States v. Teixeira, 

 (1st Cir. 2023) ("Interrupting

a judge in mid-stride is risky business for a lawyer."). Resisting

this conclusion, the government urges that the "mere mention" of

the jurors' comfort was insufficient to "adequately preserve an

argument    regarding   improper   juror     contact."   But   we   do   not

mechanically require objecting litigants to "use any particular

form of words," or for that matter, "cite to the specific rule" or

case that applies when making a contemporaneous objection, Bryant,

, particularly where, as here, the long-standing


                                   - 26 -
default rule is juror secrecy and privacy, see Olano, 

.    And we will not penalize Matta for his counsel's laxity in

explaining more clearly the basis of the objection when it is

evident     from   the   record   that   counsel    was   not   afforded   an

opportunity to do so.       See United States v. Fernandez-Garay, 

 (1st Cir. 2015) (treating all claims of sentencing error

as preserved where the district court "cut defense counsel's

argument short, precluded further argument, and did not allow the

lawyer to complete the record").11

             The government also claims that Matta consented to the

procedure proposed by the district court.                 Specifically, the

government points to the start of the conference, when the defense

stated that their "only objection" was a request that the jury be

allowed to "carry the ammunition in the presence, obviously, of

the agent or of the CSO."         It further identifies moments in which

defense counsel responded in the affirmative to the district

court's proposed procedure.         If these snippets of the transcript

comprised the entirety of the relevant discussion, we might readily

conclude that the issue had been waived.           See, e.g., United States

v. Curran, 

 (1st Cir. 2008) (concluding that an



        When defense counsel insisted that the case agent could
       11

place the weapon on the table rather than handing it to the jurors,
the district court retorted, "don't make a federal case out of
it."   The district court then interrupted counsel's attempted
explanation and said, "[s]o that's it."


                                    - 27 -
argument was waived where the defendant "was granted an explicit

opportunity below to object . . . , affirmatively stated he had no

objections, and did no more than express frustration over the

existing state of the law"); United States v. Richardson, 

, 669 n.1 (1st Cir. 1994) (noting that counsel gave "the judge

a go-ahead signal" by saying "Fine" when asked about proposed

procedure).         The problem is that although defense counsel may have

initially claimed to have only one objection, the actual course of

the conference revealed that the defense in fact had multiple

objections to the proposed procedure, not only with respect to

proximity between the case agent and the jury, but also regarding

the    jury's       freedom    to   interact   with   the   evidence.      In   such

circumstances, our preservation policy does not require us to close

our eyes and ears to clear expressions of disagreement, simply

because a litigant's initial reaction to a proposal included a few

words of affirmation.           See United States v. Silva, 

(1st    Cir.    2009)       (reviewing   challenge    to    jury    instruction   as

preserved where defendant "initially agreed with the instruction

but later objected").

               On    this     record   in   whole,    Matta's      objections   were

sufficient to preserve the issue because it was apparent that he

thought that the proximity of the case agent and jury could

negatively impact deliberations.               See United States v. Pereira,

 (1st Cir. 2017) (explaining that a party's


                                         - 28 -
"objections suffice" because "the ground for the objection was

obvious   from   the   context   in   which   it    was   made"   (quotation

omitted)).   We turn then to the merits.

           The Sixth Amendment and due process give all criminal

defendants the right to have their cases heard by an impartial

jury.   Turner v. Louisiana, 

, 472 n.10 (1965).

Matta's claim is one of "juror misconduct," a broad term that

captures not only a juror's personal biases or failure to obey a

judge's instructions, but also conduct by individuals outside the

jury that could impact a juror's impartiality.            United States v.

Gastón-Brito, 

 (1st Cir. 1995) (analyzing claim that

the prosecution's case agent made a hand gesture under "the broad

rubric of juror misconduct").         When a party makes a colorable or

plausible claim of juror misconduct, "the district court must

undertake an adequate inquiry to determine whether the alleged

incident occurred and if so, whether it was prejudicial."               

(citation omitted).     The district court "has wide discretion to

determine the scope of the resulting inquiry and the mode and

manner in which it will be conducted."        United States v. Paniagua-

Ramos, 

 (1st Cir. 2001).          While the district court

may hold an evidentiary hearing or conduct voir dire of individual

jurors, we do not require it in every case, in deference to the

district court's "superior 'feel' for the nuances of the case,"

which make it well-suited to craft a procedure for addressing a


                                 - 29 -
case-specific claim of juror misconduct.                 

 (quoting Neron v.

Tierney, 

 (1st Cir. 1988)).

             That     said,   we    have   referred     to   the    trial      judge's

obligation      to    investigate    juror     misconduct    as    "an    unflagging

duty."    

    And our law makes clear that the district court "does

not   have      discretion    to    refuse      to   conduct      any    inquiry       at

all . . . ."         United States v. Lara-Ramirez, 

 (1st

Cir. 2008).

             Here, Matta's claim centers around the case agent's

direct and personal contact with the deliberating jury.                            Such

improper contact creates a concern that jurors will decide the

case based (at least in part) on outside influence, rather than

the evidence presented at trial.               See Gastón-Brito, 

(quoting United States v. Day, 

 (10th Cir.

