In the
United States Court of Appeals
For the Seventh Circuit
____________________
No. 22-1691
UNITED STATES OF AMERICA,
Plaintiff-Appellee,
v.
MARCOS BAHENA,
Defendant-Appellant.
____________________
Appeal from the United States District Court for the
Northern District of Illinois, Eastern Division.
No. 19-cr-00744-2 — Gary Feinerman, Judge.
____________________
ARGUED APRIL 6, 2023 — DECIDED JUNE 22, 2023
____________________
Before FLAUM, ST. EVE, and PRYOR, Circuit Judges.
FLAUM, Circuit Judge. Marcos Bahena appeals from a jury
conviction for conspiring to possess cocaine with intent to dis-
tribute. He argues that multiple errors occurred during the
trial—most notably, that the government’s expert witness tes-
tified beyond the scope of his expertise. He also contends that
the government did not present enough evidence to support
the conviction. For the reasons discussed below, we affirm.
2 No. 22-1691
I. Background
In March 2019, agents intercepted calls via a wiretap on
Jose Bahena’s phone. Despite Jose’s attempts to obscure his
plan by using coded language, the wiretap revealed that he
was arranging an illicit transaction. He spoke with a supplier
who would be bringing new product into town on a semi-
truck, as well as with a distributor who would help sell the
product upon its arrival. In addition, Jose had frequent calls
with his brother, Marcos, the defendant in this case. Marcos’s
main role was to arrange a clandestine meeting spot where
they could pick up the product from the supplier’s courier. To
that end, Marcos contacted “Juanito,” who had access to a pri-
vate parking space big enough for a semitruck. Juanito agreed
to let them use the space if they paid him; the brothers de-
cided to offer him $500. Marcos also informed Juanito of the
meeting’s purpose so that he would not be surprised and
would let them use the spot for future drop-offs.
On the day of the deal, Jose and Marcos exchanged multi-
ple calls settling final logistics. That night, authorities
watched Marcos leave his home and head to the parking
space. Jose and Juanito joined him. A semitruck then drove
up to the parking lot and, after someone opened the gate to
the lot, backed in. Before long, the group disbanded. When
Marcos called Jose later that night, he relayed that Juanito had
been “getting kind of scared” due to the risk he was taking.
The next day, authorities observed Jose meet with the dis-
tributor’s courier under a bridge. Jose got into the courier’s
car carrying a plastic bag. Within a couple minutes, he exited
the car empty-handed and drove off. The courier left too, but
No. 22-1691 3
officers promptly pulled him over and found the plastic bag.
It contained a powdery substance later identified as cocaine.
Marcos was arrested and charged with possessing cocaine
with intent to distribute as well as with conspiring to do so.
He went to trial, where the government called numerous
agents and officers to testify. Relevant for our purposes, an
expert in drug-dealing practices and terminology interpreted
some of the wiretap transcripts. Marcos called no witnesses;
his main strategy was to cast himself as a pawn in Jose’s
scheme. The jury found Marcos guilty of the conspiracy but
not of the substantive possession offense. Marcos appeals.
II. Discussion
On appeal, Bahena mounts a series of attacks on his con-
viction. 1 Primarily, he challenges the scope of the expert wit-
ness’s testimony. He also requests a mistrial based on two ju-
rors’ receipt of unadmitted exhibits and two witnesses’ refer-
ences to his incarceration. These three issues, Bahena con-
tends, cumulatively deprived him of a fair trial. Finally,
Bahena argues that the evidence does not support the jury’s
verdict. We address each subject in turn.
Scope of Expert Testimony
Bahena’s first argument concerns the scope of Special
Agent German Samaniego’s expert testimony. The govern-
ment called Samaniego to testify about drug-trafficking prac-
tices in general and to interpret portions of the wiretap call
transcripts. As to the latter, the government asked Samaniego
1 For the rest of this opinion, we refer to Marcos as “Bahena.”
4 No. 22-1691
to read aloud entire conversations from the transcripts. Sama-
niego would then opine as to what the callers discussed over
the course of the exchange.
We have often recognized the admissibility of expert tes-
timony to “explain the methods and the jargon and code
words used in complex or unfamiliar criminal enterprises.”
