United States Court of Appeals
                       For the First Circuit

No. 10-1930

                      UNITED STATES OF AMERICA,

                              Appellee,

                                 v.

                       WILLIAM VÁZQUEZ-RIVERA,

                        Defendant-Appellant.


           APPEAL FROM THE UNITED STATES DISTRICT COURT
                  FOR THE DISTRICT OF PUERTO RICO

              [Hon. José A. Fusté, U.S. District Judge]


                               Before

                    Torruella, Boudin, and Dyk,*
                          Circuit Judges.


     Martin G. Weinberg, with whom Kimberly Homan, were on brief
for appellant.
     Jenifer Y. Hernández-Vega, Assistant United States Attorney,
with whom Rosa Emilia Rodríguez-Vélez, United States Attorney,
Nelson Pérez-Sosa, Assistant United States Attorney, Chief,
Appellate Division, and Thomas F. Klumper, Assistant United States
Attorney, were on brief for appellee.



                          December 22, 2011




*
    Of the Federal Circuit, sitting by designation.
             TORRUELLA,    Circuit   Judge.       William    Vázquez-Rivera

("Vázquez") was charged with (1) possession of child pornography in

violation    of 18   U.S.C.   §   2252(a)(4)(B),    (2)    three   counts   of

transportation of child pornography via computer in interstate

and/or foreign commerce in violation of 18 U.S.C. § 2252(a)(1), and

(3) two counts related to use of the internet in order to transfer

obscene matters to an individual the appellant knowingly believed

to be under the age of sixteen in violation of 18 U.S.C. § 1470.1

On February 12, 2010, a jury found Vázquez guilty of all counts

against him.      Vázquez now appeals his conviction mainly on the

grounds that the government's conduct and use of improper testimony

at trial warrant the reversal of his conviction.               In addition,

Vázquez claims that the district court erroneously refused to admit

parts   of   an   investigative   form     memorializing    portions   of   an

interview with his son that he alleges contained exculpatory

evidence.     Vázquez also argues that the prosecution made improper

remarks during its opening statement and closing argument that

constituted prejudicial plain error.          We agree with Vázquez that

the prosecution's case against him at trial extensively relied on

improper testimony.       Accordingly, we reverse and vacate Vázquez's

conviction.




1
    The indictment against Vázquez also included a forfeiture
allegation under 18 U.S.C. § 2253.

                                     -2-
                   I.   Background and Procedural History

              In   April    2008,    Agents   of    the   Federal   Bureau   of

Investigation ("FBI") began an operation in which they went online

posing   as    a   Puerto    Rican    fourteen-year-old     girl.     Entering

LatinChat.com, a Spanish speaking chatroom, Special Agent Edward

Cabral ("Agent Cabral") and Special Agent Christine Segarra ("Agent

Segarra") went undercover using the screen name "Patsychula14."2

Agent Cabral served in an advisory role, while Agent Segarra

assumed the Patsychula14 identity.                 On April 16, 2008, Agent

Segarra was online as Patsychula14 when an individual using the

screen name "IncestoPR" initiated an online conversation with her.

IncestoPR inquired about her age -- which Agent Segarra said was

fourteen -- and chatted about subjects including incest and sexual

relationships between adults and minors. IncestoPR eventually gave

Patsychula14 his email address, bienhotpr@hotmail.com,3 and the

chat continued on MSN Messenger, an instant messaging program, with

IncestoPR now communicating with the screen name "Secreto."4




2
    The screen name is a combination of "Patsy," the online
persona's nickname, the word "chula," which translates to English
as "sexy" or "cute," and "Patsy's" age -- i.e., fourteen.
3
   "Bienhotpr" may be translated as "'very' hot pr," with "pr"
being a likely reference to Puerto Rico.
4
   "IncestoPR" translates from Spanish as "IncestPR," with "PR"
again being a likely reference to Puerto Rico.      In Spanish,
"Secreto" means "Secret."

                                       -3-
           Over    the    course      of    the   next   three   months,   Secreto

initiated eight chat sessions with Patsychula14. Secreto discussed

sexual   themes    and    sent   Patsychula14       pictures     depicting   child

pornography.      During a messaging session on June 5, 2008, Secreto

also sent Patsychula14 a webcam video of a man masturbating, which

Secreto said was himself.          In the video, Agent Segarra and Agent

Cabral were able to see a man wearing red flannel pajamas, his

hands and genitalia, and part of the room in the background.

However, the agents were not able to see the man's face.

           In a final chat session on July 2, 2008, Patsychula14

asked Secreto if he resided in Camuy, Puerto Rico, which Secreto

then acknowledged. Agent Segarra also asked if Secreto's real name

was "William," to which Secreto responded "no . . . José."                 Secreto

then ceased all communication.

