                 United States Court of Appeals
                            For the Eighth Circuit
                        ___________________________

                                No. 19-2574
                        ___________________________

                             United States of America

                        lllllllllllllllllllllPlaintiff - Appellee

                                           v.

                                Thomas D. Overton

                       lllllllllllllllllllllDefendant - Appellant
                                       ____________

                    Appeal from United States District Court
                  for the Southern District of Iowa - Davenport
                                 ____________

                             Submitted: June 19, 2020
                              Filed: August 19, 2020
                                  ____________

Before KELLY, ERICKSON, and STRAS, Circuit Judges.
                           ____________

KELLY, Circuit Judge.

      Thomas Overton appeals after a jury convicted him of conspiracy to
manufacture, distribute, and possess with intent to distribute 100 grams or more of
heroin in violation of 21 U.S.C. §§ 841(a)(1), (b)(1)(B), and 846. He primarily
challenges the district court’s1 admission of dual-role testimony from an officer who
interpreted recorded telephone calls as both a lay and expert witness. We conclude
that portions of the challenged testimony were admitted in error. But because the
error was harmless, we affirm.

                                  I. Background

       Thomas Overton was indicted based on allegations that he was part of a heroin
conspiracy headed by his nephew, Kearnice. The government presented four
categories of evidence at trial: (1) Special Agent Jay Bump’s testimony about the
investigation into Kearnice’s drug organization, which spanned several years; (2) a
text message and recorded telephone calls between Overton and Kearnice, which
Task Force Officer Paul Girskis interpreted for the jury; (3) Task Force Officer
Douglas Scott’s testimony about his efforts to locate individuals connected to
Overton, and testimony from three of them—Nicole Oaks, Lacey Schram, and Frank
Barron—that they obtained heroin from Overton; and (4) extensive testimony from
Khiemonte Smith, who was described as Kearnice’s “right-hand man,” about
Overton’s participation in the drug organization.

       Before trial, defense counsel filed a motion in limine seeking to exclude
portions of Officer Girskis’s anticipated testimony. Defense counsel argued that
Officer Girskis’s interpretations of the text message and recorded telephone calls
constituted improper expert testimony. The government argued that it was
permissible for Officer Girskis to testify as a lay witness based on his perceptions
during the investigation and as an expert witness based on his training and
experience. The district court denied the motion. At trial, the government introduced
11 recorded telephone calls and one text message between Overton and Kearnice.


      1
       The Honorable Rebecca Goodgame Ebinger, United States District Judge for
the Southern District of Iowa.

                                         -2-
Officer Girskis interpreted these communications for the jury. Defense counsel
repeatedly objected to this testimony, but the court overruled each objection.

       At the close of evidence, defense counsel requested an instruction informing
the jury that the relationship between a mere buyer and seller of drugs does not
establish a conspiracy. Khiemonte Smith had testified that, early in the conspiracy,
Overton “ran off with the heroin and [Kearnice] was upset.” After that, Kearnice told
Smith to “bird feed Thomas Overton,” meaning “not give him a lot at one time so that
he won’t run off, so a couple grams here, a gram there . . . therefore he can sell and
when he sell it, [Kearnice] don’t have to worry. If [Overton] did run off with that,
then it really ain’t nothing.” Defense counsel argued that a buyer-seller instruction
was appropriate because Overton used heroin and the organization gave him only
small quantities at a time. Defense counsel also argued that Nicole Oaks’s and Lacey
Schram’s testimony that they had purchased heroin from Overton on multiple
occasions was insufficient to establish more than a mere buyer-seller relationship
because the government did not identify those witnesses until shortly before trial.
The district court denied the request for a buyer-seller instruction, concluding that it
was not warranted by the evidence.

      During closing arguments, defense counsel highlighted that the government
had not made controlled purchases of heroin from Overton as it had from other
members of the conspiracy, and that the government made last-minute changes to its
witness list. In response, the prosecutor told the jury: “If I made mistakes, if [the case
agents] made mistakes, then please complain to the DEA and call the U.S. Attorney’s
Office and tell them that [we] all made mistakes; but do not let a guilty man go free
because I made a mistake. That is not what you are here to do.” Defense counsel did
not contemporaneously object to these remarks. Later on, during a bench conference
on another matter, defense counsel requested a mistrial based on the prosecutor’s
statements. The district court denied the motion, finding that the statements were
“imprudent” but not “improper.”

