United States Court of Appeals
                      For the First Circuit

No. 11-2271

                    UNITED STATES OF AMERICA,

                            Appellee,

                                v.

              HIPÓLITO DÍAZ-ARIAS, a/k/a HIPÓLITO,

                      Defendant, Appellant.


          APPEAL FROM THE UNITED STATES DISTRICT COURT
                FOR THE DISTRICT OF MASSACHUSETTS

          [Hon. George A. O'Toole, U.S. District Judge]


                              Before

                Torruella, Boudin,* and Thompson,
                         Circuit Judges.


     John F. Cicilline, for appellant.
     Theodore B. Heinrich, Assistant United States Attorney, with
whom Carmen M. Ortiz, United States Attorney, was on brief for
appellee.



                          April 29, 2013




*
  Judge Boudin heard oral argument in this matter and participated
in the semble, but he did not participate in the issuance of the
panel's opinion in this case. The remaining two panelists therefore
issued the opinion pursuant to 28 U.S.C. § 46(d).
            TORRUELLA, Circuit Judge.               Following a four-day jury

trial, Defendant-Appellant Hipólito Díaz-Arias was found guilty of

conspiring    to    distribute         cocaine,     in    violation      of   sections

841(a)(1) and 846 of Title 21 of the United States Code.                                He

received a sentence of 120 months' imprisonment to be followed by

a supervised release term of five years.                   Díaz-Arias now appeals

his conviction and sentence, claiming that the district court erred

in (1) permitting a non-expert witness to identify him as one of

the speakers in several wiretap recordings, which the government

introduced at trial to establish his involvement in the conspiracy;

(2)    allowing    the    jury    to    receive     the     transcripts       of   those

recordings, which were labeled with his first name, "Hipólito," in

order to identify him as one of the speakers; (3) allowing the

government to introduce evidence about his co-defendants' unrelated

drug    activity;    (4)    declining       to    give     the    jury   a    specific

instruction regarding any animosity they may have towards his race

and    ethnicity;    (5)    refusing       to     allow    the    jury   to    make     a

determination as to the specific drug quantity that could be

attributed   to     him    in    the   conspiracy;        and   (6)   finding,     by   a

preponderance of the evidence, that he was involved with five or

more kilograms of cocaine.               Finding no error in the district

court's actions, we affirm its judgment in all respects.




                                          -2-
                             I.     Background

          A.   The Indictment and Investigation

          On   July   27,   2005,    Díaz-Arias   and   twelve   other   co-

defendants were charged pursuant to a four-count, first superseding

indictment issued by a grand jury in the District of Massachusetts.

Díaz-Arias was only charged in Count One of the indictment, which

alleged that he participated in a conspiracy to distribute at least

five kilograms of cocaine, from January to October 2004, at various

locales within the District of Massachusetts.            Among the other

defendants who were charged in Count One were Manuel Pinales,

Rafael Heredia,1 Richard Pena and Tajh M. White.            The following

facts are recounted in the light most favorable to the verdict.

United States v. Poulin, 

, 18 (1st Cir. 2011).

          The charges brought against Díaz-Arias arose out of an

investigation conducted by the Drug Enforcement Administration

("DEA") during the summer and fall of 2004.             The focus of the

investigation was an organization involved in the distribution of

large quantities of cocaine in the Boston area. Manuel Pinales was

identified as the leader of the organization, receiving cocaine in

quantities of between 30 and 80 kilograms at a time from a source

of supply in the Dominican Republic.       Pinales and his cohorts then



1
   Heredia was also known as Luis Clas or "Cuba." During Díaz-
Arias' trial, the government referred to him as Luis Clas.    On
appeal, both parties refer to him in their briefs as Heredia. We
do the same here.

                                     -3-
distributed these drugs to customers in the Boston, New Bedford and

Lowell areas of Massachusetts, as well as to customers in Rhode

Island.    According to the results of the investigation, the core

members of the Pinales organization were Heredia, Rodríguez and

Pena.

            The DEA investigation relied on court-authorized wiretaps

on phones belonging to Pinales, Rodríguez, Pena and Heredia.                The

evidence submitted at trial against Díaz-Arias consisted primarily

of recordings of conversations between Pinales, Pena, Heredia and

a   man   referred   to   as   "Hipólito,"      whom   the   government   later

identified as Díaz-Arias.        The government also relied on several

"drug ledgers" that were seized on October 8, 2004, pursuant to

search warrants executed on 115 Navarre Street, where Heredia

maintained an inventory of cocaine, and at another location known

as the "Park Avenue Market," a grocery store run by Pinales.                The

government's position at trial was that the ledgers linked Díaz-

Arias (referred to in the ledgers as "Hipólito" or "H.P.") with

several kilograms of cocaine and thousands of dollars paid or owed

to the Pinales organization.         The wiretap recordings, which the

government    also   used   to   prove   that    Díaz-Arias    was   a   regular

customer of the Pinales organization, are discussed in more detail

below.




                                     -4-
            B.   The Wiretapped Conversations

            In July 2004, law enforcement agents began intercepting

several    telephone   calls   between   Hipólito,   Pinales,   Pena   and

Heredia.    These telephone calls depicted Hipólito attempting to

broker several drug transactions with Pinales, with Hipólito asking

Pinales to "give me some stuff" and later reminding Pinales "I owe

you seven and a half." The intercepted conversations also revealed

that the parties spoke in code, referring to kilograms of cocaine

as "cars" and money as "tickets."

            The low point for Hipólito came in the final days of

September, when one of his planned cocaine transactions with

Pinales went awry.      It all began on September 28, when agents

intercepted a telephone call where Hipólito told Pinales the

following: "so, tomorrow, I am going to send the guy over there

. . . to bring the tickets, the little tickets, yes, and so you

give him that."    Pinales responded, "[a]lright . . . [t]ell him to

call me, so that he meets up with Viejo . . ."2

            The next day, at 11:47 a.m., Alex Hernández, Hipólito's

courier, called Pinales and said: "I am Hipólito's guy.         I will, I

am going to call you . . . in a couple of minutes, do you hear?"

Pinales told Hernández that this was fine, but gave him another


2
    Trooper Cepero testified that, over the course of the
investigation, he concluded that "Viejo," which in this context
translates into English as "Old Man," was a reference to either
Heredia or Pena. In this particular call, the government posited
that Pinales was referring to Heredia.

                                   -5-
phone number and asked him to "[c]all him there."    An hour later,

Hernández placed a call to the phone number that Pinales gave him,

which turned out to belong to Heredia.   Hernández again identified

himself as "Hipólito's guy," and Heredia instructed him to "come by

here, by near here, by Hyde Park," where the "little store"3 was

located.   Hernández told Heredia that he would stop by there to

"pick up a pair of pants."   Heredia then called Pinales to ask what

he should give to Hernández, to which Pinales responded "the usual"

or "the complete one."   Massachusetts State Trooper Jaime Cepero,

who was eavesdropping on these calls while sitting in a wire room,

alerted surveillance officers that there was a person heading to

the Park Avenue Market to meet with Heredia, and that said person

was going to be receiving a kilogram of cocaine.

           At 1:00 p.m., several law enforcement officers, including

DEA Task Force Agent Kevin McDonough, were conducting surveillance

around the Park Avenue Market.     Twenty minutes later, McDonough

observed Heredia come out of the Park Avenue Market, wearing an

unzipped jacket.   As Heredia stood outside, a red Mustang pulled

over next to him, and he began to talk with the driver.     At that

point, Heredia entered the vehicle through the passenger door, and

the vehicle then proceeded down Hyde Park Avenue.   It stopped just

a few blocks away from 115 Navarre Street.     Heredia emerged from

the vehicle and entered a residence at that location.    One or two


3
    This is apparently a reference to the Park Avenue Market.

                                 -6-
minutes later, Heredia exited the residence, this time with his

jacket zipped up and his hands inside his pockets. Agent McDonough

perceived him to be holding something around his stomach area.

Heredia then traveled to the Mustang, reconvened with the driver,

and together they headed back to the area of the Park Avenue

Market.   Now back there, Heredia stepped out of the vehicle, and

the vehicle continued on its way.      The officers, including Agent

McDonough, proceeded to follow it in their unmarked cars.

          The red Mustang made its way through several streets in

Boston, eventually embarking on Interstate 93, northbound.       As

Agent McDonough was shadowing the vehicle, Trooper Cepero, who was

still in the wire room, contacted a nearby Massachusetts State

Police barracks to arrange for a marked police cruiser to stop the

Mustang. Trooper John Costa and Sergeant McCarthy, who were in the

area driving separate police cruisers, spotted the Mustang as it

was approaching the town of Wilmington, Massachusetts and ordered

it to pull over onto the hard shoulder lane.4    They identified the

driver as Alex Hernández and conducted a search of the vehicle

using trained canines.   The canines sniffed around the vehicle and

alerted the officers to an area under the rear of the passenger

seat; the officers inspected the floor around this area and found

a possible hidden compartment.   Hernández was placed under arrest,


4
   Trooper Costa testified that, at the time, the Mustang was
traveling over the speed limit and was following the vehicle in
front of it too closely.

