FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                 No. 07-50546
                Plaintiff-Appellee,          D.C. No.
               v.                         CR-07-00488-
CARLOS ZARATE LIERA,                          LAB-1
             Defendant-Appellant.
                                           OPINION

       Appeal from the United States District Court
         for the Southern District of California
        Larry A. Burns, District Judge, Presiding

                Argued December 10, 2008
                 Submitted May 5, 2009
                   Pasadena, California

                  Filed November 4, 2009

     Before: Harry Pregerson, Dorothy W. Nelson and
           David R. Thompson, Circuit Judges.

                Opinion by Judge Pregerson




                           14841
                    UNITED STATES v. LIERA                14845




                         COUNSEL

Steven F. Hubacheck, Federal Defenders of San Diego, San
Diego, California, for the defendant-appellant (argued and on
the briefs).

Mark R. Rehe, Assistant United States Attorney (argued and
on the briefs), Bruce R. Castetter, Assistant United States
Attorney, and Karen P. Hewitt, United States Attorney (on the
briefs), San Diego, California, for the plaintiff-appellee.


                          OPINION

PREGERSON, Circuit Judge:

   Carlos Zarate Liera (“Liera”) was convicted of two counts
of bringing aliens into the United States for financial gain and
aiding and abetting, in violation of 8 U.S.C.
14846                   UNITED STATES v. LIERA
§ 1324(a)(2)(B)(ii) and 18 U.S.C. § 2. Liera was also con-
victed of two counts of bringing aliens into the United States
without presentation, in violation of 8 U.S.C.
§ 1324(a)(2)(B)(iii). On appeal, Liera’s primary argument is
that the district court erred by not suppressing incriminating
statements Liera made to law enforcement officers during the
time they unreasonably and unnecessarily delayed presenting
him before a magistrate judge for arraignment.1 We have
jurisdiction under 28 U.S.C. § 1291. We agree and vacate
Liera’s convictions and remand for a new trial.

                               I.   FACTS

   On February 15, 2007, at about 4:15 a.m., Liera entered the
United States from Mexico at the Calexico West Port of
Entry. Liera was driving a 1989 Chevrolet pickup truck with
Mexican license plates. During a border search of the truck,
Customs and Border Protection (“CBP”) officers found two
unrelated aliens, Le Chen and Wu Chen, under the truck’s
hood lying in separate built-in compartments located on each
side of the engine.2 CBP officers also found a cell phone. It
is unclear whether the cell phone was found in the truck or
whether the cell phone was found in one of Liera’s pockets
during a pat-down search.

  Following Liera’s arrest, CBP Officer Figueroa interro-
gated Liera on two separate occasions.3 At 9:18 a.m., about
  1
     Liera also argues that: (1) the district court improperly admitted into
evidence Le Chen’s hearsay testimony regarding what his mother told him
it would cost to have a person smuggled into the United States; (2) the dis-
trict court should have suppressed all of Liera’s statements to CBP Officer
Figueroa because of non-compliance with Miranda v. Arizona, 

(1966); and (3) the district court’s jury instructions denied Liera his
right to a jury finding on the “specific intent” element of the aiding and
abetting charge.
   2
     Le Chen and Wu Chen are citizens of the People’s Republic of China.
At the time of their arrest, neither Le Chen or Wu Chen had applied for
or been granted permission to be present or reside in the United States.
   3
     The record reflects that Liera was advised of and waived his Miranda
rights during both interrogations.
                    UNITED STATES v. LIERA                14847
five hours after Liera’s arrest, Officer Figueroa interrogated
Liera for the first time. During this first interrogation, Liera
denied knowing that Le Chen and Wu Chen were under the
truck’s hood. Liera told Officer Figueroa that the truck
belonged to his uncle’s neighbor, Raul Gonzales, and that he
borrowed the truck because his truck had two flat tires and he
needed to get to work. Liera also told Officer Figueroa that he
was an agricultural field worker in Calipatria, California, and
was on his way to work.