           As part of its investigation, the FBI issued a subpoena

to   Microsoft    in     order   to    obtain     the    subscriber   information

corresponding     to     the   bienhotpr@hotmail.com         email    address   and

associated internet protocol ("IP") address.5                    Armed with the

relevant IP address, agents subpoenaed Liberty Cable, the address's

owner, requesting additional subscriber and account information.




5
   "An IP address is the unique address assigned to every machine
on the internet. An IP address consists of four numbers separated
by dots, e.g., 166.132.78.215." In re Pharmatrak, Inc., 

, 13 n.1 (1st Cir. 2003).

                                           -4-
This subpoena yielded Vázquez's name and an address in Camuy,

Puerto Rico.

             On August 22, 2008, FBI agents -- including Agent Cabral

and Agent     Segarra   --    executed   a   search   warrant    on    Vázquez's

residence.6       When the agents arrived, Vázquez answered the door

wearing red pajamas which testimony at trial suggested were similar

to   those    Agent   Cabral    and     Agent   Segarra   observed       in    the

masturbation webcam video Secreto had sent Patsychula14.                      Tile

found in the residence and a chair and filing cabinet found in

Vázquez's office also were similar to those Agent Cabral and Agent

Segarra observed in the webcam video.

             Computers seized at Vázquez's residence contained over

one-hundred images of child pornography –- including the two sent

to Patsychula14 –- as well as cartoons relating to incest found in

password-protected subdirectories labeled "William."                    Forensic

analysis     of   Vázquez's   primary    desktop   computer     showed    memory

relating to screen names "Secreto" and "IncestoPR."                   Two images

found on Vázquez's computer also matched two profile pictures used

during the chats.

             Based on this information, a grand jury returned an

indictment charging Vázquez with the above-referenced six counts.



6
   This was the second search warrant that the government executed
in connection with this investigation. A few days earlier, FBI
agents executed a search warrant on a residence they mistakenly
identified as belonging to Vázquez.

                                      -5-
Vázquez pled not guilty and a five-day jury trial was held in

February 2010.    Agent Cabral and Agent Segarra both testified as

two of the government's five witnesses.   Opening the government's

case against Vázquez, Agent Cabral described the steps taken in the

investigation.    The government then called Microsoft and Liberty

Cable custodians, who testified on the subscriber information and

company records the government used to obtain a search warrant for

Vázquez's residence.     As the fourth government witness, Agent

Segarra then described the online sting operation in greater detail

and read transcripts of several chats she had with the individual

using the Secreto and IncestoPR screen names.        As the final

government witness, Agent Hesz Rivera, the FBI forensic examiner

who reviewed the seized computers, offered testimony regarding his

findings.    Among other evidence, the jury was allowed to see the

online conversations between Agent Segarra and Secreto, relevant

child pornography images, and the webcam video of the masturbation

incident.

            The defense focused its efforts on trying to show that

the prosecution could not conclusively link Vázquez to the chats

and contended that the government could not prove Vázquez knew the

home computers contained child pornography.   On direct, Vázquez's

wife offered testimony explaining that all four family members




                                -6-
residing in the home had access to the seized computers,7 including

the desktop computer containing the pictures sent to Patsychula14.

Vázquez's wife also testified that a housekeeper had keys to the

residence and that her children and her grandchildren -- including

a nineteen-year-old male named Mario and two older adult males

named José and Luis -- could access the home, even in the family's

absence.   During cross-examination of Agent Cabral, counsel also

presented evidence that various IP addresses were used to access

the email account used to communicate with the Patsychula14 decoy,

one of them registered to an owner by the name of José Acevedo.

Agent Cabral testified that the government did not investigate

these addresses.

           On February 12, 2010, the jury returned a verdict finding

Vázquez guilty as to all counts of the indictment.      This timely

appeal followed.

                          II.   Discussion

           Vázquez challenges his conviction on several grounds.

Vázquez's primary contention is that the district court erred when

it admitted much of Agent Segarra's testimony, which Vázquez

alleges was improper, and impermissible opinion regarding his

guilt. Vázquez also contends that the district court erred when it

did not admit portions of an FBI form related to an interview with



7
  Vázquez resided with his wife, his sixteen-year-old son, and his
ten-year-old daughter.

                                 -7-
Vázquez's son. Finally, Vázquez claims that statements made during

the prosecution's opening and closing remarks were improper and

amounted to plain error.          Because we agree with Vázquez that a

troublingly large amount of Agent Segarra's testimony was improper,

we reverse on those grounds and do not find it necessary to address

his other claims.       As we must, we consider the facts in the light

most favorable to the verdict.           United States v. Stevens, 

, 49 (1st Cir. 2011).