                                 -7-
and the Mustang was towed to the Andover barracks, where an

inspection of the hidden compartment yielded a kilogram of cocaine.

            As   time   passed,   Hipólito    grew     anxious   awaiting

Hernández's arrival.     At 3:31 p.m., he called Pinales and asked

"[a]t what time did you guys give the car to the guy?"           Pinales

replied, "[a] while ago . . . [i]s he not answering the phone?"

"No, he is not answering now . . . [y]ou know how that is," said

Hipólito.    A worried Pinales then told Hipólito "[o]h, damn . . .

[b]ad sign . . . [t]here are problems there, bro . . . I hope . . .

God willing there are not . . ."        The two agreed that they would

wait and see what happened to Hernández, with Hipólito promising to

call Pinales as soon as he had news.

            At 4:57 p.m., Hipólito finally called Pinales and told

him: "[t]hey caught the man, dude." Dismayed, Pinales asked where,

and Hipólito replied, "in Andover."        Hipólito then told Pinales

that he was going to call someone to figure out what was going on.

Pinales and Hipólito spoke again on the phone at 7:39 p.m.       Pinales

warned Hipólito that "[i]t seems the friend is singing" to the

police, and Hipólito advised Pinales to change his phone numbers.

Almost two hours later, Hipólito called Pinales and told him that

he had spoken with Hernández's lawyer, who confirmed that the

police had "caught him with that, yes."              Several other phone

conversations between Hipólito and Pinales were intercepted on the




                                  -8-
following   day.     Those   recordings    mostly    featured   discussions

concerning the amount of Hernández's bail.

            C.   Jacqueline Fresa

            During trial, Trooper Costa testified that on October 2,

2004, he received a phone call from a woman who identified herself

as Jacqueline Fresa.       He testified that Fresa expressed anger at

the arrest of Hernández, and that she complained about receiving

threats, because "somebody had said that she was the informant that

had told the police about Hernández" and therefore was responsible

for his arrest. Fresa denied being the informant, but admitted she

knew Hernández.

            On the same day, Hipólito told Pinales over the phone

that, "[t]he mother of my daughters . . . I got told that . . . she

screwed me over."     "But which one of them, who?" asked Pinales.

"The one who was in jail, who came out," replied Hipólito.

Hipólito told Pinales that, shortly before Hernández was arrested,

"the mother of [his] daughters" had called Hernández to find out

where he was.      Hipólito then claimed that, as soon as Hernández

told her his location, "like five hundred showed up . . . she is a

rat[,] man . . ."    A few days later, on October 7, Hipólito called

Pinales again and told him that the mother of his daughters had

filed a restraining order against him.

            During   the   trial,   the   district   court   admitted   into

evidence certified birth records from the city of Haverhill,


                                    -9-
Massachusetts, which showed that Díaz-Arias and Fresa were in fact

the parents of two daughters.          In addition, the district court

admitted a certified record from the Haverhill District Court,

which   reflected   that    on   October   4,   2004,    Fresa   had   filed   a

restraining order against Díaz-Arias.           Thus, the government claims

that Fresa was the one Hipólito referred to as "the mother of [his]

daughters," and that this was conclusive evidence proving that

Hipólito was in fact Díaz-Arias.5

            D.   Arrest and Sentencing

            Díaz-Arias was arrested on October 22, 2004, in Lowell,

Massachusetts, while using the name of Carlos Santiago.                 He was

also known to use other aliases, such as "Junio Humberto Santana

Ortiz," "Raphael Ortiz Santino," "Guillermo Sánchez" and "José

Nieves."    Díaz-Arias was subsequently released on bail, but became

a fugitive when he was indicted on the federal drug charge.                    On

June 11, 2009, he was arrested in Lynn, Massachusetts.                 At that

time, the officers found Díaz-Arias to be in possession of a

Dominican   passport   in    the   name    of   Rafael   Bienvenido    Reynoso



5
   Fresa also testified at trial and identified Díaz-Arias as the
father of two of her three daughters. She stated that she knew
Hernández, that she was supposed to go out with him on the day he
was arrested, and that after learning of his arrest, she called the
Andover police station to complain about people commenting that she
was the informant who helped them apprehend Hernández.        Fresa
further testified that, later on, she asked Hipólito to "beat up"
Hernández in retribution for Hernández accusing her of being the
snitch. When Hipólito refused, Fresa took out a restraining order
against him.

                                    -10-
Hernández and a Social Security Card in the name of Rafael Matos

Bruno.

          The jury found Díaz-Arias guilty of participating in the

charged conspiracy.   At sentencing, the district court found, by a

preponderance of the evidence, that he was responsible for at least

five kilograms of cocaine and therefore subject to a mandatory

minimum sentence of ten years.         21 U.S.C. § 841(b)(1)(a)(ii)

(2006).   The court determined that the applicable guideline range

for Díaz-Arias, taking into account an offense level of 32 and a

criminal history category of III, was 151 to 188 months.    The court

nevertheless varied downward to reflect the culpability of Díaz-

Arias in comparison to the other defendants in the case and

sentenced Díaz-Arias to 120 months' imprisonment to be followed by

five years of supervised release.      This timely appeal followed.

                          II.   Discussion

          A.   The Voice Identification Testimony

          Díaz-Arias' main argument in this appeal is that the

district court abused its discretion when it allowed the government

to introduce the lay opinion testimony of Trooper Cepero, who

identified Díaz-Arias as the speaker in the intercepted telephone

conversations.    He contends that this testimony ran afoul of

Federal Rule of Evidence 701 for lay opinion testimony because it:

(1) was not helpful to the jury; (2) was not based on personal

knowledge; (3) constituted expert testimony masked as lay opinion;


                                -11-
and (4) was factually flawed.     The following background on Trooper

Cepero's testimony at trial will assist us in sorting through these

arguments.

                   1.   Background

            Trooper Cepero is a trooper with the Massachusetts State

Police, where he has served for approximately 30 years, primarily

in narcotics enforcement.       At trial, he testified that he has

fulfilled many roles there, including working undercover, serving

search warrants, doing surveillance and serving as affiant on

wiretaps.     He stated that he has participated in hundreds of

investigations, including over 30 that involved wiretaps.             He was

born in Puerto Rico, and Spanish is his native language; he

continues to speak Spanish fluently and uses it in connection with

his duties as a state trooper.           For example, he has used his

Spanish skills in several wiretap investigations involving Spanish

speakers.    He testified that he is familiar with individuals from

the   Dominican   Republic   (where   Díaz-Arias   is   from)   and   their

speaking intonations and accents.

            Trooper Cepero testified that he was a co-case agent on

the DEA investigation that led to Pinales' and Díaz-Arias' arrests.

During most of the investigation, Cepero was stationed in a "wire

room," overseeing and reviewing the audio of the intercepted

telephone calls from the day before, as well as the transcripts and

summaries of those calls.      Whenever a phone call was made to or


                                  -12-
from an intercepted phone line, the call would be recorded via

computer onto an optical disk that would contain the audio of the

call, the data furnished by the phone company, and any additional

comments    provided   by   the   officer    monitoring   the   call.     In

preparation for trial, Trooper Cepero copied the recorded calls

that involved Hipólito onto a separate optical disk and reviewed

the transcripts and translations of those recorded conversations.

The parties do not seem to dispute that the transcripts accurately

reflected    the   words    spoken   among   the   speakers,    which   were

translated from Spanish into English.

            During trial, the government introduced into evidence

Exhibits 26 and 27, which featured the recorded telephone calls

that involved "Hipólito" and the transcripts of those calls.

Trooper Cepero testified that he had reviewed all of those calls

with their companion transcripts, and assured that the transcripts

accurately identified the speakers and the words spoken.                 He

testified that he spent approximately "five or six hours" listening

to the calls in preparation for trial.

            In order to adequately compare the voice of "Hipólito" in

Exhibits 26 and 27 with the voice of Díaz-Arias, the prosecution

introduced Exhibit 41, a compact disk that contained at least 16

recorded telephone calls, which the parties stipulated were "recent

recordings of the defendant Hipólito Díaz-Arias' voice obtained by

lawful means."      Some of the recordings included conversations


                                     -13-
between Díaz-Arias and Fresa.               Trooper Cepero testified that he

spent about three hours listening to the calls in Exhibit 41 in

their entirety and went over some of them a couple of times.                      In

preparation for trial, he compared the voice of Díaz-Arias on

Exhibit 41 with the voice of Hipólito on Exhibit 27.                     In making

that comparison, Trooper Cepero testified that he took into account

several factors, including: (1) things that were unique to the

voice,   such      as   greetings,     laughter,   tone,     manner     and    speech

pattern;     (2)      certain     expressions   that   could      not   have    been

rehearsed;      (3)     certain     expressions    that    were    indicative      of

something the speaker did all the time; and (4) if the speaker

used, or responded to, his name, and whether the speaker referenced

to having spoken with someone else beforehand.                    Based on these

factors, Cepero testified that, in his opinion, the voices belonged

to   "the    same     gentleman,     same   voice."       Díaz-Arias    lodged    an

objection to this testimony, but it was overruled by the district

court.      He now renews his objection to the admission of the lay

opinion testimony before us, which we review for manifest abuse of

discretion.     United States v. Valdivia, 

, 50 (1st Cir.