   At 10:45 a.m., Officer Figueroa interrogated material wit-
nesses Le Chen and Wu Chen. Neither identified Liera as part
of a scheme to bring Le Chen, Wu Chen, or any other aliens
into the United States.

   At 1:30 p.m., Officer Figueroa discovered that the video
recording equipment used in the first set of interrogations
malfunctioned. Liera, Le Chen, and Wu Chen’s interrogations
were recorded without sound because of a battery problem.
Officer Figueroa then contacted the United States Attorney’s
Office. An Assistant United States Attorney gave Officer
Figueroa the “green light” to interrogate Liera, Le Chen, and
Wu Chen a second time.

   At 2:57 p.m., more than ten hours after Liera’s arrest, Offi-
cer Figueroa interrogated Liera for a second time. During the
second interrogation, Officer Figueroa asked Liera questions
regarding the cell phone found during Liera’s arrest. These
questions were not asked during the first interrogation. In par-
ticular, Officer Figueroa asked Liera if the phone was his and
if he was able to access the phone’s electronic information
using an access code. Liera answered “yes,” and entered the
phone’s access code. Officer Figueroa reviewed the log of
received, missed, and outgoing calls and learned that Liera’s
phone had received three calls from a phone number stored in
the phone’s internal memory under the name “Pollos.” In
Spanish slang, “Pollos” (or “chickens”) refers to people who
are illegally smuggled into the United States. During the inter-
14848                     UNITED STATES v. LIERA
rogation, Liera confirmed that the three calls occurred on Feb-
ruary 14 and 15, 2007. Liera also acknowledged that one
meaning for “Pollos” was “smuggled aliens.” Liera, however,
claimed that the “Pollos” entry in his cell phone referred to a
friend of his who sold chickens. In closing argument, the gov-
ernment referred to the “Pollos” entry in Liera’s cell phone as
a “smoking gun.”

   The chambers of Magistrate Judge Peter Lewis are located
at the United States Courthouse in El Centro, California,
about fifteen miles from the Calexico West Port of Entry
where Liera was arrested. Because Officer Figueroa interro-
gated Liera for a second time, Liera was not arraigned during
Magistrate Judge Peter Lewis’s 3:00 p.m. calendar call.
Instead, Liera was arraigned at 10:48 a.m. on February 16,
2007, more than thirty hours after his arrest.4
  4
   The following chart reflects the relevant dates and times:
Date         Time      Time Since Arrest        Event
2-15-07     4:15 a.m.     0 hrs                Customs and Border Pro-
                                               tection Officers arrest
                                               Liera.
2-15-07     9:18 a.m.     5 hrs 3 min          Officer Figueroa interro-
                                               gates Liera for a first time.
2-15-07     10:45 a.m.      6.5 hrs            Officer Figueroa interro-
                                               gates Le Chen and Wu
                                               Chen.
2-15-07      1:30 p.m.      9 hrs 15 min        Officer Figueroa discovers
                                                the video equipment mal-
                                                functioned and did not
                                                record audio.
2-15-07      2:57 p.m.      10 hrs 42 min       Officer Figueroa interro-
                                                gates Liera for a second
                                                time.
2-15-07      3:00 p.m.      10 hrs 45 min       Magistrate Judge Lewis
                                                conducts an arraignment
                                                calendar at the El Centro
                                                United States Courthouse.
                                                Liera is not arraigned dur-
                                                ing the 3:00 p.m. calendar.
2-16-07      10:48 a.m.      30 hrs 33 min      Liera is arraigned.
                    UNITED STATES v. LIERA                 14849
   Before trial, Liera moved to suppress the statements he
made during the second interrogation. The district court
denied his motion. In particular, the district court noted that
“the delay that led up to the second interrogation . . . was jus-
tified by the need to get recorded statements from both [Liera]
and the material witnesses” and that the delay was “necessary
given the failure of the [recording] equipment.”

