 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued December 8, 2015               Decided March 8, 2016

                        No. 14–3039

                UNITED STATES OF AMERICA,
                        APPELLEE

                              v.

                    SHERMAN MITCHELL,
                        APPELLANT


                 Consolidated with 14–3040


        Appeals from the United States District Court
                for the District of Columbia
                   (No. 1:12-cr-00258-2)


    Douglas J. Behr, appointed by the court, argued the cause
and filed the briefs for the appellant.

    Elizabeth H. Danello, Assistant United States Attorney,
argued the cause for the appellee. Vincent H. Cohen Jr.,
Acting United States Attorney, Elizabeth Trosman, John K.
Han and Stratton C. Strand, Assistant United States Attorneys,
were with her on brief.

   Before: HENDERSON and GRIFFITH, Circuit Judges, and
RANDOLPH, Senior Circuit Judge.
                               2
    Opinion for the Court filed by Circuit Judge HENDERSON.

     KAREN LECRAFT HENDERSON, Circuit Judge: Sherman
Mitchell (Mitchell) was convicted by jury of multiple counts of
drug crimes resulting from his role in a phencyclidine (PCP)
distribution ring. Mitchell challenges his convictions on
several grounds, including, inter alia, the government’s
purported failure to properly authenticate and demonstrate
chain of custody for PCP samples used to establish his guilt
and the district court’s alleged error in admitting summary
witness evidence. We reject his challenges and affirm his
convictions.

                      I.   BACKGROUND

                              A.

     In February 2012, the U.S. Drug Enforcement Agency
(DEA), led by Special Agent Jamey Tarrh (Tarrh), opened an
investigation into drug trafficking between California and the
District of Columbia focused on Mitchell and his associate,
Harvey Couser (Couser). In early May 2012, Mitchell moved
into an apartment at the Onyx on First (Onyx) in the District of
Columbia, which was leased by Mitchell’s half-brother,
Stephon. Although the apartment was leased in Stephon’s
name, either Mitchell or Couser paid the rent on the apartment
from June through November 2012 and Couser had apartment
keys Stephon had given him.

    Between May and August 2012, Mitchell took seven
roundtrip flights to Los Angeles, remaining there for short
periods each time. During every trip, one or more packages
were shipped via UPS to Mitchell’s apartment at the Onyx
from Los Angeles, with multiple packages addressed to “Jane
Mitchell”—“Jane” matching Mitchell’s mother’s given name.
The government did not seize any of the packages but DEA
                             3
agents observed Couser retrieving the packages addressed to
Jane Mitchell at the Onyx several times. Specifically, on
August 10, 2012, Tarrh’s team identified Couser entering the
Onyx and retrieving a package shipped from Los Angeles by
“James Campbell”—“James” matching Mitchell’s father’s
given name and “Campbell” matching Mitchell’s mother’s
surname—to Jane Mitchell at the Onyx. The August 10, 2012
package was labelled with a contact number corresponding to a
cell phone later seized from Couser.

                             B.

     Mitchell eventually moved to Los Angeles in late August
2012, where he resided in various hotels until his arrest in
February 2013. The shipments to the Onyx apartment from
Los Angeles continued, with Couser retrieving multiple
packages at the Onyx in September, October and November
2012. On November 24, two packages were shipped from
Los Angeles to the Onyx apartment for delivery on November
26. The two concierges at the Onyx, who cooperated with the
ongoing investigation, notified Tarrh of the delivery of the
packages. Tarrh asked the concierges not to deliver the
packages to Couser until he, Tarrh, gave them permission.
When Couser arrived at the Onyx to retrieve them, the
concierge on duty told Couser that no package addressed to
Mitchell’s apartment had been delivered that day. Couser
returned to the concierge desk a few hours later and again
requested the packages. The concierge again reported that no
packages had been delivered and, at that point, Couser handed
the concierge a cell phone to speak with Mitchell. Mitchell
identified himself and excitedly explained the importance of
the packages and asked her to contact Couser immediately
when the packages arrived.
                                  4
     While the delivery of the packages to Couser was delayed,
Tarrh obtained a warrant, picked up the two packages from the
Onyx and searched them. Inside the boxes, Tarrh found a
total of four 64-ounce apple juice bottles filled with amber
liquid. The bottles were delivered to Metropolitan Police
Department (MPD) Detective Joseph Abdalla (Abdalla), who
weighed the bottles, removed samples of the amber liquid from
each and prepared the bottles for controlled delivery by
refilling three of the bottles with tea and the remaining bottle
with a mixture of tea and a small amount of the amber liquid.
Following protocol, Abdalla then sent the remaining amber
liquid to the MPD property division for destruction. 1 Tarrh
repacked the two boxes and returned the boxes to the Onyx for
delivery. The next day, Mitchell telephoned the Onyx
manager hourly about the packages until they were picked up
by Couser once Tarrh had given permission to release them.