                                           -3-
      The jury found Overton guilty of conspiring to manufacture, distribute, and
possess with intent to distribute 100 grams or more of heroin in violation of 21 U.S.C.
§§ 841(a)(1), (b)(1)(B), and 846. Defense counsel subsequently filed a motion for a
new trial based on the prosecutor’s statements about calling the DEA and the U.S.
Attorney’s Office. Defense counsel also argued that the prosecutor improperly
bolstered the case agents’ testimony by summarizing evidence about their back-
grounds. The district court denied the motion, again finding that the prosecutor’s
statements were “imprudent, but not improper.” The court further concluded that,
even if the statements were improper, they were not prejudicial.

      This appeal followed. Overton challenges the denial of his motion in limine,
the admission of Officer Girskis’s testimony, the sufficiency of the evidence, the
denial of his request for a buyer-seller instruction, and the denial of his motion for a
new trial. He also argues that other statements made by the prosecutor during closing
arguments were improper because they stated facts not in evidence and disparaged
defense counsel. We address each argument in turn.

                           II. The Dual-Role Testimony

       The Federal Rules of Evidence generally require witnesses to testify based on
personal knowledge. See Fed. R. Evid. 602. They permit only two types of opinion
testimony. A lay witness may offer opinion testimony if it is “rationally based on the
witness’s perception,” “helpful to clearly understanding the witness’s testimony or
to determining a fact in issue,” and “not based on scientific, technical, or other
specialized knowledge.” Fed. R. Evid. 701. And an expert witness may offer opinion
testimony if “the expert’s scientific, technical, or other specialized knowledge will
help the trier of fact to understand the evidence or to determine a fact in issue,” “the
testimony is based on sufficient facts or data,” “the testimony is the product of
reliable principles and methods,” and “the expert has reliably applied the principles
and methods to the facts of the case.” Fed. R. Evid. 702.

                                          -4-
      Investigating officers are sometimes in a position to provide both forms of
permissible opinion testimony. As lay witnesses, they may offer testimony that is
rationally based on their perceptions during the investigation. See Fed. R. Evid. 701.
And as expert witnesses, they may offer opinion testimony that is based on
specialized knowledge gained from training and experience. See Fed. R. Evid. 702.
We have not “categorically prohibited” dual-role testimony by case agents when the
prosecution needs to make use of the expertise of a case agent providing lay
testimony. See United States v. Moralez, 808 F.3d 362, 366 (8th Cir. 2015).
However, we have identified “several risks associated with dual-role testimony,”
including that:

      (1) the witness’s aura of credibility as an expert may inflate the
      credibility of her perception as a fact witness in the eyes of the jury;

      (2) opposing counsel is limited in cross-examining the witness due to
      the risk that an unsuccessful attempt to impeach her expertise will
      collaterally bolster the credibility of her fact testimony;

      (3) the witness may stray between roles, moving from the application of
      reliable methodologies into sweeping conclusions, thus violating the
      strictures of Daubert and Federal Rule of Evidence 702;

      (4) jurors may find it difficult to segregate these roles when weighing
      testimony and assessing the witness’s credibility; and

      (5) because experts may rely on and disclose hearsay for the purpose of
      explaining the basis of an expert opinion, there is a risk the witness may
      relay hearsay when switching to fact testimony.

Id. at 365 (citing United States v. Dukagjini, 326 F.3d 45, 53–54, 56–59 (2d Cir.
2003)).




                                         -5-
      “Ideally, the lay and expert testimony would be provided by separate
witnesses.” Id. at 366. When this is not possible, “district courts and counsel should
take appropriate measures to minimize the problems that may arise from dual-role
testimony by a case agent.” Id. One measure that is often appropriate is “bifurcating
the questioning,” but other measures may also be appropriate so long as “the
questioning and jury instructions sufficiently guard[] against the risks” associated
with dual-role testimony. Id.