   After a two-day jury trial, Liera was convicted of two
counts of bringing aliens into the United States for financial
gain and aiding and abetting, in violation of 8 U.S.C.
§ 1324(a)(2)(B)(ii) and 18 U.S.C. § 2. Liera was also con-
victed of two counts of bringing aliens into the United States
without presentation, in violation of 8 U.S.C.
§ 1324(a)(2)(B)(iii). The district court sentenced Liera to
thirty-six months concurrent imprisonment for each of the two
financial gain and aiding and abetting counts, and twenty-
seven months concurrent imprisonment for each of the two
failure to present counts. All four sentences were to run con-
currently.

  This timely appeal followed.

 II.    THE DISTRICT COURT’S FAILURE TO SUPPRESS LIERA’S
       INCRIMINATING STATEMENTS MADE DURING HIS SECOND
                         INTERROGATION

   The primary issue here is whether the district court erred by
not suppressing the incriminating statements Liera made to
law enforcement officers during his second interrogation.
Liera argues that any evidence obtained during his second
interrogation must be suppressed because of an unnecessary
or unreasonable delay under Federal Rule of Criminal Proce-
dure 5(a), 18 U.S.C. § 3501(c), and the McNabb-Mallory
Rule. We agree.
14850                UNITED STATES v. LIERA
 A.     The McNabb-Mallory Rule, Federal Rule of Criminal
            Procedure 5(a), and 18 U.S.C. § 3501(c)

  We first provide background information regarding the
McNabb-Mallory Rule, Federal Rule of Criminal Procedure
5(a), and 18 U.S.C. § 3501(c).

   [1] McNabb v. United States, 

(1943), and
Mallory v. United States, 

(1957) “generally
rende[r] inadmissible confessions made during periods of
detention that violat[e] the prompt presentment requirement
of [Federal Rule of Criminal Procedure] 5(a)” (the “McNabb-
Mallory Rule”). Corley v. United States, ___ U.S. ___, 129 S.
Ct. 1558, 1563 (2009) (quoting United States v. Alvarez-
Sanchez, 

, 354 (1994) (alteration in original).
Federal Rule of Criminal Procedure 5(a) states that “[a] per-
son making an arrest within the United States must take the
defendant without unnecessary delay before a magistrate
judge.” Fed. R. Crim. P. 5(a).

   [2] In response to the Supreme Court’s rulings in McNabb
and Mallory, Congress enacted 18 U.S.C. § 3501(c). Section
3501(c) states that “a confession made . . . by . . . a defendant
. . . , while . . . under arrest . . . , shall not be inadmissible
solely because of delay in bringing such person before a mag-
istrate judge . . . if such confession is found by the trial judge
to have been made voluntarily and . . . within six hours [of
arrest].” 18 U.S.C. § 3501(c). Section 3501(c) also provides
that the six-hour “time limitation . . . shall not apply in any
case in which the delay in bringing [the defendant] before [a]
magistrate judge . . . beyond such six-hour period is found by
the trial judge to be reasonable considering the means of
transportation and the distance to be traveled to the nearest
available such magistrate judge.” 18 U.S.C. § 3501(c).

  [3] On April 6, 2009, the Supreme Court reaffirmed the
applicability of the McNabb-Mallory Rule in Corley v. United

. The Supreme Court held that if a
                       UNITED STATES v. LIERA                     14851
“confession occur[s] before presentment and beyond six hours
. . . the court must decide whether delaying that long was
unreasonable or unnecessary under the McNabb-Mallory
cases, and if it was, the confession is to be suppressed.” 

confessions are inadmissible if given after
an unreasonable delay in presentment” exceeding six hours.

(citing Upshaw v. United States, 

(1948)).5

  Here, it is undisputed that Liera’s second interrogation “oc-
curred before presentment and beyond six hours.” 

also
undisputed that the delay was not a result of the distance
needed to travel to the nearest magistrate, since the nearest
available magistrate, Magistrate Judge Lewis, was located
only fifteen miles away.