1987)).      The most obvious form of improper contact occurs when

someone   attempts       to   persuade     a   juror   to    decide      the    case   a

particular way (whether through reason, bribery, threats, or some

other means).         See, e.g., Remmer v. United States, 

   (1954)     (describing       incident     in   which   unknown      individual

informed jury foreman that "he could profit by bringing in a

verdict favorable to the [defendant]"); United States v. Tsarnaev,

 (1st Cir. 2024) (describing Facebook comment

made to juror which stated "[p]lay the part so u get on the jury

then send him to jail where he will be taken care of").                        However,


                                      - 30 -
improper conduct can consist of more subtle interactions.        There

need not be any conversation about the case itself,12 see United

States v. Betner, 

 (5th Cir. 1974) (reversing

conviction and remanding for a new trial where the district court

did not investigate prosecutor's conversation with the jury beyond

ascertaining that it was not about the pending case), nor any

verbal communication at all.        Even hand gestures and facial

expressions can cause concern. See, e.g., United States v. Tejeda,

 (1st Cir. 2007) (concluding that the trial judge

conducted   a   sufficient   investigation   into   a   throat-slitting

gesture made in view of jury); Gastón-Brito, 

(vacating conviction and remanding for new trial where a case agent

pointed at the defense table in view of the jury).         The risk of

improper influence is magnified when the outsider who interacts

with the jury is affiliated with one of the parties in the pending

case, because the jury's view of the evidence might be influenced

by any positive or negative impression of the outsider. See, e.g.,

Paniagua-Ramos, 

 ("The proposition that private

communications between jurors and prosecutors during the course of


     12Of course, the fact that any contact between a juror and
an outsider did not include conversations about the case itself
might contribute to a district court's finding that no party was
prejudiced as a result of the contact.      See United States v.
O'Brien, 

 (1st Cir. 1992) (affirming the district
court's finding of no prejudice where an out-of-uniform police
officer engaged in casual conversation with jurors in the hallway
during a recess).


                                - 31 -
a criminal trial are absolutely forbidden is so elementary as to

require no citation of authority."); Tejeda, 481 F.3d at 52–53

("This case involves (1) a risk of a perception by a juror of an

implicit threat from someone who might, in the juror's view, be

associated with the defendant; and (2) the risk that this 'threat'

might influence the juror's ability to impartially evaluate the

evidence."); see also United States v. Freeman, 

 (10th Cir. 1980) ("The danger of improper influence adheres

in every contact between an interested party and a jury.").

            Matta's   claim   has     another    dimension,        however.    The

potential    prejudice   in    this    case     arose   not    only     from   the

interaction between the case agent and jury, but also from the

district    judge's   role    in    allowing     an   individual       distinctly

associated with one of the adversary parties to act as a neutral

officer of the court and assistant to the jury.               Although we have

not squarely addressed this subcategory of juror contact claim,

several of our sister Circuits have.                  In particular, we are

persuaded by the reasoning of the Ninth Circuit in United States

v.   Pittman,   which    examined      the      propriety     of     sending   the

government's case agent into the jury room to assist the jury in

playing a tape recording.          

 (9th Cir. 1971).

The Ninth Circuit concluded that the case agent was thus presented

"in a trustworthy, friend-of-the-jury capacity wholly at odds with

the adversary posture in which [he] should be regarded by the jury


                                    - 32 -
if the credibility of [the prosecution's] factual assertions is to

be decided fairly."     

.      Here, as in Pittman, the case

agent's affiliation with the prosecution was known to the jury:

he was introduced as a member of the prosecution team at the

beginning of trial, sat at the prosecution table throughout the

trial, and assisted prosecutors with the presentation of at least

one exhibit.      The district court nevertheless allowed the case

agent to take on a trusted role outside the presence of the other

adversaries, ostensibly to ensure the jurors' physical safety.

See 

; cf. Gonzales v. Beto, 

 (1972)

(Stewart,   J.,   concurring)   ("Our    adversary   system   of   criminal

justice demands that the respective roles of prosecution and

defense and the neutral role of the court be kept separate and

distinct in a criminal trial.").        As a result, the jury might have

viewed the prosecution as more objective and deserving of trust

when assessing the parties' competing theories of the case.

            At least three of our sister Circuits have severely

restricted a district court's discretion to use an individual

affiliated with an adversary party to assist a deliberating jury

with its review of the evidence.         These decisions recognize that

the district judge's seal of approval enhances the risk that the

interaction between the adversary and the jury will be prejudicial,

but that such prejudice will be difficult to establish after the

fact.   For instance,     Pittman opined that "the potential for


                                 - 33 -
prejudice inherent in any adversary's intrusion into the jury room

and the uncertainties in ascertaining the extent of such prejudice

require the extreme measure of a new trial in cases where the

invasion was at the direction of the court and not inadvertent."

 (emphasis added).              Confronted with a similar set

of facts in United States v. Florea, the Sixth Circuit set forth

a prospective "per se rule" that "without prior stipulation a trial

court should not permit any unauthorized person especially one

associated with either prosecution or defense to communicate with

or otherwise have any contact with a jury in any proceeding."              

   (6th    Cir.     1976).13    This   rule   was

"necessary . . . because although the danger of improper influence

inheres in every contact between an interested party and a jury,

actual prejudice may be difficult to establish."              

   The Tenth

Circuit has also vacated a conviction and remanded for a new trial


       We note that although the Sixth Circuit did not find the
       13

improper contact in Florea violative of the defendant's due process
rights because it was sufficiently limited, the court went on to
utilize its "supervisory authority over the administration of
justice" in its district courts, to announce its new rule
prohibiting unauthorized persons from having contact with a jury.

 (distinguishing Turner, 

, which
involved "continuous and intimate association with a sequestered
jury on three consecutive days").     But in determining that the
defendant there had suffered no harm by the improper contact, the
Sixth Circuit had the benefit of the district court's exploratory
hearing at which the FBI agent who had played tapes for the jury
and two neutral observers testified about what happened. 

. As we'll explain, the record does not permit us to reach
a similar conclusion in this case, because the district court
conducted no such inquiry.


                                       - 34 -
under similar circumstances, ruling that "[a]bsent a stipulation

by the parties and the approval of that stipulation by the court,

the [FBI] agent should not have been in the jury room."          Freeman,

.