      A. The Admission of Officer Girskis’s Dual-Role Testimony

        It is well-established that the district court “may allow law enforcement officers
to testify as experts about drug-related activities unfamiliar to most jurors,” including
“jargon used in the drug trade.” United States v. Lowe, 9 F.3d 43, 47 (8th Cir. 1993)
(cleaned up). However, the officer’s testimony should not “go beyond the plain
meaning of the recorded conversations.” United States v. Delpit, 94 F.3d 1134, 1145
(8th Cir. 1996) (cleaned up). The officer’s expert testimony may be inadmissible
when it pertains to ordinary language and “jurors can make a common sense
determination of the evidence without the technical aid of an expert.” See United
States v. Rodebaugh, 561 F.3d 864, 868 (8th Cir. 2009), vacated on other grounds sub
nom. Johnson v. United States, 558 U.S. 1144 (2010). The officer’s testimony also
may not rely “merely upon the hearsay testimony of non-witness drug dealers.”
United States v. Avalos, 817 F.3d 597, 601 (8th Cir. 2016) (quoting United States v.
Placensia, 352 F.3d 1157, 1165 (8th Cir. 2003)).

       We review the district court’s ruling on a motion in limine, and its admission
of expert testimony, for an abuse of discretion. See United States v. Fincher, 538
F.3d 868, 872 (8th Cir. 2008) (motions in limine); Avalos, 817 F.3d at 601
(expert testimony). An abuse of discretion occurs when a “relevant factor that should
have been given significant weight is not considered; when an irrelevant or improper
factor is considered and given significant weight; or when all proper factors, and no

                                           -6-
improper ones, are considered, but the court, in weighing those factors, commits a
clear error of judgment.” Moralez, 808 F.3d at 365 (cleaned up).

       In its pretrial motion in limine, defense counsel argued that Officer Girskis’s
anticipated testimony would “exceed the bounds of acceptable expert testimony”
because it “goes beyond interpreting code words and instead summarizes
Officer Girskis’s beliefs regarding the meaning of the conversations based on his
knowledge of the case [as a case agent].” Defense counsel asserted that “Officer
Girskis should be limited to interpreting individual code words. He should not be
allowed to provide an overall conclusion or interpretation of the meaning of
conversations.” The motion specifically requested “that the Court direct the
Government to clearly distinguish between when Officer Girskis is testifying as an
expert and when he is testifying as an investigator.”

       The district court denied the motion, noting that defense counsel had not
challenged Officer Girskis’s qualifications to testify as an expert and that “the
anticipated testimony and the method of the experience-based testimony interpreting
these cryptic phone calls is consistent with accepted expert testimony in drug
trafficking cases.” To the extent the dual-role testimony raised “concerns as to
confusion or otherwise,” the court stated that it would give an expert-testimony
instruction and anticipated that the government would “present the testimony in terms
of the lay witness testimony and the expert testimony in a concise and differentiated
way so that there’s no confusion on the basis for the witness’ testimony.”

      We perceive no abuse of discretion in this pretrial ruling. We have not
categorically prohibited dual-role testimony, and when that testimony is presented in
a “concise and differentiated way so that there’s no confusion,” it may be admissible.2


      2
       In its motion, the defense suggested that Officer Girskis’s “factual testimony
should be segregated from his expert testimony.” In denying the motion, the district

                                         -7-
       The problem is that the testimony at trial was not presented in a concise and
differentiated fashion. Portions of Officer Girskis’s testimony translated specific
pieces of drug code and slang terminology. For example, he testified that “plug”
meant “source”; “scratch” meant “money”; “65 ag” meant “$65 a gram”; and “little
babies” meant “heroin.” A properly qualified expert may testify about this type of
coded language to help the jury understand the world of drug trafficking, as the terms
may otherwise seem “nonsensical” to them. Avalos, 817 F.3d at 601. As the district
court noted, Overton did not object to Girskis’s qualifications as an expert in drug
trafficking, and his motion in limine requested that Girskis’s expert testimony be
limited to testimony of this type.