   Accordingly, our analysis in this case turns on whether
delaying Liera’s arraignment to conduct a second interroga-
tion “was unreasonable or unnecessary under the McNabb-
Mallory cases.” 

or Unnecessary Delay

   [4] “We review a district court’s finding that a pre-
arraignment delay was reasonable for clear error.” See United
States v. Padilla-Mendoza, 

, 732 (9th Cir. 1998).
Although in Corley the Supreme Court specifically declined
to address what constitutes an “unreasonable or unnecessary
delay,” the court noted that “delay for the purpose of interro-
gation is the epitome of ‘unnecessary delay.’ ” Corley, 129 S.
Ct. at 1563 (quoting 

).

  [5] We recently addressed what constitutes an “unreason-
able or unnecessary delay” in United States v. Garcia-
  5
   Under § 3501(e) a confession is defined as “any confession of guilt or
any self incriminating statement made or given orally or in writing.” 18
U.S.C. § 3501(e) (emphasis added).
14852                  UNITED STATES v. LIERA
Hernandez, 

, 1106 (9th Cir. 2009). In Garcia-
Hernandez, we stated that “administrative delays due to the
unavailability of government personnel and judges necessary
to completing the arraignment process are reasonable and nec-
essary.” 

held that the nineteen hour delay
in presenting Garcia-Hernandez to a magistrate did not violate
the prompt presentment requirement of Rule 5(a) because the
delay “was caused not by a desire to interrogate Garcia further
but by a shortage of personnel necessary to process Garcia
and determine whether he should be criminally charged.“ 

(emphasis added); see also United States v. Matus-
Leva, 

, 1217 (9th Cir. 2002) (holding that a
twenty-four hour pre-arraignment delay was reasonable and
necessary because the defendant needed to receive medical
treatment); United States v. Gamez, 

, 1141-43
(9th Cir. 2002) (holding that a thirty-one hour pre-
arraignment delay was necessary because the defendant spoke
only Spanish, and the “first available Spanish-speaking FBI
agent did not arrive until approximately 27 hours after defen-
dant’s arrest”).

   Here, however, unlike in Garcia-Hernandez, the delay in
presenting Liera to a magistrate judge was not necessary to
redress a “shortage of personnel necessary to process [Liera]
and determine whether he should be criminally charged.”

. At about 4:15 a.m.,
Customs and Border Protection Officers arrested Liera. At
9:18 a.m., over five hours after Liera’s arrest, Officer Figue-
roa interrogated Liera for the first time. At 10:45 a.m., Officer
Figueroa interrogated the two material witnesses, Le Chen
and Wu Chen. After interrogating Liera and both material wit-
nesses the first time, the government had more than enough
information to determine whether Liera should be criminally
charged, and was not prevented by personnel shortages from
processing Liera appropriately.6
  6
    We note, however, that a delay in presenting a defendant to a magis-
trate judge may be independently unreasonable regardless whether addi-
                         UNITED STATES v. LIERA                        14853
   The government could have arraigned Liera during Magis-
trate Judge Lewis’s 3:00 p.m. arraignment calendar at the El
Centro United States Courthouse, if not earlier. At 1:30 p.m.,
Officer Figueroa discovered that the video recording equip-
ment used during Liera’s first interrogation malfunctioned
and did not record any audio. Rather than proceed with the
arraignment at 3:00 p.m., the government conducted a second
interrogation at 2:57 p.m., nearly eleven hours after Liera’s
arrest. As a result, Liera was not arraigned until 10:48 a.m.
the next day, over thirty hours after his arrest.

