                                                                         FILED
                                                             United States Court of Appeals
                                                                     Tenth Circuit

                    UNITED STATES COURT OF APPEALS April 12, 2018
                                                                 Elisabeth A. Shumaker
                                 TENTH CIRCUIT                       Clerk of Court




 UNITED STATES OF AMERICA,

              Plaintiff - Appellee,

 v.                                                       No. 15-1432
                                                           (D. Colo.)
                                               (D.C. No. 1:13-CR-00302-CMA-2)
 EDGAR LEOPOLDO
 GARCIA-MARTINEZ,

              Defendant - Appellant.



                            ORDER AND JUDGMENT *



Before HOLMES, KELLY, and MORITZ, Circuit Judges.



      Following a three-day trial, a federal jury convicted Defendant-Appellant

Edgar Leopoldo Garcia-Martinez (“Garcia-Martinez”) of conspiracy to possess

and possession with the intent to distribute over a kilogram of heroin and 500


      *
              After examining the briefs and appellate record, this panel has
determined unanimously to honor the parties’ request for a decision on the briefs
without oral argument. See F ED . R. A PP . P. 34(f); 10 TH C IR . R. 34.1(G). The case
is therefore submitted without oral argument. This order and judgment is not
binding precedent, except under the doctrines of law of the case, res judicata, and
collateral estoppel. It may be cited, however, for its persuasive value consistent
with Fed. R. App. P. 32.1 and 10th Cir. R. 32.1.
grams of methamphetamine, and the district court sentenced him to 121 months’

imprisonment. Garcia-Martinez challenges his conviction, arguing (1) that the

government violated Brady v. Maryland, 373 U.S. 83 (1963), and Giglio v. United

States, 405 U.S. 150 (1972), by failing to disclose certain impeachment

information concerning two confidential informants, 1 and (2) that the district

court erred by permitting an expert witness to offer an opinion on Garcia-

Martinez’s “mental state,” in contravention of Federal Rule of Evidence 704(b).

      Exercising jurisdiction under 28 U.S.C. § 1291, we affirm the district

court’s judgment.

                                         I2

      This drug-trafficking case arises from a confidential sting operation

involving the Drug Enforcement Administration (“DEA”) and two confidential

informants, Roberto and Juan (together, the “CIs”).

                                         A

      The undercover operation began in July 2013, when the DEA received

information that Javier Garcia (“Garcia”)—a co-defendant in the underlying

      1
             As explicated infra, the disclosure obligations that the Supreme
Court established in Giglio with respect to impeachment information fall under
Brady’s general rubric. For shorthand purposes only, this order and judgment
frequently refers only to the name “Brady” when discussing materials that the
government is constitutionally obliged to disclose; such references should be
understood to include the impeachment materials that the Supreme Court
addressed in Giglio.
      2
            We include as background only those limited aspects of the factual
and procedural history that relate to the issues we address.

                                         2
criminal case—claimed an ability to deliver “pound” and “multiple ounce”

quantities of methamphetamine and heroin from Oregon to Denver. R., Vol. III,

at 277 (Trial Tr., dated July 20, 2015). Roberto told the DEA that Garcia drives a

black BMW convertible and gave the agency a phone number for him.

      Pretending to be a drug buyer, Roberto met Garcia in Oregon on July 12,

2013, and arranged for Garcia to deliver drugs to Colorado. During these

negotiations, Roberto recognized Garcia-Martinez sitting “[m]aybe 10[ or] 15

feet” away. Id. at 641 (Trial Tr., dated July 22, 2015). On the day of the

Colorado delivery, the DEA tracked Garcia’s phone and car to a Comfort Inn in

Wheat Ridge, Colorado. At that time, DEA Special Agent Cronin (“Agent

Cronin”) identified two vehicles in the Comfort Inn parking lot—a “black BMW

convertible” and a “red Chevy Cobalt”—with out-of-state plates, both registered

to Garcia. Id. at 282. In the meantime, Roberto met Garcia at a nearby Taco Bell

to discuss the logistics of the drug transaction. During these discussions, Roberto

again recognized Garcia-Martinez sitting “maybe 12 or 14 feet” from their table.

Id. at 644.

      After the meeting, Garcia and Garcia-Martinez picked up the vehicles from

the Comfort Inn, and returned to the Taco Bell (with Garcia driving the BMW and

Garcia-Martinez driving the Cobalt). From there, Roberto led Garcia and Garcia-

Martinez to a DEA-controlled warehouse, where the drug transaction was

supposed to be consummated with Juan, the other confidential informant. Once



                                         3
they arrived inside the warehouse, a video captured Garcia-Martinez opening the

hood of the Cobalt, while Garcia opened the trunk. After Garcia and Garcia-

Martinez revealed the drugs to Roberto and Juan, DEA agents arrested Garcia and

Garcia-Martinez.

      Following the arrest, DEA agents discovered approximately two pounds of

heroin and seventeen pounds of methamphetamine “in the front end of the

[Cobalt], specifically behind the headlights, the front headlight units.” Id. at 305.

Subsequent forensic analysis revealed that Garcia-Martinez’s fingerprints were on

the drugs’ “internal packaging.” Id. at 361 (Trial Tr., dated July 21, 2015); see

id. at 618 (answering Garcia-Martinez’s name, when the prosecutor asked, “So, in

your expert opinion, whose fingerprints were located on four separate wrappings,

which would be the two separate plastic wraps and the two separate Ziplock

bags?”).

                                          B

      On July 22, 2013, a federal grand jury in the District of Colorado returned

an indictment charging Garcia-Martinez with conspiracy to distribute heroin and

methamphetamine and possession with intent to distribute heroin and

methamphetamine. In anticipation of trial, on August 29, 2014, Garcia-Martinez

moved for the “timely” disclosure of Brady and Giglio materials, id., Vol. I, at

87–98 (Def.’s Unopposed Mot. for Timely Disc. of Giglio Materials, dated Aug.

29, 2014), which the district court granted on September 3, 2014.


                                          4
      Shortly thereafter, however, the government opposed certain aspects of

Garcia-Martinez’s discovery requests and the district court directed the parties to

“simultaneous[ly] re-brief” issues concerning the scope of the government’s

disclosure of Brady and Giglio materials. Id., Vol. III, at 50 (Tr. Mots. Hr’g,

dated Dec. 22, 2014). In its supplemental submission, the government explained

that its summary disclosures—primarily in the form of two letters—to Garcia-

Martinez included the following information regarding the two CIs:


                  Juan                                       Roberto
 1.    His full name;                          1.   His full name;
 2.    The amount he was paid for              2.   The amount he was paid for
       participation in this case                   participation in this case
       ($4,000);                                    ($9,000 by the DEA and an
 3.    The amount he had been paid by               additional $1,000 by the Rocky
       the DEA, in total, for all of his            Mountain High Intensity Drug
       work in this case and in prior               Trafficking Area (“HIDTA”)
       cases ($453,431);                            program);
 4.    That the DEA did not provide            3.   The amount he has been paid by
       him with any further                         the DEA, in total, for all of his
       consideration or benefits besides            work as a confidential
       these payments;                              informant, including his work in
 5.    His criminal history;                        this case and prior cases
 6.    A redacted DEA Form 473                      ($21,481);
       (“Confidential Source                   4.   That the DEA did not provide
       Agreement”) and a blank DEA                  him with any further
       Form 473;                                    consideration or benefits besides
 7.    Impeachment information                      these payments;
       (specifically, that the DEA is          5.   His criminal history
       unaware of any instances where               (specifically noting that he had
       he testified falsely or                      a history of marijuana use);
       dishonestly);                           6.   A redacted DEA Form 473
 8.    That the DEA is not aware of                 (“Confidential Source
       any history of mental illness or             Agreement”);


                                           5
           substance abuse;                   7.   Impeachment information
 9.        That he did not receive any             regarding his traits for honesty
           immigration benefits; and               and/or issues with his integrity
 10.       That he had never worked for            (specifically including four
           another law enforcement                 instances when federal agencies
           agency.                                 questioned his honesty, which
                                                   eventually led to his termination
                                                   as a CI by the DEA);
                                              8.   That he received no immigration
                                                   benefits and that the DEA
                                                   believed he had entered the
                                                   country “in a status described as
                                                   Conventions Against Torture”;
                                                   and
                                              9.   That the DEA was aware of his
                                                   use of marijuana, but not of any
                                                   history of mental illness.