2012).

                        2.   Helpfulness to the Jury

             Díaz-Arias claims that the proffered testimony by Trooper

Cepero was not helpful to the jury because the jurors were just as

capable as Trooper Cepero of comparing the voice of Hipólito with


                                        -14-
that of Díaz-Arias.    We disagree.    In order for lay opinion

testimony to be admissible under Federal Rule of Evidence 701, the

testimony must be "helpful to clearly understanding the witness'

testimony or to determining a fact in issue."      Fed. R. Evid.

701(b); United States v. Flores-de Jesús, 

, 20 (1st Cir.

2009).

          Lay opinion testimony will not be "helpful" to the jury

"when the jury can readily draw the necessary inferences and

conclusions without the aid of the opinion."     United States v.

Sanabria, 

, 515 (1st Cir. 2011) (quoting Lynch v. City

of Boston, 

, 17 (1st Cir. 1999))(emphasis added).   The

"nub" of this "helpfulness" 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."

United States v. Meises, 

, 16 (1st Cir. 2011) (internal

quotations and citations omitted); see also United States v.

Vázquez-Rivera, 

, 361 (1st Cir. 2011) ("[T]estimony,

the 'sole function' of which is 'to answer the same question that

the trier of fact is to consider in its deliberations . . . [m]ay

be excluded as unhelpful.'") (quoting 4 J. Weinstein & M. Berger,

Weinstein's Federal Evidence § 701.05 (Joseph M. McLaughlin, ed.,

Matthew Bender 2d ed. 2011)).    We are mindful that lay opinions

which make an assertion as to the ultimate issue in a case "will


                                -15-
rarely meet the requirement of Rule 701(b), since the jury's

opinion is as good as the witness's."         United States v. Rodríguez-

Adorno, 

, 39 (1st Cir. 2012) (internal quotations and

citation omitted).

           Díaz-Arias contends that Trooper Cepero's opinion was

just as good as the jury's because Trooper Cepero had never spoken

with Díaz-Arias in person. Furthermore, the testimony in question

went directly to the ultimate issue: it asserted that Díaz-Arias

was the speaker in the recordings, thus identifying him as the

guilty party and leaving no room for the jury to draw its own

conclusions as to what the evidence established.         The government,

for its part, argues that Trooper Cepero's testimony was helpful to

the jury because, as a native Spanish speaker who is familiar with

the intonations and accents of people from the Dominican Republic,

Trooper Cepero possessed particularized knowledge which may have

proven helpful to a reasonable juror in making a voice comparison

of a native Spanish speaker. The government calls our attention to

United States v. Ayala, No. 09-CR-0138, 

, at *2

(N.D. Okla. Aug. 24, 2010), where the district court for the

Northern District of Oklahoma allowed the lay opinion testimony of

an   interpreter   who   made   a   voice   identification   of   a   Spanish

speaking defendant.

           We agree with the government that, in this particular

case, Trooper Cepero's testimony should have proven useful to the


                                     -16-
jury in identifying Díaz-Arias' voice.            Given the fact that the

wiretapped conversations were in Spanish, the district court did

not abuse its discretion by determining that the jury may not have

been able to readily draw the inferences and conclusions necessary

to identify Díaz-Arias' voice, in the absence of Trooper Cepero's

testimony.       Díaz-Arias    can   point   to   no   evidence   that   this

particular jury, sitting in Massachusetts, possessed the same

mastery of the Spanish language as did Trooper Cepero, who is a

native speaker familiar with the particular accents, intonations

and speaking habits of persons from the Dominican Republic.6

Lacking this background, the jurors were in a less advantageous

position than Trooper Cepero was in making the voice comparison, as

they would have had trouble understanding the words being spoken

amongst the speakers and telling their voices apart.               This, in

turn, would have hampered their efforts to detect how specific

words were being repeated and vocalized by the speakers, to the

detriment of their efforts to make a voice comparison.

              The jurors also benefited from Trooper Cepero's guidance

in   making    their   voice   identification     because   Trooper   Cepero

testified as to the particularities they should look for, including

the speaker's unique intonation of certain words, greetings and



6
  It is irrelevant that Trooper Cepero had never spoken with Díaz-
Arias prior to trial, as the helpfulness of his testimony centers
upon his fluency in the Spanish language, and not on any contact he
may have had with Díaz-Arias beforehand.

                                     -17-
laughter.     Trooper Cepero was able to derive these indicators

thanks to the significant amount of hours he was able to devote,

before trial, to listening to and comparing the voices of Hipólito

and Díaz-Arias.     In this regard, Trooper Cepero's testimony may

have actually saved time for the jury.

            We conclude that Trooper Cepero and the jurors were not

in the same position when it came to comparing the voices in the

recordings, and therefore, the jury could have found the trooper's

testimony to be helpful.

                   3.     Personal Experience

            Federal Rule of Evidence 701 also requires that lay

opinion     testimony     be    "rationally   based    on   the      witness's

perception." Fed. R. Evid. 701(a). Díaz-Arias argues that Trooper

Cepero's testimony failed to comport with this requisite, because

Trooper Cepero allegedly based his identification of Díaz-Arias'

voice on information that was relayed to him from the other agents

working on the case.      Specifically, Díaz-Arias claims that Trooper

Cepero testified that he "coordinated" with the other agents in the

case and read their reports. Because Trooper Cepero never spoke to

Díaz-Arias in person, the argument goes, Trooper Cepero's lay

opinion was not based on personal knowledge, but rather resulted

from the overall investigation.

            We have repeatedly warned that "prosecutors should not

permit    investigators    to   give    overview   testimony,   in    which   a


                                       -18-
government witness testifies about the results of a criminal

investigation, usually including aspects of the investigation the

witness did not participate in . . . ." United States v. Rosado-

Pérez, 

, 55 (1st Cir. 2010).                Such testimony improperly

exposes the jury to conclusory statements that are not based on the

witness' personal knowledge, and which are unreliable because they

often consist of inadmissible hearsay evidence derived from other

government agents who participated in the investigation, but who

were never brought to testify at trial.                   See Flores-De Jesús, 569

F.3d at 19 (stating that, when a government witness expresses his

opinion as to a defendant's culpability based on the overall

results of an investigation, "these conclusory statements often

involve impermissible lay opinion testimony, without any basis in

personal   knowledge,        about    the    role    of     the    defendant     in   the

conspiracy.").

           We    are     satisfied          that      Trooper        Cepero's      voice

identification    testimony          was    squarely       based    on   his    personal

knowledge.      Díaz-Arias      claims       that,    during       cross-examination,

Trooper Cepero admitted that he worked with the other agents

participating    in    the    investigation          and    read    their      reports.

However, Trooper Cepero never said that his identification of Díaz-

Arias' voice was based on the contents of those reports or on his

interactions with the other agents, and Díaz-Arias' counsel did not

follow up on this line of questioning by asking Trooper Cepero


                                           -19-
whether he had in fact based his opinion on outside evidence.

Rather, a review of the testimony reveals that Trooper Cepero

adequately based his testimony on the knowledge he developed from

personally listening to, and analyzing, the recorded telephone

conversations of "Hipólito," as well as the stipulated audio

recordings containing exemplars of Díaz-Arias' voice.7 If a proper

foundation is laid establishing the basis of a government lay

witness' knowledge, opinion or expertise, then such a witness may

testify about matters within his personal knowledge and give lay

or, if qualified, expert opinion testimony. Rosado-Pérez, 605 F.3d

at 56.     This was clearly done in this case, as the prosecutor

properly      authenticated   Trooper    Cepero's      voice   identification

testimony, by having him testify at length about (1) the procedures

that   were    used   to   intercept    and   record    the    relevant   phone

conversations; (2) his experience handling wiretap investigations;

(3) his fluency in the Spanish language as a native speaker from

Puerto Rico who is familiar with the accents and intonations of



7
  Díaz-Arias' reliance on our decision in Vázquez-Rivera, 365 F.3d
at 361, is misplaced, because in that case, the government had
asked the government witness who the investigation had identified
as the culpable party, and the witness answered that it was the
defendant. We held that such testimony was improper under Rule 701
because the agent had never personally heard or observed the
defendant; instead, the agent based her testimony on the combined
perceptions of others.    This is not the case here, as Trooper
Cepero testified that he was familiar with Díaz-Arias' voice due to
the hours he spent listening to the admitted recordings, and based
his voice identification testimony on his own perceptions of those
recordings.