             As he did below, Matta cites to Pittman, Florea, and

Freeman and argues that the district court presented the case agent

in "a trustworthy, friend-of-the-jury capacity wholly at odds with

the adversary posture in which he should be regarded," thus

necessitating a new trial.     In view of the risk that materializes

any time an adversary party has contact with the jury —— a risk

which was aggravated by the district judge's endorsement —— we

think that Matta met his burden to set out a colorable claim of

juror misconduct.14    At that point, we believe the district court

had an "unflagging" duty to investigate.       Paniagua-Ramos, 

; see Gastón-Brito, 

.            As with any claim of

juror misconduct, we ask whether the district court "fashion[ed],

and   then    even-handedly   implement[ed],    a    sensible   procedure



      14The government complains that Matta did not "ever ask for
a hearing in his motion for a new trial," but does not argue that
this amounted to waiver.      Nor did it identify any authority
suggesting that a party's failure to request a hearing absolves
the district court of its duty to investigate a claim of juror
misconduct.    Any such requirement would seem contrary to the
"unflagging" nature of the district court's duty. See Paniagua-
Ramos, 

; see also Freeman, 

 (holding
that where a party did not request a hearing on the FBI agent's
presence in jury room, the district court "of its own motion should
have ordered an immediate hearing").


                                 - 35 -
reasonably calculated to determine whether something untoward had

occurred[.]"   Paniagua-Ramos, 

.   The answer here

is no, for the simple fact that the district court declined to

make even a cursory inquiry.15

          As a result, the district court's decision on the motion

for a new trial simply assumed that the case agent had followed

its instructions.   The government echoes this assumption, claiming

"there is no reason to believe the agent ever spoke to the jury

while they handled the machineguns" and that "Matta has failed to

show any prejudicial impact."      This reasoning misses the point.

The purpose of the investigation is to create a record of what

occurred and what prejudicial effect, if any, existed.      Without

such an inquiry, there is no way to know whether the district

court's instructions were followed, much less judge whether any

aspect of the interaction between the case agent and the jury,

including non-verbal interaction, would have prejudiced Matta.

See Tsarnaev, 

 (explaining that it was not possible

to determine whether a juror was dishonest because no one had asked

the juror to explain himself).     Because the error is the district

court's failure to conduct an investigation, we do not require



     15  We need not adopt a new per se rule prohibiting the use
of case agents to present evidence to the deliberating jury, as in
Florea and Pittman, to resolve this case.      Here, the district
court's failure to investigate colorable claim of misconduct was
erroneous in light of our existing precedent.


                                 - 36 -
Matta to present evidence of the case agent's conduct or actual

prejudice.16    See Zimny, 

 (concluding that the

district     court      erred    by    not      investigating         "a   specific,

nonspeculative        impropriety . . . that        could    have      been      highly

prejudicial     to     [defendant]");        Gastón-Brito,       

(reversing where "the district court summarily concluded that even

if   the   incident     had     occurred,     no   harm    had    inured        to   the

defendants," but "made no effort whatsoever to see if [case agent's

gesture to jury] was in fact harmless").

            We are not persuaded by the government's assertion that

the presence of the CSO and the marshal ameliorated any risk or

prejudice.     While we recognize that trial judges have sometimes

relied on the supervision of a court officer, such as the courtroom

deputy or CSO, to ensure that jury contact is non-prejudicial, see

United States v. Pratt, 

 (4th Cir. 2003), the CSO

and marshal were not lawyers.               There is nothing on the record

suggesting     that    either    was   trained     or     instructed       to   detect


      16We note the parties debate the applicability of the
presumption of prejudice articulated in Remmer, 

, to
the facts of this case.      We need not reach the vitality and
applicability of the Remmer presumption to resolve this appeal.
See United States v. Bradshaw, 

 (1st Cir. 2002)
(declining to extend Remmer presumption). The district court had
a duty to investigate regardless of whether prejudice was presumed.
See 

 (affirming denial of motion for mistrial where
the district court conducted a sufficient investigation while
declining to apply Remmer presumption); Gastón-Brito, 

 (recognizing that a "danger of prejudice" existed "regardless
of the presumptions employed").


                                       - 37 -
potentially subtle and innocent conduct by the case agent that

might have improperly influenced the jury.17                  See United States v.

Brown, 

 (9th Cir. 1987) (explaining that appellate

court could not conclude that "no prejudicial contact occurred"

because      "[s]uch      contact      could   be     very    subtle,      such    as     a

nod . . . [and] might have been unintended, or even unnoticed by

the case agent himself").              Moreover, at the risk of sounding like

a broken record, we do not know what the CSO or marshal observed,

because the district court never asked.                See Tsarnaev, 

.        Thus whatever assurances the CSO or marshal might have

provided are not part of the record.

              Similarly,        we   are    unmoved   by     the    district      court's

reasoning, adopted by the government on appeal, that its procedure

was designed around juror safety.                   If this safety purpose was

"transparent," as the district court claims, it would seem to

magnify the risk of prejudice, if anything, by enhancing the jury's

perception of the agent's trustworthiness and importance.                               See

Turner,      

    (explaining     that       where   prosecution

witnesses were used as jury bailiffs, the fairness of the trial

was impeded by "jurors' confidence in those who were their official



       The district court's order on the motion for a new trial
       17

noted that the CSO took an oath after closing arguments to "not
permit any person to speak to or communicate with" the jury. It
is not evident whether the CSO understood this as an oath to also
shield the jury from non-verbal communications.


                                           - 38 -
guardians"). It is not apparent on this record why safety required

the presence of the case agent, as opposed to a neutral party like

the CSO, especially where the firearms had been disabled.                   Cf.

State v. Newson, No. M2021-00444-CCA-R3-CD, 

, at

*11 (Tenn. Crim. App. June 23, 2022) (affirming the trial judge's

response to a jury's request to view a gun by permitting a court

officer to take the gun to the jury room).

          In a letter submitted under Federal Rule of Appellate

Procedure 28(j), the government also suggested the district court

was influenced by Local Rule 123.              Local Rule 123 generally

requires that evidence submitted during a trial be "held in the

custody of the clerk . . . , except that exhibits which because of

their size or nature require special handling shall remain in the

possession   of   the   party    introducing    them."      D.P.R.   Loc.   R.

