          United States Court of Appeals
                     For the First Circuit


No. 15-1716

                    UNITED STATES OF AMERICA,

                            Appellee,

                               v.

                     ROBEL KIDANE PHILLIPOS,

                      Defendant, Appellant.


          APPEAL FROM THE UNITED STATES DISTRICT COURT
                FOR THE DISTRICT OF MASSACHUSETTS

         [Hon. Douglas P. Woodlock, U.S. District Judge]


                             Before

                    Barron, Selya, and Stahl,
                         Circuit Judges.


     Derege B. Demissie, with whom Demissie & Church was on brief,
for appellant.
     Randall E. Kromm, Assistant United States Attorney, with whom
Carmen M. Ortiz, United States Attorney, was on brief, for
appellee.


                        February 24, 2017
            BARRON, Circuit Judge.                 On October 28, 2014, Robel

Phillipos was convicted under 18 U.S.C. § 1001(a)(2) on two counts

of making false statements to federal authorities in the weeks

following the Boston Marathon bombing.                    The bombing occurred on

April 15, 2013.         The statements related to Phillipos's possible

participation, three days later, in the removal and disposal of a

backpack thought to contain evidence related to the attack from

the college dormitory room of Dzhokhar Tsarnaev, one of the bombing

suspects and a friend of the defendant's at college.                         Phillipos

was   sentenced    to    three   years'          imprisonment    and   three    years'

supervised release.       He now challenges his convictions on a number

of grounds that we will address, along with the facts relevant to

each, in turn.     Because we find that none of these challenges has

merit, we affirm.

                                            I.

            We start with Phillipos's challenges to the admission

into evidence of a signed confession, in which Phillipos admitted

to making the false statements that are at issue during two

informal interviews with federal agents in the two weeks following

the bombing.      Phillipos signed that confession at the conclusion

of    an   interview     with    an    agent       of     the   Federal     Bureau    of

Investigation ("FBI") on April 26, 2013.                   Phillipos contends that

the   District    Court    erred      in    both    (1)    refusing    to   conduct   a

preliminary hearing on the admissibility of the confession unless

                                           - 2 -
Phillipos would agree to submit to cross-examination at that

hearing on the contents of an affidavit that he submitted regarding

the circumstances of the confession, and (2) failing to make a

determination prior to the introduction of the confession into

evidence as to whether Phillipos made the confession voluntarily.

Neither challenge warrants reversal of the convictions.

                                      A.

             We begin with the first of Phillipos's challenges to the

admissibility of the confession, which concerns the denial of his

request for an evidentiary hearing on the voluntariness of his

confession because he refused to submit to cross-examination.

Phillipos sought the hearing in connection with his motion to

suppress the confession pursuant to the Fifth Amendment's Due

Process Clause.

             Phillipos acknowledged that he had been informed of his

rights, as required by Miranda v. Arizona, 384 U.S. 436 (1966),

prior   to   making     the   confession.      But    he   contended   that   the

circumstances under which he made it were coercive.               In support of

this    motion,   Phillipos      relied     solely    on   his   own   affidavit

recounting his version of those circumstances.

             Specifically, Phillipos's affidavit alleged that the

interviewing      FBI     agent,     Michael         Delapena,    "interrogated

[Phillipos] for several hours in a small room."                  Phillipos also

alleged that, during that time, Delapena administered a polygraph


                                     - 3 -
test, and told Phillipos that Phillipos could only answer questions

with "yes or no."        As a result, Phillipos alleged, he answered

"no" to certain questions because he could not give the truthful

answer, which would have been that he did not remember.                  Phillipos

also alleged that Delapena did not offer Phillipos food; that

Delapena "got close to [Phillipos's] face" and cursed at him; and

that Delapena locked the door and told Phillipos, "[T]ell me

everything that happened.        There are wolves outside the door, you

don't want me to unlock the door."             In addition, Phillipos alleged

that, at the end of the interrogation, Delapena presented him with

a typed confession to sign, which Phillipos signed because "[he]

felt that [he] had no choice but to sign it if [he] were to leave

without being arrested."

             Phillipos    argued      that     the   affidavit      he   submitted

sufficed to show that there were facts in dispute regarding the

confession's     voluntary      nature,      because    the   account     in    the

affidavit    conflicted    in    key    respects       with   the    account    the

government set forth in its opposition to his motion to suppress

the confession that it had filed.              In its filing, the government

did not dispute that Delapena questioned Phillipos for several

hours in a small room.