     When Couser returned to the Onyx to make the pick-up,
Tarrh arrested him as he left the building. Two cell phones
were recovered from Couser at that time. A subsequent
search of the Onyx apartment led to the seizure of a
money-counting machine, starter fluid, an oral syringe, a
funnel and empty half-ounce glass vials—all tools of the PCP
distribution trade.




     1
          The DEA laboratory subsequently tested the unmixed
sample of amber liquid removed from one of the bottles, weighing
1,470 grams, and determined that it contained 9.9 per cent PCP.
This amount sufficed to support Count II of the indictment. See
infra at 6; see also 21 U.S.C. § 841(b)(1)(A)(iv) (unlawful to possess
with intent to distribute “1 kilogram or more of a mixture or
substance containing a detectable amount of phencyclidine”).
                                5
                               C.

     Based on information obtained at Couser’s arrest, Tarrh
and his team executed an arrest warrant for Mitchell at a
Gardena, California hotel on February 6, 2013. 2 During
Mitchell’s arrest, DEA agents seized a scrap of paper from his
pocket with the name “Eric Gates” written on it. The agents
found four cell phones in Mitchell’s hotel room, one of which
displayed a text message with a UPS tracking number that was
open and visible to the agents, and another scrap of paper with
addresses for an “Eric Gates” in Gardena and a “Lisa Carter” in
the District of Columbia. Based on this information, Corporal
Dennis Reighard (Reighard) of the Prince George’s County
Police Department intercepted two packages from the Prince
George’s County UPS facility before the packages could be
delivered to the District addresses. Reighard seized the first
package—corresponding to the tracking number displayed on
Mitchell’s phone at the time of his arrest—on February 8,
2013. The package contained three 64-ounce bottles filled
with amber liquid. As he had done with the November 2012
package, Abdalla took samples from the bottles and the DEA
laboratory determined that the amber liquid in one of the
bottles, weighing 1,148 grams, contained 15.7 per cent PCP.
Reighard seized the second package—addressed to “Lisa
Carter” and shipped by “Eric Gates”—on February 12. This
package contained a 32-ounce bottle filled with amber liquid.
After Abdalla again removed a sample from the bottle, the
DEA laboratory determined that the bottle’s amber liquid,
weighing 776.7 grams, contained 15.9 per cent PCP.




    2
       The record does not explain the gap between Couser’s arrest
in November 2012 and Mitchell’s arrest in February 2013.
                              6
                              D.

     Reighard had also been involved with the seizure of a
package before the start of the DEA investigation. On July 1,
2011, Reighard took custody from the UPS facility in
Burtonsville, Maryland of a package that was addressed to the
mother of one of Mitchell’s children. The UPS security team
had opened the package and contacted Reighard because it was
leaking a substance with a strong odor the security team
believed to be PCP. The package contained two one-gallon
and four 64-ounce plastic bottles filled with amber liquid.
Reighard stored the unopened bottles at the Prince George’s
County Police Department until May 7, 2013, when the DEA
connected the tracking number for the July 1, 2011 package to
Mitchell. At that point, Abdalla removed a sample from each
of the six bottles and the DEA laboratory, after testing one
sample, found that the amber liquid from that bottle, weighing
482.8 grams, contained 13.9 per cent PCP.

                              E.

     On April 4, 2013, Mitchell and Couser were indicted on
one count (Count I) of conspiracy to possess with intent to
distribute one kilogram or more of a mixture or substance
containing PCP between February 2011 and February 2013 in
violation of 21 U.S.C. § 841(a)(1), (b)(1)(A)(iv) and 21 U.S.C.
§ 846 and one count (Count II) of possession with intent to
distribute, or aiding and abetting possession with intent to
distribute, one kilogram or more of a mixture or substance
containing PCP on November 27, 2012 in violation of 18
U.S.C. § 2(a) and 21 U.S.C. § 841(a)(1), (b)(1)(A)(iv). 3
Mitchell was further indicted on two counts of attempted

