          United States Court of Appeals
                        For the First Circuit


Nos. 16-2386, 16-2392

                    UNITED STATES OF AMERICA,

                               Appellee,

                                  v.

               MALCOLM FRENCH and RODNEY RUSSELL,

                        Defendants, Appellants.


          APPEALS FROM THE UNITED STATES DISTRICT COURT
                    FOR THE DISTRICT OF MAINE

        [Hon. John A. Woodcock, Jr., U.S. District Judge]


                                Before

                  Thompson, Selya, and Kayatta,
                         Circuit Judges.


     Jamesa J. Drake, with whom Benjamin Donohue, Thomas Hallett,
Hallett, Zerillo & Whipple, PA, and Drake Law, LLC were on brief,
for appellant Malcolm French.
     William S. Maddox for appellant Rodney Russell.
     Renée M. Bunker, Assistant United States Attorney, with whom
Halsey B. Frank, United States Attorney, was on brief, for
appellee.


                          September 17, 2018
             KAYATTA, Circuit Judge.    After their convictions on

charges arising out of a large-scale marijuana-farming operation,

Rodney Russell and Malcolm French sought a new trial based on

claims that one juror lied in filling out the written questionnaire

given to all prospective jurors prior to trial, and that a second

juror lied in voir dire.     As we will explain, we agree that the

district court's investigation concerning the answers given by one

of the jurors was inadequate, so we vacate its denial of the

defendants' motion for a new trial.        We otherwise reject the

defendants' various other challenges to their convictions and

sentences.

                                  I.

             Malcolm French first entered the logging business as a

college student, contracting with landowners to cut down trees.

He grew the business, first hiring his own crew, and then buying

land of his own.    By 2009, French -- either personally or through

various companies he controlled -- owned approximately 80,000

acres of land, including an area in Washington County, Maine, known

as Township 37.    French employed co-defendant Rodney Russell as an

office manager of sorts, keeping the books for his businesses,

writing company checks, and using a company credit card.

             In September 2009, Maine law enforcement discovered a

series of substantial marijuana-cultivation sites on French's

Township 37 property.     Following an investigation, a grand jury


                                - 2 -
indicted     Russell   and   French   for    conspiring   to    manufacture

marijuana,    manufacturing     marijuana,    maintaining      drug-involved

premises, harboring illegal aliens, and conspiring to distribute

and possess with intent to distribute marijuana.                  At trial,

numerous eyewitnesses described the direct involvement of Russell

and French in the marijuana production.             According to those

witnesses, French hired one witness to recruit migrant workers to

clean the product, and both French and Russell handled incoming

payments from marijuana sales and sold the crop.               The property

contained shacks for drying the crop.         And one witness explained

how workers grew marijuana in wire baskets containing a fertilizer

called Pro-Mix that was purchased either through a credit card in

French's name or by Russell, via check or cash.

             French and Russell both testified in their own defense,

denying culpability.         French testified that he had previously

discovered marijuana elsewhere on his property and called a warden,

but the warden did nothing, and as a result, he chose not to alert

authorities when he discovered other growing operations.            Asked to

explain his large purchase of the Pro-Mix fertilizer, he testified

that after a man named Steve Benson (who testified as part of

French's case-in-chief) inadvertently destroyed some marijuana,

the putative owners of that marijuana, "the Red Patch gang,"

demanded reimbursement, which Russell gave in the form of a large

amount of Pro-Mix.       Evidently unpersuaded, the jury convicted


                                   - 3 -
French and Russell on all counts.         Eventually, the district court

sentenced    Russell   to   151 months'    imprisonment   and   French   to

175 months' imprisonment.     Transcript of Sentencing Proceedings at

135, 139, United States v. French, No. 12-cr-00160-JAW (D. Me.

Nov. 10, 2016), ECF No. 729 [hereinafter "Transcript of Sentencing

Proceedings"].     They now appeal both their convictions and their

sentences.

                                   II.

             We consider first the appeal from the district court's

denial of a motion for a new trial based on the alleged bias of

Juror 86.

                                   A.

             Shortly after sentencing, defense counsel reported that

they had just learned that a prisoner housed in the Somerset County

Jail with co-defendant Kendall Chase told Chase that Juror 86, who

sat on the jury before which the case was tried, was the mother of

a small-time marijuana trafficker.            After Chase told French,

French's counsel investigated Chase's report.         They learned that

Juror 86's son had indeed been convicted of marijuana and other

drug-related offenses multiple times between 2002 and 2014 arising

out of his use and sale of marijuana and cocaine.          At one point,

Juror 86 visited her son in jail.          She also paid the legal fees

arising out of his offenses on multiple occasions.