             The government did, however, dispute other aspects of

Phillipos's account. Specifically, the government stated that,

prior   to   administering      the    polygraph,      Delapena     explained    to


                                       - 4 -
Phillipos that the polygraph questions had to be answered with a

"yes or no," and that if Phillipos did not remember something,

Delapena would rephrase the question so that Phillipos could

truthfully answer with a "yes" or "no."       The government's account

also   conflicted   with   Phillipos's   in   the   following   respects:

Delapena did offer Phillipos food; Delapena "at no time . . .

raise[d] his voice, curse[d], or otherwise treat[ed] the defendant

discourteously"; Delapena locked the door to the interview room

only after Phillipos expressed concern that agents outside were

angry with him, and, in doing so, Delapena told Phillipos, "Don't

worry about them.     They're outside; I'm here with you.        I don't

judge you."     Finally, the government stated in its filing that

Phillipos sat with Delapena as Delapena typed up the confession,

that Delapena "conferred constantly" with Phillipos to ensure that

Delapena was accurately setting forth Phillipos's account, and

that, at several points, Phillipos asked Delapena to make specific

changes to the account, which Delapena did.

            A defendant is entitled to an evidentiary hearing as to

the voluntariness of his confession only if the defendant "makes

a sufficient threshold showing that material facts are in doubt or

dispute, and that such facts cannot reliably be resolved on a paper

record."     United States v. Staula, 80 F.3d 596, 603 (1st Cir.

1996).     Applying that requirement to Phillipos's request for the

hearing, the District Court acknowledged that the allegations in


                                 - 5 -
Phillipos's affidavit, if credited, would suffice to establish a

factual dispute that would warrant a hearing.            But the District

Court went on to explain that the affidavit could suffice to

establish that factual dispute only if Phillipos agreed to be

cross-examined about the affidavit's contents at the hearing.

Otherwise, the District Court ruled, the affidavit "cannot be

tested" and would be "illusory."      And, as a result, there would be

no basis for finding that Phillipos had established the requisite

factual dispute.

             We review a preserved challenge to a denial of a request

for a preliminary hearing for abuse of discretion. United States

v. Jiménez, 419 F.3d 34, 42 (1st Cir. 2005).          "Abuse of discretion

occurs 'when a relevant factor deserving of significant weight is

overlooked, or when an improper factor is accorded significant

weight, or when the court considers the appropriate mix of factors,

but commits a palpable error of judgment in calibrating the

decisional scales.'"     Id. at 43 (quoting United States v. Gilbert,

229 F.3d 15, 21 (1st Cir. 2000)). "Within this framework, an error

of law is always tantamount to an abuse of discretion."              Torres-

Rivera v. O'Neill-Cancel, 524 F.3d 331, 336 (1st Cir. 2008).

             Phillipos contends that the District Court abused its

discretion     by   making   his   willingness   to    submit   to   cross-

examination a condition of holding the hearing. Phillipos contends

that the condition effectively -- and impermissibly -- "[f]orc[ed]


                                   - 6 -
him to choose between" asserting his constitutional right against

self-incrimination    and   asserting    his   right   to   an   evidentiary

hearing regarding the voluntariness of his confession.              But, we do

not agree.

             Phillipos points to nothing in the record besides his

affidavit that could have provided a basis for finding that he had

met his burden of demonstrating a factual dispute that would

warrant an evidentiary hearing at the time that the District Court

imposed   the   cross-examination   condition.         In   fact,    when   the

District Court asked one of Phillipos's attorneys, prior to denying

the motion for the hearing, to "[p]oint [the court] to" evidence

in the record besides Phillipos's own affidavit that would support

Phillipos's contention that his confession was not voluntary, the

attorney failed to do so.1



     1 At oral argument, Phillipos contended for the first time
that there was enough evidence in the record, apart from
Phillipos's affidavit, to create a factual dispute regarding the
voluntariness of the confession so as to warrant a pre-trial
hearing. Leaving aside the allegations set forth in his affidavit,
Phillipos pointed to the evidence otherwise in the record that
Phillipos was interviewed from 10:00 A.M. until 3:00 P.M., was
interviewed in a small room, and that, before he gave his
confession, he was told, among other things, that he had failed
the polygraph test and thus would be in trouble. But Phillipos
conceded at oral argument that none of these facts were disputed
by the government at the time that he moved for the evidentiary
hearing. And "[a] hearing is required only if the movant makes a
sufficient threshold showing that material facts are in doubt or
dispute, and that such facts cannot reliably be resolved on a paper
record[] . . . which, if resolved in his favor, would entitle him
to the requested relief." Staula, 80 F.3d at 603.