See id., Vol. I, at 173–76 (U.S.’s Mot. Concerning Outstanding Issues, dated Jan.

16, 2015). 3 Given the avowed breadth of these disclosures, the government

labeled any additional information that Garcia-Martinez requested cumulative or

immaterial.




       3
              As to Roberto’s prior instances of misconduct and dishonesty, the
summary specifically revealed: (1) Roberto “was involved in illegal activity in
December of 2013 and lied to DEA agents,” (2) “another allegation in 2011 of
dishonesty in which [Roberto was] reported to be manipulative and not to be
trusted,” (3) “[i]n December of 2010 [Roberto] met with targets of an
investigation without notifying the agents, in violation of his agreement,” and (4)
“[i]n 2009 an ICE [i.e., Immigration and Customs Enforcement] agent reported
[Roberto] was unreliable and had integrity issues.” R., Vol. I, at 233 (Def.’s Mot.
for Recons. of Ct.’s Ruling Regarding Disclosure of Information of Confidential
Informants, dated Mar. 3, 2015).

                                          6
      Garcia-Martinez challenged the adequacy and completeness of the

government’s disclosures on essentially two grounds: first, he claimed that the

summary information was too sparse to enable his counsel to impeach the CIs or

to conduct an impeachment-related investigation into their backgrounds; and

second, Garcia-Martinez speculated, based on the contents of the summary

disclosures, that the DEA must have additional, but undisclosed, Brady and Giglio

materials. Accordingly, defense counsel demanded production of additional

information, including the CIs’ unredacted cooperation agreements, the CIs’ tax

returns, records regarding the DEA’s payments to the CIs, and information

regarding the informants’ history of criminal activity, especially outside of

Colorado. See id. at 160–67 (Def.’s Mem. Regarding Disclosure & Disc. of

Confidential Informants & Giglio Materials, dated Jan. 16, 2015).

      Crediting the veracity of the government’s representations, the district

court initially denied these requests as essentially cumulative. See id. at 206

(Order Den. Def.’s Mot. for Disclosure & Disc. of Confidential Informants &

Giglio Materials, dated Feb. 11, 2015). More specifically, the court stated that “a

close comparison between what Defendant has already received from the

Government and what he currently requests reveals that much of what he requests

is cumulative and would reveal no substantial additional information.” Id. at 211.

Notably, the court underscored the government’s representations that “the DEA

did not provide either informant [i.e., Roberto or Juan] with any further

                                         7
consideration or benefits besides the monetary payments,” and, more specifically,

that the DEA did not provide either CI with immigration benefits. Id. at 212–13.

      The district court, however, granted Garcia-Martinez’s motion to reconsider

its discovery ruling. As a result, the court conducted an in camera review of the

DEA’s files with respect to the CIs. The district court confirmed that the

government had properly honored its disclosure obligations with respect to Juan;

as to him, no further disclosures were required. However, as to Roberto, the court

found (without significant discussion) that the disclosures the government had

already made should be supplemented in a limited fashion with certain

information that generally (1) clarified the precise amount of money that Roberto

had been paid by the DEA and the HIDTA, and (2) elaborated on the disclosed

impeachment information that attacked Roberto’s truthfulness and integrity.

                                         C

      Following these pretrial rulings, the case proceeded to trial, during which

the government introduced the testimony of Juan (one of the government’s two

confidential informants), Agent Cronin, and various task force officers and

forensic specialists, while Garcia-Martinez relied only on the testimony of

Roberto (the government’s other confidential informant). Agent Cronin testified,

in particular, concerning his factual familiarity with the underlying investigation

into Garcia-Martinez’s drug activities, and—as an expert—regarding “drug

transportation and trafficking of illegal substances” and on the investigative use

                                         8
of “confidential sources.” Id., Vol. III, at 266–67. As part of that expert

testimony, Agent Cronin discussed the “methods . . . used in the transportation

and trafficking of drugs”—including secreting drugs in “batteries, . . . bumpers,

[and] the back door panels of private vehicles”—and explained that in certain

instances “people can transport drugs without their knowledge.” Id. at 268–69.

      Specifically, Agent Cronin explained that some transporters have

“knowledge of the drugs being secreted in the vehicle” but “most often . . . no

contact with the true controllers of the drugs.” Id. at 269. Others “are not told

what they’re carrying”; that is, they have “no exact knowledge” of “the criminal

activity of transporting drugs,” but are simply paid “to drive a vehicle [with

unknown contents] from one point to another.” Id. at 269, 354. According to

Agent Cronin, law enforcement refers to the latter group as “unwitting

participants.” Id. at 354.

      Applying that knowledge distinction, Agent Cronin then testified, as an

expert, that Garcia-Martinez’s involvement failed to fall within “the definition of

an unwitting person” because surveillance captured Garcia-Martinez

accompanying Garcia “at the Taco Bell,” “subsequently driving the red Cobalt

. . . to the warehouse,” and then “opening up the hood of the vehicle and being

present at the” intended location of the drug transaction. Id. at 356. Defense

counsel objected, arguing that Agent Cronin’s expert testimony improperly




                                          9
“defin[ed] . . . the elements of the offense” and “crosse[d] into the purview of the

jury’s decision.” Id. at 356. The district court overruled the objection.

      Agent Cronin later added, without objection, that a fingerprint analysis

identified Garcia-Martinez’s fingerprints on the drugs’ “internal packaging”—a

fact which, in Agent Cronin’s view, proved inconsistent with an “unwitting

individual” because “it would be obvious that [the individual] actually handled

the dope.” Id. at 361. A forensic expert confirmed the presence of Garcia-

Martinez’s fingerprints on the packaging.

      The CIs then testified to different recollections concerning Garcia-

Martinez’s involvement in the drug transaction. Specifically, Juan testified that

Garcia-Martinez “lift[ed] the hood of the red Cobalt,” and then “[brought the

drugs] over to [him].” Id. at 552–53. Roberto testified, by contrast, that he

recalled Garcia-Martinez’s presence at the negotiations and the ultimate drug

transaction, but denied observing Garcia-Martinez “tak[ing] anything out from

under the hood” or “hand[ing] anything” to Juan. Id. at 652–53.

      Following the presentation of evidence, the jury convicted Garcia-Martinez

on all counts, and this appeal followed.