                                  - 4 -
          The government does not challenge the accuracy of this

information concerning Juror 86, none of which had been disclosed

by Juror 86 in response to questions asked of her during the jury

selection process.      As part of that process, prospective jurors

filled out a questionnaire, which included the following prompt:

          3. a.) Please describe briefly any court
          matter in which you or a close family member
          were involved as a plaintiff, defendant,
          witness, complaining witness or a victim.
          [Prospective jurors were given space to write]
          b.) Was the outcome satisfactory to you?
          [Prospective jurors were given "yes" and "no"
          check boxes here]
          c) If no, please explain. [Prospective jurors
          were given space to write]

Order Denying Motion for New Trial at 4, United States v. French,

No.   12-cr-00160-JAW    (D.   Me.   Nov.   16,   2016),   ECF   No.   734

[hereinafter "Order Denying Motion for New Trial"]. Juror 86 wrote

"n/a" after part (a), and left parts (b) and (c) blank.          She also

did not complete the second page of the questionnaire, which

contained six additional prompts and a space to sign and declare

under penalty of perjury that the prospective juror had answered

all the questions truthfully and completely.

          When jury selection began, the magistrate judge asked

the following of the prospective jurors:

          Now, as you've heard for a couple hours now
          this morning, this is a case about marijuana,
          which is a controlled substance under federal
          law. Is there anyone on the jury panel who
          themselves personally or a close family member
          has had any experiences involving controlled


                                 - 5 -
            substances,   illegal   drugs,  specifically
            marijuana, that would affect your ability to
            be impartial?

            And by any experiences, I'm talking about
            whether you or a close family member have been
            involved in a situation involving substance
            abuse or involving treatment that -- maybe
            professionally treating that condition, or
            being the victim of a crime involving those
            substances, or being the perpetrator of a
            crime where someone alleged those substances
            were   involved.       Any . . .   experiences
            regarding illegal drugs, and specifically
            marijuana, but any illegal drug, controlled
            substance under federal law, is there anyone
            who's had that sort of experience?

Id. at 5-6.      Juror 86 did not respond to this question.                    Later in

the process, the magistrate judge asked:

            Is there anyone here who knows of any other
            reason, some question I haven't asked or
            something that's been sitting there troubling
            you, why hasn't she asked me about this, those
            attorneys, those people should know about this
            fact and it might interfere with me being a
            fair and impartial juror or it might appear
            that it would interfere, is there any other
            fact that you feel would affect in any way
            your ability to be a fair and impartial juror?

Id. at 6.     Again, Juror 86 was silent.

            In    a   motion   for    a    new     trial     filed    a     week    after

sentencing,      defendants    argued      that    Juror 86's        answers       to   the

questionnaire     and   her    lack   of    a     response    to     oral    voir       dire

questions amounted to dishonest answers to material questions, and

that had the answers been honest, there would have been a valid




                                      - 6 -
basis    for       a    challenge     for    cause.        They   also   asked   for   an

evidentiary hearing to question Juror 86 about her answers.

               Just over six months later, the district court denied

the motion in a written order.                     It first surveyed the possible

meanings of "n/a" as well as the term "court matter" in the

questionnaire, and also noted that it did not know "what exactly

Juror 86 was thinking when she wrote 'n/a' because defense counsel

did not seek to question her during voir dire."                     Id. at 21-23.      It

went    on    to       state   that   "[w]ith      these    ambiguities,    the   Court

concludes that the Defendants have not demonstrated that Juror 86

failed to answer honestly a material voir dire question."                         Id. at

23 (internal quotations omitted).                   At the same time, the district

court concluded that the response to the questionnaire was "likely

mistaken" and that "the question as to whether any close family

member -- her son obviously qualifies -- was involved in any court

matter should have elicited a response from Juror 86 that alerted

the magistrate judge and the attorneys . . . about her son's

involvement with court matters." Id. at 23-24. The district court

stated, however, that because this was mere mistake, and not

dishonesty, a new trial was unwarranted absent a more flagrant

showing of juror bias.                Id. at 24-25.         The district court also

held that defense counsel's failure to inquire further of Juror 86

based    on        her    obviously         incomplete     questionnaire     precluded

defendants         from    relying    on     the   questionnaire     to   claim    juror


                                             - 7 -
misconduct.      Id. at 29-30.          The district court found Juror 86's

non-answers      to   the        oral    voir     dire   questions     similarly

inconsequential.      Noting that the oral question, by its terms,

only asked for information that in the juror's opinion affected

her ability to be impartial, it reasoned that Juror 86 might well

have known of her son's criminal matters but felt that they did

not affect her ability to be impartial, and thus, a non-answer at

oral voir dire was appropriate.               Id. at 32-36.

              The district court also concluded that defendants had

failed to demonstrate that truthful answers would have offered a

valid basis for a challenge for cause.                Id. at 36-42.     Finally,

the district court found that the passage of two years from the

close of the trial cut against any request for an evidentiary

hearing.     Id. at 44-50.