    3
        Mitchell and Couser were also indicted on two money
laundering counts that were dismissed pre-trial.
                               7
unlawful possession with intent to distribute, aiding and
abetting unlawful possession with intent to distribute or
attempting to cause unlawful possession with intent to
distribute one kilogram or more on February 8, 2013 (Count
III) and one hundred grams or more on February 12, 2013
(Count IV) of a mixture or substance containing PCP in
violation of 18 U.S.C. § 2 and 21 U.S.C. § 841(a)(1),
(b)(1)(A)(iv), (b)(1)(B)(iv). His jury trial lasted from October
1, 2013 through October 15, 2013. On October 21, 2013, the
jury found Couser not guilty on Counts I and II and found
Mitchell guilty on Counts I–IV. After denying Mitchell’s
motions for acquittal and for a new trial, the district court
sentenced Mitchell to life imprisonment and 120 months’
supervised release on Counts I–III and 360 months’
imprisonment and 96 months’ supervised release, to run
concurrently, on Count IV. Mitchell timely appealed. Our
jurisdiction arises under 28 U.S.C. § 1291.

                        II. ANALYSIS

     Mitchell raises multiple challenges to his conviction,
almost all of which are without merit and require no further
discussion. See, e.g., United States v. Hoover-Hankerson,
511 F.3d 164, 168 (D.C. Cir. 2007) (“[The defendants] present
a large number of issues on appeal, not all of which deserve
discussion.”); United States v. Thomas, 97 F.3d 1499, 1503
(D.C. Cir. 1996) (“Thomas’s remaining contentions do not
warrant discussion.     These have been considered and
rejected.”). We address only two arguments in full: the
government’s alleged failure to authenticate and prove chain of
custody for the samples of amber liquid the DEA tested for
PCP and the government’s use of a summary witness at the end
of its case-in-chief.
                                8
                    A. Chain of Custody

     Mitchell claims that the government failed to adequately
authenticate and prove chain of custody for the samples tested
at the DEA laboratory and used to show Mitchell’s
constructive possession of the PCP. Mitchell specifically
points to two related evidentiary gaps: (1) the government
allegedly failed to track, with specificity, the evidence from its
seizure by Tarrh or Reighard to Abdalla and thence to the DEA
laboratory; and (2) the government allegedly failed to
authenticate that the vials the DEA tested matched the samples
Abdalla collected. Because of these gaps, Mitchell argues,
the DEA laboratory evidence should have been excluded. We
disagree.

                               1.

     We review the trial court’s admissibility rulings for abuse
of discretion if the defendant made a timely objection and plain
error if the defendant did not. See United States v. Coumaris,
399 F.3d 343, 347 (D.C. Cir. 2005); see also FED. R. CRIM. P.
52(b). Mitchell claims that he objected to chain of custody
before DEA forensic chemist John Liu (Liu) testified and again
in his motion for acquittal. The first colloquy Mitchell relies
on involved an objection under the Confrontation Clause. 4
Sherri Tupik (Tupik), a DEA chemist, initially tested the 2012
and 2013 samples. Tupik was unavailable to testify at trial
and, consequently, the government enlisted Liu to retest the
samples, produce new reports and be available to testify
regarding his reports at trial. Mitchell claimed that he should
have had the opportunity to confront Tupik because Liu
allegedly relied on her reports in generating his reports and his

    4
       Mitchell does not raise a Confrontation Clause challenge to
the admissibility of the PCP testing reports on appeal.
                                  9
reports were the only ones introduced into evidence at trial.
Mitchell also claimed that there was inadequate chain of
custody evidence for the period between Tupik’s and Liu’s
reports. See, e.g., Oct. 9, 2013 Trial Tr. at 76 (“There is no
chain of custody for [Liu’s] reports, and so there is no way to
establish what drugs these were seized from.”); id. at 85
(“Because they have to prove chain of custody; otherwise,
there is no evidence whatsoever that these are the drugs that
were recovered on November 27th or sent to the DEA lab on
the 30th other than Agent Tupik’s report that we can’t
confront.”). Later, when the government moved to introduce
the reports into evidence during Liu’s direct testimony,
Mitchell objected to the reports relating to the 2012 and 2013
samples Liu retested. 5 In arguing Couser’s motion for
acquittal, Couser’s counsel claimed that “[t]here is absolutely
no chain of custody in connection with the” 2012 samples
taken by Abdalla and with Liu’s retesting reports. Oct. 10,
2013 Trial Tr. at 163–64. Mitchell’s counsel adopted
Couser’s “argument with respect to chain of custody.” Id. at
167.