123(c)(1)(A).       Weapons     qualify   as   "sensitive   exhibits,"      

(d)(1), which "shall remain in the custody of the arresting or

investigating agency during the trial of the case," 

(e).

While neither party has questioned the validity of the local rule,

no such rule can be applied with blind disregard for Matta's

constitutional right to trial by an impartial jury.              See United

States v. Panzardi Alvarez, 

 (1st Cir. 1987)

("Local rules of court designed to regulate attorney conduct cannot

unduly handicap the constitutional right of an accused to counsel

of his choice.").    In other words, where a colorable claim of juror


                                   - 39 -
misconduct arises, the district court cannot shirk its duty to

investigate by claiming it took a path that complied with the Local

Rules.

          We acknowledge that the government has pointed out some

distinctions between the present case and others in which a

conviction is overturned based on an improper and potentially

prejudicial contact between an adversary and the jury.           For

instance, in many cases, the individuals who were in contact with

the jury served as prosecution witnesses.     See, e.g., Turner, 

; Pittman, 

.    And the contact between

the case agent in this case was not as extensive as in Turner.

See 

 (explaining that the deputies doubling as jury

bailiffs and government witnesses drove the sequestered jurors to

their meals and lodgings, had meals with the jurors, conversed

with the jurors, and ran errands for the jurors).          But these

distinctions go to whether the contact in the present case was

prejudicial. We do not think they undermined the fact that Matta's

claim of juror misconduct was colorable and necessitated some sort

of inquiry in the first instance.18    As we have said, the situation


     18 One distinction proposed by the government which we find
unpersuasive is the assertion that this case is different because
the improper contact occurred in the courtroom itself, rather than
in the jury room. In our view, the "sanctity" of the jury room
referred to in Pittman arises from the presence of the deliberating
jury, not from the room itself. 

. The case law
demonstrates that events supporting a colorable juror misconduct



                              - 40 -
presented here, wherein the district court treated an individual

affiliated with one of the parties as a friend to the jury, trusted

to assist them in their deliberations, was sufficient to establish

a colorable basis of juror misconduct.                  See Pittman, 

.     In similar cases, judges were not excused of any duty to

investigate the claimed misconduct simply because the case agent

was not called as a witness and did not socialize with the jury

over    an   extended      period.        See   Gastón-Brito,        

(involving gesture made by case agent who was not identified as a

witness).         The failure to conduct any inquiry was an abuse of

discretion.        See Zimny, 

; Gastón-Brito, 

; cf. Lara-Ramirez, 

 (concluding that decision

to     declare       a    mistrial       without     conducting        a     sufficient

investigation into a "colorable claim of juror taint" was an abuse

of discretion).

              We    further     acknowledge      that   the    government      and      the

district     court       cite   cases    from   some    of    our    sister    Circuits

upholding         convictions     when    individuals        affiliated       with      the

prosecution briefly interacted with jury members, including to

facilitate the jury's review of the evidence.                      But the nature and

posture      of    defendants'     claims       in   some     of    those    cases      are

distinguishable.           See Pratt, 

 (noting that


claim can occur outside the jury room. See Gastón-Brito, 

 (describing gesture made in courtroom).


                                         - 41 -
"[t]he   risk   attendant     to   the   practice    of   sending    a   [drug

enforcement agent] into the jury room to cue up an audiotape on a

tape recorder is sufficiently great that we do not condone it,"

but holding that procedure did not violate defendant's right to be

present at every stage of trial per Fed. R. Crim. P. 43); Scott v.

Culliver, 

 (11th Cir. 2009) (affirming Alabama

Supreme Court's denial of habeas relief where petitioner argued

that trial counsel's performance was deficient for failing to seek

mistrial based on prosecution witness who served as jury bailiff);

Lee v. Marshall, 

 (9th Cir. 1994) (explaining

that although police officers' unauthorized entry into jury room

was erroneous, there was no specific showing of prejudice as

required for successful collateral challenge to conviction).               In

others, affirmance was based on the district court's findings after

an inquiry into the circumstances of the jury contact.              See, e.g.,

United States v. Stephenson, 

 (2d Cir. 1999)

(describing     voir   dire   of    jurors    following      encounter   with

government witnesses); Day, 

 (describing the

district court's questioning of an FBI agent who spoke to a juror

in the restroom); United States v. Harrell, 

(11th Cir. 1986) (affirming findings from a hearing in which the

government's     expert     witness      testified   about     providing    a

deliberating jury assistance with a mini-cassette player).                 We

reiterate the chief problem in this case was the district court's


                                   - 42 -
failure    to    investigate    Matta's    nonfrivolous   claim     of    juror

misconduct, and thus we have no basis on which to hold that the

contact, even if ill-advised, was harmless and non-prejudicial.

And although the district court cited some of this out-of-Circuit

case law in denying Matta's new trial motion, it never addressed

binding precedent in this Circuit requiring it to conduct a

reasonable inquiry in response to a colorable claim of jury

misconduct.      See Zimny, 

; Gastón-Brito, 

.

            In short, we find that the district court erred by

refusing    to    investigate    Matta's     colorable    claim     of    juror

misconduct,      thereby   depriving   Matta   of   any   ability    to    show

prejudicial effect.        Given the passage of time, we do not think

remanding for an investigation into this matter is viable.                  See

Betner, 

 (reversing and remanding for a new trial

where "so many months of delay" would make a remand for a hearing

on the juror misconduct issue unreliable); Freeman, 

 (recognizing the difficulty in distinguishing between juror

testimony allowed and prohibited by Fed. R. Evid. 606(b) if

remanded for hearing on juror misconduct).           The juror misconduct

in this case is not supported by written evidence and did not

involve "strange events unfold[ing] in such a tense environment"

that the individuals involved are likely to still remember what

occurred.       Cf. Zimny, 

 (remanding for further


                                   - 43 -
investigation into highly prejudicial blog comments made by juror

whose     conduct    "annoyed"     several    other    jury    members,   while

acknowledging that if "memories have faded" the district court can

determine if a new trial is warranted); Tsarnaev, 

(remanding to district court to conduct investigation into juror

bias "suggested by the apparent discrepancies between" jurors'

answers     in      selection     process     and     "their    social    media

communications"       about     highly-publicized     death    penalty    case).