                                          B.

              To obtain a new trial based on a juror's failure to

respond accurately to questions asked of prospective jurors prior

to   their    selection     to    sit    as    jurors,   "a   party   must   first

demonstrate that a juror failed to answer honestly a material

question on voir dire, and then further show that a correct

response would have provided a valid basis for a challenge for

cause."      McDonough Power Equip., Inc. v. Greenwood, 464 U.S. 548,

556 (1984) (emphasis in original).               "The outcome of this inquiry

depends on whether a reasonable judge, armed with the information


                                        - 8 -
that the dishonest juror failed to disclose and the reason behind

the juror's dishonesty, would [have struck the juror for cause]."

Sampson v. United States, 724 F.3d 150, 165–66 (1st Cir. 2013)

(emphasis added).      In evaluating the juror's "capacity and . . .

will to decide the case solely on the evidence," id. at 166, the

court may consider factors including but not limited to "the

juror's    interpersonal   relationships;    the   juror's      ability   to

separate her emotions from her duties; the similarity between the

juror's experiences and important facts presented at trial; the

scope and severity of the juror's dishonesty; and the juror's

motive for lying."     Id. (citations omitted).

            Separate and apart from the showing that a defendant

must make to obtain a new trial in such cases, there is the question

of process. Specifically, to what extent should the district court

allow or conduct an investigation into an allegation of juror

misconduct? Given the important interest in the finality of trial,

trial courts should not accommodate fishing expeditions after a

verdict   has   been   rendered,   especially   years   after    the   fact,

conducted in the hope of establishing a toehold for a misconduct

claim.    See, e.g., Neron v. Tierney, 841 F.2d 1197, 1205 (1st Cir.

1988) ("[C]ourts generally should be hesitant to haul jurors in

after they have reached a verdict to probe for potential instances

of bias, misconduct, or extraneous influences." (alterations and

internal quotation marks omitted)).         At the same time, we have


                                   - 9 -
said that defendants seeking to establish juror misconduct bear an

initial   burden     only   of   coming   forward    with    a    "colorable      or

plausible" claim.       United States v. Zimny, 846 F.3d 458, 464 (1st

Cir. 2017).    Once defendants have met this burden, an "unflagging

duty" falls to the district court to investigate the claim.                      Id.

(quoting United States v. Paniagua-Ramos, 251 F.3d 242, 250 (1st

Cir. 2001)).    The type of investigation the district court chooses

to conduct is within the district court's discretion; it may hold

a formal evidentiary hearing, but depending on the circumstances,

such a hearing may not be required.             Id. at 465.       "[T]he court's

primary obligation is to fashion a responsible procedure for

ascertaining    whether     misconduct    actually    occurred      and   if     so,

whether   it   was   prejudicial."        Id.    (internal    quotation     marks

omitted) (quoting United States v. Rodriguez, 675 F.3d 48, 58 (1st

Cir. 2012)).

           Here,     the    defendants     came     forward       with    factual

information    fairly    establishing     that    Juror 86       likely   gave   an

inaccurate answer to question 3 on the written questionnaire.

Further, the uncontested facts submitted by defendants also made

it quite likely -- although not certain -- that the juror's

inaccuracy was knowing.          Defendants also showed that the correct

answer to question 3 may well have been quite relevant to assessing

the juror's ability to fairly sit in judgment in this case.                      The

mother of a drug user arrested for dealing to support his drug


                                     - 10 -
habit might have some strong thoughts about those who produce the

drugs.

              The district court posited that perhaps "n/a" meant

something other than "not applicable." And the government supposes

that the juror may not have regarded her son's experience as

involving a "court matter."            Perhaps, too, her son's prosecution

had    left    her    hostile    toward      government          prosecutors.       Each

hypothesis is plausible, but insufficiently likely so as to warrant

rejecting without investigation the claim of juror misconduct as

improbable.      The defendants' initial burden is only to establish

that their claim of juror misconduct is "colorable or plausible."

Id. at 464.      They need not show at the outset that their claim is

so strong as to render contrary conclusions implausible.                        Nor need

the defendants support their claim initially with testimony from

the juror. In this circuit, counsel cannot even question the juror

until the court gives permission.               See United States v. Kepreos,

759    F.2d   961,    967    (1st    Cir.    1985).         So    a   court-supervised

investigation aimed at confirming and then exploring further the

apparent dishonesty was called for.

              In concluding otherwise, the district court placed great

weight on the fact that defense counsel did not ask Juror 86 more

questions at voir dire or bring to the court's attention the fact

that   the    juror    did   not    complete     or    sign       the   questionnaire.