     The government assumes without conceding that Mitchell
preserved a challenge to the chain of custody for the samples
Liu retested—the 2012 and 2013 samples—but claims that we
should review the chain-of-custody evidence of the 2011
samples for plain error. We need not determine the applicable
standard of review as we conclude that the district court did not
err—whether under an abuse of discretion standard or plain
error standard—in admitting Liu’s reports.



     5
        Mitchell did not object to the introduction of Liu’s report on
the 2011 samples because Liu was the only DEA chemist who tested
those samples.
                                 10
                                 2.

    “It is generally recognized that tangible objects become
admissible in evidence only when proof of their original
acquisition and subsequent custody forges their connection
with the accused and the criminal offense.” 6 United States v.
Mejia, 597 F.3d 1329, 1335 (D.C. Cir. 2010) (quoting Gass v.
United States, 416 F.2d 767, 770 n.8 (D.C. Cir. 1969)). The
government has the burden to demonstrate that the “item still is
what the [government] claims it to be.” Id. at 1336 (quoting 2
MCCORMICK ON EVID. § 213 (6th ed. 2009)). “In order for
evidence to be admissible, however, a complete chain of
custody need not always be proved.” United States v. Garcia,
757 F.3d 315, 319 (D.C. Cir. 2014) (internal quotation mark
omitted).     The proponent of the evidence need only
“demonstrate that, as a matter of reasonable probability,
possibilities of misidentification and adulteration have been
eliminated.” Mejia, 597 F.3d at 1336 (internal quotation
marks omitted). Once the evidence is admitted, a gap in the
chain of custody goes only to the weight given to the evidence
by the trier of fact. Garcia, 757 F.3d at 319; see also
Melendez-Diaz v. Massachusetts, 557 U.S. 305, 311 n.1 (2009)
(“[G]aps in the chain . . . normally go to the weight of the
evidence rather than its admissibility.”). “A break in the chain

     6
         Mitchell claims that there are both authentication and
chain-of-custody problems with the samples taken by Abdalla and
tested by Liu. Here, the authentication and chain-of-custody
concerns are one and the same—whether the samples tested by Liu
were the same as the amber liquid in the containers seized by Tarrh
and Reighard. We therefore proceed with a single chain-of-custody
analysis instead of separate chain-of-custody and authentication
analyses. Cf. FED. R. EVID. 901(a) (“To satisfy the requirement of
authenticating or identifying an item of evidence, the proponent must
produce evidence sufficient to support a finding that the item is what
the proponent claims it is.”).
                               11
of custody,” however, “can be serious enough that the district
court may abuse its discretion in admitting the evidence.”
Mejia, 597 F.3d at 1336. To assess an allegedly faulty chain
of custody, we look for “ample corroborative evidence as to
[the evidence’s] acquisition and subsequent custody.” Id.

     The information necessary for the government to prove
chain of custody is fairly clear. The government must
demonstrate that the jury could have “reasonably believe[d]”
that the amber liquid contained in the various packages seized
by Tarrh or Reighard was the same as the samples Liu tested.
Garcia, 757 F.3d at 319. The government must have
therefore traced the liquid from its seizure to its transfer to
Abdalla for sampling and then to the DEA laboratory for
testing.

     For the sample taken from the July 2011 package,
Reighard testified that he seized the package from the UPS
facility on July 1, 2011, and placed the contents (six bottles) in
a labelled storage bin at the Prince George’s County Police
Department. The bottles remained in storage there until May
7, 2013, when, Abdalla testified, he picked them up for
sampling. Abdalla stated that on that date he took samples
from all six bottles, gave each sample a separate exhibit
number and placed the samples into evidence bags labelled by
DEA Special Agent Andy Harris (Harris). Liu testified that
the DEA laboratory received the samples from Abdalla for
testing on May 9, 2013, he tested one of the samples and he
then created the report introduced at trial. For the four bottles
contained in the two packages seized in November 2012, Tarrh
testified that he retrieved them from the Onyx on November
26–27, 2012. Abdalla testified that either Tarrh or DEA
Agent Brian Mulcahy (Mulcahy), another member of the DEA
investigative team, delivered the packages to him for sampling
on November 27. Abdalla further testified that he took five
                               12
samples from the four bottles and put the samples in evidence
bags that Mulcahy then sealed and signed. Liu explained that
the laboratory received the samples on November 30, 2012,
that Tupik originally tested them in May 2013 and that he
retested them in October 2013 and prepared the reports
introduced into evidence. And finally, for the two February
2013 packages containing four bottles in toto, Reighard
testified that he seized one package from the UPS facility on
February 8 and 12, 2013, respectively. Again, Abdalla
testified that either Tarrh or Mulcahy then delivered the
packages to him, he sampled the four bottles, placed the
samples in evidence bags and gave the bags to Mulcahy to seal
and sign. Liu testified that the DEA laboratory received the
samples on February 13, 2013, and that he eventually retested
the samples and generated the reports introduced into
evidence. Liu explained that he generally used the same
procedures and analytical methods to test all samples.