A.   Improper Overview Testimony

              Vázquez argues, based on several of our recent cases,

that   much    of   Agent   Segarra's     testimony    amounted   to   improper

overview testimony.         See, e.g., United States v. Meises, 

(1st Cir. 2011); United States v. Flores-de-Jesús, 

(1st     Cir. 2009); United States v. Casas, 

(1st Cir.

2004).      The     problematic   form    of   this   testimony   consists   of

declarations by a witness -- commonly a law enforcement officer

involved in the investigation at issue -- presented early during

trial to describe the government's general theory of the case. See

n.13 (noting such evidence "often provides

an anticipatory summary of the prosecution's case by previewing the

testimony of other witnesses").           We have denounced the use of this

kind of testimony "in which a government witness testifies about

the results of a criminal investigation, usually including aspects

of the investigation the witness did not participate in, before the


                                        -8-
government has presented evidence." United States v. Rosado-Pérez,

, 55 (1st Cir. 2010).   In doing so, we have noted that

the problems inherent in such testimony are patently clear "if the

evidence promised by the overview witness never materializes," but

have warned that even if the substance of the witness's preview is

later corroborated during trial, the overview testimony of a law

enforcement agent still represents a problematic "endorsement of

the veracity of the testimony that will follow."   

; see also 

(discussing this "imprimatur

problem" at length).8

          While our decision today in no way detracts from our

prior admonishments regarding overview testimony, we believe that



8
   Our cases have not, however, foreclosed the use of overviews
entirely.   Subject to the overarching precept that lay witness
testimony should be grounded on personal knowledge, we have
acknowledged "[t]here may be value in having a case agent describe
the course of his investigation in order to set the stage for the
testimony to come . . . ." 

. We
have also recognized that "if properly limited to constructing the
sequence of events in [an] investigation," an agent's testimony
"could be valuable to provide background information and to explain
how and why the agents even came to be involved with the particular
defendant." 

quotation marks omitted). Finally,
our cases have also recognized that the complexity of a given case
may play a role in helping to determine whether such descriptive
testimony is appropriate.      

involving money
laundering and tax evasion charges to note "we have explicitly
distinguished between the kind of 'overview' testimony that we
[have criticized]" and an IRS agent's testimony proffered as a
"'description   of   his  investigation'    into  the   defendant's
activities, which [was] based on personal knowledge" (citing United
States v. Hall, 

, 57 (1st Cir. 2006))); see also 

("summary testimony" introduced towards the end of
trial "permissible to summarize complex aspects of a case").

                               -9-
the trial declarations at issue here can be distinguished from the

ones we considered problematic in those cases.           In the instant

case, Agent Segarra took the stand as the government's penultimate

witness on the first day of a five-day trial and, as such, did not

"preview" the government's case.         See United States v. Hall, 

, 56-57 (1st Cir. 2006) (noting appellant's reliance on

cases discussing overview testimony "misplaced" where testimony in

question proffered "near the end of the government's case-in-

chief").   However, as we now explain, we still find that much of

Agent Segarra's testimony bore distinct and serious deficiencies

and should not have reached the jury.

B.   Agent Segarra's Improper Testimony

           Vázquez   challenges   six     specific   portions   of   Agent

Segarra's testimony.      Where counsel properly objected to and

preserved testimony for appellate review, we usually review for

abuse of discretion.    

.       However, because

defense counsel did not object to, or otherwise failed to preserve,

much of the testimony on which Vázquez now bases his appeal, we

review most of the challenged portions of Agent Segarra's testimony

only for plain error.     United States v. Flemmi, 

, 86

(1st Cir. 2005).     Where we review for plain error, we ascertain

whether "(1) an error occurred (2) which was clear or obvious and

which not only (3) affected [] substantial rights, but also (4)

seriously impaired the fairness, integrity, or public reputation of


                                  -10-
judicial proceedings."             

States v. Duarte, 

, 60 (1st Cir. 2001) (alterations omitted)).

              1.    Initial Identification Testimony

              Shortly after Agent Segarra took the stand during the

first day of trial, the prosecution asked her, with regards to the

investigation, whom the investigation identified as the individual

using the screen name "IncestoPR."                Agent Segarra responded:           "We

ended up identifying him as William Vazquez Rivera."                              At the

prosecution's request, Agent Segarra proceeded to describe the

conversations        that    she    had   with    IncestoPR     while    posing     as a

fourteen-year-old girl using the screen name Patsychula14.