   [6] The purpose of the McNabb-Mallory Rule is not merely
to “avoid all the evil implications of secret interrogation of
persons accused of crime.” McNabb v. United States, 

, 344 (1943). Rather, the McNabb-Mallory Rule was
also designed to insure that a defendant is brought “before a
judicial officer as quickly as possible so that he may be
advised of his rights and so that the issue of probable cause
may be promptly determined.” Mallory v. United States, 

, 454 (1957). Under Federal Rule of Criminal Proce-
dure 5(a) the government was required to present Liera to a
magistrate as quickly possible so that Liera could be advised
of his rights by a judicial officer. Instead of presenting Liera
to a magistrate as quickly as possible, the government delayed
Liera’s arraignment so that it could interrogate Liera a second
time and obtain an audio recording of his statements. An
audio recording of Liera’s statements was, however, unneces-
sary to complete the arraignment process or determine
whether to file criminal charges against Liera.7

tional information is necessary for the government to determine whether
to file criminal charges. See, e.g., United States v. Alvarez-Sanchez, 

(9th Cir. 1992), rev’d on other grounds, 

(1994)
(holding that delaying a defendant’s arraignment “specifically to provide
federal officers with time to interrogate him . . . . is one of the most patent
violations of Rule 5(a) and suppression is required on the basis of that
delay alone”).
   7
     Although we do not believe that the video recorder malfunction justi-
fied delaying Liera’s arraignment to conduct a second (recorded) interro-
gation, we commend the government’s general practice of recording
interrogations.
14854                   UNITED STATES v. LIERA
  [7] Accordingly, we hold that the district court clearly erred
by refusing to suppress statements Liera made during his sec-
ond interrogation.8

                      III.     HARMLESS Error

   The government argues that even if the district court erred
in refusing to suppress the statements and evidence obtained
during Liera’s second interrogation, the error was harmless.
This argument fails.

   [8] An error is harmless if “it is more probable than not that
the error did not materially affect the verdict.” See United
States v. Seschillie, 

, 1214 (9th Cir. 2002), cert.
denied, 

(2003); United States v. Morales, 

, 1040 (9th Cir. 1997) (en banc). The government
bears the burden of persuasion and “ ‘we must reverse . . .
unless it is more probable than not’ that the error was harm-
less.” 

(emphasis in original)
(quoting 

). “[I]n cases of ‘equi-
poise,’ we reverse.” 

States v. Mitchell,

, 1111 (9th Cir. 1999)).

   Here, the government, at trial, repeatedly relied upon the
information gathered from the second interrogation. In partic-
ular, the government relied heavily on the data in the cell
phone and Liera’s statements regarding the “Pollos” cell
phone entry. The government also referred to the “Pollos”
cell-phone entry as the “smoking gun” during closing argu-
ment. Indeed, the government’s reference to the information
as a “smoking gun” strongly suggests that the improperly
admitted evidence was significant.
  8
   There is, however, insufficient evidence in the record to determine
whether, absent Liera’s statements, it was proper to admit into evidence
the data entries contained in the cell phone. On remand, the district court
should address this issue.
                        UNITED STATES v. LIERA                       14855
   Moreover, absent the cell phone entries and testimony
regarding “Pollos,” the evidence against Liera was not over-
whelming.9 There was no direct evidence to establish that
Liera had knowledge that Le Chen and Wu Chen were in the
engine compartment. Neither Le Chen nor Wu Chen identi-
fied Liera as a participant in the smuggling, and the govern-
ment does not dispute that the pick-up truck did not belong to
Liera, but instead belonged to his uncle’s neighbor.