Instead, here, the risk of prejudice is clear, but evidence of

prejudice may be subtle and difficult to ascertain.               See Pittman,

 (holding that such uncertainties "require the

extreme measure of a new trial" (emphasis added)).                Accordingly,

we believe the most prudent course of action is to vacate Matta's

convictions and sentence on the possession and remand for a new

trial.    See Gastón-Brito, 

 (vacating convictions and

remanding for new trial).          And as we've already explained, a new

trial will not implicate any double jeopardy issue because there

was sufficient evidence to support the vacated convictions.

            Before moving on, we address Matta's request that we

"vacate the consecutive 18-month revocation sentence and remand

for resentencing on the technical violations."19               The government


     19 These "technical violations" apparently include use of
controlled substances and changing his residence without
Probation's prior approval. Matta is not asking us to vacate the



                                     - 44 -
takes no position on the revocation sentence.          The revocation

hearing transcript shows the district court considered Matta's gun

related convictions the "most serious violation" and a Grade A

violation, which in turn determined the guidelines range.          U.S.

Sent'g Guidelines Manual § 7B1.1(a)(1) (defining Grade A violation

as "conduct constituting (A) a federal, state, or local offense

punishable   by   a   term   of   imprisonment   exceeding   one   year

that . . . involves possession of a firearm or destructive device

of a type described in 

(a)"); see 

 § 7B1.4

(recommending terms of imprisonment based on violation grade and

criminal history category).        There was no fact finding by the

district court regarding Matta's prohibited possession of firearms

independent of the convictions.        In light of the government's

silence, we have no reason to believe that the district court would

have imposed the same sentence if presented with a lower Guidelines

range.   Therefore we also vacate the revocation of supervised

release sentence and remand for resentencing.       See United States

v. Jones, 

 (5th Cir. 2019) (vacating revocation

of supervised release alongside conviction where the district

court "made no independent factual findings as to [the defendant's]

underlying criminal conduct").




revocation and reinstate his release, presumably because he does
not dispute these less serious violations.


                                  - 45 -
III. Evidentiary Rulings

           Having explained why we think vacating the convictions

and remanding for a new trial is the appropriate remedy for the

juror misconduct in this case, we need not reach Matta's remaining

arguments to resolve this appeal.          That said, we briefly address

two   claims   of   evidentiary   error    advanced    by   Matta   to   avoid

repetition of the same errors on remand.              See United States v.

Velazquez-Fontanez, 

 (1st Cir. 2021) (addressing

an evidentiary issue "likely to arise at any retrial" despite

vacating for an independently reversible error).             And we address

these evidentiary challenges with the benefit of good appellate

briefing from both parties. Our review is for abuse of discretion.

See Sec'y of Lab. v. DeSisto, 

 (1st Cir. 1991)

(reviewing evidentiary determinations for abuse of discretion

although the case was reversible on other grounds "to ensure that

they do not recur").20

      A.   Form 302

           First, Matta wished to impeach Officer Vidal's testimony

based on an interview Vidal had with FBI agent José Rosario ("Agent



      20Because the juror misconduct issue provides an independent
basis for vacating the conviction, we need not address whether any
evidentiary errors were harmless (and thus not a basis for
reversing the conviction). United States v. Gonzalez-Maldonado,

, 17 n.2 (1st Cir. 1997) (declining to "engage in a
harmless error analysis" where the case would be reversed and
remanded on other grounds).


                                  - 46 -
Rosario") after Matta's arrest.       Agent Rosario authored a report

of what Officer Vidal said in the interview.           (We'll refer to this

report as the "Form 302" because the FBI classifies the form on

which the report was written as FD-302.)              That Form 302 stated,

"Four individuals were at the drug point area, Strike Force members

identified    themselves   as    police   and   the    individuals   started

running away." This conflicts with Officer Vidal's trial testimony

that Matta was alone at the scene of his encounter with police and

it supports Matta's theory that the contraband belonged to someone

else.     The parties formulate the issue on appeal in somewhat

imprecise terms:     they contest whether Matta could "use" this Form

302 to impeach Vidal or impeach Vidal "with" the Form 302, even

though Agent Rosario wrote the Form 302.         As our analysis is about

to show, "using" a document to impeach a witness could mean several

things.

            The government claims Matta wanted to introduce the Form

302 as extrinsic evidence of Vidal's prior inconsistent statement

under Federal Rule of Evidence 613(b), a possibility that Matta's

reply brief leaves open.        Our Circuit has not definitively ruled

on the admissibility of a document purporting to memorialize a

witness's    prior   inconsistent    statement    when    the   document   is




                                  - 47 -
authored by someone other than said witness.21                 But we find

persuasive the majority view, which requires the proponent of such

a document to show that the document is a substantially verbatim

transcription, in the witness's own words, or signed, adopted, or

subscribed by the witness.           See, e.g., Carnell Const. Corp. v.

Danville Redev. & Hous. Auth., 

 (4th Cir.

2014); United States v. King, 

 (5th Cir.