     There are three gaps in the chain of custody for the
samples Liu either tested or retested. The government
concedes one of the gaps, Appellee’s Br. 51–52, namely, that it
presented no evidence to explain precisely how the sealed
evidence bags went from Abdalla to the DEA laboratory for
testing. Id. It argues, however, that the gap is “minor” and
goes to the weight, not admissibility, of the testing reports. Id.
at 52. We agree that this is a relatively minor gap in the chain
of custody. For all four sets of samples, the time lag between
Abdalla’s or Mulcahy’s sending the evidence bags to the DEA
laboratory and the laboratory’s receipt thereof was fairly
short—a few days at most. Further, the evidence bags were
signed and sealed and Liu testified that he checked evidence
bag seals for tampering before opening and retesting them.
Liu also explained that an evidence technician put information
about the evidence bags, including their date of delivery, into
an internal tracking system at the time of receipt and that Liu
                                 13
checked the bags against the tracking system information
before performing his analysis. We are thus convinced that
the government met its burden to show that “as a matter of
reasonable probability, possibilities of misidentification and
adulteration have been eliminated” for the evidence bags from
the time of their creation to their receipt by the DEA laboratory
for testing. Mejia, 597 F.3d at 1336 (quoting United States v.
Stewart, 104 F.3d 1377, 1383 (D.C. Cir. 1997)) (internal
quotation marks omitted).

      The other breaks in the chain of custody—the break
caused by Abdalla’s apparent failure to label his samples and
the lack of evidence regarding the creation of the evidence
bags 7 —present closer questions. During the sampling
process, Abdalla removed a one-ounce sample of amber liquid
from each seized bottle and placed it into a separate vial for
each sample. Abdalla then photographed the vial next to a
typewritten placard with identifying information; he did not,
however, label the vials themselves. Abdalla testified that
either he gave the one-ounce samples to Mulcahy to place into
the labeled evidence bags or, for the 2011 samples, he and
Harris prepared and sealed the evidence bags themselves.
Abdalla did not identify or authenticate the evidence bags at
trial. And although Mulcahy testified at trial, he also was not
asked about his preparation of the evidence bags. Liu,
however, identified the evidence bags that contained the
samples he tested. The government therefore failed to
introduce testimony establishing that the evidence bags
prepared by Abdalla or Mulcahy were the ones that contained
the samples tested by Liu—instead, Abdalla testified that he

    7
       The evidence bags Abdallah and Mulcahy prepared held the
sample vials. The record is unclear whether the evidence bags also
held the bottles used to ship the liquid, except for the four bottles
used for the November 2012 controlled delivery to Couser.
                                 14
matched the samples with the case numbers 8 given to him by
Tarrh and with the exhibit numbers Abdalla himself generated.
Liu then explained that generally he checked the evidence bags
against the DEA’s internal system to make sure he was testing
the sample with the correct case and exhibit numbers. Thus,
the only evidence linking the vials photographed by Abdalla to
the vials tested by Liu are the evidence bags themselves. 9
Mulcahy and Harris should have testified that the evidence
bags Liu authenticated were the same evidence bags they
prepared using the samples obtained from Abdalla. The
government thus failed to close this evidentiary gap.