   The fact that Liera was the sole occupant and driver of the
pick-up truck is insufficient to establish harmless error. See
United States v. Foster, 

, 1098-1101 (9th Cir.
2000) (stating that a less than compelling but plausible
account was sufficient to defeat harmless error); United States
v. Velarde-Gomez, 

, 1035 (2001) (en banc)
(refusing to find harmless error in a sole occupant and driver
case where the “theory of the defense, while not necessarily
compelling, was equally plausible”). Here, Liera’s claim that
he did not know that Le Chen and Wu Chen were under the
truck’s hood, while perhaps not particularly compelling, was
certainly plausible. This is sufficient to defeat the govern-
ment’s harmless error argument.10
  9
    The government also contends that the error was harmless because
Liera repeated the statements he now claims should be suppressed while
testifying at trial. This argument is unpersuasive. Absent the evidence
regarding “Pollos” obtained solely during the second interrogation, there
is no guarantee that Liera would have testified.
   10
      Additionally, the cases the government cites to support its harmless
error argument are not persuasive because they apply a more stringent
standard than the harmless error standard we must apply here. For exam-
ple, the government relies heavily upon United States v. Schemenauer,

, 752 (9th Cir. 2005) which presented a factual scenario simi-
lar to Liera’s case. In Schemenauer, we reviewed the sufficiency of the
evidence for clear error. Under the clear error standard, the court must
“view the evidence in the light most favorable to the government and ask
whether it is quite clear that no reasonable juror could have found the ele-
ments of each charge beyond a reasonable doubt.” 

States
v. Alarcon-Simi, 

, 1176 (9th Cir. 2002). Under a harmless
error standard, in contrast, the government bears the burden of establishing
that “it is more probable than not that the error did not materially affect
the verdict.” 

. Schemenauer‘s analysis is there-
fore inapplicable here.
14856                    UNITED STATES v. LIERA
   [9] Because the government placed significant emphasis on
the improperly admitted evidence, and because the evidence
establishing Liera’s knowledge was limited to the fact that he
was the sole occupant and driver of the truck, we find that the
government has failed to establish that “it is more probable
than not that the error did not materially affect the verdict.”

(citations and quotations omit-
ted). Accordingly, we hold that the error was not harmless.

              IV.     LIERA’S REMAINING ARGUMENTS

   Liera also argues that: (1) the district court improperly
admitted into evidence Le Chen’s hearsay testimony regard-
ing what his mother told him it would cost to have a person
smuggled into the United States; (2) the district court should
have suppressed all of Liera’s statements to CBP Officer
Figueroa because of non-compliance with Miranda v. Ari-
zona, 

(1966); and (3) the district court’s jury
instructions denied Liera his right to a jury finding on the
“specific intent” element of the aiding and abetting charge.
We reverse the district court’s ruling on the admission of Le
Chen’s testimony regarding his mother’s statements concern-
ing the cost of smuggling a person into the United States, but
affirm the district court’s ruling on the Miranda waiver and
jury instruction.

A. Le Chen’s Testimony Regarding What His Mother Told
 Him It Would Cost to Smuggle a Person into the United
                        States

   During Liera’s trial, Le Chen testified that while he was in
China his mother told him what it would cost to have a person
smuggled into the United States. The district court determined
that Le Chen’s mother (the “declarant”) was a co-conspirator
and that her statements to Le Chen were admissible as non-
hearsay under Federal Rule of Evidence 801(d)(2)(E).11 Liera
  11
     Rule 801(d)(2)(E) provides that a statement is not hearsay if “the
statement is offered against a party and is . . . a statement by a coconspira-
                         UNITED STATES v. LIERA                        14857
argues that there was insufficient evidence to establish that Le
Chen’s mother was involved in a conspiracy and that the testi-
mony was therefore inadmissable. We agree.

   [10] Before an alleged co-conspirator’s statement can be
admitted into evidence under Rule 801(d)(2)(E), the govern-
ment must establish that the declarant (Le Chen’s mother)
knowingly participated in a conspiracy. See United States v.
Castaneda, 

, 1507 (9th Cir. 1994) (“[A]n
accused’s knowledge of and participation in an alleged con-
spiracy with the putative co-conspirator are preliminary facts
that must be established, by a preponderance of the evidence,
before the co-conspirator’s out-of-court statements can be
introduced into evidence.”). To establish that the declarant
knowingly participated in a conspiracy, “the government can-
not rely solely on the [alleged] co-conspirator statements
themselves.” 