                                   -20-
individuals from the Dominican Republic; (4) his familiarity with

the voices present in the recordings, given the extent of his

preparation    before       trial   in    listening     to    them;      and    (5)   the

particularities he looked for in comparing the voices present in

the recordings.

            Therefore, we conclude that the voice identification

testimony was properly authenticated pursuant to Federal Rule of

Evidence 901, and that the content of this testimony was squarely

based on Trooper Cepero's personal knowledge.

                      4.    Lay vs. Expert Opinion

            Díaz-Arias' fourth challenge is that the district court

erred in allowing Trooper Cepero's voice identification testimony

as it did not comply with the requirements of Federal Rule of

Evidence    702,    which    governs      the    admission        of   expert   witness

testimony.         Specifically,     he    complains         that      the   government

attempted    to    portray     Trooper     Cepero      as    an     expert     in   voice

identification, by having him testify about his fluency in the

Spanish language and his familiarity with the accents of Spanish

speakers from the Dominican Republic.                  However, apart from this

impression,    Díaz-Arias       makes     no     attempt     to     explain     how   the

trooper's familiarity with the Spanish language constituted the

type   of   "specialized      knowledge         and   heightened        sophistication

normally associated with expert testimony."                       United States v.

Espinal-Almeida, 

, 614 (1st Cir. 2012) (ellipsis


                                         -21-
omitted).    Neither does he elaborate on how the methods used by

Trooper Cepero in making the voice comparison were unreliable or

how he was prejudiced by the district court's decision to allow the

testimony as lay, instead of expert, opinion. See United States v.

Hilario-Hilario, 

, 72 (1st Cir. 2008)("to succeed in

obtaining a reversal on appeal, a defendant must prove both an

abuse of discretion and prejudice.") (citing United States v.

Álvarez, 

, 85 (1st Cir. 1993), cert denied, 

(1993)).

            In addition, these arguments are irrelevant to the issues

presented by Trooper Cepero's testimony identifying Díaz-Arias as

the speaker in question.   During cross-examination, Trooper Cepero

clearly admitted that he was not an expert in voice identification,

and stated that the jury had as much expertise as he did in voice

recognition. Further, at the close of evidence, the district court

reminded the jurors that they were not obligated to accept his

testimony, and that they could disregard it if they concluded it

was unreliable or inadequately supported.     As a result, we cannot

conclude that the jurors were misled into thinking that Trooper

Cepero was an expert witness and that they needed to accord any

undue deference to his testimony. Accordingly, we find no abuse of

discretion here.




                                 -22-
                   5.    Factual Inconsistencies

           Díaz-Arias' final challenge to the admission of the voice

identification    testimony    is     that   the    testimony   was   factually

flawed.    He    makes   the   case    that,   in    the   recordings   of   the

wiretapped conversations, Hipólito represented that he was facing

certain events and circumstances in his life which are directly at

odds with the events and circumstances surrounding Díaz-Arias' life

in 2004.    Firstly, he notes that in the recordings, Hipólito

identified himself as being age 34 and that he was born in the

month of April.     Conversely, Díaz-Arias claims he is 41 years of

age and that his birthday falls on January 29.             Secondly, he notes

that in the recordings, Hipólito made reference to the "sacrifices"

he was making for "Angie," who presumably was his daughter.               Díaz-

Arias now claims that the evidence at trial revealed that he only

had three children, none of whom were named "Angie."              Thirdly, on

one of the calls, Hipólito mentioned that he had not been able to

see a certain woman, because she had put a restraining order on

him, and that this, in turn, had prevented him from seeing his

oldest daughter, whom he had raised.           Díaz-Arias argues that the

recording does not identify the woman as Jacqueline Fresa, that the

government did not elicit testimony from Fresa going to her efforts

to impede Díaz-Arias from seeing his oldest daughter, and that

Fresa's oldest daughter was in fact fathered by a man named Jason

Pina, which makes it extremely unlikely that Díaz-Arias would have


                                      -23-
been the one that raised her. Lastly, Díaz-Arias contends that the

speaker in the recordings was not clear on whether he had one or

more daughters with the woman he spoke about.

            Having thoroughly reviewed the record, including Díaz-

Arias' smorgasbord of aliases and liaisons, we are convinced that

a reasonable jury may still have elected to credit Trooper Cepero's

testimony, despite these seeming inconsistencies. In fact, many of

the inconsistencies cited by Díaz-Arias are not inconsistencies at

all.    First of all, the Presentence Report (PSR) lists Díaz-Arias

as having been born on January 29, 1971.            In the summer and fall of

2004, Díaz-Arias would have been 33 years old, turning 34 the

following year.     In his brief, he states that he is 41 years old,

but that probably refers to his age in 2012, when the brief was

written.    That said, there is a valid question as to the month of

his birthday, January vs. April, but the record in this case

establishes that Díaz-Arias was an avid user of false identities,

which   allowed    him   to   assume   several     false   dates   of   birth.

Therefore, a reasonable jury would have acted well within in its

discretion    in   concluding     that        Díaz-Arias   was   merely   being

untruthful when he asserted that he "was 34 years old as of April."

It was also free to surmise that Díaz-Arias' true date of birth was

not conclusively established at trial.

            Likewise, Díaz-Arias' assertion that he only had three

daughters, none of whom were named "Angie," is unsupported by the


                                       -24-
record.   First of all, the record indicates that it was Fresa, and

not Díaz-Arias, who testified that she only had three daughters,

two with Díaz-Arias and one with Jason Pina.        Second, having

reviewed the pertinent transcripts, it is apparent to us that

Hipólito never explicitly stated that he had procreated "Angie"

with the woman who placed the restraining order against him, and

whom the government argued was Fresa.    Hipólito only appeared to

mention that he had raised "Angie" and that the woman in question

had taken her away from him.   Third, there was evidence that Díaz-

Arias had romantic relationships with other women, and so the jury

could have inferred that "Angie" was another one of Díaz-Arias'

daughters, procreated with someone other than Fresa.   In fact, the

PSR noted that Díaz-Arias reported having four other children,

including two with Angie Christo, one of his former girlfriends. In

any case, it is difficult to argue that the reference to "Angie"

could have created any reasonable doubt within the minds of the

jurors while evaluating the sufficiency of the evidence against

Díaz-Arias.

           We are similarly unpersuaded by Díaz-Arias' remaining

arguments, to the effect that the recordings did not identify Fresa

as the woman who had placed the restraining order against him. The

content of the recorded phone conversations, Fresa's testimony, and

the admission of the restraining order itself (which was filed only

a few days before Hipólito referred to it in the recordings) as


                                -25-
well as the other evidence presented at trial, comprised enough

circumstantial evidence for the jury to conclude that it was Fresa

who   filed   the   restraining        order   against    "Hipólito."         Any

uncertainty as to the amount of children Hipólito had with Fresa is

minimal compared      to   the    corroborating      circumstantial evidence

presented at trial, which strongly indicated that Hipólito was

indeed Díaz-Arias.     Moreover, it is the prerogative of the jury to

"choose between varying interpretations of the evidence."                 United

States v. Sánchez-Badillo, 

, 32 (1st Cir. 2008)(citing

United States v. Wilder, 

, 7 (1st Cir. 2008)); see also

United States v. Rodríguez-Durán, 

, 758 (1st Cir. 2007)

("The government need not succeed in eliminating every possible

theory   consistent    with      the   defendant's    innocence   .   .   .   and

circumstantial evidence alone may be sufficient to provide a basis

for conviction." (internal quotations and citations omitted));

United States v. Martínez, 

, 923 (1st Cir. 1991)("The

evidence need not exclude every reasonable hypothesis inconsistent

with guilt, and the jury is entitled to choose among varying

interpretations of the evidence so long as the interpretation it

chooses is a reasonable one.").

           Based on the foregoing, we find that the district court

did not abuse its discretion in allowing Trooper Cepero’s voice

identification testimony.




                                       -26-
          B.   Labeling of Transcripts

          Díaz-Arias' second argument is that the district court

abused its discretion when it allowed the government to provide the

jury with transcripts of the intercepted phone conversations which

identified one of the speakers by his first name, i.e. Hipólito.

                  1.   Background

          On July 25, 2011, Díaz-Arias filed a motion in limine

aimed at precluding the government from introducing the transcripts

of the wiretapped conversations it prepared, because one of the

speakers was labeled as "Hipólito."    After hearing arguments, the

district court ruled that the transcripts could be used as the

government proposed, "with the caution to the jury that it's a

point the government has to prove, not only to identify who the

speaker is but that, in fact, it is the defendant."