Concluded      the    district      court,    "it     was    the      Defendants'   own


                                       - 11 -
responsibility to recognize the problem and address the issue when

the voir dire commenced."     Order Denying Motion for New Trial at

30.   We disagree.     As for question 3, taking "n/a" according to

its most customary meaning, there was no reason to ask any follow-

up.       So the relevant inquiry is whether defendants effectively

waived any ability to complain about a possible lie by a juror in

responding to question 3 because defendants did not complain about

the juror's failure to answer other, unrelated questions and sign

the form.

              Certainly, counsel could have insisted that the juror

finish the form and sign it.     And we have no reason to doubt that

their failure to do so likely precluded the defendants from later

pointing to those omissions as a basis for any relief.     We see no

good reason, though, to extend that preclusion to a request for

relief based on the later discovery that an answer actually given

was dishonest and materially false.         Waiver is too strong a

sanction to be extended so broadly.      Given no apparent connection

between question 3 and the unanswered questions, and no good reason

to conclude that answers to those questions likely would have

revealed the problem with the answer to question 3,1 it would be

unduly speculative to conclude that any insistence that Juror 86




      1The unanswered questions asked for the names of any spouse,
educational   background,  criminal   history,    English-language
comprehension, and health.


                                - 12 -
complete the questionnaire would have put either party in a

different position.

           The district court was concerned, too, that the long

passage of time since trial would render it "very difficult . . .

to recreate what happened at voir dire."   Id. at 47.    That might

be the case, but then again it might well not, particularly if

Juror 86's reasons for answering inaccurately were strongly felt.

The only way to tell if the passage of time would have erased

Juror 86's memory of events would be to ask her to recall these

events, something the district court declined to do.

           The district court also based its holding on a finding

that Juror 86 "honestly" answered question 3.    Id. at 23-25.   But

this conclusion was simply another application of the waiver theory

that we have just discussed and rejected, as the able district

court judge frankly acknowledged, in stating:    "The Court does not

know what exactly Juror 86 was thinking when she wrote 'n/a'

because defense counsel did not seek to question her during voir

dire."   Id. at 23.

           Additionally, the district court decided that a correct

answer to question 3 would have produced no grounds to have

Juror 86 stricken for cause.   Id. at 41-42.    Even now, though, we

only know what the truthful answer to question 3(a) would have

been.    What the answers were to parts 3(b) and (c), or to any

likely follow-up questions, remain mysteries.    Moreover, we do not


                               - 13 -
see how a court can say whether the juror in this instance was

unduly biased without knowing why she answered as she did.                For

this reason, the ultimate inquiry under Sampson requires that the

court consider "the reason behind the juror's dishonesty."                724

F.3d at 165–66.     Again, it seems unlikely that the district court

misconstrued Sampson, and more likely that its finding on this

point presumed the correctness of its ruling that waiver precluded

proof of dishonesty.

            As to Juror 86's non-response during oral voir dire, we

agree with the district court that the questions posed were

ambiguous and thus Juror 86's lack of an affirmative response was

not itself cause for finding juror misconduct.           For our purposes,

though, the important point is that nothing about the juror's

conduct at the voir dire served to put counsel on notice that the

answer to question 3 on the questionnaire was false.

                                      C.

            One major loose end remains.          The district court also

concluded that even if Juror 86 had committed misconduct, there

was no prejudice to defendants because the government had a strong

case.     Order Denying Motion for New Trial at 50.            The government

latches    onto   this   finding,    contending   that   the    case   against

defendants was "overwhelming" and that following Wilder v. United

States, 806 F.3d 653, 659–60 (1st Cir. 2015), we should find any

error here to be harmless.          Unsurprisingly, defendants disagree.


                                    - 14 -
They   contend     that   to    the   extent   harmless     error   analysis    is

appropriate at all, the question of prejudice is not answered by

determining whether an unbiased jury would have convicted, but

rather, by determining whether the potentially biased juror was

actually biased.

            Defendants have the better of the argument.                  Wilder is

distinguishable from the present case on several axes.                   First and

foremost, Wilder concerned a procedurally defaulted claim, raised

for the first time on a petition pursuant to 28 U.S.C. § 2255,

challenging a federal court conviction, and the Supreme Court has

made very clear that relief under section 2255 is only appropriate

when "actual prejudice" results to the defendant.                   Id. at 658

(citing Bousley v. United States, 523 U.S. 614, 622 (1998)).                    No

such categorical bar exists on direct appeal.               Second, and perhaps

more fundamentally, the nature of the right violated in Wilder was

different than that at issue here.               In Wilder, the petitioner

claimed to have been denied the right to a public jury selection

process and the right to be present for that process.               Id. at 655–

66.    The petitioner in Wilder made no claim that any member of the

jury was biased, only that he might have asked different questions

during voir dire thus securing a more favorable jury.               Id. at 659–

60.    Here, by contrast, defendants have made a colorable claim

that a biased juror was seated, and seek to investigate that claim

further.     And    since      rejecting   a   claim   of   error   as    harmless


                                      - 15 -
presupposes the existence of the error in question, we would assume

in harmless error analysis that Juror 86 was, in fact, biased.