United States v. Gan,
54 F.4th 467, 474 (7th Cir. 2022); see also
United States v. York,
572 F.3d 415, 423 (7th Cir. 2009) (“[T]he
Rules of Evidence allow expert law enforcement witnesses to
translate drug jargon and code words that might seem en-
tirely innocuous to an untrained jury.”). Bahena does not
challenge Samaniego’s testimony about drug-dealing prac-
tices and drug-specific parlance.
Instead, Bahena objects that the government’s technique
of eliciting testimony about the wiretap transcripts resulted in
“wholesale interpretations of uncoded communications that
the jury should have been left to interpret on its own.” See
Gan, 54 F.4th at 474. Bahena did not raise this objection below,
so we review for plain error. Id. at 475. That means Bahena
must show “(1) an error occurred, (2) the error was plain,
(3) it affected [his] substantial rights, and (4) it seriously af-
fected the fairness, integrity, or public reputation of the pro-
ceedings.” United States v. Thomas,
933 F.3d 685, 690 (7th Cir.
2019).
To Bahena’s point, the government’s questioning was not
precise. For example, at the government’s request, Samaniego
read aloud the following exchange:
Jose: Where are you?
Bahena: Here at the house. Um, I
just got here.
No. 22-1691 5
Jose: Hey, call up Juanito and ask
him where – some of the big ones
so they can deliver to me tomor-
row or the day after tomorrow.
Bahena: I’ll ask him right now and
see what he tells me. 2
Afterwards, the government directed Samaniego to “walk the
jury through [his] interpretation of what that meant.” He be-
gan, “They’re discussing where they are. He’s at the house.
He just got there.” Samaniego then said that Jose told Bahena
to ask “somebody named Juan where they can put one of the
big ones, referring to a tractor-trailer or semi, so that they can
deliver tomorrow, meaning that there’s going to be a meeting
between the courier and either Jose or Marcos who’s going to
pick up the drugs there.” Samaniego’s testimony contains
many more exchanges of this variety.
Our recent Gan decision reviewed for plain error similar
(albeit, arguably less open-ended) expert testimony interpret-
ing intercepted communications. See Gan, 54 F.4th at 474–75.
We held that the defendant did not satisfy plain error’s third
prong, which asks whether the claimed error affected the de-
fendant’s “substantial rights.” Id. at 475.3 In other words, the
expert testimony did not “affect[] the outcome of the district
court proceedings.” See United States v. Cotton,
535 U.S. 625,
2 The calls were in Spanish but had been translated to English.
3 We noted in Gan that we were “not saying there were errors, let alone
plain ones, at steps one and two,” but we added that the defendant did
not satisfy plain error’s fourth prong (regarding “the fairness, integrity, or
public reputation of judicial proceedings”).
Id. In this case, we confine our
holding to just the substantial-rights prong.
6 No. 22-1691
632 (2002) (quoting United States v. Olano,
507 U.S. 725, 734
(1993)). The same is true here.
In Gan, several pieces of evidence “independent” from the
challenged testimony went to showing the defendant’s guilt
for the at-issue charge. Gan, 54 F.4th at 476–77. Here, the gov-
ernment notes that it too introduced evidence besides Sama-
niego’s testimony. Bahena responds that, whereas the expert
testimony in Gan mostly concerned a charge on which the de-
fendant had been acquitted, id. at 476, Samaniego’s testimony
was obviously relevant to the conspiracy conviction. He thus
suggests that no amount of “independent” evidence could
make up for the prejudice Samaniego’s testimony caused.
Accepting that this case is closer than Gan, Bahena over-
states the importance of Samaniego’s testimony. The govern-
ment called eleven witnesses other than Samaniego—includ-
ing numerous agents and officers who investigated the case
and provided their eyewitness accounts of the transactions. In
all, Samaniego’s testimony about the wiretap transcripts takes
up approximately twenty-five pages of over 250 total pages of
witness testimony. Cf. United States v. Hawkins,
934 F.3d 1251,
1267 (11th Cir. 2019) (holding that similar testimony affected
the defendant’s substantial rights because the expert “was the
principal prosecution witness,” taking up “over two hundred
pages of trial transcript” compared to the “fewer than one
hundred transcript pages” for “the other eight trial witnesses
combined”). Samaniego was hardly the centerpiece of the
government’s case.