     8
        The DEA assigns a case number to a particular investigation
and an exhibit number to a specific piece of evidence collected in the
course of that investigation.
     9
        Apart from the samples taken directly from the bottles in
2011, 2012 and 2013, there was a potential evidentiary problem with
a sample sent to the DEA laboratory that was purportedly removed
from the amber liquid/tea mixture created for the November 2012
controlled delivery. Abdalla failed to testify that he in fact removed
a sample from the mixture before the controlled delivery. The
government asks us to rely on a series of inferences based on the
timing of the DEA laboratory’s testing of the samples to confirm that
the specific report at issue corresponds to the mixed sample taken
from the 2012 package. We need not resolve this question because
the government met its chain-of-custody burden for the unmixed
2012 sample, see supra n.1, and therefore any error related to the
mixed sample would be harmless. See Garcia, 757 F.3d at 319
(“Like other evidentiary rulings, a district court’s decision to admit
evidence over a chain-of-custody objection is subject to harmless
error review.”); see also United States v. Johnson, 216 F.3d 1162,
1166 n.4 (D.C. Cir. 2000) (“[N]onconstitutional error is harmless if
it did not have ‘substantial and injurious effect or influence in
determining the jury’s verdict.’ ” (quoting Kotteakos v. United
States, 328 U.S. 750, 776 (1946))).
                                 15
     Nevertheless, we do not think these gaps mean that the
district court abused its discretion in admitting Liu’s reports
into evidence.      The government had the burden to
demonstrate that the jury could have “reasonably believe[d]”
that the samples tested by Liu were the samples prepared by
Abdalla. Garcia, 757 F.3d at 319. We believe the
government met its burden, albeit not with flying colors.
Abdalla testified that he matched each sample with its case
number and the specific bottle seized, as demonstrated by the
photographs showing the unlabeled sample next to an
identifying placard. Abdalla further stated that he transferred
the samples to Mulcahy to place into the evidence bags and the
evidence bags—which were themselves authenticated by Liu
and introduced into evidence—display identifying
information, including the case number, exhibit number, date
and location of acquisition of the sample and either Mulcahy’s
or Harris’s signature. 10 And Liu explained that he checked
the evidence bags against the DEA’s internal tracking system
for congruity and that the case and evidence numbers on the
reports matched those on the evidence bags and the placards.
This testimony and the use of identical case and exhibit
numbers provide “ample corroborative evidence as to [the
sample’s] acquisition and subsequent custody.” Mejia, 597
F.3d at 1336. The jury could have reasonably concluded that

     10
          Mitchell argues that the government forfeited any reliance
on the evidence bag labels as proof of chain of custody by failing to
discuss the labels during trial. But during a colloquy with the
district judge, the prosecution asserted that it relied on the case
number as it appeared throughout the evidence—including on the
placard in Abdalla’s photograph and on the evidence bags—to
connect the samples Abdalla prepared to the samples Liu tested.
Thus, even though the government did not explicitly use the labels as
proof of chain of custody, it did rely on the case number to establish
chain of custody.
                               16
the samples tested by Liu were the samples prepared by
Abdalla and packaged by Mulcahy—thus confirming a low
probability that the samples were misidentified or adulterated.
See generally id. at 1335–36. Although Mulcahy and Harris
should have presented testimony about their role in preparing
the evidence bags and Abdalla should have labelled the vials
themselves, we conclude that the gaps in the chain of custody
were not so substantial that the district court committed
reversible error in admitting Liu’s reports into evidence.

                   B. Summary Witness

     Mitchell also argues that the district court erred in
admitting portions of DEA Investigator Lisa Amoroso’s
(Amoroso) testimony as a summary witness. Mitchell claims
that Amoroso exceeded the proper scope of summary witness
testimony by improperly drawing conclusions and inferences
from earlier–introduced evidence based on her independent
investigation or personal opinion. Mitchell also claims the
district court’s failure to give a limiting instruction regarding
Amoroso’s testimony compounded the error. We find that
any such error was harmless.

                               1.

     To prove conspiracy, the prosecution relied on a series of
telephone calls allegedly made by Couser or Mitchell from
eight different phone numbers. Two numbers were tied to the
phones seized from Couser on his arrest and one was registered
in Mitchell’s name. Three numbers belonged to various
persons named “Michael” at addresses connected to Mitchell.
And two phone numbers were linked to default addresses
under the name “Michael Smith” or “Del Ta.” Amoroso’s
testimony focused on the introduction and explanation of an
exhibit—Exhibit 30—that summarized voluminous records of
all eight phone numbers. Exhibit 30 listed, in table form, the
                              17
owner and number of the phone initiating the call; 11 the date,
time and duration of the call; and the number of the recipient
phone and that phone’s owner and address.

      Before Amoroso testified, the prosecution and defense
disputed the admissibility of a preliminary version of Exhibit
30. That version included parentheticals next to the owner’s
name that connected certain phone numbers to Couser and
Mitchell even though those phones were registered either to
different names or to no name at all. The prosecution asserted
that it planned to establish links between the numbers and
Couser or Mitchell based on Amoroso’s analysis. The
defense objected to the introduction of a version of Exhibit 30
that included the parentheticals, particularly because the
parenthetical comments were derived from Amoroso’s own
interpretation and investigation. The defense agreed to
Exhibit 30 with the parentheticals removed and only the
registered owners listed—counsel for both defendants stated
that such a chart would be “consistent with what the records
show.” Oct. 9, 2013 Trial Tr. at 239; see also id. at 239–40
(Couser’s counsel stating “I would have no objection to the
column that contains [the] target name and the dialed
name . . . .”); id. at 241 (Mitchell’s counsel agreeing with
Couser’s “position with respect to the parentheticals”). The
government prepared a version of the table without the
parentheticals, producing the version of Exhibit 30 introduced
at trial.