               In any event, the decisive point is that we view the

presence of a biased juror as structural error -- that is, per se

prejudicial and not susceptible to harmlessness analysis.                      While

we have not previously stated the matter so directly, precedent

from    this    court    and    from    the    Supreme     Court    dictates     that

conclusion.        The   Supreme       Court     has    explained   that,     though

structural error is rare, it is the appropriate finding for

"defect[s]       affecting     the     framework       within   which   the    trial

proceeds, rather than simply an error in the trial process itself,"

Arizona v. Fulminante, 499 U.S. 279, 310 (1991), and for those

errors that "deprive defendants of 'basic protections' without

which 'a criminal trial cannot reliably serve its function as a

vehicle for determination of guilt or innocence,'" Neder v. United

States, 527 U.S 1, 8–9 (1999) (quoting Rose v. Clark, 478 U.S.

570, 577-78 (1986)).           In that vein, the Supreme Court has held

that trial before a biased judge is structural error, Tumey v.

Ohio, 273 U.S. 510, 522-24, 535 (1927), as is trial before a jury

whose   impartiality      has    been     fatally       compromised,    Turner    v.

Louisiana, 379 U.S. 466, 471–74 (1965).

               In Sampson, we noted that "[i]f even a single biased

juror participates in the imposition of the death sentence, the

sentence is infirm and cannot be executed."                     724 F.3d at 163


                                        - 16 -
(citing Morgan v. Illinois, 504 U.S. 719, 729 (1992)).                  We also

described   the      right   to   an   impartial   jury   as    "constitutional

bedrock."      Id.      While the concern for an impartial jury is

certainly at its highest when a defendant's life is on the line,

it is still highly significant when defendants face the prospect

of incarceration.        Other circuits have squarely held that the

presence of a biased juror in a criminal case is structural error.

See Estrada v. Scribner, 512 F.3d 1227, 1235 (9th Cir. 2008).                We

think it only logical to agree and to state the rule clearly today:

The presence of a juror whose revealed biases would require

striking the juror for cause in a criminal case is structural error

that, if preserved, requires vacatur.

            Because the presence of a biased juror is structural

error,   the    government's       contention      that   its    case   against

defendants was very strong is of no moment.                If defendants can

establish Juror 86's disqualifying bias after the investigation by

the district court, the conviction would necessarily be set aside

regardless of the strength of evidence.

            Cognizant that the passage of time may create problems

on remand, defendants suggest that we skip remand altogether and

order a new trial.           Defendants abandoned this position at oral

argument, and wisely so.          While we appreciate that the passage of

time can cause memories to fade, we are aware of no case in which,

faced with a potentially biased juror and the need to investigate


                                       - 17 -
further, an appellate court has ordered a new trial without first

permitting the district court to investigate.       We decline to do so

here.

             However, to the extent that memories have faded in the

two years between the defendants' filing of their motion for a new

trial and this decision, we place the responsibility for that

possible loss of evidence at the feet of the government, not the

defendants.      Defendants first became aware of the issue with

Juror 86 in March 2016, and filed their motion approximately one

month later, all while in the midst of preparing for sentencing.

That    timeframe   exhibits   sufficient   diligence   on   the   part   of

defendants.    The government then had the option of acquiescing to

the defendants' request to bring Juror 86 in for an evidentiary

hearing, but elected to oppose it, resulting in now over two more

years of litigation on the issue. If the staleness of the memories

resulting from that additional two-year period becomes a problem

that cannot be solved on remand, we think it only fair for that to

cut against the government.

             To sum up:   Defendants' motion for a new trial based on

the alleged bias of Juror 86 presented a "colorable or plausible"

claim of the type of juror misconduct that could require a new

trial, and defendants did not waive the ability to raise such a

challenge.     The district court was therefore required to do more

before ruling on the new trial motion.       For this reason, we vacate


                                  - 18 -
the denial of the defendants' motion for a new trial based on the

possible bias of Juror 86 and remand for further proceedings on

that motion.

                                    III.

           Defendants also filed a separate motion for a new trial

based on the voir dire responses of another juror, Juror 79.            Only

Russell, and not French, appeals the denial of this motion.

Defendants contend that Juror 79 gave a dishonest answer at voir

dire when he did not acknowledge knowing Steve Koenig, a trial

witness.   Koenig is the executive director of a salmon habitat

restoration group, Project SHARE.          At trial he testified that he

worked on land owned by Haynes Timberland and Malcolm French to

construct culverts on rivers so that salmon could pass through

them.   He testified that although there were gates in Township 37,

he was regularly allowed on the land.               Koenig's testimony was

uncontroversial   and   not   by   its     nature    conducive   to   raising

credibility questions.