                                 - 7 -
             As a result, the District Court simply determined that

Phillipos failed to establish a sufficient threshold basis for

finding that there was a factual dispute over the voluntariness of

his confession because he had proffered only an untested -- and

thus illusory -- affidavit. In doing so, the District Court

followed a course that we approved, albeit in a different context,

in United States v. Baskin, 424 F.3d 1 (1st Cir. 2005), which is

a case that Phillipos fails to address.

             There, a defendant relied solely on factual allegations

set forth in his own affidavit in moving on Fourth Amendment

grounds to suppress the fruits of a search.             Id. at 3.         The

defendant refused, however, to submit to cross-examination that

would allow the government to "test the truth" of the factual

allegations set forth in the affidavit; the defendant instead

invoked his Fifth Amendment privilege against self-incrimination.

Id.   In consequence, the District Court refused to credit the

affidavit and then denied the motion to suppress.           Id.       We held

that the district court did not abuse its discretion in so ruling,

because the district court was entitled to conclude that the

defendant's own untested affidavit was not in and of itself

sufficient    to   "establish   any   ground   for   asserting    a    Fourth

Amendment right."     Id.

             To be sure, Baskin involved a district court's denial,

after an evidentiary hearing, of a defendant's motion to suppress


                                  - 8 -
evidence allegedly acquired in violation of the defendant's Fourth

Amendment right against an unreasonable search.          Id.   By contrast,

here we confront a defendant's motion for an evidentiary hearing

to determine whether, under the Fifth Amendment, a confession was

voluntarily made.       But, like the defendant in Baskin, Phillipos

sought to establish the requisite factual predicate for his motion

solely on the basis of his own affidavit, which he would not allow

the   government   to   test    through    cross-examination.        Nor   did

Phillipos identify any additional evidence that he would be able

to present at the hearing, other than his speculative assertions

that he might have established support for his affidavit's account

through his own cross-examination of the government agents who

conducted the interviews that led to the confession.

           In light of Baskin, we see no basis for concluding that

the District Court abused its discretion in finding that the

affidavit, on its own, failed to establish the sufficient threshold

showing of a factual dispute that Phillipos was required to make.

As we have said before, "[t]he district court has considerable

discretion in determining the need for, and the utility of,

evidentiary hearings, and we will reverse the court's denial of an

evidentiary hearing in respect to a motion in a criminal case only

for manifest abuse of that discretion."          Staula, 80 F.3d at 603.

Accordingly,   this     first   challenge    regarding   the   use   of    the

confession at trial fails.


                                   - 9 -
                                 B.

          Phillipos next contends that the District Court erred by

failing to make a finding as to the voluntariness of the confession

before admitting it into evidence.      Phillipos does not contend

that the District Court was required to find that Phillipos's

confession was involuntary, as he concedes that the record as it

then stood supported the voluntariness finding made.      Phillipos

contends only that the timing of the District Court's voluntariness

determination prejudiced Phillipos's ability to develop a complete

record in support of his contention that the confession was not

voluntarily given.

          Phillipos failed to raise this objection below, and so

our review is only for plain error.     United States v. Olano, 507

U.S. 725, 732 (1993).     "Review for plain error entails four

showings: (1) that an error occurred (2) which was clear or obvious

and which not only (3) affected the defendant’s substantial rights,

but also (4) seriously impaired the fairness, integrity, or public

reputation of judicial proceedings."    United States v. Duarte, 246

F.3d 56, 60 (1st Cir. 2001).

          Although the District Court made a preliminary finding

pre-trial that the confession was voluntary, the government does

not appear to dispute that the District Court erred in failing to

make a conclusive voluntariness determination "[b]efore [the]

confession [was] received in evidence."    18 U.S.C. § 3501(a).   See


                               - 10 -
also Sims v. State of Georgia, 385 U.S. 538, 543–44 (1967) ("[A]

jury is not to hear a confession unless and until the trial judge

has determined that it was freely and voluntarily given."); Crane

v. Kentucky, 476 U.S. 683, 687–88 (1986) ("To assure that the

fruits of such techniques are never used to secure a conviction,

due process also requires 'that a jury [not] hear a confession

unless and until the trial judge . . . has determined that it was

freely and voluntarily given.'" (alteration in original) (quoting

Sims, 385 U.S. at 543-44)); United States v. Feliz, 794 F.3d 123,

130 (1st Cir. 2015) ("Although the judge need not make formal

findings of fact or write an opinion, his conclusion that the

confession     is   voluntary   must   appear   from    the    record   with

unmistakable clarity." (quoting Sims, 385 U.S. at 544)).            But, as

Phillipos identifies no way in which the timing of the District

Court’s   voluntariness    determination     affected    his    substantial

rights, we agree with the government that there is no plain error.