       Other portions of Officer Girskis’s testimony, however, purported to translate
non-coded English language and went beyond simply interpreting the words at issue.
For instance, Officer Girskis testified that “[t]his is the number that I am at” meant
“this is the number I currently have, I will be calling from this number when I need
more heroin.” He also testified that “[a]bout to get that paper like that” meant “about
to get all the paper from the heroin I’ve sold.” And he explained that “[t]his is just
goin[g] crazy. It’s been a lot and lot, going on” meant “[a] lot of people are getting
heroin, he’s selling this heroin, people are crazy about it, and lots going on like he’s
going to need some more.” This pattern of partially translating slang terminology,
partially translating ordinary English words, and partially providing opinions about



court relied on United States v. Moreland, 703 F.3d 976, 983–84 (7th Cir. 2012),
which suggested that it is not necessary to separate this testimony. We note that the
Seventh Circuit has since “clarif[ied]” its opinion in Moreland and instructed that
“[w]hen a district judge learns that the government intends to put on dual-role
testimony from a case agent, it should first encourage the government to present the
expert and lay testimony separately. ‘Seamlessly switching back-and-forth between
expert and fact testimony does little to stem the risks associated with dual-role
witnesses.’” United States v. Jett, 908 F.3d 252, 269 (7th Cir. 2018) (quoting United
States v. Jones, 763 F.3d 777, 803 (7th Cir. 2014)).

                                          -8-
the conversations that went beyond the words themselves, was repeated throughout
Officer Girskis’s testimony.

       This mixed testimony was presented to the jury in an undifferentiated form.
To the extent Officer Girskis’s opinions were based on his personal perceptions as an
investigator on the case, rather than on his expert training and experience, this was
never communicated to the jury, and Officer Girskis did not testify about any personal
perceptions on which his testimony was based. As a result, there was no way for the
jury or counsel—or now, us—to know whether the portions of Officer Girskis’s
testimony that went beyond the specific code words at issue were based on personal
perceptions or whether they were impermissibly based on hearsay statements. See
Avalos, 817 F.3d at 601 (“In cases involving coded drug phrases, [Rule 702] requires
that the expert base her opinion on personal experience and training and not merely
upon hearsay testimony of non-witness drug dealers.” (cleaned up)).

      The manner in which Officer Girskis’s testimony was presented highlights the
potential problems with offering this type of dual-role testimony. Testimony about
the meaning of drug-code jargon, if based on experience and training, is permissible
expert testimony. But Girskis’s testimony “about the meaning of conversations in
general, beyond the interpretation of code words” is an example of “how an expert
on drug code can stray from the scope of his expertise.” Dukagjini, 326 F.3d at 55.
And the jury was not given the necessary information to distinguish between the lay
and expert testimony. See Moralez, 808 F.3d at 366.

       We conclude that, while portions of Officer Girskis’s testimony constituted
admissible expert testimony, other portions did not. Dual-role testimony in a case
like this is “not categorically prohibited,” but “district courts and counsel should take
appropriate measures to minimize the problems that may arise from dual-role
testimony by a case agent.” Id. In this case, those problems were not sufficiently
minimized.

                                          -9-
      B. Harmless Error

      We must next consider whether this error was harmless. “An evidentiary error
is harmless when, after reviewing the entire record, this court determines that the
substantial rights of the defendant were unaffected, and that the error did not
influence or had only a slight influence on the verdict.” United States v. DeMarce,
564 F.3d 989, 997 (8th Cir. 2009). “Improper admission of evidence which is
cumulative of matters shown by admissible evidence is harmless error.” Wilson v.
City of Des Moines, 442 F.3d 637, 644 (8th Cir. 2006).

         We conclude that Officer Girskis’s improper testimony did not have more than
a slight influence on the jury’s verdict. Much of the testimony was cumulative of
matters shown by other evidence at trial. The text message and recorded calls were
properly admitted, and other witnesses shed light on their meaning. Smith testified
that “little baby” and “white boy” meant “heroin”; that “I need you to come through”
meant “I need a gram of heroin”; that “plug” meant “source”; and that $65 a gram was
a wholesale price for heroin. Officer Scott testified, without objection, that in one of
the calls “Overton [was] speaking to his nephew, Kearnice” and “telling Kearnice .
. . that he sold the heroin that he had and he can’t get in touch with Khiemonte Smith
and he needed more.”