           Though he was called by the government, Koenig was

actually on French's witness list.          Counsel included no further

information on this list, such as Koenig's job or employer or even

residence. The entire witness list, containing the names of twelve

potential witnesses, was read to the pool of potential jurors,

including Juror 79. As found by the district court after reviewing

an audio recording of voir dire, the magistrate judge mispronounced


                                   - 19 -
Koenig's name without any correction by counsel who presumably

knew his name. Order Denying Motion for New Trial at 34-35, United

States v. French, No. 12-cr-00160-JAW (D. Me. Apr. 27, 2015), ECF

No. 499.   In response to general inquiry of the pool, Juror 79

gave no indication that he knew Koenig.

           After the trial French spoke with Koenig, who mentioned

that he knew and had had contact prior to trial with Juror 79, a

biologist working for the federal government.     Id. at 24-25.   On

the basis of this information, defendants moved for a new trial,

claiming that Juror 79 had concealed a familiarity with Koenig to

their detriment.

           The district court deemed this report enough to warrant

further inquiry in the form of hearing directly from Koenig. After

doing so at an evidentiary hearing at which Koenig testified, the

district court found as fact that Koenig and Juror 79 spoke to one

another on the phone for five to ten minutes sometime in the year

prior to trial about a project Koenig was managing near Acadia

National Park.     Id. at 34.   The two had never met before trial,

nor was there any probative evidence of any other direct contact

between the two prior to trial.    Id.

           Having so found, the district court concluded that no

further investigation was required.      In so doing, the district

court expressed concern that defendants, who had unrestricted

access to their listed witness (Koenig) and who knew both Koenig's


                                - 20 -
job and the job of Juror 79, did not explore the issue (with Koenig

himself, perhaps?) prior to trial.       Id. at 55.       The district court

also expressed much concern about the effect on Juror 79 and on

other prospective jurors of calling Juror 79 in to be examined on

why he did not say that he knew Koenig when the evidence made the

answer reasonably obvious. Id. at 55-58. On this record, we think

there is certainly some merit to this reasoning, but we need not

decide if Russell waived any concern about Juror 79 because, even

setting   aside     the   possibility        that    defense    counsel   were

sandbagging, the claim would fail.

           As we explained in connection with discussing Juror 86,

once a defendant makes a colorable claim of juror bias, the

district court has a duty to investigate.            See Zimny, 846 F.3d at

464.   Though a defendant need only present a "colorable" claim to

trigger an investigation, he or she nonetheless retains the burden

to prove juror bias by a preponderance of the evidence based on

that investigation.       See Sampson, 724 F.3d at 166.             Here, in

response to an initially colorable claim, the district court

brought in Koenig for questioning, but saw no reason to go further

and bring in Juror 79 after hearing Koenig's testimony.               For the

following reasons, we find no reason to deem that decision to be

an abuse of discretion.

           First,   the   limited    nature     of   Koenig's   contact   with

Juror 79 renders speculative any claim that Juror 79 would have


                                    - 21 -
recognized     Koenig's    name    when     read    out      of   context    and

mispronounced.    Koenig was one of presumably many individuals who

had occasion to be in contact with Juror 79, a government employee.

The contact itself was isolated and lacked any attributes that

would make it more memorable than any of the many other similar

calls and inquiries Juror 79 likely had reason to conduct in his

professional life.        Importantly, and unlike the situation with

Juror 86, there is no reason to think that Juror 79 had any motive

to withhold information in response to the question posed.                    In

other words, if he recalled the brief, inconsequential call with

Koenig, he had no obvious reason not to say so. Before the district

court, defense counsel actually speculated that Juror 79 somehow

knew at the time of voir dire that forfeiture of the land was a

possible result of conviction, so he lied to be sure he could serve

on the jury to participate in getting the environmentally valuable

land for the public.       But Russell has abandoned this position on

appeal.   And it would fail in any event; the improbable product of

rank speculation is no basis for a finding of juror bias.

             Relatedly,   the   information    lost     to   counsel    --   that

Koenig and Juror 79 spoke on the phone once for five to ten minutes

-- was at best barely material.           So we have here several very

likely explanations for the lack of a response by Juror 79 (he

never knew, or forgot Koenig's name, or did not recognize it as

mispronounced),     no    plausible   reason       to   lie,      and   marginal


                                   - 22 -
materiality at best.    On such a record, having heard testimony

from Koenig, the district court did not abuse its discretion in

deciding to deny the motion without additional investigation.

                               IV.