See Duarte, 246 F.3d at 60.

             Phillipos argues otherwise on the ground that the late

timing of the voluntariness determination interfered with his

ability to make his case for suppressing the confession pre-trial,

as he contends that it would have been easier for him to make his

case for suppression at that time.          But Phillipos did have the

chance to make that pre-trial case.        He simply failed at that time

to establish any factual dispute with the government's account.


                                  - 11 -
Thus, the fact that the District Court made only a preliminary

voluntariness determination prior to the start of the trial did

not    prejudice   Phillipos.     Accordingly,   this    version    of   his

challenge concerning the use of the confession at trial also fails.

                                     II.

             Phillipos next contends that the District Court erred by

excluding testimony from Phillipos's proposed expert on false

confessions, Dr. Richard Leo, without first conducting a hearing

under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579

(1993), as to whether Dr. Leo's testimony qualified as expert

testimony.     We do not agree.

             Daubert   establishes    that   before     admitting   expert

testimony, the trial court must fulfill its "gatekeeping role" by

making an independent determination that the expert's proffered

scientific knowledge is both reliable and relevant.           509 U.S. at

597.    Daubert also explains that the reliability determination

"entails a preliminary assessment of whether the reasoning or

methodology underlying the testimony is scientifically valid and

of whether that reasoning or methodology properly can be applied

to the facts in issue."     Id. at 592-93.

             Phillipos contends that such an assessment may be made

only after a hearing.       There is, however, no such requirement.

Phillipos identifies no precedent that supports his view.           And we

have made clear that "[t]here is no particular procedure that the


                                  - 12 -
trial court is required to follow in executing its gatekeeping

function under Daubert."      Smith v. Jenkins, 732 F.3d 51, 64 (1st

Cir. 2013) (internal quotation marks and citation omitted); see

also Kumho Tire Co. v. Carmichael, 526 U.S. 137, 152 (1999)

(affirming district court's Daubert inquiry where the court did

not hold a hearing because "[t]he trial court must have the same

kind of latitude in deciding how to test an expert's reliability

. . . as it enjoys when it decides whether or not that expert's

relevant testimony is reliable" (emphasis in original)); United

States v. Nichols, 169 F.3d 1255, 1262-64 (10th Cir. 1999) (a

district court has discretion not to hold a pretrial evidentiary

reliability hearing in carrying out its gatekeeping function);

Hopkins v. Dow Corning Corp., 33 F.3d 1116, 1124 (9th Cir. 1994)

("The district court is not required to hold a . . . hearing, but

rather must merely make a determination as to the proposed expert's

qualifications.").

          The only cases that Phillipos relies on in arguing

otherwise are not on point. Each held only that the district court

erred in excluding testimony under Daubert because the district

court had not considered the Daubert factors at all.           See United

States v. Hall, 93 F.3d 1337 (7th Cir. 1996); United States v.

Belyea,   159    F.   App'x   525     (4th   Cir.   2005)   (per   curiam)

(unpublished).




                                    - 13 -
             The District Court made no such mistake here.                      It

provided both Phillipos and the government multiple opportunities

to explain why Dr. Leo's testimony should or should not be admitted

under Daubert.         Moreover, when the District Court ultimately

decided    to    exclude     Dr.   Leo's   testimony,    the    District    Court

explained that it had given a fair amount of thought to the issue

and provided a detailed explanation of why it was excluding the

testimony under the Daubert factors.            It is thus clear to us that

the District Court performed the gatekeeping role that Daubert

requires.

             Phillipos does appear to contend, separately, that the

District Court erred in performing that gatekeeping role by ruling

that Dr. Leo's testimony was insufficiently reliable and thus must

be   excluded.     Because     Phillipos   preserved    this    challenge,     our

review is for abuse of discretion.              Smith, 732 F.3d at 64.          We

find none.

             Under    Daubert,     "[t]o   determine    whether    an    expert’s

testimony is sufficiently reliable, the trial court considers

whether 'the testimony is based on sufficient facts or data';

whether 'the testimony is the product of reliable principles and

methods';    and     whether    'the   expert   has    reliably    applied     the

principles and methods to the facts of the case.'"                      Id. at 64

(quoting Fed. R. Evid. 702(b-d)).               The trial court may also

consider    other     factors,     "including    but    not    limited    to   the


                                       - 14 -
verifiability of the expert's theory or technique, the error rate

inherent    therein,    whether    the    theory     or   technique   has   been

published and/or subjected to peer review, and its level of

acceptance within the scientific community."              Samaan v. St. Joseph

Hosp., 670 F.3d 21, 31-32 (1st Cir. 2012) (internal quotation marks

and citation omitted).