              Although the defense did not object to these statements

at trial, Vázquez now claims that this testimony was admitted in

error.   We agree.         By identifying Vázquez as IncestoPR, the person

who "approached" Agent Segarra's online avatar and continued to

chat   with    her       using   the   Secreto     screen      name,    Agent    Segarra

addressed the ultimate issue before the jury: whether the conduct

the government observed on its end of the computer screen could be

imputed to Vázquez.          Because the government agents conducting the

investigation that led to Vázquez's arrest did not directly observe

the individual chatting with Agent Segarra, Vázquez's fate depended

on   whether       the   government       could   prove   to    the    jury     beyond   a

reasonable doubt that the evidence it had against him -- most of




                                           -11-
which was circumstantial in nature9 -- placed him at the other end

of these online conversations.    While ultimate issue opinions are

not always prohibited, lay testimony of this nature must comport

with the requirement that proffered testimony be helpful to the

jury.   See Fed. R. Evid. 701(b); see also United States v. García,

, 214 (2d Cir. 2005) ("If such broadly based opinion

testimony as to culpability were admissible under Rule 701, 'there

would be no need for the trial jury to review personally any

evidence at all.'" (quoting United States v. Grinage, 

,

750 (2d Cir. 2004)).    On these facts, we are compelled to reaffirm

our warning that lay opinions going to the ultimate issue will

rarely meet this requirement, "since the jury's opinion is as good

as the witness's."     United States v. Sanabria, 

05, 516

(1st Cir. 2011)(quoting Mitroff v. Xomox Corp., 

, 276

(6th Cir. 1986)).

           Agent Segarra's testimony was also improper because her

statements were based in large part on the overall investigation

rather than her personal observations.      See Fed. R. Evid. 602,

701(a); see also 

(noting "basic

principle in the Federal Rules of Evidence that witnesses, other


9
  At oral argument, the government correctly acknowledged that the
only piece of direct evidence introduced in the prosecution's case
against Vázquez came when Agent Segarra testified about what she
observed in the webcam video of the masturbation incident. As we
explain below, however, while portions of this testimony were
proper, we find that much of it amounted to improper identification
evidence not grounded in personal knowledge.

                                 -12-
than experts giving expert opinions, should testify from personal

knowledge").       Despite being closely involved in all aspects of the

underlying investigation, Agent Segarra never personally observed

Vázquez chatting on the seized computers on the mentioned dates,

nor, for example, was her testimony based on surveillance of the

premises that would place Vázquez inside the residence with the

computer at the time the chats occurred.                  Cf. 

-56 (concluding testimony proper where investigator

witness "went to [drug point] at least fifty times; and repeatedly

participated       in     video    and     personal      surveillance,      wiretap

surveillance, and controlled drug buys").

            The    only    opportunity      Agent   Segarra    had   to   directly

observe conduct at issue in Vázquez's trial came during the chat

she   had   with    Secreto   on    June    5,   2008.      During   that   online

conversation, Agent Segarra was able to observe the webcam video

that Secreto sent and discerned an adult male masturbating.

According to her later testimony, however, Agent Segarra was only

able to see the man's hands and genitals, as well as the red

pajamas he wore and parts of the room in the background.                     At no

point did Agent Segarra see the man's face, hear the man speak, or

otherwise observe distinguishing marks on the man's body.10                   Even


10
   At trial, the prosecution requested and received permission to
photograph Vázquez's "genital area and hands" for the purpose of
comparing any resulting pictures with the webcam video of the
masturbation incident. For reasons the record does not reveal, the
prosecution opted not to use these images.

                                         -13-
if that limited opportunity for personal observation would support

an identification of Vázquez as the individual in the video, her

purported identification was largely based on other evidence that

could   not    support     such   an   identification       based   on    personal

knowledge. Here, we cannot say that Agent Segarra's identification

testimony was "rationally based on the witness's perception" as the

evidentiary rules command.         Fed. R. Evid. 701(a).

              We   pause   to   highlight     a   related   concern      that   will

unfortunately surface again in our discussion infra. In responding

to the prosecutor's questions in the manner she did -- i.e., "we

ended up identifying [the subject] as William Vazquez Rivera" --

Agent Segarra implied that her comments expressed the combined

opinion of both her and other unidentified officers, based on the

totality of similarly-unidentified information gathered over the

course of the investigation, that the defendant on trial was the

person who sent the illicit material and was therefore guilty.                   We

stress our disapproval of such testimony at trial and agree with

the Second Circuit, writing in United States v. García, that:

              [W]hen an agent relies on the "entirety" or
              "totality" of information gathered in an
              investigation to offer a "lay opinion" as to a
              person's culpable role in a charged crime, he
              is not presenting the jury with the unique
              insights    of    [a    witness's]    personal
              perceptions. Thus, in such circumstances, the
              investigatory results reviewed by the agent --
              if admissible -- can only be presented to the
              jury for it to reach its own conclusion.