                                           II

      On appeal, Garcia-Martinez raises two separate challenges: first, he claims

that the government suppressed material impeachment information in violation of

Brady and Giglio; and second, he submits that the district court improperly

                                           10
admitted certain aspects of Agent Cronin’s expert testimony. We review each

issue in turn.

                                         A

      In a nutshell, Garcia-Martinez argues that “it is clear the United States

suppressed the necessary Brady and Giglio evidence contrary to the due process

and confrontation clauses of the United States Constitution by providing a simple

summary letter that could not be effectively used in court.” Aplt.’s Opening Br.

at 22–23. He asks us to conduct an in camera review of “the actual files of the

DEA” to confirm that such suppression has taken place and, based on that

suppression determination, to reverse the district court’s judgment and remand for

a new trial. Id. at 23. We reject Garcia-Martinez’s Brady/Giglio challenge for

three distinct and independent reasons. First, because he relies on speculation and

conjecture, Garcia-Martinez has not made an adequate showing to warrant our

engaging in an in camera review of the DEA documents. Second, having taken

the step in an abundance of caution of engaging in a properly circumscribed in

camera review of the DEA documents—viz., a review focused on the documents

pertaining to the government’s CI witness, Juan—we find no merit in Garcia-

Martinez’s argument that the DEA has suppressed material impeachment

information. And, third, we conclude as a matter of law that even if the

government had suppressed impeachment information with respect to CIs Roberto

and Juan, such suppression could not have prejudiced Garcia-Martinez because

                                        11
the government introduced ample evidence of Garcia-Martinez’s guilt quite apart

from the CIs’ testimony. In other words, even if Garcia-Martinez’s access to, and

use of, suppressed impeachment information had convinced the jury to disregard

entirely the testimony of CIs Roberto and Juan, there is no reasonable probability

that the outcome of the trial would have been different. That is, any suppressed

impeachment information could not have been material as a matter of law under

the facts and circumstances of this case.

      Before addressing these three grounds for upholding the district court’s

Brady ruling, we begin by discussing the basic principles that the Supreme Court

established in Brady and its progeny. Specifically, in Brady, the Court concluded

that “the suppression by the prosecution of evidence favorable to an accused upon

request violates due process where the evidence is material either to guilt or to

punishment, irrespective of the good faith or bad faith of the prosecution.” 373

U.S. at 87. For Brady purposes, exculpatory evidence includes evidence usable

only for impeachment purposes. See United States v. Tracy Smith, 534 F.3d 1211,

1222 (10th Cir. 2008) (“Impeachment evidence is exculpatory for Brady

purposes.”). Further, the prosecution’s Brady obligation carries an underlying

“duty to learn of any favorable evidence known to the others acting on the

government’s behalf in the case.” Kyles v. Whitley, 514 U.S. 419, 437 (1995); see

William Smith v. Sec’y of N.M. Dep’t of Corr., 50 F.3d 801, 824 (10th Cir. 1995)

(“[T]he ‘prosecution’ for Brady purposes encompasses not only the individual

                                            12
prosecutor handling the case, but also extends to the prosecutor’s entire office, as

well as law enforcement personnel and other arms of the state involved in

investigative aspects of a particular criminal venture.” (citation and footnote

omitted)); accord McCormick v. Parker, 821 F.3d 1240, 1246–47 (10th Cir.

2016).

         In order to establish a Brady violation, “the defendant must prove by a

preponderance of the evidence [that]: (1) the government suppressed evidence; (2)

the evidence was favorable to the defendant; and (3) the evidence was material.”

United States v. Garcia, 793 F.3d 1194, 1205 (10th Cir. 2015) (quoting United

States v. Reese, 745 F.3d 1075, 1083 (10th Cir. 2014)), cert. denied, 136 S. Ct.

860 (2016). “Evidence is ‘material’ under Brady ‘only if there is a reasonable

probability that, had the evidence been disclosed to the defense, the result of the

proceeding would have been different.’” United States v. Mendez, 514 F.3d 1035,

1046 (10th Cir. 2008) (quoting United States v. Robinson, 39 F.3d 1115, 1118

(10th Cir. 1994)). A “reasonable probability” means “a probability sufficient to

undermine confidence in the outcome.” Id. (quoting Robinson, 39 F.3d at 1118).

         It is important to underscore that “[t]here is no general constitutional right

to discovery in a criminal case, and Brady did not create one.” Weatherford v.

Bursey, 429 U.S. 545, 559 (1977). In this regard, the Supreme Court explained:

               The Brady rule is based on the requirement of due process. Its
               purpose is not to displace the adversary system as the primary
               means by which truth is uncovered, but to ensure that a

                                               13
             miscarriage of justice does not occur. Thus, the prosecutor is not
             required to deliver his entire file to defense counsel, but only to
             disclose evidence favorable to the accused that, if suppressed,
             would deprive the defendant of a fair trial.

United States v. Bagley, 473 U.S. 667, 675 (1985) (footnotes omitted). Simply

because information may aid a defendant in the preparation of his or her case does

not mean that the prosecution is obliged under Brady to disclose it. See, e.g.,

United States v. Agurs, 427 U.S. 97, 109–10 (1976) (“Whether or not procedural

rules authorizing such broad discovery might be desirable, the Constitution surely

does not demand that much. . . . The mere possibility that an item of undisclosed

information might have helped the defense, or might have affected the outcome of

the trial, does not establish ‘materiality’ in the constitutional sense.”); William

Smith, 50 F.3d at 823 (“The Constitution, as interpreted in Brady, does not require

the prosecution to divulge every possible shred of evidence that could

conceivably benefit the defendant.”); United States v. Smaldone, 544 F.2d 456,

462 (10th Cir. 1976) (“[Defendant’s] argument [under, inter alia, Brady] is, for

all practical purposes, simply that the Government prosecutor has an obligation to

produce evidence which may or might in any manner aid in his defense. The

contention is without merit. It fails to recognize the basics of our adversary

system.”). In order to prevail on his or her Brady claim, a defendant must

marshal arguments that are more than “merely speculative” that demonstrate by a

preponderance of the evidence that the three Brady criteria are satisfied—viz., the


                                          14
government suppressed the information and it “constituted material, exculpatory

evidence.” Sandoval v. Ulibarri, 548 F.3d 902, 915 (10th Cir. 2008); see Garcia,

793 F.3d at 1205.

                                          1

      In his appellate briefing, Garcia-Martinez relies on speculation and

conjecture in requesting that we conduct an in camera review of the DEA’s CI

files. That is not enough. As a general matter, Brady’s “holding places no

investigative obligation on courts, but rather only mandates that the prosecution

must turn over all potentially exculpatory evidence in its possession.” United

States v. Dabney, 498 F.3d 455, 459 (7th Cir. 2007); see United States v. Bland,

517 F.3d 930, 935 (7th Cir. 2008) (“The district court is under no general

independent duty to review government files for potential Brady material.”).

Moreover, in camera review is frequently time-consuming and may tax limited

judicial resources; therefore, it is not a remedy to be unstintedly granted. Cf. 6

Wayne R. LaFave et al., C RIMINAL P ROCEDURE § 24.3(b), at 447 (4th ed. 2015)

(noting that “[c]ourts tend to be reluctant to undertake pretrial review of Brady

requests,” inter alia, because such “in camera inspection can ‘impose an

intolerable burden on already taxed judicial resources’” (quoting Bennett L.