            In this case, the District Court considered competing

analyses of the reliability of Dr. Leo's studies and found that

there was "no indication that there is a body of reliable material

that constitutes understanding in this area," and that "it would

introduce the jury . . . to a kind of faux science to present Dr.

Leo's   testimony."      Whether    or    not   we    would   reach   the   same

conclusion, the record certainly shows that the one that the

District Court reached is reasonable.           Cf. People v. Kowalski, 821

N.W.2d 14, 31-32 (Mich. 2012) (no abuse of discretion where trial

court concluded that Dr. Leo's testimony relied on "unreliable"

sources    and   used   "unreliable      methodology"      that   "resulted   in

conclusions consistent with Leo's own preconceived beliefs rather

than testable results consistent with an objective, scientific

process"); State v. Rafay, 285 P.3d 83, 112 (Wash. Ct. App. 2012)

(no abuse of discretion where "Leo was unable to testify about any

meaningful correlation between specific interrogation methods and

false confessions or provide any method for the trier of fact to

analyze the effect of the general concepts on the reliability of


                                   - 15 -
the defendants' confessions"); Vent v. State, 67 P.3d 661, 667-

670 (Alaska Ct. App. 2003) (no abuse of discretion where trial

court concluded that "there was no way to quantify or test Dr.

Leo's conclusions that certain techniques might lead to false

confessions").

                                       III.

              Finally, and most significantly, Phillipos appeals the

District Court's denial of his motion for acquittal.                    The jury

found Phillipos guilty of two counts of violating 18 U.S.C.

§ 1001(a)(2), which applies to those who "make[] any materially

false, fictitious, or fraudulent statement or representation" to

federal authorities.

              Specifically, the jury found Phillipos guilty, under

Count   One    of   the    indictment,   of    making   the   following    false

statements to a federal agent during an interview on April 20,

2013: (1) Phillipos did not remember going to Tsarnaev's dormitory

room on the evening of April 18; and (2) Phillipos went to the

room with Dias Kadyrbayev and Azamat Tazhayakov, two friends of

his and Tsarnaev's from college, on the evening of April 18, but

no one entered the room.

              The jury also found Phillipos guilty, under Count Two of

the indictment, of making the following three false statements

during an April 25, 2013 interview with a federal agent: (1)

Phillipos     had   only    entered   Tsarnaev's    dormitory    room     on   one


                                      - 16 -
occasion on April 18, which was sometime in the afternoon when he

spoke to Tsarnaev for approximately ten minutes; (2) neither

Phillipos,     Kadyrbayev,    or    Tazhayakov       took    a     backpack    from

Tsarnaev's room on the evening of April 18; and (3) Phillipos was

not aware of Kadyrbayev or Tazhayakov removing anything from

Tsarnaev's room on the evening of April 18.

             On appeal, Phillipos does not contest the falsity of

these statements.       Instead, he makes three separate arguments as

to why the denial of his motion for acquittal must be reversed.

First, he contends that there was insufficient evidence to support

a finding that these statements, even though false, were ones to

which section 1001 applies.         Second, he contends that there was

insufficient evidence to support a finding that he made the

statements "knowingly and willfully."          Third, he contends that, as

applied   to    his   statements,   the   statute     is     unconstitutionally

vague.

             Reviewing the denial of Phillipos's motion for acquittal

de   novo,     eschewing   credibility       judgments,      and     drawing    all

reasonable inferences in favor of the verdict, see United States

v. Mardirosian, 602 F.3d 1, 7 (1st Cir. 2010), we conclude that a

rational jury could have found beyond a reasonable doubt that

section   1001    encompassed   statements      in    each    count    for     which

Phillipos was convicted and that Phillipos made these statements




                                    - 17 -
knowingly    and     willfully.        We   also     reject      Phillipos's

constitutional vagueness challenge.

                                      A.

            Phillipos relies on two separate arguments in contending

that the record does not suffice to show that the five false

statements at issue are of the type which violate section 1001.

We reject both.

                                      1.

            Phillipos first argues that the evidence at trial did

not suffice to show that his statements were "material," as section

1001 requires.     In rejecting this aspect of Phillipos's challenge,

we base our analysis on our decision in United States v. Mehanna,

735 F.3d 32 (1st Cir. 2014), cert denied, 135 S. Ct. 49 (2014).

            There,   a   jury   had   convicted    the   defendant,    Tarek

Mehanna, of violating section 1001 by making false statements in

connection with an ongoing terrorism investigation to the FBI

during informal interviews not unlike the ones that are at issue

here. 735 F.3d at 41-42. The statements concerned the whereabouts

of one of Mehanna's friends, Daniel Maldonado.             Id.     When FBI

agents asked Mehanna when he had last heard from Maldonado, Mehanna

falsely told the agents that he had last heard from Maldonado two

weeks earlier and that Maldonado was living in Egypt.            Id. at 54.