          Because we are vacating and remanding for an evidentiary

hearing concerning the possible bias of Juror 86, we could defer

review of the drug quantity issue, and only reach it if it becomes

necessary following that hearing.    However, we find the matter to

be straightforward, and resolving it now may provide efficiencies

down the road.

          In drug conspiracy cases, the sentencing guidelines are

largely driven by the quantity of drugs involved in the conspiracy.

See U.S.S.G. § 2D1.1 (sentencing table).        In cases in which

marijuana plants are seized, the quantity is determined either by

the actual usable weight of the marijuana or, if that is not

available, by assigning a weight of 100 grams per plant recovered.

See id. (background).

          Although the government discovered and could count the

number of plants growing in 2009, the government did not have

direct evidence of the number of plants grown during the other

three years relevant to sentencing; instead, it relied upon the

amount of Pro-Mix fertilizer purchased as a proxy for the number

of marijuana plants grown.   In a nutshell, a supplier's business

records showed how much Pro-Mix fertilizer the supplier sold to


                              - 23 -
French and his associates over a four-year period, and government

witnesses in turn testified as to how much Pro-Mix was used on

each basket of marijuana (1/2 to 1-1/2 bags) and how many plants

were in each basket (three to six plants).   The PSR, and then the

district court, assumed favorably to defendants that 1-1/2 bags

were used for each basket and each basket contained only three

plants.   The district court also put to one side the number of

plants discovered in 2009, which greatly exceeded the number of

plants that one would expect using those conservative assumptions

unless one posited that much of the Pro-Mix bought in prior years

was not used until 2009.

          This doubly conservative approach correlated the number

of plants to the amount of fertilizer, resulting in a finding of

9,180 plants, which, using the 100 gram-per-plant formula, yielded

a drug quantity calculation of 918 kilograms.   Sentencing Order on

Drug Quantity at 22, United States v. French, No. 12-cr-00160-JAW

(D. Me. Apr. 12, 2016), ECF No. 647 [hereinafter "Sentencing Order

on Drug Quantity"].   This in turn led to the calculation of a base

offense level of 28 for both Russell and French.        Id. at 23.

Ultimately, the district court sentenced Russell to 151 months'

imprisonment and French to 175 months' imprisonment.    Transcript

of Sentencing Proceedings at 135, 139.

          Russell and French argued that this methodology was

speculative, proposing instead to use a methodology based on the


                              - 24 -
amount of money the migrant workers involved in harvesting the

plants sent home. In subsequent sentencing memoranda, French urged

the court to use the amount of baskets found at the grow sites as

a proxy for marijuana plants.

            We review drug quantity calculations for clear error,

and these calculations "need not be precise to the point of

pedantry.     A reasoned estimate based on historical data will

suffice."     United States v. Bernier, 660 F.3d 543, 546 (1st Cir.

2011) (citations and internal quotation marks omitted).                 The

district court reviewed the evidence and found that the testimony

of the seller of the Pro-Mix, as well as that of co-conspirators,

established    the   connection   of   the   Pro-Mix   to   the   operation.

Sentencing Order on Drug Quantity at 17.        It also found that there

was no evidence in the record as to any other use for the Pro-Mix

beyond cultivating marijuana.          Id.   Further, it noted that the

basket methodology presumed that no reuse of baskets occurred, but

the record did not rule out this possibility.           Id. at 24.    Based

on this reasoning, the district court expressly found that the

Pro-Mix method allowed for the "reasoned estimate" required by

Bernier.      Id. at 15-16.       And at the sentencing hearing, the

district court stated that "among the alternatives that have been

proposed, [the Pro-Mix method] is the most accurate of them."

Transcript of Sentencing Proceedings at 46.




                                   - 25 -
             Given   the    district    court's         cogent    reasoning       and

engagement    with   the    evidence   on    this      issue,    as   well   as   its

willingness to indulge several defendant-friendly assumptions, we

cannot conclude that the use of the Pro-Mix methodology was clearly

erroneous.    Accordingly, the drug quantity calculation provides no

basis to vacate the defendants' sentences.

                                       V.

             In addition to the juror-bias challenges and the drug

quantity issue, Russell raises three additional challenges on

appeal.    As we noted above, since we are vacating and remanding

the matter for an evidentiary hearing, we could simply decline to

resolve these challenges at present.                   But, as with the drug

quantity issue, we find Russell's further challenges to be easily

addressed, so we resolve them now for efficiency's sake.

                                       A.

             During jury selection, French's counsel objected to the

government's    peremptory     strike       of   the    only     African-American

prospective juror.         See Batson v. Kentucky, 476 U.S. 79, 96-98

(1986).    The government in response offered three race-neutral

reasons for its strike, including most notably the fact that the

juror had been sleeping from time to time during the selection

process.   Counsel for French then withdrew the objection.                   Russell

did not make a Batson challenge of his own, nor did his counsel

protest French's counsel's withdrawal of the challenge.                      Now on


                                   - 26 -
appeal, Russell concedes that this issue was unpreserved and is

reviewable for plain error only. By contrast, the government urges

us to find waiver because French's counsel -- the attorney who

actually made the objection -- explicitly withdrew it.