       Smith also provided extensive testimony about Overton’s role in the
conspiracy. Smith explained that the organization was not selling heroin before
Overton came to town and that Overton “had business with more connects and . . .
clientele with the heroin”; that Kearnice purchased the heroin and provided it to
Smith, who in turn provided it to Overton; that Smith gave Overton a small quantity
at a time because he previously “ran off” with some of the heroin; that Smith
frequently delivered the heroin to Overton at an apartment complex called Spencer
Towers; that Overton was present on at least one occasion when Kearnice was
packaging the heroin; and that Overton sold the heroin to others. Lacey Schram

                                         -10-
testified that she purchased heroin from Overton on about three occasions, including
once at Spencer Towers. And Nicole Oaks testified that she purchased heroin from
Overton “[a] lot of times,” often at Spencer Towers.

      In light of the text message, recorded telephone calls, properly admitted
testimony interpreting these communications, extensive co-conspirator testimony, and
testimony from customers, we conclude that the evidentiary error was harmless. See
Delpit, 94 F.3d at 1145 (finding that an officer’s expert testimony was improper to
the extent it went “beyond the plain meaning of the recorded conversations,” but
affirming because the error was harmless (cleaned up)).

                         III. Sufficiency of the Evidence

       Next, Overton argues the evidence was insufficient to prove “either that [he]
conspired, or that [he] conspired to distribute at least 100 grams of heroin.”
“We review the sufficiency of the evidence de novo,” viewing the evidence in the
light most favorable to the verdict, and reversing “only if no reasonable jury could
have found the defendant guilty beyond a reasonable doubt.” See United States v.
Conway, 754 F.3d 580, 587 (8th Cir. 2014) (cleaned up). We conclude that, based
on the evidence described above, a reasonable jury could have found beyond a
reasonable doubt “(1) that there was a conspiracy, i.e., an agreement to distribute the
drugs; (2) that the defendant knew of the conspiracy; and (3) that the defendant
intentionally joined the conspiracy.” Id. (cleaned up).

        A reasonable jury could also have found that at least 100 grams of heroin was
reasonably foreseeable to Overton and within the scope of the conspiracy. See United
States v. Jimenez-Villasenor, 270 F.3d 554, 561 (8th Cir. 2001). Smith testified that
Overton set up an arrangement for at least 100 grams of heroin. Smith also testified
that, to get a price of $65 a gram, it would be necessary to purchase approximately
500 grams to 1,000 grams of heroin. Smith further stated that Overton was present

                                         -11-
while heroin was packaged at Kearnice’s residence. Officers later found approxi-
mately 600 grams of heroin buried in the backyard of that residence. Agent Bump
testified that this may be the largest quantity of heroin that has “ever been found at
one location in the Quad Cities.” This evidence was sufficient to enable a reasonable
jury to conclude that at least 100 grams of heroin was within the scope of the
conspiracy and that Overton could have reasonably foreseen the extent of the
conspiracy. See United States v. Foxx, 544 F.3d 943, 951 (8th Cir. 2008).

                         IV. The Buyer-Seller Instruction

       Overton also contends the district court erred by denying his request for an
instruction that a mere buyer-seller relationship does not establish a conspiracy to
distribute drugs. “We review the adequacy of instructions by considering them as a
whole, and we grant the district court broad discretion in formulating appropriate jury
instructions.” United States v. Hester, 140 F.3d 753, 757 (8th Cir. 1998).
“A defendant is entitled to an instruction explaining his defense theory if the request
is timely, the proffered instruction is supported by the evidence, and the instruction
correctly states the law.” Id.