2011); United States v. Schoenborn, 

, 1429 n.3

(7th Cir. 1993).22         We think that the Fourth Circuit put it best

when    it   said   that    the   prior   inconsistent   statement   must   be

"reasonably attributable" to the witness being impeached.              United

States v. Barile, 

 (4th Cir. 2002).                 Thus, if

Matta wants to introduce the Form 302 as an exhibit, he will have

to lay a foundation by showing that the Form 302 reflected Vidal's


        Matta cites to a footnote in which of one member of this
       21

court stated that there was "no basis in the rules of evidence or
the common law of impeachment" for a district court to permit the
defendants to call law enforcement officers for impeachment
purposes if they authored interview summaries signed by the
witnesses, but not officers whose interview summaries were not
signed by the witnesses. United States v. Catalán-Roman, 

, 464 & n.12 (1st Cir. 2009) (opinion of Lipez, J.), as amended
(Dec. 23, 2009). Not only was this footnote non-precedential, the
authoring judge was addressing whether a defendant should have
been permitted to impeach a witness by calling others to testify
as to the witness's prior statements, not whether the defendant
should have been allowed to submit documents authored by others as
extrinsic impeachment evidence. Id. at 464.
        See also United States v. Saget, 

 (11th
       22

Cir. 1993); United States v. Almonte, 

 (2d Cir.
1992); United States v. Hill, 

 (10th Cir. 1975).


                                     - 48 -
own words or that Vidal signed, adopted or subscribed to the

statement.

           That said, the parties apparently agree that Matta,

nonetheless, should have been allowed to appropriately "use" the

information contained in the Form 302 to formulate his cross-

examination questions about statements Vidal made to police.                      We

concur that "a witness's prior oral statement may be the subject

of    cross-examination"   and    whether       the   prior    oral       statement

"happens to have been recorded in writing" should not limit counsel

from simply asking the witness about that statement.                  Jankins v.

TDC Mgmt. Corp., 

, 442 (D.C. Cir. 1994); see United

States v. Meserve, 

 (1st Cir. 2001) ("Pursuant to

the Federal Rules of Evidence, a witness's credibility may be

impeached by asking him about prior inconsistent statements.").

Yet when defense counsel asked Officer Vidal whether he spoke with

federal agents about Matta's arrest, the district court sustained

the    government's   objection     on    the     ground      that    Matta      was

"[i]mpeaching with another person's statement."                 The government

claims   that   the   district    court   did     not    intend      to    bar   all

questioning about Vidal's prior statement and faults Matta for

"not clarify[ing] that he merely wanted to ask a question about

the interview without using the 302."                   But at the time the

government lodged its objection, Matta had not yet mentioned the

Form 302 in his questioning.         Combined with the district court


                                  - 49 -
telling counsel, "[y]ou cannot impeach him," we think the district

court effectively cut off all attempts by defense counsel to ask

Officer Vidal about the statement recorded in the Form 302.    This

was an abuse of discretion.23   See Bergus v. Florian, 

 (1st Cir. 2024) (concluding that district court correctly

precluded extrinsic evidence of witness's character but abused its

discretion by not allowing cross-examination attacking witness's

character for truthfulness); United States v. Pridgen, 

 (1st Cir. 2008) (concluding that district court erred in

not allowing witness to be impeached by testimony about prior

inconsistent statement).

          We further clarify that we impose no strict rule against

Matta referring to or reading from the Form 302 without showing

that Vidal signed or adopted it, something the government seems to

advocate for.   See Jankins, 21 F.3d at 442 (rejecting argument

that counsel should not have been permitted to "read[] from the

investigator's notes" of his conversation with witness); see also

Great W. Cas. Co. v. Rodriguez-Salas, 

, 325-26


     23 Cutting off cross-examination might well have prevented
Matta from laying a foundation for admission of the Form 302. See
United States v. Brika, 

 (6th Cir. 2005) (noting
that a witness's police statement could be used for impeachment
where she signed and adopted it and "upon examination, [she]
acknowledged that she recognized the document as the statement she
had given to the police"); cf. United States v. Gonzalez-Melendez,

 (1st Cir. 2009) (explaining, in another context,
that "a witness may orally adopt a statement, even if he has
reviewed the statement only aurally").


                                - 50 -
(5th Cir. 2011) (holding that witness was not required to adopt

transcript of telephone conversation before counsel could read

from the transcript to impeach witness).              Cases prohibiting the

"use" of an investigator's report that has not been signed or

adopted   by   the   witness   do   not   uniformly     forbid   any   line   of

questioning that reads from the report.         Compare     United States v.

Adames, 

 (7th Cir. 1995) (concluding that district

court   did    not   abuse   discretion    where   it    allowed   lawyer     to

"continue" to "read directly from the agent's written summary"

over the government's objection, but also instructed lawyer that

he must "lay a foundation that the statement was [witness]'s or

had been adopted by [witness]" before "it could be used for

impeachment"), and Hill, 

 & n.5 (noting that

"counsel was allowed to question based upon the information in the

302 statement" though he failed to frame the question in a non-

argumentative manner), with Saget, 

 (reasoning that

by "reading directly from the agent's summary," defense attorney

was "[i]n effect . . . introducing extrinsic evidence to the jury

of [witness's] prior inconsistent statement via the FBI agent's

summary").     In our view, cross-examination questions that quote

from a document are not always improper attempts to introduce the




                                    - 51 -
document itself into evidence.24                See Great W. Cas., 

 ("Counsel who uses a statement as impeachment is not

required to introduce it into evidence."); but see Saget, 

.          This case is a prime example:             there are only so many

ways    to       characterize     a    statement     about    seeing    four    other

individuals at the scene of Matta's arrest.                      And while the Form

302 may not reflect Officer Vidal's exact words, forcing Matta's

lawyers to paraphrase Agent Rosario's summary of Vidal's prior

statement, instead of just quoting from the Form 302, might enhance

the risk of abstraction and inaccuracy.               See Great W. Cas., 

    (explaining     that    although    a    lawyer's     lengthy

quotations from the written document may be prejudicial, "the more

abstract         the    interrogator's    summary,    the    more   susceptible     it

becomes          to     an   objection    for      being     unrepresentative       or

misleading").