          At trial, Díaz-Arias requested a limiting instruction

when the government began playing the recorded telephone calls and

providing the jury with the transcripts.       The district court

imparted the following instruction:

          Let me just tell the jurors that the
          government's labeled these conversations, and
          the transcripts have been prepared, obviously,
          from their point of view as to who the
          speakers are and what their names are and so
          on and so forth. Ultimately, that's your
          judgment to make, whether those people are who
          are actually recorded on the matter to the
          extent it's important. Particularly, the
          person identified as Hipólito. You'll have to
          decide if there was such a person and,
          ultimately, the question will be whether that

                                -27-
          was the defendant or not, or somebody else.
          But because the government has labeled it as
          "Hipólito"    doesn't    mean   that    that's
          determinative. You will make the determination
          at the appropriate time.

The jury was allowed to use the transcripts several times in order

to follow along whenever the government played a recording of an

intercepted telephone call. The jury was also provided with a copy

of the transcripts to use during their deliberations.8   Díaz-Arias

now reiterates his objections to the use of the transcripts before

this forum.

                 2.   Standard of Review

          We review for abuse of discretion the district court's

decision to allow the use of a transcript at trial.   United States

v. Anderson, 

 (1st Cir. 2006).

                 3.   Analysis

          Díaz-Arias mainly advances three arguments regarding the

admissibility of the contested transcripts: (1) that there was no

compelling evidence supporting Trooper Cepero's identification of

him as one of the speakers; (2) that the district court did not

properly instruct the jury that it was up to them to decide whether

the speaker labeled as "Hipólito" was indeed Díaz-Arias; and (3)




8
   Díaz-Arias lodged a continuing objection to the use of the
transcripts at trial. He also objected to the government's request
to provide the jury with the transcripts for their deliberations.
The district court overruled both objections.

                                 -28-
that    labeling      one   of    the    speakers     as     "Hipólito"    constituted

impermissible vouching by the government.

              The first two arguments are derived from Díaz-Arias'

reading of our decision in United States v. Jadlowe, 

(1st Cir. 2010).        In Jadlowe, the district court admitted the lay

opinion testimony of a police officer identifying the defendant's

voice in several recordings of wiretapped communications. 628 F.3d

at 24.     The defendant had argued that it was error to admit such

testimony,      because     the     identification         was   not   based   on   the

officer's prior personal experience with him, and because the jury

"was perfectly capable of drawing its own independent conclusion[s]

based    on    the    evidence      presented."        Id.    (internal     quotations

omitted).      We agreed with the defendant that it was error for the

district      court    to   admit       as   lay    opinion    testimony    the   voice

identification of the officer, because the officer was "not in a

better position than the jurors to make the identity judgments."

Id.     We also agreed with the defendant that the district court

erred when it allowed the prosecution to furnish the jury with the

transcripts of the recorded conversations, because the transcripts

reflected the officer's identification of the defendant's voice by

labeling one of the speakers with his name.                      However, since the

record    established       that    there      was    "compelling      circumstantial

evidence that Jadlowe was properly identified as the speaker in the

calls" and the district court providently instructed the jury that


                                             -29-
it was up to them to make a determination as to whether the

transcripts accurately identified the speaker as Jadlowe, we held

that any error in admitting the lay opinion testimony and allowing

the transcripts was harmless. Id. at 25.

             Díaz-Arias    claims    that,     contrary      to    Jadlowe,      the

circumstantial evidence pointing to him as the speaker in the phone

call recordings was not compelling, and that while the district

court did give the jury an instruction as to the use of the

transcripts, this instruction was not given at the time that the

transcripts were provided to the jury.                Díaz-Arias' arguments,

however,     are   misplaced,    because    the    situation      in   Jadlowe   is

completely distinguishable from the one present in this case.                    The

centerpiece of our holding in Jadlowe, as it pertained to the use

of the transcripts, was that the officer's testimony identifying

Jadlowe as one of the speakers was not helpful to the jury, because

the evidence the officer relied upon to make that assessment was

readily available to the jury.            Id. at 24.       Instead, here one of

the speakers in the transcript was labeled with the name "Hipólito"

based on Trooper Cepero's identification of Díaz-Arias as said

speaker, and as we have already explained, Trooper Cepero in this

case   was   in    a   better   position    than     the   jury   to    make   that

assessment, based primarily on his mastery of the Spanish language

and    his   familiarity    with    the    accents    of    native     speakers.




                                     -30-
Therefore, Díaz-Arias' attempts to frame his arguments within the

context of our holding in Jadlowe are unavailing.

           In any event, we agree with the government that there is

sufficient    evidence    to    establish     that    the    speaker   in     the

intercepted telephone conversations was someone named "Hipólito,"

and that "Hipólito," in turn, was the defendant, Díaz-Arias. There

is strong circumstantial evidence that the speaker in question was

referred to as "Hipólito" by the other members of the Pinales

organization when they communicated with each other over the phone.

For example, on the night of July 11, 2004, Pinales told Pena to

call Hipólito the next day so that Pena and Hipólito could meet.

A minute after that conversation took place, Pena called Hipólito

to ask if he could visit him.            On September 28, 2004, Hipólito

called Pinales to inform him that "tomorrow, I am going to send the

guy over there" and the next day, Hernández called Pinales and

identified himself as "Hipólito’s guy."              Later that day, Pinales

called a phone number and asked to speak with "Hipólito," after

which he spoke with the speaker in question.                Apart from Trooper

Cepero's     admissible      testimony     identifying       the   speaker     as

"Hipólito,"    there   was    enough    circumstantial      evidence   here    to

support the labeling of the transcript with the name "Hipólito."9



9
   In addition, two of the phone numbers used by Hipólito during
the intercepted telephone calls were listed in Pinales’ address
books as belonging to "H.P.," which a reasonable juror could infer
is an abbreviation for Hipólito.

                                       -31-
           The same can be said about the government's theory that

Hipólito was the defendant, Díaz-Arias.                  As we have previously

recounted, a reasonable jury could have concluded that Fresa was

the woman Hipólito referred to in the tapes, given the ample

evidence connecting the two.         This evidence, coupled with Trooper

Cepero's   testimony   that    he    was     able   to     match    the    voice    of

"Hipólito" with the voice of Díaz-Arias, the latter of which he was

able to discern from stipulated recordings of Díaz-Arias' voice, is

enough to support the jury's conclusion that the voice of Hipólito

belonged to Díaz-Arias.

           The record also belies Díaz-Arias' second argument, that

the district court did not properly instruct the jury that it was

up to them to decide if the speaker labeled as "Hipólito" was in

fact Díaz-Arias.    As previously recounted, the district court did

give the jury such an instruction when the government began playing

the audio recordings of some of the intercepted calls.                         This

instruction was given at the behest of Díaz-Arias' counsel.                        The

district court again reminded the jury that the labeling of the

transcripts was not determinative when it gave its concluding

instructions, stating that "it is the government's position that

the person referred to in . . . the transcripts of the intercepted

telephone conversations as Hipólito is this defendant.                    To convict

the defendant, the government must convince you of that fact beyond

a   reasonable   doubt."      We    thus   find     that    the    district   court


                                      -32-
sufficiently instructed the jury that it was up to them to decide

whether the speaker in question was Díaz-Arias.

          Lastly, we are similarly unswayed by Díaz-Arias' third

argument, that permitting the transcript to identify the speaker in

question as "Hipólito" constituted improper governmental vouching.

          Improper    vouching   occurs   when    prosecutors   place     the

prestige of the United States behind one of their witnesses "by

making personal assurances about the credibility of [that] witness

or by indicating that facts not before the jury support [that]

witness' testimony."    United States v. Rosario-Díaz, 

,

65 (1st Cir. 2000).    Improper vouching can also be said to occur

when a prosecutor implies to the jury that they "should credit the

prosecution's   evidence   simply   because      the   government   can   be

trusted." United States v. Castro-Davis, 

, 66 (1st Cir.

2010) (citing United States v. Pérez-Ruiz, 

, 9 (1st Cir.

2003) and Flores-De Jesús, 569 F.3d at 18).        We fail to see how any

vouching took place with regards to the district court's allowance

of the impugned transcripts.      In his appellate brief, Díaz-Arias

cites to some of our case law on the vouching doctrine, but fails

to explain how the situations in those cases -- of government

witnesses and prosecutors improperly bolstering the credibility of

other government witnesses -- are mirrored in this case.            Neither

can we find any evidence on the record to suggest that the

prosecutor improperly implied to the jury that they should take the


                                  -33-
transcript at its word that the speaker in question really was

"Hipólito," simply because the government and Trooper Cepero could

be trusted to speak the truth.            On the contrary, the government

properly    authenticated       the    transcripts    via   Trooper    Cepero's

testimony, and the labeling of those transcripts with the name

"Hipólito" merely memorialized a part of that testimony: the

identification       of   the   speaker    in    question   as   a   man   named

"Hipólito."      Therefore, we reject Díaz-Arias' claims of improper

vouching.