Gershman, P ROSECUTORIAL MISCONDUCT § 5:17 (2d ed. 2015))).

      To justify a court undertaking an in camera review for Brady material, at

the very least, a defendant must make a “plausible showing” that the government

                                         15
files at issue contain “material” exculpatory or impeachment information. United

States v. Williams, 576 F.3d 1149, 1163 (10th Cir. 2009); accord Riley v. Taylor,

277 F.3d 261, 301 (3d Cir. 2001) (en banc) (“A defendant seeking an in camera

inspection to determine whether files contain Brady material must at least make a

‘plausible showing’ that the inspection will reveal material evidence.” (quoting

Pennsylvania v. Ritchie, 480 U.S. 39, 58 n.15 (1987))); see Godlock v. Fatkin, 84

F. App’x 24, 29 (10th Cir. 2003) (unpublished) (noting that “we are not obligated

to remand for an in camera review of the medical report to determine whether it

contains Brady material” because the habeas petitioner’s “conclusory allegations

and speculation about what the medical report might contain fail to meet the

Brady standard”); see also United States v. Prochilo, 629 F.3d 264, 268–69 (1st

Cir. 2011) (noting that to merit in camera review of disputed Brady materials, the

defendant must “articulate with some specificity what evidence he hopes to find

in the requested materials, why he thinks the materials contain this evidence, and

finally, why this evidence would be both favorable to him and material,” and, in

this regard, his “showing cannot consist of mere speculation”); Bland, 517 F.3d at

935 (noting that “mere speculation that a government file might contain Brady

material is not sufficient” to justify in camera review); cf. United States v.

Moralez, 908 F.2d 565, 567–69 (10th Cir. 1990) (where the only contested matter

was the identity of the informant still insisting that “the defendant must present

more than mere speculation about the possible usefulness of an informant’s

                                          16
testimony,” and concluding that “[u]nder the circumstances [there], an in camera

hearing will best accommodate the competing governmental and individual

interests in this case,” where the defendant “clearly stated how the informant’s

testimony was essential to [his] defense”).

      Garcia-Martinez’s request that we conduct an in camera review does not

satisfy the above-noted plausibility standard; instead, it is based on sheer

speculation and conjecture. For example, Garcia-Martinez asserts that there is a

“likelihood”—despite the government’s contrary representations in its disclosure

materials—that the government gave CI Juan “immigration benefits”—viz., there

is a likelihood that the government suppressed information regarding such

immigration benefits and that this information is contained in the DEA’s CI files.

See Aplt.’s Opening Br. at 19.

       However, this assertion is entirely conclusory and Garcia-Martinez offers

nothing more than speculation in an effort to substantiate it. He simply reasons,

without any evidentiary support that, though it is “possible” CI Juan (a Mexican

national) became an American citizen prior to his DEA-informant work, as Juan

testified at trial, Garcia-Martinez had no “immigration information” “to counter”

Juan’s testimony on this point. Id. at 19–20. Presumably, he speaks of

information that would tend to establish that the DEA—or some federal

immigration agency at the DEA’s behest—gave Juan immigration benefits that

helped him to become a citizen, or even “extended [immigration benefits] to [his]

                                          17
family,” in exchange for Juan’s CI work. Id. However, these speculative

arguments do nothing to plausibly indicate that such immigration-benefit

information exists in the DEA’s CI files. 4

      Garcia-Martinez is correct in contending that the prosecution also may be

held accountable under Brady for material exculpatory information that is in the

files of “governmental agencies closely aligned” with it. See id. at 20 (quoting

United States v. Harry, 927 F. Supp. 2d 1185, 1209 (D.N.M. 2013), aff’d, 816

F.3d 1268 (10th Cir. 2016)); see, e.g., Kyles, 514 U.S. at 437 (discussing the

prosecution’s Brady “duty to learn of any favorable evidence known to the others

acting on the government’s behalf in the case”). However, he does not even

attempt to demonstrate that any federal immigration agency was closely aligned

with the prosecution in this case— viz., part of “the prosecution team.”

McCormick, 821 F.3d at 1242 (imputing knowledge of material impeachment

information regarding a sexual assault nurse examiner, who was not an employee

of a criminal law enforcement agency, to the prosecutor, because “under the

circumstances of this case” the nurse “was a member of the prosecution team”);

accord William Smith, 50 F.3d at 824. Perhaps more to the point, Garcia-

Martinez does not tell us how the requested in camera review would shed light on



      4
            Garcia-Martinez offers similar, non-specific speculation regarding
the “immigration benefits” that were allegedly “promised” and then “withdrawn”
from CI Roberto. Aplt.’s Opening Br. at 20.

                                          18
any such alignment or lead to the discovery of material exculpatory information.

In sum, Garcia-Martinez’s arguments regarding possibly undisclosed immigration

benefits do not satisfy the plausibility standard.

      Similarly, Garcia-Martinez observes that, because it is undisputed that CI

Juan worked for the DEA for “over [] twenty years,” the DEA must have “many

prior statements” of Juan “memorialized through de-briefings,” and criminal-

history information regarding Juan that is more specific and detailed than the

information that the government already had provided. Aplt.’s Opening Br. at 18.

Garcia-Martinez argues that such criminal-history information “would have

yielded some fertile ground for investigation.” Id. However, Garcia-Martinez

does not offer a plausible explanation for why he believes Juan’s allegedly

numerous prior statements and any more detailed criminal-history information

about him may contain material impeachment information within the meaning of

Brady and its progeny. 5



      5
             Notably, Garcia-Martinez has not alleged on appeal that the
government violated its distinct and independent duty under the Jenks Act to
produce statements of CI Juan or any other government witness. See 18 U.S.C.
§ 3500 (“After a witness called by the United States has testified on direct
examination, the court shall, on motion of the defendant, order the United States
to produce any statement . . . of the witness in the possession of the United States
which relates to the subject matter as to which the witness has testified.”); United
States v. Carter, 613 F.2d 256, 261 (10th Cir. 1979) (“[T]he [Jencks] Act assures
defendants their Sixth Amendment rights to confront their accusers by compelling
the Government to produce ‘statements’ that may be useful for impeachment of
Government witnesses.”).

                                          19
      Garcia-Martinez also makes much of the fact that, during his trial

testimony, CI Juan indicated that he had not paid taxes on the money that the

DEA had paid to him for informant work and had collected disability payments

from the federal government despite working during this period for the DEA.

Garcia-Martinez states that Juan’s testimony in this regard indicates that he lied

to the U.S. Internal Revenue Service (“IRS”) and the U.S. Social Security

Administration (“SSA”) during his DEA service and, yet, the government in its

summary disclosure indicated that the “DEA was not aware of any instances of

false testimony or falsity” involving Juan. Id. at 19. These events have led

Garcia-Martinez to wonder: “If the DEA was not disclosing these crimes, what

else . . . were [they] complicit in covering up to protect their source?” Id.

Garcia-Martinez leaves the question hanging, however; he makes no effort to

offer a plausible theory of what information the DEA might be covering up and

how it might qualify as favorable and material within the meaning of Brady. In

short, he has not carried his burden of establishing an adequate basis for in

camera review.