    Amoroso then testified, connecting the relevant phone
numbers to Couser or Mitchell through a series of inferences.
Amoroso took the jury through each phone number at issue,
detailing how, based on the phone records and subscriber

    11
         The table listed the owner as “NONE NONE” if there was
no registered owner.
                               18
information, it could be tied to Couser or Mitchell. For
example, Amoroso testified that the eight phone numbers
could be linked to Couser or Mitchell because: (1) phones
associated with certain numbers were taken from Couser at the
time of his arrest; or (2) the number belonged to a person who
lived at Couser’s home address; 12 or (3) the number listed one
of Mitchell’s previous addresses or the Onyx apartment
complex; or (4) there was an unusually large number of calls
between the listed number and a number directly associated
with Couser or Mitchell at the time packages were being
shipped to the Onyx from Los Angeles. Amoroso also
explained that she had learned during her investigation that, for
the numbers registered to various Michaels, no one with that
name lived at the registered address at the relevant time.

     During cross-examination, Amoroso conceded that her
conclusions were not based on information about the persons
who in fact made the calls listed in Exhibit 30 but on the phone
records themselves and the registered names and addresses.
Amoroso also admitted that her information did not specify
which apartments in the relevant complexes were connected to
certain phone numbers.

                               2.

     At no point during Amoroso’s testimony did the defense
object to the scope of her testimony. When the government
moved to introduce Exhibit 30, the defense simply repeated its
earlier objections, one of which unnecessarily challenged the
content of the preliminary (and excluded) version of Exhibit
30—and was granted—and one involved hearsay statements

    12
         The number was registered to someone living at the same
street address as Couser but in an adjacent town where no such
address existed.
                                   19
regarding the phones seized from Couser. 13 Because Mitchell
failed to object to the scope of Amoroso’s testimony, we
review for plain error. 14 See United States v. Kayode, 254
F.3d 204, 212 (D.C. Cir. 2001); see also FED. R. CRIM. P.
52(b).

     Federal Rule of Evidence 1006 permits the use of a
“summary, chart, or calculation to prove the content of
voluminous writings, recordings, or photographs that cannot
be conveniently examined in court.” FED. R. EVID. 1006. A
summary “can help the jury organize and evaluate evidence
which is factually complex and fragmentally revealed in the
testimony of a multitude of witnesses throughout the trial.”
United States v. Lemire, 720 F.2d 1327, 1348 (D.C. Cir. 1983).
To be admissible, the summary must be “accurate and
nonprejudicial; and the witness who prepared the summary
should introduce it.” United States v. Fahnbulleh, 752 F.3d
470, 479 (D.C. Cir. 2014). The witness who prepared the

     13
          While testifying, Amoroso used the excluded version of
Exhibit 30 with parentheticals to refresh her recollection. That
version was not introduced into evidence. The defendants objected
to its use to refresh her recollection but the court denied the objection
because Mitchell had the opportunity to cross-examine Amoroso on
the basis of her knowledge. The defense also objected to Amoroso
testifying that certain phones were seized from Couser during his
arrest, claiming it was impermissible hearsay—the district court also
denied the objection. Mitchell does not challenge the hearsay
objection on appeal.
     14
          In his reply brief, Mitchell highlights statements made
during the Exhibit 30 colloquy purportedly sufficient to avoid plain
error review. See Reply Br. 20. Those statements were made in
the context of his challenge to the parentheticals used in the first
version of Exhibit 30. Mitchell did not raise a similar objection to
the version of Exhibit 30 admitted into evidence and did not object to
the scope of Amoroso’s testimony based on Exhibit 30.
                               20
summary may testify about how he prepared it. 15 See Lemire,
720 F.2d at 1347 (admitting “one witness’s summary of
evidence already presented by prior witnesses”).