            Consequently, we find no abuse of discretion in the

district court's decision allowing the jury to use the transcripts.

However, notwithstanding our validation of the evidence in this

case, we suggest that in future cases it would be better practice

for the government to establish the basis for the labeling of the

transcripts, before these documents are initially presented to the

jury, in addition to the court instructing the jury as was done by

the district court in this case.

            C.   Admission of Unrelated Drug Seizures

            Díaz-Arias' third claim of error is that, while the

indictment charged him with participating in a single, overarching

conspiracy    with    the   other     twelve    co-defendants,   the   evidence

marshaled at trial indicated the existence of multiple independent

conspiracies.     Specifically, Díaz-Arias maintains that he was only

"one of [the] many customers" of the Pinales organization, and that


                                       -34-
he only entered into a limited conspiracy with two of the co-

defendants (presumably Pinales and Heredia) to purchase cocaine

from them, and not into the broader conspiracy charged in the

indictment. Because of this, Díaz-Arias contends that the district

court erred when it allowed the government to introduce evidence

pertaining to the seizure of a kilogram of cocaine from Tajh White

on September 27, 2004, as well as the seizure of 53 kilograms of

cocaine from the stash house stewarded by Heredia at 115 Navarre

Street.     He claims this caused an impermissible variance to result

at trial, which fomented an evidentiary spillover that allowed the

jury to transfer the guilt of the other co-defendants to him,

thereby abridging his "substantial rights."                The following is a

brief overview of the law in this regard.10

             To sustain a conviction for conspiracy under 21 U.S.C.

§    846,   the   government   must    establish    that   "(1)   a   conspiracy

existed; (2) the defendant had knowledge of the conspiracy; and (3)

the    defendant    knowingly   and     voluntarily    participated      in   the

conspiracy."       United States v. Maryea, 

, 73 (1st Cir.

2013) (citing United States v. Dellosantos, 

, 116 (1st

Cir. 2011)).        The third element requires a showing that the

defendant intended to join the conspiracy and also intended to

effectuate its objectives.            Id.     A tacit agreement to join the


10
     Díaz-Arias also seems to challenge the drug quantity
attributable to him in this section. For the sake of clarity, we
will address said issue in the final section of this opinion.

                                       -35-
conspiracy is sufficient.   United States v. Portela, 

,

695 (1st Cir. 1999).

          A prejudicial variance may result when "(1) the facts

proved at trial differ from those alleged in the indictment; and

(2) the error affects the defendant's substantive rights. . . ."

Maryea, 704 F.3d at 73 (citation omitted). The question of whether

the evidence supports the existence of a single conspiracy is a

factual one for the jury to determine.    United States v. Escobar-

Figueroa, 

, 48 (1st Cir. 2006).    Assuming the jury was

properly instructed on this matter, something which Díaz-Arias does

not challenge here, the initial question boils down to "one of

evidentiary sufficiency."     Dellosantos, 649 F.3d at 116.      On

review, we frequently regard the totality of the circumstances when

evaluating whether the evidence proffered at trial suffices to

establish the overarching conspiracy.    Pérez-Ruiz, 353 F.3d at 7.

We must reject Díaz-Arias claims that a variance occurred if a

"plausible reading of the record supports the jury's implied

finding that he knowingly participated in the charged conspiracy."

Id.

          After carefully reviewing the record in this case, we

first conclude that there was abundant evidence for the jury to

determine that Díaz-Arias entered into a conspiracy to distribute

cocaine. The evidence showed that Díaz-Arias purchased multiple

kilograms of cocaine from the Pinales organization on several


                               -36-
occasions.   See, e.g., United States v. Mitchell, 

, 23

(1st Cir. 2010)("pattern of drug sales between individuals for

redistribution supports conclusion that individuals were involved

in drug conspiracy." (citing United States v. Moran, 

,

1303 (1st Cir. 1993))).     It also established, as reflected in the

wiretap recordings, that Díaz-Arias arranged for drug transactions

with the core members of the conspiracy using the conspiracy's

coded language.      Mitchell, 596 F.3d at 24 ("use of drug code

probative of membership in conspiracy" (citing United States v.

Morales-Madera, 

, 12-13 (1st Cir. 2003))).              The drug

ledgers also indicated the Díaz-Arias was a recurrent customer of

the Pinales organization and that, at one point, he was indebted to

the   organization   by   more   than   $50,000.   Id.   ("drug    ledger,

containing nicknames of defendant and other conspiracy members, is

direct evidence of membership in conspiracy." (citing United States

v. Tejada, 

, 487 (1st Cir. 1989))).11



11
   In Mitchell, we rejected a similar argument made by one of Díaz-
Arias' co-defendants. 

. Marcus Mitchell, who was tried
separately from Díaz-Arias, also argued that the evidence was
insufficient to establish his participation in the conspiracy,
although he did so as part of his challenge against the district
court's decision to admit wiretap recordings as co-conspirator
statements.   See Fed. R. Evid. 801(d)(2)(E).      We rejected his
argument and found that the government had "offered substantial
evidence . . . to establish that Mitchell was an active conspiracy
member," by a preponderance of the evidence. Mitchell, 596 F.3d at
24. The evidence used against Mitchell was substantially the same
as that used against Díaz-Arias, except that a co-defendant, Oscar
Rodríguez, testified at Mitchell's trial as a government witness.
Id.

                                   -37-
              There was also a sufficient evidentiary foundation for

the    jury   to     determine     that    a   single       conspiracy        existed.     In

conducting our inquiry as to this issue, several factors are of

use,    including:      "(1)      the    existence         of   a    common      goal,    (2)

interdependence among participants, and (3) overlap among the

participants."         Dellosantos, 649 F.3d at 117.                   No single one of

these factors, standing alone, is necessarily determinative.

Sánchez-Badillo,        540      F.3d    at    29.         As   to    the   common       goal

requirement, we have found it satisfied when the goal is to sell

cocaine for profit or to further the distribution of cocaine.

Portela,      167    F.3d   at    695;    Dellosantos,          649    F.3d       at   117.

Interdependence concerns "whether the activities of one aspect of

the scheme are necessary or advantageous to the success of another

aspect of the scheme." United States v. Ciresi, 

, 27

(1st Cir. 2012) (internal quotation omitted).                         The final factor,

overlap among the participants, can be found to exist when the

conspiracy features "the pervasive involvement of a single core

conspirator, or hub character."                  Dellosantos, 649 F.3d at 118

(internal quotation omitted).

              Here,    Díaz-Arias        seems   to        argue     that   the    evidence

introduced      at    trial      established         the    existence       of    multiple,

independent drug trafficking conspiracies instead of the single,

overarching conspiracy described in the indictment. He claims that

while all the defendants had the purpose of profiting from the


                                          -38-
distribution of cocaine, "that objective was achieved by different

methods of operation, at different places, and with different

people,"   which,    according   to    him,   suggests   there   was   no

interdependence between the parties. Although Díaz-Arias admits he

received his supply of cocaine from Pinales, he contends the

evidence did not establish that either of them believed that the

success of the distribution operation depended on the ventures of

the remaining eleven defendants.         He also argues there was no

evidence presented at trial indicating that he had any interactions

with the other members of the conspiracy, thus reflecting a lack of

overlap between them.

           Since it appears that Díaz-Arias concedes the conspiracy

had the common goal of selling and distributing cocaine for profit,

we   address   the   remaining   two   factors:   whether   overlap    and

interdependency existed among the participants of the conspiracy.

The overlap factor is easily established, as the government proved

that Díaz-Arias' supply of cocaine came directly from Pinales and

Heredia, who spearheaded the organization.          Hence, Pinales and

Heredia neatly fit into the roles of core conspirators or hub

characters of the conspiracy.

           As to interdependency, we are not convinced by Díaz-

Arias' argument that there was no interdependency because his co-

defendants, who also purchased cocaine in wholesale quantities from

the Pinales organization, were independent criminals whose criminal


                                  -39-
activity was unforeseeable to him. It is well established that the

government does not need to prove that the defendant knew all of

the details of the conspiracy, nor that he participated in every

aspect of the conspiracy.         Sánchez-Badillo, 540 F.3d at 29.            It

also does not have to show that the defendant knew of or had any

contact with each and every one of the conspirators. Id.

              Further, in United States v. Soto-Beníquez, we stated

that an example of interdependence is when "the success of an

individual's own drug transactions depends on the health and

success of the drug trafficking network that supplies him . . . ."