In fact, however, Mehanna had spoken to Maldonado that week and




                                  - 18 -
was aware that Maldonado was in Somalia training for violent jihad.

Id.

              On appeal, Mehanna argued that no reasonable jury could

find that his false statements were material, because the agents

knew the answers to their questions even before they asked them,

such that Mehanna's false statements did not in fact mislead them.

Id.   We rejected that argument.     Id. at 54-55.         We held that to be

material, a false statement "need not actually have influenced the

governmental function," id. at 54, but rather need only be of the

kind that "could have provoked governmental action,"               id. (quoting

United States v. Sebaggala, 256 F.3d 59, 65 (1st Cir. 2001)).               We

explained that "the proper inquiry is not whether the tendency to

influence bears upon a particular aspect of the investigation but,

rather, whether it would bear upon the investigation in the

abstract or in the normal course."         Id.

            Applying that standard, we then concluded that a jury

reasonably could find that Mehanna's statements about Maldonado

"had a natural tendency to influence an FBI investigation into

terrorism."       Id. at 55.    In setting forth this conclusion, we

explained that the record supported a jury's finding that "the

defendant   was    plainly   attempting    to    obscure    both   Maldonado's

participation in terrorist endeavors and the telephone call in

which he and Maldonado had discussed jihad and terrorist training,"




                                  - 19 -
and that "the defendant's mendacity was undertaken for the purpose

of misdirecting the ongoing FBI investigation."                Id.

            Given    Mehanna,   we    have    little     difficulty        rejecting

Phillipos's   contention      that    the    evidence     is   insufficient      to

support Phillipos's convictions under both of the false statement

counts in the indictment.       The jury found Phillipos guilty, under

both counts of the indictment, of making false statements that are

akin to the statements we found material in Mehanna.                  See, e.g.,

United   States     v.   Natelli,    527   F.2d   311,   324   (2d    Cir.    1975)

(recognizing that where a single count of an indictment charges a

defendant   with     multiple   false       statements,    jury      can    convict

provided that it unanimously agrees defendant was guilty of making

at least one of the false statements charged); United States v.

Duncan, 850 F.2d 1104, 1105 (6th Cir. 1988) (same), overruled on

other grounds by Schad v. Arizona, 501 U.S. 624 (1991); United

States v. Mangieri, 694 F.2d 1270, 1279-81 (D.C. Cir. 1982) (same);

United States v. Jessee, 605 F.2d 430, 431 (9th Cir. 1979) (per

curiam) (same).

            Specifically, the jury found Phillipos guilty under

Count One for stating, on April 20, that, when he returned to the

door of Tsarnaev's dormitory room on April 18 at approximately

10:00 P.M. with Kadyrbayev and Tazhayakov, no one entered the room.

And the jury found Phillipos guilty under Count Two for the

following statements on April 25:           that Phillipos was not aware of


                                     - 20 -
Kadyrbayev or Tazhayakov taking anything from Tsarnaev's dormitory

room on the evening of April 18; and that neither he nor Kadyrbayev

or Tazhayakov took a backpack from Tsarnaev's dormitory room on

the evening of April 18.

            These statements were made in the midst of a federal

terrorism investigation.        And they provided false information

about whether Phillipos and his compatriots entered the bombing

suspect's dormitory room soon after the deadly bombing, went into

the suspect's backpack, and left the room with evidence in tow.

Thus, like the statements in Mehanna, these statements by Phillipos

could reasonably be deemed to have been intended to obscure the

potentially unlawful activities of the defendant's friends from

law enforcement and thereby to frustrate an ongoing terrorism

investigation.    See Mehanna, 735 F.3d at 55 ("During the critical

interview, the defendant was plainly attempting to obscure both

Maldonado's participation in terrorist endeavors and the telephone

call in which he and Maldonado had discussed jihad and terrorist

training. The misinformation imparted by the defendant thus had a

natural     propensity   to   influence    an   FBI   investigation   into

terrorist activity.").

            To be sure, other individuals had given law enforcement

information about the backpack.      Phillipos thus contends that law

enforcement already knew the information that his false statements

obscured.     Mehanna makes clear, however, that such knowledge on


                                  - 21 -
the part of law enforcement is of no moment in determining whether

false statements are material.             What matters is whether the

statement in question would be material to an investigation in the

normal course, not whether the statement was actually material to

the particular investigation in fact.            And, here, a jury could

reasonably find that Phillipos's statements deprived the agents of

important corroborating information regarding where, when, and by

whom key evidence had been removed.