States v. Silverman, 

, 578 (9th Cir. 1988)).

   [11] Here, the only evidence offered by the government to
establish that Le Chen’s mother was involved in a conspiracy
are the hearsay statements the government sought to introduce
regarding what Le Chen’s mother told Le Chen. During
Liera’s trial, Le Chen testified that his mother told him that
a “middleman” was going to help smuggle Le Chen into the
United States. In particular, Le Chen’s mother told Le Chen
that they “would pay the same amount [their] neighbors paid
before,” and that Le Chen would work to pay back the money
once he arrived in the United States. Under Federal Rule of
Evidence 801(d)(2), these statements are insufficient to estab-
lish that Le Chen’s mother was involved in a conspiracy.12 See

tor of a party during the course and in furtherance of the conspiracy.” Rule
801(d)(2)(E) further provides that “[t]he contents of the statement shall be
considered but are not alone sufficient to establish . . . the existence of the
conspiracy and the participation therein of the declarant and the party
against whom the statement is offered.”
   12
      The government argues that there is sufficient independent evidence
to establish that Le Chen’s mother was a co-conspirator, because on one
14858                   UNITED STATES v. LIERA

(“[T]he government cannot rely
solely on the [alleged] co-conspirator statements them-
selves.”).

  [12] Accordingly, we hold that the district court erred by
admitting, under Rule 801(d)(2)(E), Le Chen’s hearsay testi-
mony regarding what his mother told him it would cost to
smuggle Le Chen into the United States.

                   B.    Liera’s Miranda Waiver

   [13] Liera also argues that the district court should have
suppressed all of his post-arrest statements for non-
compliance with Miranda v. Arizona, 

(1966). A
district court’s finding that a Miranda waiver was knowing
and intelligent is a factual finding and is reviewed for clear
error. Collazo v. Estelle, 

, 415-16 (9th Cir. 1991)
(en banc). Here, the record demonstrates that Liera knowingly
and voluntarily waived his Miranda rights. Liera testified that
he waived his Miranda rights and Liera’s counsel repeatedly
stated that there had been a valid and knowing Miranda
waiver. The district court therefore properly denied Liera’s
motion to suppress his post-arrest statements to the CBP offi-
cers.

          C.    The District Court’s Jury Instructions

   [14] Finally, Liera argues that the district court’s jury
instructions denied Liera his right to a jury finding on the
“specific intent” element of the aiding and abetting charge.
Because Liera did not raise an objection to the jury instruc-

occasion Le Chen saw his mother speaking to a man he thought was the
“middleman.” This argument fails. Le Chen testified that he never person-
ally met or spoke to the “middleman” and that he was not present for the
conversation between his mother and this man. Accordingly, it does not
constitute sufficient independent evidence to establish that Le Chen’s
mother was involved in a conspiracy.
                    UNITED STATES v. LIERA                14859
tions at trial, we review for plain error. United States v. Arm-
strong, 

, 1244 (9th Cir. 1990). Here, the district
court’s jury instructions on the aiding and abetting theory
required the jury to find that: (1) someone committed the
underlying offense; and (2) that Liera aided and abetted its
commission. Under the plain error standard of review, this is
all that is required. 

.

                       V.   CONCLUSION

   [15] We hold that the district court erred by not suppressing
statements Liera made during the second interrogation
because law enforcement officers unnecessarily delayed pre-
senting Liera to a magistrate for arraignment in violation of
Rule 5(a), 18 U.S.C. § 3501(c), and the McNabb-Mallory
Rule. The district court’s admission of the statements Liera
made during the second interrogation was not harmless. We
also hold that the district court erred by admitting into evi-
dence Le Chen’s testimony regarding his mother’s statements
concerning the cost of smuggling a person into the United
States. We affirm the district court’s ruling on the Miranda
waiver and the district court’s jury instructions. Liera’s con-
victions are vacated, and we remand for a new trial.

  VACATED and REMANDED.