, 19 (1st Cir. 2003).          This is readily apparent here,

where   the     evidence   established   that    Díaz-Arias      was   a   repeat

customer of the Pinales organization, purchasing multiple kilograms

of cocaine, often on consignment, and regularly paying down debts,

amounting to thousands of dollars, to the organization. A rational

jury    could   have   inferred   that   the    proceeds   the    organization

obtained from customers such as Díaz-Arias allowed it to continue

importing large quantities of cocaine, thus furthering the criminal

enterprise.      Therefore, it can be said that Díaz-Arias' success as

a distributor was predicated upon the success of the other co-

conspirators; were it not for the combined collective effort of all

of them, the Pinales organization would have faltered, possibly

leaving Díaz-Arias bereft of a supplier.           See Maryea, 704 F.3d at

77 ("This interdependence makes it reasonable to speak of a tacit


                                    -40-
understanding between [a core conspirator] and others upon whose

unlawful acts his success depends.") (internal quotation marks

omitted). Accordingly, there was sufficient evidence for a jury to

infer   interdependency,     and       thus    the   existence     of     a    single

conspiracy.

            Having determined that there was sufficient evidence to

support   the    existence   of    a    single     conspiracy,     we   must     also

determine that the district court did not err in admitting the

evidence from the cocaine seizures of Tajh White and Heredia's

stash house.     The evidence proffered by the government tended to

establish     that   White   was       also    a   customer   of    the       Pinales

organization and that the stash house at 115 Navarre Street was

used by that organization as a repository for cocaine.                  Therefore,

the evidence stemming from the cocaine seizures were plainly

relevant to proving the existence of the charged conspiracy.                      See

Fed. R. Evid. 401.

            D.   The Race and Ethnicity Instruction

            Díaz-Arias has also lodged an objection to the district

court's refusal to provide the jury with his requested instruction

on race, ethnicity and national origin.              The requested instruction

stated the following:

            It would be improper for you to consider, in
            reaching your decision as to whether the
            government sustained its burden of proof, any
            personal feelings you may have about the
            defendant's race or ethnicity, or national


                                        -41-
          origin, or his or any witness' immigration
          status.

          The district judge declined to give this instruction,

stating "I don't think I will give that specifically.                 I will

emphasize that they are to be completely fair-minded and impartial

and not to be influenced by private views of any of the instances

in the case, but I won't be any more specific than that."            Instead,

the court opted to charge the jury with the following instruction:

          You should determine what facts have been
          shown or not based solely on a fair
          consideration    of    the   evidence.    That
          proposition means two things, of course. First
          of all, you'll be completely fair-minded and
          impartial, swayed neither by prejudice, nor
          sympathy, by personal likes or dislikes toward
          anybody involved in the case, but simply to
          fairly and impartially judge the evidence and
          what it means.

          In his brief, Díaz-Arias points to surveys which "have

established that large portions of the community believe that drug

trafficking is more prevalent amongst Hispanics than it is with any

other ethnic group."   He also provides citations to other studies

which have indicated that: (1) Blacks and Hispanics are more likely

to be incarcerated for drug offenses than are Caucasians; and (2)

the correlation   between   race    and   drug activity    is    a   popular

misconception.    Therefore,       Díaz-Arias   contends   his       proposed

instruction was necessary to dispel any notion among the jurors

that being Hispanic in and of itself is evidence of guilt in a drug

crime.   By not giving the instruction, he argues, the district


                                   -42-
court diminished the burden of proof and "allowed a misconception

to infect the jury trial process."      He contends the district

court's lapse in this regard constituted reversible error.      We

reject that contention.

           Properly preserved challenges to jury instructions are

reviewed de novo, "taking into account the charge as a whole and

the body of evidence presented at trial."        United States v.

Sampson, 

, 29 (1st Cir. 2007).      A district court's

refusal to provide a requested instruction is reversible error only

when the requested instruction "(1) was substantively correct; (2)

was not substantially covered elsewhere in the charge; and (3)

concerned an important point in the case so that the failure to

give the instruction seriously impaired the defendant's ability to

present his defense." United States v. Willson, 

, 54-55

(1st Cir. 2013).   "Cases satisfying all three [of these] factors

are 'relatively rare.'"   Id. (quoting United States v. González,

, 21 (1st Cir. 2009)).

          In this case, Díaz-Arias' instruction fails to surmount

the second prong of the test.       The district court adequately

instructed the jury that it should be "completely fair-minded and

impartial, swayed neither by prejudice, nor sympathy, by personal

likes or dislikes toward anybody involved in the case . . . ."

Díaz-Arias' proposed instruction was a more specific version of the

court's instruction; it merely recited the possible forms of


                               -43-
prejudice that a person might have against Díaz-Arias: race,

ethnicity, national origin or immigration status.12 The court's

instructions effectively incorporated the essence of Díaz-Arias'

request; they advised the jurors that they could not be swayed by

any form of prejudice towards anybody involved in the case, which

obviously included the defendant.             See United States v. Rose, 

, 1416 (1st Cir. 1997) ("[T]rial court's charge need not

use the exact wording requested by the defendant so long as the

instruction      incorporates     the    substance     of     the    defendant's

request."); United States v. McGill, 

, 12 (1st Cir.

1992) (similar); Calhoun v. Acme Cleveland Corp., 

, 564

(1st Cir. 1986) (holding that instruction to jury to "avoid bias or

prejudice"    was      sufficient,     despite    defendant     requesting    an

"anticorporate bias" instruction).               Thus, the district court's

decision to use a general term such as "prejudice," without listing

the   examples    of    concern   to    Díaz-Arias,    does    not   constitute

reversible error.

           Our conclusion here is also based upon a number of

factors.   We first note that a plurality of the Supreme Court has

stated that "[t]here is no constitutional presumption of juror

bias either for or against members of any particular racial or

ethnic groups."     Rosales-López v. United States, 

, 190


12
   The proposed instruction also referred to "the defendant," while
the court's instruction referred to "anybody involved in this
case."

                                       -44-
(1981). Although Díaz-Arias expresses a concern in his brief as to

one or more of the jury members possibly bringing "to the process

some bias or just some inkling that the drug problem in this

country is created by the presence of Hispanic's [sic] in our

society," nothing in the record supports such an assertion.                    The

district court docket reflects that Díaz-Arias was able to propose

voir dire questions that went directly to the issue of prejudice on

account of race, ethnicity, national origin and immigration status.

Díaz-Arias has not argued before us that the district court refused

to ask the venire those questions, or that the venire members who

ultimately served as jurors demonstrated signs of harboring any

kind of prejudice towards him.              Neither can he point to any

incident during the proceedings which would have given rise to a

heightened concern of potential bias in any of the jurors.

              Díaz-Arias'   reliance   on   cases     such    as   Miller-El    v.

Dretke, 

 (2005) and United States v. Casas, 

(1st Cir. 2005), is also misplaced.           While the Court in Miller-El

did reaffirm that "racial discrimination by the State in jury

selection offends the Equal Protection Clause," 545 U.S. at 238,

there   are    no   allegations   in   this    case    that    the   prosecutor

discriminatorily used her peremptory strikes against venire members

on account of their race or ethnic background.                In Casas, on the

other hand, we did warn that "[w]hen a non-frivolous suggestion is

made that a jury may be biased or tainted by some incident, the


                                   -45-
district court must undertake an adequate inquiry to determine

whether the alleged incident occurred and if so, whether it was

prejudicial."    425 F.3d at 48 (quoting United States v. Gastón-

Brito, 

, 12 (1st Cir. 1995)).    However, Casas concerned

an incident during trial where it was discovered that some of the

jurors may have been biased in favor of certain defendants.    Here,

in contrast, Díaz-Arias has not alleged that any incidents took

place during the course of the proceedings which may have called

into question the impartiality of the jurors.      Furthermore, we

emphasize that Díaz-Arias did not inform the district court of his

belief that some of the jurors may have been prejudiced against

him; much less did he provide the court with any evidence to

support such a claim, as he attempts to do on appeal.   Accordingly,

we see no legal basis to find reversible error in the district

court's decision to forgo using the requested instruction.13

          E.    Drug Quantity Determination

          The fifth claim of error broached by Díaz-Arias in this

appeal concerns whether the district court erred in refusing

another of his proposed jury instructions, one that would have


13
   Our decision does not foreclose the possibility that, on facts
not presented here, we would take up and reconsider the issue in
the future.    While the surveys and studies cited by Díaz-Arias
present legitimate concerns, the record does not reflect that the
jurors in this case were afflicted with the kind of bias said
studies point to.    In addition, we are confident the district
courts will remain vigilant when it comes to detecting possible
signs of jury bias, particularly during the jury selection stage of
the proceedings.

                                -46-
asked the jury to determine the drug quantity attributable to him.

The district court, however, opted to instruct the jury that "proof

of the quantity of cocaine is not an issue for you to determine."