          We recognize that Phillipos contends that Mehanna is

distinguishable because the investigation into the Boston Marathon

bombing was already complete at the time Phillipos made the false

statements. But, as the government rightly notes, it is impossible

to conclude that a jury could not reasonably find otherwise. Even

though Tsarnaev had been apprehended at the time of Phillipos's

interviews, the government still had an interest in continuing to

investigate   the    matter,   given   the   significant   public   safety

interest in determining who might have been involved in the bombing

and the government's need to develop the case for prosecution.

Thus, Phillipos's materiality-based sufficiency challenge fails.

                                      2.

          Phillipos also contends that his motion for acquittal

was   wrongly       denied     --    Mehanna's     materiality      holding

notwithstanding -- because none of the false statements at issue

are "the type of statements and conduct that [C]ongress intended


                                    - 22 -
to criminalize."       To support this contention, Phillipos relies on

a line of cases that had established, for a time, what was known

as the "exculpatory no" doctrine.

             When the cases in that line were decided, the version of

section 1001 that was in place prohibited the making of "any false,

fictitious     or    fraudulent    statements"    in   certain    government

matters.     See Brogan v. United States, 522 U.S. 398, 400 (1998)

(quoting 18 U.S.C. § 1001 (1988 ed.)). The "exculpatory no"

doctrine interpreted that version of section 1001, despite its

seemingly all-encompassing sweep, not to apply to a statement that

a defendant made to a law enforcement officer during an informal

interview    in     which   the   defendant   simply   denied    engaging   in

wrongdoing.       See, e.g., United States v. Chevoor, 526 F.2d 178,

182 (1st Cir. 1975) (holding that statements that "fall within the

'exculpatory no' category of responses . . . are outside the scope

of 'statements' within the meaning of the statute").

             Phillipos contends that "Chevoor's scenario is nearly

identical" to his own, because, like the defendant in Chevoor,

Phillipos "did not fabricate a misleading story . . . or send the

[federal] agents on a wild goose chase."         Instead, he merely "gave

negative, oral responses to the questioning."            As the government

points out, however, the "exculpatory no" doctrine that we adopted

in Chevoor was overturned by the Supreme Court in Brogan, 522 U.S.

398.   In Brogan, the Supreme Court held that, by its plain terms,


                                     - 23 -
the   earlier   version    of   section     1001   "cover[ed]     'any'   false

statement -- that is, a false statement 'of whatever kind,'" and

"[t]he word 'no' in response to a question assuredly makes a

'statement.'"       Id. at 400-01 (citation omitted).             As such, the

Court held that the plain text of the statute as it then existed

applied to "exculpatory no" statements, even though, as Justice

Ginsburg observed, "[i]t is doubtful Congress intended § 1001 to

cast so large a net."      Id. at 412 (Ginsburg, J., concurring in the

judgment).

             Phillipos's   only   answer     is    to   suggest   that    Brogan

overruled only "portions" of Chevoor, and that Chevoor's holding

regarding     the    "exculpatory     no"     doctrine      remains      binding

regardless.     This contention, of course, has no merit, given that

Chevoor's construction of the statute was explicitly rejected.

And Phillipos develops no argument as to how some version of the

"exculpatory no" lives on in the current version of section 1001.2


      2We note that the "exculpatory no" doctrine was, in many
circuits, based on an implied materiality requirement that we --
and many of our sister circuits -- read into the earlier version
of section 1001. Brogan did away with the doctrine due to the
absence of a textual basis for it in an earlier version of section
1001. See Brogan, 522 U.S. at 400 (construing version of section
1001 that applied broadly to "any false, fictitious, or fraudulent
statement" (quoting 18 U.S.C. § 1001(a)(2) (1988 ed.))). In 1996,
however, Congress added the statute's current materiality
requirement for the express purpose of resolving the "conflict
among circuits as to whether materiality is an element" of the
false statements prohibition. H.R. Rep. No. 104-680, at 8 (1996).
Several of our sister circuits have since held, albeit with little
analysis, that Brogan precludes application of the "exculpatory


                                    - 24 -
           In any event, for the same reasons that a jury could

reasonably find material the statements by Phillipos that we

discussed above about who did or did not enter the lead suspect's

dormitory room and take evidence from his backpack shortly after

the   bombing    occurred,   a   jury    also   could   reasonably     reject

Phillipos's contention that such statements were not meant "to

fabricate a story or send agents on a wild goose chase."                 See

Mehanna, 735 F.3d at 55 ("[W]here a defendant's statements are

intended to misdirect government investigators, they may satisfy

the materiality requirement of section 1001 even if they stand no

chance   of     accomplishing    their     objective.").       Thus,     this

sufficiency challenge fails as well.