      To be sure, we recognize that, at bottom, Garcia-Martinez’s argument is

that, if the DEA knew of allegedly material impeachment information regarding

CI Juan with respect to these tax and disability matters and did not disclose the

information, it is reasonable to believe that the DEA may have other impeachment

information in its CI file regarding Juan that it has not disclosed. However, even

                                          20
assuming arguendo that there is some cogency to the logic of this argument, it

depends in substantial part on a central proposition—that the DEA actually knew

of CI Juan’s apparently false statements to the IRS and SSA and failed to disclose

this information. Yet, Garcia-Martinez has provided no information that tends to

establish this point. (Nor has Garcia-Martinez argued that either the IRS or the

SSA was part of the prosecution team of the criminal investigation leading to his

indictment such that the prosecution might be held responsible for inquiring of

either agency, to avoid a possible Brady violation, whether it possessed

impeachment information regarding CI Juan.) Accordingly, Garcia-Martinez’s

arguments related to CI Juan’s purported false statements to the IRS and SSA do

not provide a plausible theory justifying our in camera review.

      Further, Garcia-Martinez repeatedly complains that the summary disclosure

(primarily in the form of two letters) that the prosecution provided to him in

carrying out its Brady duty was inadequate because “the summary document was

hearsay and could not be used to impeach or discredit the witnesses.” Id. at 21.

Garcia-Martinez underscores that he “asked for the original documents and raw

data concerning each informant’s activities [] because the summaries provided

were largely ineffective to impeach the Government’s informant witnesses.” Id.

      At the outset, we note that Garcia-Martinez’s suggestion that hearsay rules

barred his use at trial of the summary disclosures to impeach the government’s

witnesses is misguided; when used solely for impeachment purposes, the

                                         21
disclosures would not be hearsay at all. See Foster v. Ward, 182 F.3d 1177, 1188

(10th Cir. 1999) (“Evidence presented to impeach the witness rather than

establish the truth of the matter asserted is not hearsay.”); cf. F ED . R. E VID . 801(c)

(noting that hearsay “means” evidence that is offered “to prove the truth of the

matter asserted in the statement”).

       Moreover, Garcia-Martinez has not supplied any plausible, non-speculative

reason to believe that the “original documents and raw data” in the DEA’s CI files

contain material impeachment information (or something likely to lead to such

impeachment information) that would be additive of, or go beyond, the

impeachment information that the government had already provided to him in the

summary disclosures. Furthermore, Garcia-Martinez has not cited any authority,

and we are not aware of any, that entitled him to receive Brady material in the

form of originals and raw data. In other words, if the summary disclosures

satisfied the prosecution’s Brady obligations in this case—viz., communicated to

Garcia-Martinez the necessary material exculpatory (i.e., impeachment)

information—Garcia-Martinez has not demonstrated that he was legally entitled

to independently receive originals and raw data containing, at least in substance,

the same information. Cf. United States v. Greatwalker, 356 F.3d 908, 911–12

(8th Cir. 2004) (per curiam) (rejecting for a lack of prejudice the defendant’s

Brady claim based on the government’s failure “to provide agents’ handwritten

notes of witness interviews” where the defendant “was provided with typed

                                            22
accounts of the interviews” and did “not indicate how the handwritten notes were

additionally exculpatory” (emphasis added)).

      True, Garcia-Martinez has “complained that the summary letters did not

contain any significant identifying information” and, consequently, he was

rendered “unable to investigate the informant’s activities that may bear upon their

credibility.” Aplt.’s Opening Br. at 21. However, as a general matter, the

government was not obliged under Brady to provide Garcia-Martinez with

information that would assist him in gathering impeachment material to bolster

his case. See United States v. Ashley, 274 F. App’x 693, 697 (10th Cir. 2008)

(unpublished) (“[T]he Due Process Clause does not require the government to

disclose before trial the names of its witnesses, just so the defense can have

sufficient time to investigate their backgrounds for impeachment information.”);

cf. United States v. Nevels, 490 F.3d 800, 803 (10th Cir. 2007) (“The Supreme

Court has established that no constitutional right to pretrial discovery of

witnesses exists in non-capital cases.”). The germane question is whether the

government was actually in possession of material information bearing on the

CIs’ credibility that it had not already disclosed. Garcia-Martinez responds to

this question with only speculation and conjecture. And that is not good enough

to warrant our in camera review.

      In sum, our conclusion that Garcia-Martinez has not made a “plausible

showing” that the DEA’s CI files contain “material” exculpatory (i.e.,

                                          23
impeachment) information warrants our rejection of his request for in camera

review. Williams, 576 F.3d at 1163. Admittedly, Garcia-Martinez is in “a tough

position” in making this plausibility showing without having an idea of what

materials are in the DEA’s CI files. Aplt.’s Reply Br. at 6. But he must

nevertheless offer us more than speculation and conjecture. Cf. United States v.

Phillips, 854 F.2d 273, 278 (7th Cir. 1988) (“[A] Brady request does not entitle a

criminal defendant to embark upon an unwarranted fishing expedition through

government files . . . .”). His failure to do so provides an independent basis for

rejecting Garcia-Martinez’s Brady claim because it asks us to find error in the

district court’s in camera review by conducting our own such review.

                                          2

      To ensure that we had the requisite materials to dispose of this appeal, we

previously granted the government’s unopposed motion to provide us with the

DEA’s CI files under seal and also set forth procedures that would control any in

camera review of those materials. Under the reasoning of Part II.A.1, supra,

Garcia-Martinez would have no entitlement to our in camera review of those

materials and his Brady claim would consequently be rendered fatally infirm.

However, even if we put aside that conclusion, we still must reject Garcia-

Martinez’s Brady claim. Specifically, we have conducted a careful, time-

intensive review of the DEA’s CI files, subject to a significant substantive

restriction noted below. The volume of these materials is not insignificant. They

                                         24
consist of papers organized in file folders; when the folders are stacked one on

top of another, they reach a height of approximately one foot (i.e., twelve inches).

Based on that in camera review, we conclude that the government did not

suppress material impeachment information favorable to Garcia-Martinez.

Accordingly, we also uphold the district court’s Brady ruling on this ground.

      As noted, our review of the DEA’s CI files was circumscribed in one

significant substantive respect. Specifically, though we ultimately examined each

piece of paper in the DEA’s CI files to avoid overlooking anything relevant to our

inquiry, the focus of that inquiry was solely on whether the government

suppressed material impeachment information with respect to its witness, CI Juan.

Though CI Roberto helped to arrange the controlled buy of narcotics that resulted

in Garcia-Martinez’s prosecution, Roberto testified as a defense witness for

Garcia-Martinez, not as a witness for the government. And this accounts for our

narrowing of the aperture for our inquiry.

      Garcia-Martinez has not cited any controlling precedent, and we are not

aware of any, that would have obliged the government under Brady to disclose

information that is exculpatory—in a purely impeachment sense—with respect to

a defense witness. 6 See United States v. Green, 178 F.3d 1099, 1109 (10th Cir.

      6
             Quite apart from this point, we would decline to conduct an in
camera review with respect to CI Roberto because Garcia-Martinez’s stated
reasons for seeking information regarding him fall outside of the ambit of the
government’s disclosure obligations under Brady. Garcia-Martinez’s principal
                                                                     (continued...)