                                       -14-


, 212 (2d Cir. 2005) (internal citation omitted).   The

situation is all the more worrisome where, as here, an agent's

testimony appears to at least partly rest on the collective insight

of other unknown investigators who may not themselves be present at

trial.   While such a composite perspective is permissible in other

non-trial contexts,11 those circumstances are not delimited by the

trial-applicable Rule 701 requirement that lay opinion be based on

personal perceptions.12   See 

see also United States v.

Dukagjini, 

, 54 (2d Cir. 2003) ("As the testimony of [a]

case agent moves . . . to providing an overall conclusion of

criminal conduct, the process tends to more closely resemble the



11
   See, e.g., United States v. Lamela, 

, 104 n.5 (1st
Cir. 1991) (noting it is common in grand jury context for
government "to present an overview of the criminal investigation
through the testimony of the case agent, rather than through the
testimony of [] investigating officers").
12
    Referring to Agent Segarra's repeated use of the plural "we"
when speaking about the government's investigation and its results,
the government concedes that Agent Segarra "could have used a
better term."    Nevertheless, the government posits that Agent
Segarra's articulation in the plural was proper, as it accounted
for the fact that Agent Segarra conducted the investigation in
conjunction with Agent Cabral, who had already testified as a
government witness.    While plausible, the government's ex-post-
facto rationalization of Agent Segarra's use of the plural form is
unavailing. If Agent Segarra meant to allude to Agent Cabral or
his views in her testimony, this should have been made clear at
trial. Neither here nor in the exchanges we examine below did the
questioning Assistant U.S. Attorney seek to clarify this point
before the jury. Thus, when Agent Segarra represented that "we
concluded 'X'," she invoked the opinions of an unknown number of
additional agents without explaining what those opinions were or,
for that matter, whether they were grounded on personal perceptions
or on evidence before the jury.

                                -15-
grand jury practice, improper at trial, of a single agent simply

summarizing an investigation by other that is not part of the

record.").

           2.    Identification Testimony on Second Day of Trial

           During the course of the first and second days of trial,

Agent Segarra described the chats that she, posing as Patsychula14,

had with the individual using the screen name Secreto on the MSN

Messenger platform.          Agent Segarra's testimony during the second

day of trial focused on conversations she had with Secreto over the

course of several days during the spring of 2008.               Reading from

chat   transcripts      at    the   prosecution's   behest,    Agent   Segarra

narrated conversations of a strong sexual nature in which Secreto

repeatedly alluded to incest and sexual acts between adults and

children, sent several images containing child pornography, and

incited Patsychula14 to engage in sexual conversations over the

phone.

           After Agent Segarra read to the jury the text of chats

between Patsychula14 and the individual named Secreto on April 28,

2008, May 20, 2008, May 22, 2008, May 27, 2008, and May 29, 2008,

the prosecution sought to clarify that the person using the Secreto

screen    name     on        MSN    Messenger     was   also    behind    the

bienhotpr@hotmail.com email account and the IncestoPR screen name

used in the LatinChat.com chat room.            At this point, the following

exchange between the prosecutor and Agent Segarra took place:


                                       -16-
          Q: And just to make -- to clarify, IncestoPR
          is the same person as Secreto, correct?

          A: Correct.

          Q: And Secreto is the            same   person   at
          Bienhotpr@hotmail.com?

          A: Correct.

          Q: And throughout your investigation, who did
          you identify that person to be?

          . . . .

          A: We identified      him   as   William   Vazquez-
          Rivera.


          Counsel objected during this exchange on grounds that the

question had already been answered several times, but the district

court allowed the testimony, noting Agent Segarra could be cross-

examined on these statements.   Because Vázquez now challenges this

testimony on grounds that it was improper, we review for plain

error. See United States v. Ríos-Hernández, 

, 462 (1st

Cir. 2011) (concluding appellant's "argument in the district court

is sufficiently different from the one raised on appeal that the

argument is forfeited and will be reviewed for plain error").

          This testimony should not have reached the jury.      Again,

Agent Segarra's statements bear many of the deficiencies we have

already discussed.      Firstly, Agent Segarra's declaration that

Vázquez was identified as the person with whom she conversed as

Patsychula14 "throughout the investigation" expressed conclusions

about Vázquez's culpability, thus implicating the ultimate issue-

                                 -17-
variety Rule 701 concerns noted above.          Second, Agent Segarra's

testimony did not evince whether this identification was based on

evidence or testimony before the jury and appeared to subsume the

perceptions or insights of other agents into her testimony.               See

.