          We need not decide whether Russell waived or merely

forfeited the issue because, even if only forfeited, the claim

would fail on plain error review.           Neither during jury selection

nor on appeal has Russell suggested that the prospective juror did

not doze off. Nor can Russell reasonably suggest that a preference

for jurors who pay attention is unreasonable.          We therefore see no

error, let alone a clear or obvious one, in finding this to be a

race-neutral explanation for the strike sufficient to forestall a

Batson challenge.

                                     B.

          Russell also contends that the district court erred in

admitting evidence concerning his prior convictions for felony

health-care   fraud.     Russell    argued     prior   to   trial   that    the

convictions should not come in, but he did not persuade the

district court to exclude them.      He then elected to testify to the

convictions   on    direct   examination,      presumably     in    hopes    of

preemptively tempering the impact those convictions would have

upon the jury's perception of his credibility.

          Because he chose to testify to the convictions on direct

examination, Ohler v. United States dictates that he waived the


                                   - 27 -
claim on appeal.    529 U.S. 753, 760 (2000) ("[W]e conclude that a

defendant    who   preemptively   introduces   evidence   of   a    prior

conviction on direct examination may not on appeal claim that the

admission of such evidence was error.").          Undeterred, Russell

contends that Justice Souter's dissent in Ohler was the more

persuasive opinion.    Whatever the merits of that position, we are

bound by the majority opinion, and thus agree with the government

that Russell waived any challenge to the introduction of his prior

convictions by testifying to them on direct examination.

                                    C.

            Finally, Russell argues that several statements the

prosecutor made during closing argument amounted to misconduct

necessitating a new trial.    We are unconvinced.    Russell concedes

that he did not object contemporaneously to the statements and

that review is thus for plain error only.      When faced with a claim

that a prosecutor's comments during a closing statement were

improper, we vacate a conviction only if the remarks "so poisoned

the well that the trial's outcome was likely affected."            United

States v. Kasenge, 660 F.3d 537, 542 (1st Cir. 2011) (quoting

United States v. Henderson, 320 F.3d 92, 107 (1st Cir. 2003)).        In

assessing this question, we consider the severity of the conduct

and whether it was deliberate, the context, the presence of

curative instructions and their likely effect, and the strength of

the prosecution's case.    Id.


                                  - 28 -
            We see no plain error meriting vacatur here.                    Two of

Russell's concerns go to the notion that the prosecutor unfairly

disparaged the defendants and various witnesses by suggesting that

Russell   and    French's   testimony    was    not   credible      given    their

motivations and the other evidence, and by describing various

witnesses as "liars" and "scoundrels."                But commenting on the

credibility of witnesses is usually appropriate in a closing

argument.       As to the suggestion of inflammatory language, the

context   of    the   remarks   makes   clear   that       the   government    was

acknowledging that its own witnesses were imperfect.

            Russell also suggests that the prosecutor made several

factual   misrepresentations      to    the   jury    --   specifically,      that

Russell had told one worker to stay away from Maine after law

enforcement became involved and that the co-conspirators burned

down their camp.      He further contends that the prosecutor told the

jury that Pro-Mix could not be sold, contrary to the evidence.                  We

see none of these statements as sufficient to cast the conviction

in doubt.       As to the first two, assuming arguendo that these

comments slightly overstated the evidence, they were isolated and

minor comments in the context of a much larger web of evidence

pointing to Russell's guilt.            As to the third, Russell simply

misconstrues the prosecutor's statement.              The prosecutor was not

saying that Pro-Mix could never be resold.            Rather, he was casting




                                   - 29 -
doubt on the far-fetched theory that defendants purchased large

amounts of Pro-Mix to pay off a local gang.

          In any event, the district court instructed the jury

that closing statements were not evidence, and we have no reason

to doubt the jury's ability to follow that instruction. See United

States v. Spencer, 873 F.3d 1, 16 (1st Cir. 2017) (noting the

court's   "long-standing     presumption      that   jurors      follow

instructions").   Furthermore, the case against Russell was strong,

consisting of both physical evidence and the testimony of multiple

witnesses directly implicating him in the conspiracy.         In short,

we see no clear error that could have prejudiced Russell.

                           VI.   Conclusion

          We vacate the order denying the motion for a new trial

based on the response of Juror 86 to question 3 on the jury

questionnaire, and remand for further proceedings on that motion.

We otherwise reject all of the defendants' challenges to their

convictions and sentences.




                                 - 30 -