       We have required a buyer-seller instruction where “there was evidence that the
defendant made only a single purchase of cocaine, that he had made no prior
agreement to purchase cocaine, and that he did not know the other alleged conspira-
tors prior to that single purchase.” See id. (citing United States v. Prieskorn, 658 F.2d
631, 636 (8th Cir. 1981)). By contrast, we have stated that the “instruction is not
appropriate when there is evidence of multiple drug transactions, as opposed to a
single, isolated sale.” Id.

      Here, the evidence showed that Overton had a close relationship with the other
members of Kearnice’s organization and that he obtained heroin from them on several
occasions. Witnesses also testified that he distributed heroin to multiple people.

                                          -12-
Although there was testimony that Overton used heroin and only received it in small
quantities, the district court did not abuse its discretion by concluding that a
buyer-seller instruction was not warranted by the evidence.

                     V. The Government’s Closing Argument

       Finally, Overton argues that a new trial is required because of improper
statements made by the prosecutor during closing arguments. Defense counsel did
not contemporaneously object to any of the prosecutor’s statements at trial, but did
file a motion for a new trial based on the prosecutor’s statements about calling the
DEA or U.S. Attorney’s office, as well as the prosecutor’s remarks about the case
agents’ backgrounds. Because there was no contemporaneous objection to these
statements at trial, they were reviewable by the district court for plain error. United
States v. Amaya, 731 F.3d 761, 764–65 (8th Cir. 2013). We review the district
court’s determination for an abuse of discretion. Id. at 765.

       The district court concluded that the prosecutor’s comments about calling the
DEA and U.S. Attorney’s office were “imprudent, but not improper,” and that the
remarks about the case agents’ backgrounds were not improper because they simply
restated uncontested evidence. Further, the district court found that these statements
were not prejudicial given the context in which they arose and the government’s
“strong” evidence at trial. We find no abuse of discretion in this ruling.

       Overton additionally argues, for the first time on appeal, that the prosecutor
misrepresented the evidence, stated facts not in evidence, and disparaged defense
counsel. Because defense counsel “did not object or otherwise bring these issues
before the trial court . . . we review for plain error.” See United States v. Littrell, 439
F.3d 875, 881 (8th Cir. 2006). Overton must show (1) an error, (2) that is plain, and
(3) that affects his substantial rights. United States v. Olano, 507 U.S. 725, 732
(1993). We will exercise our discretion to correct such an error only if it “seriously

                                           -13-
affects the fairness, integrity or public reputation of judicial proceedings.” Id.
(cleaned up).

        The statements that allegedly misrepresented evidence and stated facts not in
evidence were based on the government’s interpretation of the evidence at trial. “It
is not improper for the government to comment on its interpretation of the evidence.”
United States v. Jewell, 614 F.3d 911, 928 (8th Cir. 2010). To the extent the
prosecutor’s comments improperly “stray[ed] from the evidence and the reasonable
inferences that may be drawn from it,” see United States v. Robinson, 110 F.3d 1320,
1327 (8th Cir. 1997), we find no error that was so obvious as to seriously undermine
the fairness, integrity, or public reputation of judicial proceedings, see Littrell, 439
F.3d at 881–82.

      The statements that allegedly disparaged defense counsel arose when the
prosecutor argued that defense counsel had tried to show that Overton was a mere
user who never distributed drugs, but had “slipped” by admitting that Overton gave
Frank Barron heroin as rent for staying at Barron’s apartment. It is improper for the
government to “encourage the jury to focus on the conduct and role of [the defen-
dant’s] attorney rather than on the evidence of [the defendant’s] guilt.” United States
v. Holmes, 413 F.3d 770, 775 (8th Cir. 2005). The prosecutor’s statement that
defense counsel “slipped” could have improperly suggested to the jury that defense
counsel was trying to mislead them but was unable to keep her story straight.
However, the prosecutor also highlighted the evidence and reasons supporting his
argument that the defense’s theory of the case was inconsistent. When viewed in
context, these comments do not rise to the level of plain error affecting Overton’s
substantial rights. See United States v. Melton, 870 F.3d 830, 841 (8th Cir. 2017).

                                   VI. Conclusion

      For the foregoing reasons, the district court’s judgment is affirmed.
                      ______________________________

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