          3.    Testimony Related to Webcam Incident

          During the second day of trial, Agent Segarra described

another chat session between Patsychula14 and Secreto that took

place on the morning of June 5, 2008.        It was during this chat that

Secreto sent Patsychula14 an invite to view a webcam video.            Agent

Segarra   testified   that    after    she    accepted   the     invite    as

Patsychula14, she could observe an adult male masturbating.            Agent

Segarra also testified that she could observe "a five-star chair

and a floor. . . . part of a desk, a desk top drawer, and a file

drawer" that were later identified when federal agents executed the

search warrant on Vázquez's home.       This testimony was proper.

          The   prosecution   then    asked    Agent   Segarra   why   these

observations were important.         Over the defense's objections on

grounds that the importance of this testimony was the jury's

province, Agent Segarra responded:

          It was very important, because it helped us
          identify that this is where William Vazquez –-
          this office where William Vazquez utilized
          [sic] to send the video and other child
          pornography    pictures    in    the    search
          warrant. . . .
          In the office we noticed there was a [sic]
          same chair, and we also compared the pictures

                                 -18-
             of the search warrant with the video . . . .
             And that also helped us identify William
             Vazquez-Rivera.


             The prosecution then showed the video.             Agent Segarra

testified that in part of the video, it was possible to see an

"individual [] wearing red flannel pajamas, which were exactly the

same flannel pajamas that William Vazquez-Rivera was wearing the

day   that   we   arrived   at   his   residence     to   conduct   the   search

warrant."

             Because defense counsel did not object to this testimony

on the Rule 701 and overview grounds it now raises on appeal, we

review for plain error.          United States v. Capozzi, 

,

718 (1st Cir. 2007).

             We conclude that this testimony was plainly improper.

First, as before, Agent Segarra's testimony was not limited to

opinion that soundly followed from her perceptions.             Second, Agent

Segarra's    statement also       summarized   the    investigation       without

indicating that her testimony was based on evidence before the

jury.   Crucially, because the determination of whether Vázquez was

the man in the webcam video could have been properly reached only

by considering evidence available to the jury, Agent Segarra's

testimony also usurped the jury's role instead of being helpful to

it.   See 4 J. Weinstein & M. Berger, Weinstein's Federal Evidence

§ 701.05 (Joseph M. McLaughlin, ed., Matthew Bender 2d ed. 2011)

(testimony, the "sole function" of which is "to answer the same

                                       -19-
question     that    the    trier      of    fact   is    to    consider    in    its

deliberations. . . . [m]ay be excluded as unhelpful").

            In its brief, the government highlights the fact that

Agent Segarra was part of the group of agents that executed the

search warrant on Vázquez's residence and observed Vázquez wearing

"the same red flannel pajamas as in the masturbation incident."

The government also notes that Agent Segarra was able to observe

items and parts of Vázquez's residence that appeared similar to

those   that     could     be   seen    in   the    video.       Based     on    these

observations,       the    government        reasons     that    Agent     Segarra's

identification statements were based on her personal knowledge.

            Here, the government misses the point.                 Even if Agent

Segarra had some basis for personal observation, her testimony

clearly    relied    heavily     on    the   overall     investigation      and    the

conclusions reached by other agents.                 It was the prosecution's

burden to lay a foundation that established the basis of Agent

Segarra's knowledge or opinion in connection with all of her

testimony.      See Fed. R. Evid. 602, 701; see also 

("A foundation should be laid establishing the basis of

a   witness's    knowledge,      opinion,      or   expertise.").        While     the

prosecution appears to have laid an acceptable foundation for Agent

Segarra to testify about the steps taken in the investigation, the

online chats she had with the individual using the screen names

IncestoPR and Secreto, and the items, events, and clothing she


                                        -20-
observed while she executed the search warrant on Vázquez's home,

Agent Segarra's testimony as to Vázquez's identity, based on the

investigation as a whole, was clearly improper.

            4.     Testimony Related to Seizure of Desktop Computer

            After Agent Segarra described the evidence collected at

Vázquez's home, the prosecution inquired about the purpose of

seizing Vázquez's desktop computer.           Agent Segarra stated that

"[t]he purpose was to corroborate all the information that we

previously had from all the chats, and all the information we had

obtained from William Vazquez-Rivera."