                                         25
      6
        (...continued)
contention is that “[t]he issue [he] was precluded from exploring under Brady” is
whether the government really terminated Roberto’s CI status and declined to call
him as a witness because of his CI integrity issues and misconduct—as the
government claimed—or because of “the substance of his testimony” that
portrayed Garcia-Martinez as “not [being] involved to the degree necessary to
establish the government’s case.” Aplt.’s Reply Br. at 4. However, it follows a
fortiori from the proposition that “Brady did not create” a “general constitutional
right to discovery in a criminal case,” Weatherford, 429 U.S. at 559, that it did
not establish a right to the disclosure of information simply because it may shed
light on the prosecution’s litigation strategy. See LaFave, supra, § 24.3(b), at 432
(citing Weatherford and noting that “the due process duty to disclose extends only
to evidence, not strategy”). Moreover, insofar as Garcia-Martinez suggests that
the government’s decision to terminate Roberto as a CI and not to call him as a
trial witness signals that the DEA’s files regarding him contain undisclosed
information favorable to the defense, he engages in pure speculation and
conjecture, and we decline to do likewise. See Ashley, 274 F. App’x at 696 n.2
(“[W]e are unwilling to infer the existence of material impeachment evidence
within the meaning of Brady and Giglio by engaging in a high degree of
speculation about the government’s litigation decision-making. In particular, we
will not speculate that at the time of the initial trial the government decided not to
call the three individuals at issue as witnesses because their testimony was
unfavorable to its case (and, thus, presumably favorable to the defense) . . . .”).

       Furthermore, Garcia-Martinez insists that he would have benefitted from
the government disclosing information covering the period when the DEA had
deemed CI Roberto reliable (i.e., the period before the DEA found CI Roberto’s
integrity and veracity unacceptably flawed); that positive information, says
Garcia-Martinez, would have been “germane and material.” Aplt.’s Reply Br. at
4. However, Brady does not oblige the government to furnish information to the
defense simply because it is relevant and helpful. See Agurs, 427 U.S. at 112
n.20 (“It has been argued that the standard should focus on the impact of the
undisclosed evidence on the defendant’s ability to prepare for trial, rather than the
materiality of the evidence to the issue of guilt or innocence. Such a standard
would be unacceptable for determining the materiality of what has been generally
recognized as ‘Brady material’ . . . .” (citation omitted)); Ashley, 274 F. App’x at
697 (“[T]he Due Process Clause does not require the government to disclose
before trial the names of its witnesses, just so the defense can have sufficient time
to investigate their backgrounds for impeachment information.”); see also
                                                                        (continued...)

                                         26
1999) (noting that “both the discovery order and Giglio apply only to

impeachment information relating to a government witness,” and that they were

“inapplicable because the government did not ever call” the witness the defendant

hoped to impeach); Hatch v. Oklahoma, 58 F.3d 1447, 1469 (10th Cir. 1995) (“In

Giglio[], the Supreme Court held that the due process protection announced in

Brady includes evidence that undermines the credibility of the prosecution’s

witnesses.” (emphasis added) (citation omitted)), overruled on other grounds by

Daniels v. United States, 254 F.3d 1180, 1188 n.1 (10th Cir. 2001) (en banc); see

also United States v. Kimley, 60 F. App’x 369, 372 (3d Cir. 2003) (unpublished)

(“[T]here is no requirement that the government must disclose to the defense that

material which would allow the defendant to impeach his own witness.”); cf. In re

Sealed Case No. 99-3096, 185 F.3d 887, 893 (D.C. Cir. 1999) (“In the usual case

there is a conceptual difference between the impeachment of a government

witness and the impeachment of a defense witness. Evidence that impeaches the

former is almost invariably ‘favorable’ to the accused, because by making the

government’s case less credible it enhances the defendant’s chances of acquittal.


      6
       (...continued)
Wardius v. Oregon, 412 U.S. 470, 474 (1973) (noting that “the Due Process
Clause has little to say regarding the amount of discovery which the parties must
be afforded”); accord Nevels, 490 F.3d at 803. Therefore, in light of Garcia-
Martinez’s stated rationale for seeking material impeachment information
regarding his witness, CI Roberto, the government was not obliged to disclose it
under Brady, and we likewise have no need in our in camera review to determine
whether the government suppressed such information.

                                        27
Evidence that impeaches a defense witness, by contrast, is not generally favorable

to the accused; by reducing the credibility of the defendant’s own witness, such

impeachment reduces the probability that he will obtain a not guilty verdict. It is

ordinarily the prosecutor rather than defense counsel who wants to use the latter

kind of evidence . . . .”).

       Indeed, in his opening brief, Garcia-Martinez recites this general

proposition. Aplt.’s Opening Br. at 15 (noting that evidence is material within

the meaning of Brady/Giglio “when it is impeachment of a critical and essential

witness for the government” (emphasis added)). And, when the government

affirmatively argued in its answer brief that it had no obligation to disclose

impeachment information regarding defense witnesses, Garcia-Martinez did not

directly respond in its reply brief; he simply faulted the government for adopting

“a very literal interpretation of Brady.” Aplt.’s Reply Br. at 3. 7 Consequently,

our in camera inquiry was properly focused on whether the government

suppressed material impeachment information with respect to its informant


       7
              For inscrutable reasons, Garcia-Martinez attempts to bolster his
(indirect) response to the government’s position regarding the absence of a duty
to disclose impeachment information with respect to defense witnesses by quoting
the standard of Federal Rule of Criminal Procedure 16(a)(1)(A), and noting that
“the standard is not actually called witnesses, but intended witness.” Aplt.’s
Reply Br. at 3 (emphasis omitted). This rule, however, is patently inapposite for
a number of reasons, most salient among them being that it relates to the
disclosure of relevant statements made by the defendant, if the government
intends to use the statements at trial; Garcia-Martinez has not suggested that any
statements made by him were used at trial but not disclosed upon request.

                                          28
witness, Juan. And, after a careful and time-intensive review of the DEA’s CI

files, we conclude that it did not.

                                          3

      We now turn to our third independent ground for upholding the district

court’s Brady determination. Specifically, even though we have undertaken supra

a careful in camera review of the DEA’s CI files to determine whether the

government suppressed material impeachment information, we need not rely on

the results of that review to uphold the district court’s rejection of Garcia-

Martinez’s Brady challenge. That is because even assuming arguendo that the

government suppressed some favorable impeachment information with respect to

the CIs, we would be hard-pressed to conclude in light of the government’s ample

evidence of Garcia-Martinez’s guilt that such information was material. Put

another way, given the strength of the government’s case against Garcia-

Martinez, there is not a reasonable probability that our confidence in the

soundness of the outcome would be undermined, even if any suppressed

impeachment evidence caused the jury to disregard entirely the CIs’

testimony—especially that of the government’s witness, Juan. See United States

v. Buchanan, 891 F.2d 1436, 1443 (10th Cir. 1989) (“[W]here a witness’

credibility is not material to the question of guilt, failure to disclose impeachment

evidence does not violate Brady.”); cf. United States v. Gonzalez-Montoya, 161

F.3d 643, 649 (10th Cir. 1998) (noting that an alleged coconspirator, turned

                                          29
cooperating witness, was “a material witness whose credibility, or lack thereof,

played a critical role in the determination of [the defendant’s] guilt or

innocence”).