                                    B.

           Phillipos next trains his focus on the fact that section

1001 applies to only those false statements and representations

that an individual makes knowingly and willfully.               18 U.S.C.

§ 1001(a).      Phillipos contends that, even if he violated the

statute, the government failed to present sufficient evidence that

he did so with the requisite mens rea.          We disagree.




no" doctrine under the amended statute, notwithstanding that it
contains an express materiality requirement. See, e.g., United
States v. Watkins, 691 F.3d 841, 852 (6th Cir. 2012); United States
v. Ali, 508 F.3d 136, 153 (3d Cir. 2007).



                                  - 25 -
           The Supreme Court has made clear that "in order to

establish a 'willful' violation of a statute, 'the Government must

prove that the defendant acted with knowledge that his conduct was

unlawful.'"     Bryan v. United States, 524 U.S. 184, 191-92 (quoting

Ratzlaf   v.    United   States,   510    U.S.   135,   137   (1994)).     But

"[w]illfulness can rarely be proven by direct evidence, since it

is a state of mind."      United States v. Bank of New Eng., N.A., 821

F.2d 844, 854 (1st Cir. 1987).           As such, willfulness is "usually

established     by   drawing   reasonable     inferences      from   available

facts."   Id.

           With respect to the false statements in Count Two, which

Phillipos made during the April 25 interview, there would have

been no need for the jury to infer much.            The interviewing agent

testified at trial that he affirmatively told Phillipos that

Phillipos could be prosecuted for making false statements.               This

direct evidence suffices to support a jury's finding that section

1001's willfulness requirement had been met.

           The government did not present similarly direct evidence

with respect to the statements at issue in Count One, which

Phillipos made during the April 20 interview.           But, the government

notes, by April 20 -- five days after the Boston Marathon bombing

occurred -- Phillipos, along with his friends, had become the focus

of intense law enforcement interest due to their relationship with




                                   - 26 -
Tsarnaev.       And, Phillipos had already been interviewed by law

enforcement the previous day, on April 19.

            A    jury    could   reasonably     infer    that     someone    who

potentially had information about the removal and destruction of

evidence in a historic terrorism investigation into a deadly attack

on a symbolic event, and who was interviewed by federal law

enforcement agents twice, would know that it was unlawful to make

false   statements      to   investigators    about   what   he   knew.      The

reasonableness of this inference is further bolstered by the fact

that, on April 20, Phillipos's interviewer told him that "now [was]

the time to tell [the government]" what he knew.             The interviewer

also asked whether "this was the story he want[ed] to go with" and

gave Phillipos the opportunity to "correct" it.                 We thus reject

this challenge.

                                       C.

            Finally,     Phillipos    contends    that    section     1001    is

unconstitutionally vague as applied to the five false statements

that he was convicted of making.        He argues that, by virtue of the

express materiality requirement that section 1001 now contains, it

is not clear which statements fall under section 1001 and which do

not.    But this argument, too, is unavailing.

            A criminal statute is void for vagueness only if it

"fails to provide a person of ordinary intelligence fair notice of

what is prohibited, or is so standardless that it authorizes or


                                     - 27 -
encourages seriously discriminatory enforcement."                  United States

v. Williams, 553 U.S. 285, 304 (2008).                Applying section 1001's

materiality standard to Phillipos's statements raises no such

concerns.    A criminal statute is not unconstitutionally vague

merely because it sets forth a standard for determining liability

that is not mathematically precise.                 And here, the challenged

standard -- "materiality" -- is a familiar one.                   Indeed, "[i]ts

use in the context of false statements to public officials goes

back as far as Lord Coke" in 1680.                Kungys v. United States, 485

U.S. 759, 769 (1987).

      Moreover,   Mehanna   laid    out       a    test   for   determining   when

statements are material under section 1001 that used the same

language as the test that had been set forth decades before in

Kungys, which itself tracked the "uniform understanding of the

'materiality' concept" that "federal courts have long displayed."

See Kungys, 485 U.S. at 770.             Under that standard, as we have

explained, the evidence was more than sufficient to permit a

reasonable jury to find the materiality requirement was satisfied

as   to   each   count.   Thus,    we    reject       Phillipos's    as-applied,

constitutional vagueness challenge.

                                        IV.

            In light of the foregoing, we affirm.




                                   - 28 -