Even more, and despite Bahena’s insistence to the con-
trary, Samaniego’s testimony was not the only source for in-
ferring that Bahena acted with ill intent. The jury had access
No. 22-1691 7
to the actual wiretap transcripts during deliberations, includ-
ing ones Samaniego had not interpreted. On these facts, the
transcripts, along with the attendant circumstances other wit-
nesses described, allowed the jurors to assess Bahena’s mo-
tives for themselves. Cf. United States v. Arrellano,
757 F.3d
623, 632–33 (7th Cir. 2014) (explaining that the context sur-
rounding a conversation using coded language to refer to
drugs “would allow a reasonable jury to” understand the
meaning without expert testimony).
In short, Samaniego’s challenged testimony was not as
critical to the conviction as Bahena submits. Like in Gan,
other, “independent” pieces of evidence supported the jury’s
decision. See Gan, 54 F.4th at 476–77.
Further, the district court addressed the risk of prejudice
through an instruction to the jury. In Gan, we partially relied
on the court’s instruction that the jurors “were free to inter-
pret the messages differently than the [expert] did and to dis-
count her testimony.” Id. at 477–78. The court’s instructions
here likewise emphasized that the jurors did “not have to ac-
cept [Samaniego’s] opinions and testimony” and should eval-
uate his reliability as they would for “any other witness.”
We assume the jury follows the district court’s instruc-
tions. Gan, 54 F.4th at 477. Of course, an instruction will not
always “fully or even partially cure a trial error.” United States
v. Barnhart,
599 F.3d 737, 746 n.8 (7th Cir. 2010). Here, how-
ever, we are satisfied that the instruction enabled the jury to
consider the evidence free from Samaniego’s “expert gloss.”
See York,
572 F.3d at 423; see also United States v. Christian,
673 F.3d 702, 712 (7th Cir. 2012) (“[T]he jury was free to disre-
gard [the expert’s] characterization of the [evidence] and eval-
uate for itself the significance of [the defendant’s] conduct.”).
8 No. 22-1691
One final note on this issue: The government urges us to
discount the potential prejudice of Samaniego’s testimony be-
cause he testified in a purely expert capacity. It is true that
that dual-role testimony—when a witness testifies in both an
expert and a lay capacity—can present an increased risk of
prejudice. E.g., Christian,
673 F.3d at 712–13. Such a witness
could potentially confuse jurors; her dual role could also lead
them to believe her expert opinion draws from information
“not presented at trial” or to overly rely on her factual testi-
mony due to “an expert’s ‘aura of special reliability.’” York,
572 F.3d at 425 (citations omitted). We therefore held in Gan
that the expert’s non-dual role gave another reason to doubt
her testimony’s prejudicial effect. Gan, 54 F.4th at 477.
It should be recognized, however, that non-dual testi-
mony like Samaniego’s presents its own risks. If an expert
witness did not participate in the investigation, jurors may as-
sume that he is less invested in obtaining a conviction. In turn,
they might ascribe more weight to his testimony. Simply put,
the appearance of objectivity could actually enhance the prej-
udice resulting from problematic expert testimony.
So, although concerns over dual-role testimony are legiti-
mate and warrant precautions during trial, see United States v.
Jett,
908 F.3d 252, 268–70 (7th Cir. 2018), there are countervail-
ing considerations too. As the Pattern Instructions recognize,
expert testimony always carries the risk of prejudice—dual-
role or not. See Pattern Criminal Jury Instructions of the Sev-
enth Circuit (2022) at 54. The government and district courts
should remain vigilant when expert witnesses provide inap-
propriate testimony even in a non-dual capacity.
No. 22-1691 9
As it stands, however, Bahena has not convinced us that
Samaniego’s testimony violated his substantial rights. 4 His
challenge fails under our plain-error review.
Jurors’ Receipt of Unadmitted Evidence
Bahena’s next contention concerns evidence sent back to
the jury. During deliberations, it came to light that two jurors
received four exhibits that had not been admitted into evi-
dence. The exhibits were transcripts of calls Bahena partici-
pated in before the relevant period for the charged offenses.