      “The potential impact of the undisclosed evidence should be weighed in

light of the whole record. What might be considered insignificant evidence in a

strong case might suffice to disturb an already questionable verdict.” Robinson,

39 F.3d at 1119. We recognize that the materiality inquiry asks more than

whether a rational jury would have found the evidence sufficient to support a

guilty verdict. As the Court stated in Kyles, “the question is not whether the State

would have had a case to go to the jury if it had disclosed the favorable evidence,

but whether we can be confident that the jury’s verdict would have been the

same.” 514 U.S. at 453. Nevertheless, logical reasoning strongly indicates that

when the government has a “strong case” in support of a guilty verdict—quite

apart from the undisclosed evidence—it becomes less likely that this evidence

could engender a reasonable probability of a different outcome—viz., less likely

that this evidence could be deemed material under Brady. Robinson, 39 F.3d at

1119; see Hammond v. Hall, 586 F.3d 1289, 1319 (11th Cir. 2009) (noting that

“the stronger the evidence of guilt to begin with, the more favorable to the

defense the undisclosed evidence will have to be to create a reasonable

probability that a jury would have acquitted had the evidence been disclosed”

(quoting Derrick Smith v. Sec’y, Dep’t of Corr., 572 F.3d 1327, 1347 (11th Cir.

                                          30
2009))). In this regard, we underscore that Garcia-Martinez only contends that

the government had a constitutional obligation to disclose the information

because it could have significantly facilitated the impeachment of the CIs—either

directly or indirectly. There is no contention here that the evidence was

otherwise exculpatory. Cf. Robinson, 39 F.3d at 1118–19 (upholding the district

court’s decision to grant a new trial under Brady where the government failed to

disclose eyewitness testimony regarding the description of the person who picked

up the narcotics that “tend[ed] to support the inference that one of the two main

witnesses against [the defendant] may in fact have committed the [drug] crime of

which [the defendant] was convicted”).

      Yet, even if Garcia-Martinez could have effectively nullified through cross-

examination the CIs’ testimony—armed with the favorable impeachment

information that the government supposedly suppressed—there is not a reasonable

probability that the jury would have reached a different verdict—viz., the

information was not material. Specifically, the government caught Garcia-

Martinez, along with his alleged co-conspirator Garcia, on camera, in a non-

public setting of a warehouse, trying to sell large quantities of narcotics to the

CIs, and Garcia-Martinez’s fingerprints were found on the internal packing of the

drugs. Contrary to Garcia-Martinez’s suggestion, this is not a situation where he

was merely present at the scene of a drug deal, and his guilt depended on CI

testimony regarding his participation in the drug conspiracy. Morever, even

                                          31
Garcia-Martinez’s own authority makes clear that, though “[m]ere presence at the

scene of the crime does not, by itself, prove involvement,” it is still “a material

factor.” United States v. Esparsen, 930 F.2d 1461, 1472 (10th Cir. 1991). And,

as noted, there was significantly more evidence of Garcia-Martinez’s guilt than

his mere presence.

      Under these circumstances, the CIs’ testimony—in particular, regarding

Garcia-Martinez’s role in the drug transaction—would not have been material to

the jury’s determination of Garcia-Martinez’s guilt. Our survey of cases

involving similar fact patterns allows us to conclude without hesitation that there

is not a reasonable probability that our confidence in the soundness of the

outcome would be undermined, even if suppressed impeachment evidence caused

the jury in this case to disregard entirely the CIs’ testimony—especially, the more

incriminating testimony of CI Juan. Cf. United States v. Williamson, 53 F.3d

1500, 1515–16 (10th Cir. 1995) (holding that the evidence supported defendant’s

conviction of aiding and abetting distribution of cocaine, even though defendant

claimed that she was merely present at the wrong place at the wrong time, where

the jury could have considered that defendant “was present during a drug

transaction taking place at night, that the transaction occurred within her line of

sight and that she counted a sum of money totalling $2,800”); United States v.

Hooks, 780 F.2d 1526, 1532 (10th Cir. 1986) (upholding defendant’s conviction

of possession with intent to distribute where the defendant was arrested while

                                          32
driving a vehicle, not his own, containing a concealed bundle of twenty-two

ounces of PCP valued at $10,000); see also United States v. Armour, 112 F.

App’x 678, 681 (10th Cir. 2004) (unpublished) (finding sufficient evidence to

support a jury’s guilty verdict for possession with intent to distribute cocaine

where (1) defendant was the only person found in the apartment where the

cocaine was discovered and (2) his thumb print was discovered on the box

containing the cocaine); United States v. Delreal-Ordones, 213 F.3d 1263, 1268

n.4 (10th Cir. 2000) (“[W]e have repeatedly stated that possession of a large

quantity of narcotics is sufficient to establish the element of intent to

distribute.”).

       Thus, there is a third independent ground for upholding the district court’s

Brady ruling. Specifically, even disregarding our conclusion—based on careful in

camera review of the DEA’s CI materials—that the government did not suppress

material impeachment information, we would conclude that Garcia-Martinez

cannot prevail on his Brady claim because there is no reasonable probability

under these facts that, if Garcia-Martinez had been given access to any suppressed

impeachment information with respect to the two CIs, the result of the proceeding

would have been different.

                                         ***

       In sum, we conclude that Garcia-Martinez’s Brady challenge must fail.



                                          33
                                         B

      Garcia-Martinez next argues that the district court erred by permitting

Agent Cronin to testify, as an expert, that Garcia-Martinez’s activities in the

underlying drug transactions did not resemble the agent’s definition of an

“unwitting” drug participant. See Aplt.’s Opening Br. at 26–27; accord Aplt.’s

Reply Br. at 7–8. Garcia-Martinez claims that Agent Cronin’s testimony ran

afoul of Federal Rule of Evidence 704(b), by allegedly directing “the jury what to

conclude from [the expert’s] own investigation.” Aplt.’s Opening Br. at 28.

      Ordinarily, we review a district court’s admission of expert testimony for

an abuse of discretion; we will reverse only if the district court reached a

“manifestly erroneous” decision. United States v. Schneider, 704 F.3d 1287, 1293

(10th Cir. 2013) (quoting United States v. Dazey, 403 F.3d 1147, 1171 (10th Cir.

2005)). But the government asserts that the standard of review is “difficult to

ascertain” here because Garcia-Martinez contended at trial only that “the expert’s

answer invaded the jury’s decision-making . . . by defining the offense’s

elements,” but did not reference Rule 704’s restrictions. Aplee.’s Resp. Br. at 15.

Indeed, Garcia-Martinez forthrightly recognizes that “it is possible” that we might

conclude that he forfeited his Rule 704 objection and that plain-error review is

thus appropriate. 8 Aplt.’s Opening Br. at 25. However, he insists that “he


      8
             To satisfy the stringent plain-error standard, a defendant must show
                                                                       (continued...)

                                         34
properly preserved the issue in the court below.” Id. at 27. We need not—and

thus do not—opine on this preservation question. That is because even under the

abuse-of-discretion standard—which is comparatively more favorable to Garcia-

Martinez—his Rule 704 challenge fails.

       Opinion testimony is “not objectionable” simply “because it embraces an

ultimate issue.” F ED . R. E VID . 704(a). Rule 704(b), however, carves out a limited

exception to that general proposition, providing that, “[i]n a criminal case, an

expert witness must not state an opinion about whether the defendant did or did

not have a mental state or condition that constitutes an element of the crime

charged or of a defense. Those matters are for the trier of fact alone.” F ED . R.

E VID . 704(b).

              As we have explained, “Rule 704(b) only prevents experts from
              expressly stating the final conclusion or inference as to a
              defendant’s mental state. The rule does not prevent the expert
              from testifying to facts or opinions from which the jury could
              conclude or infer the defendant had the requisite mental state.”