                 In short, while Matta must show that the Form 302

statement         is    reasonably    attributable     to    Officer    Vidal    (for


       24Of course, counsel's recitation from the document may be
problematic in specific cases, such as when it creates confusion
as to the authorship of the document, Jankins, 21 F.3d at 442, or
"plac[es] highly prejudicial language before the jury," Great W.
Cas., 

. But a trial judge retains the tools to
combat any potential prejudice.      See Jankins, 21 F.3d at 442
("[T]here was obviously no obstacle to the court's issuing suitable
instructions to counsel, or simply instructing the jury that the
paper in counsel's hand was not signed or approved by [the
testifying witness]."); Great W. Cas., 

(emphasizing "district court's inherent power to control the
trial[ and] the availability of limiting instructions").


                                         - 52 -
instance, that the report was a substantially verbatim transcript

or that Officer Vidal signed, adopted, or subscribed to the report)

before he could introduce the Form 302 as an exhibit, he should

nevertheless be permitted to cross examine Officer Vidal about

prior   statements    he     made    to   federal    agents,    including    those

recorded in the Form 302, without such a showing.

     B.    Receipt for Property Form

           Next,     Matta    sought      to   introduce   a   document     titled

"Receipt   for   Property,"         authored    by   United    States    Probation

Officer Grace Moringlane ("PO Moringlane") as a business record.

(We'll refer to this as the "Receipt Form" for short.)                  The Receipt

Form indicated Agent Rosario transferred the seized cell phones to

Probation for forensic analysis shortly after Matta's arrest.                   In

a field labeled "Location Where Property Was Obtained," Moringlane

wrote "seized by FBI.          Inside of client's pockets."              At trial,

Matta admitted that the Receipt Form was hearsay, but contended

that it fit under the business records exception.                  Fed. R. Evid.

803(6).    The defense called PO Moringlane to lay a foundation for

the admission of the Receipt Form as a business record.                        But

shortly after her testimony began, the district court sustained a

renewed hearsay objection by the government and dismissed PO

Moringlane   from     the    witness      stand,     disallowing    any    further

testimony on her part.        Before us, neither party disputes that the

Receipt Form itself is a business record subject to the hearsay


                                      - 53 -
exception. Instead, the government says the Receipt Form contained

another layer of hearsay to which the business records exception

did not apply:      namely, information about where the cell phones

were   seized   came   from   a   statement   Agent   Rosario   made    to    PO

Moringlane.     After careful review, we think the district court was

too hasty in accepting the government's view of the law and that

it abused its discretion by ignoring factors which would have

suggested that the business records exception could apply to the

multiple levels of hearsay in the Receipt Form.          Bergus, 

.   Here's why.

           We have previously stated that "the business records

exception does not embrace statements contained within a business

record that were made by one who is not a part of the business."

United States v. Vigneau, 

 (1st Cir. 1999).                   But

that pronouncement does not amount to a "categorical rule" against

application of the exception to a business record containing

information received from an individual outside the business that

keeps the record.      See U.S. Bank Tr., N.A. as Tr. for LSF9 Master

Participation Tr. v. Jones, 

 (1st Cir. 2019).                To

understand when and why the business records exception might apply

to multiple levels of hearsay, it is helpful to consider the

rationale behind the exception:          namely that "the regularity of

the procedure" in creating and maintaining the record, "coupled

with   business    incentives     to   keep   accurate   records,      provide


                                    - 54 -
reasonable assurance" of the record's reliability.                 Vigneau, 

.    Using this logic, courts admit records containing

multiple layers of hearsay when a chain of employees, all acting

in the regular course of business, conveys information to a co-

worker who duly records it.         See McCormick on Evid. § 324.1 (9th

ed. 2025) (explaining that "no further exception need be invoked"

where a business record includes a further hearsay statement if

both "statements are by persons acting in the routine of the

business" (footnote omitted)); United States v. Baker, 

 (D.C. Cir. 1982) ("If both the source and the recorder of

the information, as well as every other participant in the chain

producing the record, are acting in the regular course of business,

the multiple hearsay is excused by Rule 803(6).").

           "[A]n     essential    link   in    the     trustworthiness    chain

fails,"   however,    if   the   business     record    contains    information

passed along by someone who was not acting in the regular course

of business, such as an outsider to the business.                    McCormick,

supra, § 290 (Feb. 2025).        The classic example is a police report

containing information a witness provided to the police officer

who authored the report.         Vigneau, 

 (citing Johnson

v. Lutz, 

 (N.Y. 1930)).            Although the police officer

who writes the report is acting in the regular course of business,

the witness talking to the officer is not.              Id. at 75-76.     Thus,

the justification behind the business records exception cannot be


                                    - 55 -
invoked.    See Fed. R. Evid. 803, advisory committee's notes to

1972 proposed rules (explaining that if "the supplier of the

information does not act in the regular course, an essential link

is broken; the assurance of accuracy does not extend to the

information itself").     Analogizing to this classic case, we have

rejected the application of the business records exception to

documents    containing   information    that   customers   provide   to

businesses or patients provide to medical professionals.        Bradley

v. Sugarbaker, 

 (1st Cir. 2018) (affirming the

exclusion of information a patient provided the hospital about

other medical providers' opinion on her condition); Vigneau, 

 (affirming the exclusion of a bank's money transfer

form containing the name, address, and telephone number of money

sender); Petrocelli v. Gallison, 

 (1st Cir. 1982)

("Where the declarant is a hospital patient, his relating of his

own history is not part of a 'business' routine in which he is

individually a regular participant.").25

            However, there may be circumstances in which information

derived from someone outside the business is still "reliable enough

to be admissible."     U.S. Bank, 

 (quoting FTC v.

Direct Mktg. Concepts, Inc., 

, 16 n.15 (1st Cir. 2010)).


     25 In the medical context, a patient's statement describing
their medical history for the purpose of diagnosis or treatment
may nevertheless be excepted from hearsay under Fed. R. Evid.
803(4).