Díaz-Arias now contends that the drug quantity finding should have

been made by the jury beyond a reasonable doubt, not by the

district judge by a preponderance of the evidence.   He invokes the

Supreme Court's landmark case of Apprendi v. New Jersey, 

 (2000), to argue that his sentence was imposed in violation of

his rights under the Fifth Amendment's Due Process Clause as well

as the Sixth Amendment's notice and jury trial guarantees.   Since

Díaz-Arias preserved this claim at sentencing, we review his

challenge to the constitutionality of his sentence de novo. See

United States v. Brown, 

, 19 (1st Cir. 2012).

           The Supreme Court in Apprendi established the principle

that, "[o]ther than the fact of a prior conviction, any fact that

increases the penalty for a crime beyond the prescribed statutory

maximum must be submitted to a jury, and proved beyond a reasonable

doubt."   530 U.S. at 490; United States v. Malouf, 

, 25

(1st Cir. 2006).   The Apprendi principle, however, does not apply

to facts that increase the mandatory minimum sentence.   Harris v.

United States, 

, 557 (2002); Malouf, 466 F.3d at 25.

In United States v. Goodine, 

, 33 (1st Cir. 2003), we

emphasized that "[a] sentencing court may use the preponderance of

the evidence standard to find facts that require the imposition of


                               -47-
a specified minimum sentence, so long as that sentence does not

exceed the maximum sentence provided by the relevant statute."

(emphasis in original).     Hence, the principle established in

Apprendi is not breached if the district judge finds that a

specific quantity of drugs can be attributed to a defendant --

thereby increasing the mandatory minimum sentence involved -- as

long as that mandatory minimum sentence remains at or below the

statutory maximum sentence that could be applied against the

defendant given the jury's verdict.   United States v. Platte, 

, 392 (1st Cir. 2009); United States v. Barnes, 

, 177-78 (1st Cir. 2001).   The Apprendi principle will not be

transgressed as long as the district judge does not impose a

sentence above that statutory maximum sentence.

           In this case, the indictment charged the defendants with

violating sections 841(a)(1) and 846 of Title 21 of the United

States Code, by conspiring with each other to possess with intent

to distribute, and to distribute, at least five kilograms of

cocaine.   At trial, the government did not seek to have the jury

determine whether the drug quantity attributable to Díaz-Arias was

at least five kilograms of cocaine. Instead, the government agreed

that if the jury decided to convict Díaz-Arias, it would not seek

a sentence in excess of 20 years, which is the default statutory

maximum sentence for crimes involving the distribution of cocaine

in any quantity.   See 21 U.S.C. § 841(b)(1)(c) (2006).   Given the


                               -48-
jury's verdict finding Díaz-Arias guilty of the crimes charged, the

maximum sentence that could have been applied against him was 20

years.    Id.    Subsequently, at sentencing, the district court found

by a preponderance of the evidence that five or more kilograms of

cocaine    were       attributable    to   Díaz-Arias     and   it   imposed     the

mandatory minimum sentence contained in section 841(b)(1)(A)(ii),

that is, ten years.          Therefore, since the imposed sentence of ten

years is not in excess of the default statutory maximum sentence of

20   years,            Díaz-Arias'     Apprendi-based       attack       on      the

constitutionality of his sentence fails.            See Goodine, 326 F.3d at

33 ("If the disputed fact (here, drug quantity) influences the

sentence, but the resulting sentence is still below the default

statutory maximum, there is no Apprendi violation.").

            F.        Sentencing

            Lastly, Díaz-Arias takes issue with the district court's

finding that more than five kilograms of cocaine were attributable

to his participation in the conspiracy. He notes that the district

court arrived at that estimate by relying on several pieces of

evidence:       (1)    the   single   kilogram   seized    from      Hernández   on

September 29, 2004; (2) a recording dated July 11, 2004, where

Díaz-Arias supposedly discussed another kilogram; (3) the amounts

shown on the seized drug ledgers from the Park Avenue Market; and

(4) several proffer statements made by two of Díaz-Arias' co-

defendants, Pinales and Rodríguez, who entered into cooperation


                                        -49-
agreements with the government.   Although Díaz-Arias admits that

the kilogram seized from Hernández could arguably be tied to him,

he claims that the remaining pieces of evidence are insufficient to

establish, by a preponderance of the evidence, that he was involved

with five or more kilograms of cocaine.       He argues that the

July 11, 2004 recording does not contain any explicit mention of a

kilogram of cocaine, that no reliable evidence was introduced to

discern the meaning of the numbers contained in the drug ledgers,

and that the proffer statements should not have been relied upon

because they violated his Confrontation Clause rights under the

Sixth Amendment.   We proceed to analyze his claims.

          When sentencing a member of a drug conspiracy, the

district court must make an individualized finding "concerning the

quantity of drugs attributable to, or reasonably foreseeable by,"

that member. United States v. Cintrón-Echautegui, 

, 5

(1st Cir. 2010). In making that determination, the court "may

consider relevant information without regard to its admissibility

under the rules of evidence applicable at trial, provided that the

information has sufficient indicia of reliability to support its

probable accuracy." Id. at 6 (quoting United States v. Zapata, 

, 485 (1st Cir. 2009)).

          Since Díaz-Arias objected to the district court's drug

quantity calculation at sentencing, we review any legal error

committed by the district court de novo, while mindful that factual


                               -50-
findings must be reviewed for clear error. United States v. Ortiz-

Torres, 

, 72 (1st Cir. 2006).     If we can discern no

legal error, then we must credit the district court's factual

findings as to drug quantity "unless, on the whole of the record,

we form a strong, unyielding belief that a mistake has been made."

Platte, 577 F.3d at 392 (quoting Cumpiano v. Banco Santander Puerto

Rico, 

, 152 (1st Cir. 1990)).   Here, we find that the

district court's determination as to drug quantity was sufficiently

grounded on reliable evidence.

          At the outset, we must reject Díaz-Arias' claim that the

use of the proffer statements subscribed by Pinales and Rodríguez

violated his rights under the Confrontation Clause, because we have

repeatedly stated that such rights do not attach during sentencing.

See United States v. Dyer, 

, 532 (1st Cir. 2009);

United States v. Luciano, 

, 178-80 (1st Cir. 2005).   In

these proffer statements, Pinales and Rodríguez described the role

of Díaz-Arias within the drug organization, with Pinales stating

that Díaz-Arias picked up a kilogram of cocaine from him every 15

days. The proffers of Rodríguez seemed to be more inconsistent; at

first he stated that he "possibly" delivered two kilograms to Díaz-

Arias, as well as another undetermined amount, to two of Díaz-

Arias' couriers.   However, a few months later, Rodríguez stated

that he met Díaz-Arias three or four times and delivered six or

seven kilograms to him.   In any event, despite this inconsistency,


                                 -51-
Díaz-Arias does not separately challenge the reliability of these

proffers; he has only assailed the district court's consideration

of these statements under the Confrontation Clause.                      Moreover, the

district   judge     made   clear   that     he    did   not      view    the    proffer

statements in isolation, but rather as part of the information

available to him as a whole, and that he did not take those

statements as "gospel."

           It is clear to us that the proffer statements, coupled

with the amounts contained in the drug ledgers and the rest of the

evidence presented a trial, adequately supported the district

court's finding that Díaz-Arias was involved with five or more

kilograms of cocaine. During trial, Trooper Cepero testified that,

at the time of the conspiracy, a kilogram of cocaine generally sold

for $23,000 to $24,000. The drug ledgers themselves suggested that

someone with the initials "H.P." effectuated three transactions of

$24,000 each, and one transaction amounting to $48,000.                               The

ledgers gave the impression that once the transactions were made,

"H.P." would proceed to amortize the resulting debts in various

installments.      Given the other evidence presented at trial, these

ledgers could reasonably be read as reflecting the purchase of at

least   five   kilograms     of     cocaine       (three    separately          and   two

together),     and   that   these     sales       were     made    on    consignment.

Furthermore, the district court did not commit clear error in

concluding that "H.P." was Díaz-Arias, because in one of Pinales'


                                      -52-
address books, introduced as Exhibit 23, there was a phone number

ending   in     1764   next   to   the   initials   "H.P."        The   wiretap

investigation carried out by the DEA revealed that Díaz-Arias used

that same phone number, among others, to communicate with Pinales.

              Accordingly,    we   are   not   convinced     by    Díaz-Arias'

arguments that the drug ledgers were too ambiguous for the district

court to have arrived at a drug quantity determination of five or

more kilograms.        When considered alongside the other information

contained in the PSR, including the proffer statements as well as

the evidence produced at trial, the ledgers were sufficiently

reliable to hold Díaz-Arias accountable for at least five kilograms

of cocaine, as required to sentence him to the mandatory minimum of

ten years under 21 U.S.C. § 841(b)(1)(A)(ii).

                              III.   Conclusion

              For the reasons elucidated above, the judgment of the

district court is affirmed.

              Affirmed.




                                     -53-