For example, in one of the calls, Bahena and his brother dis-
cussed “doing a line” of cocaine.
Clearly, “materials not admitted into evidence simply
should not be sent to the jury for use in its deliberations.”
Baugh ex rel. Baugh v. Cuprum S.A. de C.V.,
730 F.3d 701, 705
(7th Cir. 2013). But Bahena made the calculated decision to
abandon this objection below; after orally bringing a motion
for a mistrial, he withdrew it, citing concerns over how a new
trial might play out. This amounts to a waiver, so we do not
review the issue on appeal. See United States v. Flores,
929 F.3d
443, 447 (7th Cir. 2019) (“Waiver occurs when a party inten-
tionally relinquishes a known right and forfeiture arises when
a party inadvertently fails to raise an argument in the district
court.”).
4 Bahena also argues that we should account for the contentiousness
of the jury’s deliberations. Essentially, he takes the heated debate to mean
that the jury would not have convicted him absent the extra push Sama-
niego’s testimony provided. Without more, this is too speculative to
evince prejudice for plain-error purposes. Cf. Brown v. Eplett,
48 F.4th 543,
560 (7th Cir. 2022) (discussing the ambiguity behind a split verdict).
10 No. 22-1691
References to Bahena’s Incarceration
Bahena also claims that certain witnesses’ references to his
pretrial incarceration deprived him of a fair trial. The first wit-
ness the government called, a Metropolitan Correctional Cen-
ter employee, intended to introduce a “jail call” as an exem-
plar of Bahena’s voice. Before the witness could get to that
point, however, Bahena objected on the grounds that her tes-
timony would inform the jury he was incarcerated. The par-
ties agreed to skirt the issue by stipulating that Bahena’s voice
was on the recorded call. Later that day, an investigating
agent testified that she compared the “jail call” (using those
words) to the wiretap recordings to identify Bahena’s voice.
Bahena objected. The court then instructed the jury to disre-
gard the witness’s “characterization” of the call.
Although Bahena objected both times the jail-call testi-
mony arose, he did not further challenge the resolutions of the
objections or move for a mistrial. Our review of whether the
district court should have sua sponte declared a mistrial is thus
for plain error only. See United States v. Adkins,
743 F.3d 176,
186 (7th Cir. 2014).
“[A] mistrial is appropriate when an event during trial has
a real likelihood of preventing a jury from evaluating the evi-
dence fairly and accurately, so that the defendant has been
deprived of a fair trial.” United States v. Hilliard,
851 F.3d 768,
778 (7th Cir. 2017) (alteration in original) (quoting United
States v. Collins,
604 F.3d 481, 489 (7th Cir. 2010)). Though not
wholly without prejudice, infrequent references to a defend-
ant’s jail calls typically do not warrant such drastic relief. See
United States v. Roux,
715 F.3d 1019, 1029 (7th Cir. 2013) (“[W]e
have no reason to believe that the single reference to ‘jail calls’
deprived Roux of a fair trial.”); see also Thomas,
933 F.3d at 692
No. 22-1691 11
(rejecting the argument that a “reference to the ‘jail phone call’
was unfairly prejudicial”); United States v. Johnson,
624 F.3d
815, 821–22 (7th Cir. 2010) (reasoning that jail-call evidence
subjects defendants to “a much diminished form of preju-
dice” compared to defendants who “stand trial in prison
garb”).
Bahena’s case aligns with this precedent. The Correctional
Center employee’s vague testimony and the agent’s fleeting
use of the term “jail call”—which the district court addressed
through a limiting instruction, see United States v. Harris,
325 F.3d 865, 871 (7th Cir. 2003)—fall short of demanding a
mistrial, especially under our plain-error review.