                                - 56 -
Reliability    "is    said   variously    to   be    supplied   by   systematic

checking, by regularity and continuity which produce habits of

precision, by actual experience of business in relying upon them,

or by a duty to make an accurate record as part of a continuing

job or occupation."          

 (quoting Fed. R. Evid. 803 advisory

committee's note to 1972 proposed rules).               Accordingly, we have

permitted     the    admission   of      records     containing      third-party

information where the third-party information was "intimately

integrated" into the business records, or the business maintaining

the records "relied on" the third-party information to conduct its

own business.       Id. at 537-38 (first quoting Direct Mktg., 

 n.15; and then quoting United States v. Doe, 

 (1st Cir. 1992)).         And although we have not previously put

words to such a rationale, a common theme seems to be that

"outsider" information is sufficiently reliable to be admitted

under the business records exception when the outsider was also

acting within the regular course of business or under a "business

duty" to provide accurate information.             See U.S. Bank, 

 (holding that mortgage records from prior loan servicers

which were integrated into current loan servicer's database could

be introduced as business records of current servicer); Direct

Mktg., 

 & n.15 (affirming admission of records

showing defendants' gross receipts which may have been based on

"third party data"); see also Peak v. Kubota Tractor Corp., 559 F.


                                   - 57 -
App'x 517, 523 (6th Cir. 2014) (explaining that "triple-level chain

of hearsay" was admissible because dealer had a contractual duty

to submit warranty claims to manufacturer and dealer's employees

were working in the regular course to diagnose technical problem);

United States v. Ary, 

 (10th Cir. 2008) (affirming

admission of museum inventory records that relied on third-party

sales invoices and documentation, because those third parties were

under a business duty to provide accurate information in their

invoices).

          With   these    principles     in   mind,   we   turn   to   the

government's assertion that the Receipt Form presents a double

hearsay problem.26    In sustaining the government's objection, the

district court seemingly accepted at face value the government's

statement of the law:    because the statement about the location of

seizure was "a statement from someone outside of the organization,"

the defense "would need another exception to get that particular

statement in."       But as we have just explained, that is not

necessarily true.     The face of the Receipt Form and the parties'



     26 We assume for the purposes of this opinion that a double
hearsay issue exists. At trial, Matta's attorneys claimed they
did not seek to use the Receipt Form to "prove the truth of the
incorporated statement" (which would have meant there was no second
level of hearsay.)    But Matta's appellate briefs do not repeat
this argument. Indeed Matta seems to suggest that the jury should
have been allowed consider the Receipt Form as substantive evidence
in determining "whether the cellphone was recovered from Mr. Matta
or from the [feed] bag."


                                - 58 -
representations   regarding   the   incorporated   statement   reveal

several indicators of reliability.

          The parties seem to agree that both Agent Rosario and PO

Moringlane were operating in the regular course, which makes Agent

Rosario's information more reliable than that received from the

classic "outsider" (such as a witness making a police report or a

customer sending money at the bank).     Both Agent Rosario and PO

Moringlane also would have sworn an oath to "faithfully discharge

the duties of [their] office[s]."    

.   Those duties

presumably involve accurately reporting where evidence was seized

and establishing a chain of custody, to ensure that the evidence

would be admissible and be given all due weight by the factfinder.

See United States v. Williams, 

 (1st Cir. 1986)

(noting defendant was "free to argue to the jury that they could

accord less weight to this evidence" because the government failed

to call witness to testify or "to present documentary evidence of

the chain of custody between the technician and the chemist" who

worked in state forensic laboratory).     Indeed, the phrase "Chain

of Custody" appears at the top of the second page of the Receipt

Form, next to the words "Receipt For Property."

          The government claims that "[t]he location of where the

property was seized was irrelevant for forensic analysis purposes"

and "nothing supports the conclusion that the probation office had

a self-interest in assuring the accuracy of whether [the phones


                               - 59 -
were] seized from Matta's pockets or a bag he threw."   This belies

common sense.   Probation was conducting a forensic analysis of

Matta's phone presumably to determine whether Matta had violated

criminal statutes or his conditions of supervised release.   See 

(2), (7), (10).   The location of the seizure, as the

parties' vigorous dispute in this case amply demonstrates, could

be relevant to whether Matta committed any violation         of his

supervised release, and a lapse in the chain of custody might well

"undercut the reliability of physical evidence" against Matta in

a revocation proceeding.   See United States v. Patrick, 

 (1st Cir. 2001) (explaining when inadequacies in police

investigation may affect admissibility of evidence), overruled on

other grounds by United States v. Salvador-Gutierrez, 

 (1st Cir. 2025); United States v. Portalla, 

(1st Cir. 1993) (stating that evidence in revocation proceedings

must be reliable).

          Rational minds may differ as to whether a business record

containing a hearsay statement from an outsider is sufficiently

reliable to be admissible.     Certainly, as the government points

out, there is no evidence that PO Moringlane or any other Probation

employee independently confirmed the accuracy of Agent Rosario's




                               - 60 -
statement.27     But    given   the    indicia   of   reliability   we    have

identified here, the district court abused its discretion by

sustaining the government's objection, at least without further

analysis.    See Bergus, 

 (explaining that "district

court abuses its discretion when it overlooks 'a relevant factor

deserving of significant weight'" (quoting              Soler-Montalvo, 44

F.4th at 14)).

                                   CONCLUSION

            We vacate Matta's convictions and related sentence for

possession of a firearm as a prohibited person and for possession

of a machinegun, and remand for further proceedings consistent

with this opinion.      We further vacate the sentence imposed based

on   the   revocation   of   his    supervised   release   and   remand    for

resentencing.




      27The government also claims we can infer the location of
property seizure was unimportant because other fields on the
Receipt Form were left blank. We are skeptical that because some
fields are blank, we should assume the filled-in fields are
immaterial.


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