            The prosecution then asked Agent Segarra if the seizure

of Vázquez's desktop computer achieved the described purpose, to

which the defense objected on hearsay grounds.            The trial judge

overruled the defense's objection, and the prosecution was allowed

to restate the question, now asking Agent Segarra whether, in her

opinion, the purpose of the seizure had been achieved. Once again,

the defense objected, now noting that Agent Segarra's opinion did

not constitute admissible evidence.          At the court's behest, the

prosecution rephrased its question and Agent Segarra testified that

the government achieved the seizure's intended purpose, at least in

part because forensic analysis of the seized computer yielded two

of   the   child    pornography   images   transmitted   during   the   chat

sessions.




                                    -21-
           To the extent Agent Segarra testified about the results

of the government's forensic analysis on the seized computers, it

appears she relied on information provided to her by FBI Agent and

computer analyst Hesz Rivera and thus predicated her statements on

hearsay.       However,    because      Agent   Rivera's   later     testimony

corroborated Agent Segarra's statements regarding forensic analysis

results, we conclude that any hearsay problem here was harmless

under review for either plain error or abuse of discretion.                See

United   States     v.   Piper,   

,   58   (1st    Cir.   2002)

("Cumulative evidence is typically regarded as harmless . . . .").

           5.   Later Identification Testimony Related to Webcam
           Video

           When Agent Segarra began to describe the video containing

the masturbation incident to the jury, the prosecution asked her:

"And throughout your investigation, do you identify who [the male

in the video] was?"       Agent Segarra answered: "Yes.           We identified

that person to be William Vazquez-Rivera."

           This testimony was admitted in error.            Without a doubt,

it purports to present Agent Segarra's opinion regarding Vázquez's

culpability based on the whole of the government's investigation

and, by relying on the plural "we," improperly alludes to unnamed

investigators' views without explaining what those were or whether

they were based upon the record in evidence or these investigators'

perceptions.      See 

.



                                     -22-
            6.   Prosecution's Redirect Examination of Agent Segarra

            Lastly, Vázquez alleges that a substantial portion of

Agent Segarra's testimony during redirect examination amounts to

plain   error.        Specifically,    Vázquez   takes    issue       with   the

prosecution's    questioning    regarding    each     online    chat    session

mentioned   in   Agent   Segarra's     testimony.     This     back-and-forth

between the prosecution and its witness went as follows:

            Q: Now, as of today, after having conducted
            the investigation, after having received all
            the information and having executed the search
            warrant, can you identify the person that you
            were chatting with on April 16 of 2008?

            A: Correct, with all the evidence we have
            gathered from the investigation, yes.

            Q: Who is that person?

            A: The person is William Vazquez-Rivera.

            Q: And on April 28, 2008.

            A: No.

            Q: Can you identify the          person    you     were
            chatting with as of today?

            A: Correct. If he is the holder of that IP
            address for Bienhotpr, yes, we could identify
            him back then.

            Q: And who is that?

            A: William Vazquez-Rivera.

            Q: And as of today, after gathering all the
            information and identifying the information,
            can you identify who you were chatting with on
            May 20, 2008?

            A: Yes.

                                      -23-
              Q: Who is that person?

              A: William Vazquez-Rivera.

              Q: And on May 22, 2008?

              A: Correct, William Vazquez-Rivera.

              Q: And May 27, 2008?

              A: Yes, William Vazquez-Rivera.

              Q: And May 29, 2008?

              A: Yes, William Vazquez-Rivera.

              Q: And May 30, 2008?

              A: Yes, William Vazquez-Rivera.

              Q: And on June 5, 2008?

              A: Yes, William Vazquez-Rivera.

              Q: And on that specific date, did you see any
              visual of William Vazquez-Rivera?

              A: Yes, I did.

              Q: What visual was that?

              A: I saw him masturbating via webcam, and we
              also saw the pajamas we were able to identify
              the day of the search warrant.

              Q: And on July 2nd, 2008, were you able to
              identify as of today who you were chatting
              with on that date?

              A: Yes, William Vazquez-Rivera.


All   told,    during   this   exchange,    Agent   Segarra   mentioned   the

defendant's name nine times, repeatedly identifying him as the




                                     -24-
individual responsible for the offending conduct –- the primary

issue disputed by Vázquez's defense at trial.

           This testimony is rife with the Rule 701-related dangers

we have already discussed at length above and in other prior cases.

Agent Segarra's statements here again run afoul of Rule 701's

demand   that   lay   opinion   testimony   be   "helpful   to   a   clear

understanding of the witness' testimony or the determination of a

fact at issue."       Fed. R. Evid. 701(b).      We have explained that

"[t]he nub of [Rule 701(b)'s] requirement is to exclude testimony

where the witness is no better suited than the jury to make the

judgment at issue, providing assurance against the admission of

opinions which would merely tell the jury what result to reach."