     We have previously limited the government’s use of
summary evidence in particular situations. Id. at 1346–50
(permitting summary evidence but detailing problems such
evidence can raise). The government must first lay a
sufficient foundation for any summary evidence. See id. at
1349. The trial judge can issue a limiting instruction
regarding its use and cross-examination can expose
inaccuracies or unfair characterizations. See id. at 1348. The
summary “should not draw controversial inferences or
pronounce[] judgment,” id. at 1350, and we have found
overview testimony given at the beginning of the government’s
case-in-chief prejudicial in contexts inapplicable here. United
States v. Moore, 651 F.3d 30, 51–52 (D.C. Cir. 2011) (per
curiam).

     We conclude that even if the trial judge committed plain
error in admitting Amoroso’s summary testimony or by failing
to give a limiting instruction, any error was harmless.
Although the portion of Amoroso’s testimony that was based
on her personal investigations was detailed, Mitchell’s
cross-examination of Amoroso helps to allay any concern.
See Lemire, 720 F.2d at 1348 (“[A] full opportunity to
cross-examine . . . alleviat[es] any danger of inaccuracy or
unfair characterization.”). Amoroso inferred that certain
phone numbers were connected to Couser or Mitchell for
several reasons, including the frequency of calls to phones
registered to Mitchell or taken from Couser on his arrest and
the fact that phones were registered to addresses connected to
    15
        Our discussion is limited to a summary witness testifying
about charts prepared and introduced under Rule 1006 and does not
address summary witness testimony standing alone.
                              21
Couser or Mitchell but under different names. Amoroso
admitted that she did independent research in concluding that
no one living at those residences matched the name listed on
the registration information. The use of a summary witness’s
independent judgment, however, should be limited. See id. at
1349 (such testimony could allow “the subtle introduction of
otherwise inadmissible evidence” and could permit
government extra opportunity to summarize its case-in-chief
before closing argument “from the witness stand rather than
the counsel’s lect[e]rn”).

     Here, Amoroso’s independent investigation was fairly
minor—she simply confirmed that no one living at the address
to which the phone number was registered had the registered
name. And Mitchell’s cross-examination made clear that
Amoroso’s conclusions were based on her own inferences.
Amoroso admitted that the phone records showed only that
someone at one phone number called someone at another at a
specific time. Mitchell also elicited from Amoroso a
concession that her conclusions about the connection between
certain addresses and Mitchell or Couser were not as clear as
the prosecution implied on direct. Oct. 10, 2013 Trial Tr. at
151–53. Thus, even if Amoroso’s limited testimony about her
independent investigation was erroneously admitted, any error
was harmless given the scope of cross examination.

     Mitchell also argues that the trial judge plainly erred in
failing to give a limiting instruction after Amoroso’s summary
testimony. Appellant’s Br. 49–51 (citing United States v.
Smith, 601 F.3d 530, 541 (6th Cir. 2010), United States v.
Fullwood, 342 F.3d 409, 413 (5th Cir. 2003) and United States
v. Johnson, 54 F.3d 1150, 1160–61 (4th Cir. 1995)).
Whatever the merits of Mitchell’s plain error argument, any
error was again harmless. We have recognized that “[o]ne
danger” of summary testimony is that the “jury will treat the
                                 22
summary as additional evidence or as corroborative of the truth
of the underlying testimony” and, to meet the danger, have
characterized limiting instructions as “requisite.” Lemire, 720
F.2d at 1348. 16 Objections to summary evidence and voir dire
examination of a summary witness help protect against the risk
that “the jury might treat the summary [witness] as substantive
evidence.” Id. Here, the district court did exactly that—it
allowed Mitchell to challenge and limit Exhibit 30 before its
introduction into evidence and to conduct vigorous
cross-examination of Amoroso. Mitchell cannot show that
any inference Amoroso made “affected [Mitchell’s] substantial
rights” or “seriously affect[ed] the fairness, integrity or public
reputation of judicial proceedings,” United States v. Marcus,
560 U.S. 258, 262 (2010), as her testimony allowed the jury to
conclude, at most, that Mitchell attempted to hide his identity
by using multiple phones and aliases. But even this
conclusion does not supply the showing of prejudice or of a
miscarriage of justice required for reversal. Nguyen v. United
States, 539 U.S. 69, 84–85 (2003) (Rehnquist, C.J., dissenting)
(“[W]e exercise our power under Rule 52(b) sparingly . . . and
only in those circumstances in which a miscarriage of justice
would otherwise result.” (citations and internal quotation
marks omitted)).

    For the foregoing reasons, the judgment of the district
court is affirmed.

                                                        So ordered.




     16
          We appear to treat summary testimony and summary
exhibits differently regarding the necessity of limiting instructions.
See United States v. Weaver, 281 F.3d 228, 233 (D.C. Cir. 2002).