       8
        (...continued)
“[1] an ‘error’ [2] that is ‘plain’ and [3] that ‘affect[s] substantial rights.’”
United States v. Olano, 507 U.S. 725, 732 (1993) (fourth alteration in original)
(quoting F ED . R. C RIM . P. 52(b)). If these requirements are satisfied, we may
exercise our discretion to reverse if we determine that “[4] the error ‘seriously
affect[s] the fairness, integrity or public reputation of judicial proceedings.’” Id.
(second alteration in original) (quoting United States v. Young, 470 U.S. 1, 15
(1985)); see also United States v. Story, 635 F.3d 1241, 1244 (10th Cir. 2011)
(setting forth the same framework).

                                          35
United States v. Goodman, 633 F.3d 963, 970 (10th Cir. 2011) (emphasis added)

(quoting United States v. Richard, 969 F.2d 849, 854–55 (10th Cir. 1992)); see

United States v. Orr, 68 F.3d 1247, 1252 (10th Cir. 1995) (explaining that Rule

704(b) “prohibits an expert witness from testifying that a defendant did or did not

possess the requisite mental intent at the time of the crime”). More specifically,

“Rule 704(b) commands the expert to be silent” concerning “the last step in the

inferential process—a conclusion as to the defendant’s actual mental state.”

Goodman, 633 F.3d at 970 (emphases added) (quoting United States v. Dunn, 846

F.2d 761, 762 (D.C. Cir. 1988)).

      Agent Cronin’s challenged testimony remained well within these

parameters. Agent Cronin testified that, in his expert opinion, Garcia-Martinez’s

presence during the various phases of the drug transaction—e.g., the negotiation

of the sale and the transportation of the drugs—combined with Garcia-Martinez’s

opening of the hood of the vehicle containing the drugs at the situs of the sale

and the presence of his fingerprints on the drug packaging, suggested that Garcia-

Martinez had a level of involvement in the transaction beyond that of “an

unwitting person.” See R., Vol. III, at 355–56, 361. To be sure, Agent Cronin’s

testimony, based upon the factual circumstances of this case, established a firm

foundation for the jury to infer that Garcia-Martinez knew about the drug

transaction and, indeed, was an active participant in it. But Agent Cronin’s

testimony stopped short of “necessarily dictat[ing] the final conclusion” that

                                         36
Garcia-Martinez “possessed the requisite mens rea” for conspiracy to possess and

possession with the intent to distribute heroin and methamphetamine. United

States v. Wood, 207 F.3d 1222, 1236 (10th Cir. 2000).

      Rather, Agent Cronin merely opined, in light of his experience and training,

that the evidence in the case was not logically consistent with a finding that

Garcia-Martinez was an unwitting participant. See R., Vol. III, at 357 (testifying

that it was “not common and illogical for an unwitting to participate” in drug-

trafficking negotiations and to be present at the point where the drugs are to be

sold). Agent Cronin left it up to the jury to decide whether to actually reject the

inference that Garcia-Martinez was an unwitting participant—viz., to decide

whether Garcia-Martinez possessed the requisite mental state for the charged

offenses. See Schneider, 704 F.3d at 1294 (explaining that Rule 704(b) does “not

prevent an expert from drawing conclusions about intent, so long as the expert

does not profess to know a defendant’s intent”); Goodman, 633 F.3d at 970

(explaining that testimony only violates Rule 704(b) when it “attempt[s] to bring

forth expert opinion as to the very mental state at issue in the case—the

defendant’s mens rea when he committed the crime”). And the district court’s

instructions made clear to the jury that it was not constrained by Agent Cronin’s

expert testimony to reach a result favorable to the government on this question

(i.e., to find that Garcia-Martinez was not an unwitting participant). In this

regard, the court informed the jurors that they should give “each expert opinion

                                          37
received in evidence . . . such weight, if any, as you may think it deserves.” R.,

Vol. I, at 375.

      In Richard, we rejected the defendants’ Rule 704(b) challenge and upheld

the district court’s admission of analogous expert testimony. See Richard, 969

F.2d at 855. There, we reasoned

             [The expert] testified that based on his experience, a drug dealer
             will not invite others to participate in this type of transaction who
             are not aware of the nature of the transaction. Further, he offered
             his opinion that [the defendants] performed certain roles typically
             performed in similar drug transactions. While these remarks may
             have implied a belief that the [the defendants] were in fact aware
             of the nature of the transaction, [the expert] did not expressly
             draw that conclusion or inference for the jury. Hence, the
             testimony was not prohibited by Rule 704(b), and the district
             court did not err in admitting it.

Id. (footnote omitted).

      This reasoning is fully in step with other decisions of our circuit. See

United States v. Gutierrez de Lopez, 761 F.3d 1123, 1137 n.16 (10th Cir. 2014)

(finding no Rule 704(b) violation, where the expert’s opinion “left for the jury the

ultimate inference on [the defendant’s] intent”); Orr, 68 F.3d at 1252 (“Although

the jury could have inferred defendant’s criminal intent from [the expert’s]

statements, [the expert] did not testify that defendant had the requisite criminal

intent for fraud. Admitting [the expert’s] testimony was not error under Rule

704(b).”); see also United States v. Becknell, 601 F. App’x 709, 714 (10th Cir.

2015) (unpublished) (finding no abuse of discretion in the district court’s


                                          38
admission of expert testimony, where the expert “did everything but state th[e]

final inference” that the defendant “possessed the gun in furtherance of drug

trafficking” (emphasis added)). We should accordingly embrace that reasoning

here. Consequently, we conclude that Rule 704(b) did not prohibit Agent

Cronin’s testimony, and the district court did not abuse its discretion in admitting

his testimony.

                                         III

      Based on the foregoing, we AFFIRM the district court’s judgment.



                                                    Entered for the Court



                                                    JEROME A. HOLMES
                                                    Circuit Judge




                                         39
No. 15-1432, United States v. Edgar Leopoldo Garcia-Martinez
KELLY, Circuit Judge, concurring.
       I join parts I and II.B of the court’s opinion. I also join the court’s statement that

the government was not obligated to disclose information that would impeach Roberto,

ultimately a defense witness. Ct. Op. at 25. With that understanding, I join part II.A.1 of

the court’s opinion holding that the contentions on appeal are “based on sheer speculation

and conjecture” and do not undermine the district court’s resolution of the Brady/Giglio

issue. Thus, an in camera review on appeal is not required, notwithstanding that both

parties requested one. I would affirm on this basis.
No. 15-1432, United States v. Garcia-Martinez
MORITZ, Circuit Judge, concurring.
       I agree with the majority that the district court didn’t abuse its discretion in

admitting Agent Cronin’s expert testimony. See Maj. Op. 35–40. Likewise, I agree with

the majority that Garcia-Martinez’s Brady claim fails because he relies solely on

conjecture and speculation in asking us to conduct an in camera review. See Maj. Op.

16–30. But because I would reject Garcia-Martinez’s Brady claim on this basis, I see no

reason to conduct our own in camera review to evaluate whether the government

suppressed any favorable impeachment evidence. See Maj. Op. 26–30. Nor do I see any

reason to determine whether—even assuming the government did suppress favorable

impeachment information—that suppressed information was material. See Maj. Op. 30–

35. Accordingly, I join all but Part II.A.2 and Part II.A.3 of the majority opinion.