(internal citations and quotation marks

omitted); see also Lynch v. City of Boston, 

, 17 (1st

Cir. 1999).     Moreover, as should be clear by now, Agent Segarra

improperly relied on far more than her personal observations or

evidence already before the jury.

C.   Whether Improper Testimony Prejudiced Vázquez

           Having concluded that much of the challenged testimony

constituted obvious error, we must now assess whether Vázquez can

"surmount the high hurdle of plain error review and show that the

improper remarks affected the outcome of the trial." United States

v. (Feliciano)-Rodríguez, 

, 96 (1st Cir. 2008).            This

inquiry is "substantially similar" to the standard we follow in


                                  -25-
harmless      error   analysis,       with    the    added        wrinkle   that   "the

petitioner, not the government, 'bears the burden of persuasion

with respect to prejudice.'"           Ramírez-Burgos v. United States, 

, 29 (1st Cir. 2002) (quoting United States v. Olano, 

, 734 (1993)).          Surveying the government's case against

Vázquez, we must conclude that, in this case, wrongly-admitted

testimony disturbed the appellant's substantial rights.

              Undercover     investigations         in    which    agents   posing   as

minors "visit" a chat room or other online location where suspected

child predators       convene       have    become    a    common    tool   to   detect

individuals who would deign to engage in the reprehensible conduct

that child pornography laws proscribe. See, e.g., United States v.

Sims,   

,    950    (10th    Cir.       2005);    United   States   v.

Chriswell, 

, 460 (6th Cir. 2005); United States v.

Cherian, 58 Fed. Appx. 596, *1 (5th Cir. 2003).                      Because much of

the transgressive acts these investigations target are carried out

in private while the offender sits at a computer terminal, even

when agents are able to zero in on a suspect -- e.g., by matching

an internet account on record or an IP address with an account

holder's residential or physical address -- it may not always be

clear that he or she is actually responsible for the conduct that

agents observed on their screens.                 As the instant case suggests,

when the subject of the investigation communicates at all times

through an online alias or "screen name" and other persons have


                                           -26-
access to the computer used to communicate with undercover law

enforcement agents, it becomes all the more necessary for the

investigation to collect evidence, direct or circumstantial, that

will link the prohibited conduct to the defendant beyond a jury's

reasonable doubt.

            Here, the issue of identification was everything at

trial.     When the prosecution started its case against Vázquez it

was beyond cavil that, hiding behind the screen names "Secreto" and

"IncestoPR," someone discussed topics of a strong sexual nature

with and sent images containing child pornography to Patsychula14,

a decoy fourteen-year-old girl. It was similarly clear that during

one of those chats, Secreto invited Agent Segarra, posing as

Patsychula14, to view a webcam video depicting an adult male

masturbating. What the prosecution had to prove to the jury beyond

a reasonable doubt, however, was that the evidence the government

collected    supported   its   theory   that   Vázquez   was   behind   this

conduct.     Correspondingly, defense counsel undertook a strategy

designed to cast a shadow of doubt over the prosecution's claim

that Vázquez was culpable.       Prompted by counsel, Vázquez's wife

testified that others -- including, notably, other adult males --

had access to Vázquez's home and the seized computers during the

period the chats took place.        Pressed on cross-examination, the

agent supervising the investigation also acknowledged that the




                                   -27-
government did not investigate several IP addresses from which the

email account that corresponded with Patsychula14 was accessed.

              The jury was free to give these attempts to undermine the

prosecution's case as much credit as it desired. Although the case

against Vázquez was largely based on circumstantial evidence, the

jury was also free to assign the evidence against him as much

weight as it considered appropriate. See United States v. Gamache,

, 8 (1st Cir. 1998) ("[C]ircumstantial evidence, if it

meets   all    the    other   criteria   of   admissibility,   is    just   as

appropriate as direct evidence and is entitled to be given whatever

weight the jury deems it should be given . . . .").            Our concern,

however, is that the prosecution's repeated and extensive use of

improper testimony may have influenced the jury at the likely

expense of Vázquez's efforts to mount an adequate defense. Because

we do not find that the evidence against Vázquez was sufficiently

compelling to assuage this concern, we conclude it is highly

probable that the errors here affected the jury's verdict and find

that they unfairly impaired the integrity of Vázquez's trial.

                              III.     Conclusion

              For    the   foregoing     reasons,   we   vacate     Vázquez's

conviction.

              Vacated.




                                       -28-