Cumulative Error
Bahena argues that the above three errors combined created
enough prejudice to warrant a new trial. It is indeed possible
for multiple errors, harmless alone, to cumulatively “infect[]
the jury’s deliberation” such that the defendant does not re-
ceive “a fundamentally fair trial.” United States v. Groce,
891 F.3d 260, 271 (7th Cir. 2018) (quoting United States v. Allen,
269 F.3d 842, 847 (7th Cir. 2001)).
Bahena waived his objection to the jurors’ receipt of unad-
mitted evidence, so the only two issues that could theoreti-
cally come into play here are Samaniego’s testimony and the
allusions to Bahena’s jail calls. See Alvarez v. Boyd,
225 F.3d
820, 825 (7th Cir. 2000). While Samaniego’s testimony is some-
what problematic, the jail-call testimony hardly tips the scales
in Bahena’s favor. See
id. (“[C]ourts must be careful not to
magnify the significance of errors which had little importance
in the trial setting.”). Thus, looking through the lens of possi-
ble cumulative prejudice, Bahena is not entitled to a new trial.
12 No. 22-1691
Sufficiency of the Evidence
Finally, Bahena maintains there was insufficient evidence
supporting the jury’s verdict. As part of this argument, he fo-
cuses on the jury’s decision to acquit him of possessing co-
caine with intent to distribute while also convicting him of
conspiring to do so. Bahena contends that these verdicts are
inconsistent and indicate the conviction on the conspiracy
charge lacked support. This is particularly so, he says, be-
cause the same evidence underlies both verdicts.
“Typically, a guilty verdict will stand (so long as the evi-
dence is sufficient to support it) notwithstanding an incon-
sistent verdict on a related offense ….” United States v. Wil-
bourn,
799 F.3d 900, 910–11 (7th Cir. 2015) (quoting United
States v. Moore,
763 F.3d 900, 910 (7th Cir. 2014)). Even when
“[t]he jury’s decision is inscrutable,” an acquittal on one count
does not invalidate a guilty verdict on another. United States
v. Weller,
40 F.4th 563, 566 (7th Cir. 2022) (affirming a verdict
when the jury had acquitted the defendant of three “substan-
tive charges” of violating securities laws while also convicting
him “on a single charge of conspiracy to violate the securities
laws”), cert. denied,
143 S. Ct. 427. So, assuming for the sake of
argument that the jury’s verdict is inconsistent here, we
would still need to “assess the conspiracy conviction as if it
had been the only charge.”
Id.
On that note, Bahena contends that the evidence does not
support the conspiracy conviction in isolation. To succeed, he
must show that, “viewing the evidence in the light most fa-
vorable to the government, [no] rational trier of fact … could
have found the essential elements of the crime beyond a rea-
sonable doubt.” United States v. Miller,
782 F.3d 793, 797 (7th
Cir. 2015). A defendant bringing this challenge faces “a nearly
No. 22-1691 13
insurmountable hurdle.”
Id. (quoting United States v. Torres-
Chavez,
744 F.3d 988, 993 (7th Cir. 2014)).
As previewed in Section II.A, the jury had a sufficient ba-
sis to find there was an agreement to distribute cocaine that
Bahena “knowingly and intentionally joined.” See United
States v. Fitzpatrick,
32 F.4th 644, 649 (7th Cir. 2022) (quoting
United States v. Pulgar,
789 F.3d 807, 813 (7th Cir. 2015)). 5 The
wiretap transcripts indicate that Bahena worked closely with
his brother and Juanito to arrange the meeting. Those tran-
scripts, along with eyewitness testimony, confirm that Bahena
was at the parking lot when the semitruck pulled in. Sama-
niego testified that drug organizations often use semitrucks
to transport drugs. The next day, authorities saw Bahena’s
brother drop off a package with a third party under a bridge;
when officers pulled the third party over, there was a package
of cocaine in the car. In addition, Bahena’s reference to Juan-
ito’s concern over the risk involved suggests Bahena was
aware of the plan. This is enough to sustain the conviction.
III. Conclusion
For these reasons, we AFFIRM Bahena’s conviction.
5 A sufficiency-of-the-evidence challenge accounts for “all of the evi-
dence admitted by the trial court[,] … regardless of whether that evidence
was admitted erroneously.” United States v. Chaparro,
956 F.3d 462, 470
(7th Cir. 2020) (quoting United States v. Rahman,
805 F.3d 822, 839 (7th Cir.
2015)). As such, we could consider Samaniego’s testimony interpreting the
wiretap transcripts in this context even if we agreed with Bahena that its
admission was in error. At any rate, the other evidence in this case suffi-
ciently supports the jury’s conviction.
