                     FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                        Nos. 16-10184
                 Plaintiff-Appellee/                   16-10225
                   Cross-Appellant,
                                                      D.C. No.
                      v.                           3:14-cr-00412-
                                                       TEH-1
 VALENTINO JOHNSON,
              Defendant-Appellant/
                   Cross-Appellee.                    OPINION



       Appeal from the United States District Court
          for the Northern District of California
  Thelton E. Henderson, Senior District Judge, Presiding

         Argued and Submitted September 14, 2017
                 San Francisco, California

                    Filed November 27, 2017

        Before: Eugene E. Siler, * Richard C. Tallman,
              and Carlos T. Bea, Circuit Judges.

                   Opinion by Judge Tallman

    *
     The Honorable Eugene E. Siler, United States Circuit Judge for the
U.S. Court of Appeals for the Sixth Circuit, sitting by designation.
2                 UNITED STATES V. JOHNSON

                          SUMMARY **


                          Criminal Law

    The panel affirmed the defendant’s conviction as a felon
in possession of a firearm, and, on the government’s cross-
appeal, vacated the sentence and remanded for resentencing.

    The panel held that the warrantless searches of the
defendant’s cell phone were constitutionally reasonable,
given his status as a parolee and his reduced expectation of
privacy. The panel held that delays in searching his phone
were not unreasonable.

    Regarding the defendant’s argument that a handgun
discovered during a search of his aunt’s residence should
have been suppressed, the panel held that the district court
did not clearly err in finding that the defendant’s aunt gave
valid verbal consent for the search, where the district court
credited the officers’ testimony and not that of the defense
witnesses.

   The panel rejected the defendant’s challenge to the
admission of testimony from an officer about the defendant’s
aunt’s out-of-court statements in a recorded interview. The
panel held that the defendant’s aunt’s statements were not
hearsay and their admission did not violate the defendant’s
Confrontation Clause rights, given the government’s need to
rebut the defendant’s third-party culpability defense. The



    **
       This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
                UNITED STATES V. JOHNSON                   3

panel held that, in any event, any error was harmless and did
not affect the defendant’s substantial rights.

    The panel held that the district court did not abuse its
discretion in denying the defendant’s Daubert motion to
exclude a firearms examiner’s testimony and a written
ballistics analysis.

    Applying United States v. Barragan, 871 F.3d 689 (9th
Cir. 2017), the panel, on the government’s cross-appeal,
vacated the defendant’s sentence and remanded with
instructions to treat the defendant’s prior armed robbery
conviction under Calif. Penal Code § 211(a) as a crime of
violence under the Sentencing Guidelines.


                        COUNSEL

Aaron T. Chiu (argued), Erin E. Wilk, and Niall E. Lynch,
Latham & Watkins LLP, San Francisco, California, for
Defendant-Appellant/Cross-Appellee.

Merry J. Chan (argued), Assistant United States Attorney; J.
Douglas Wilson, Chief, Appellate Division; Brian J. Stretch,
United States Attorney; United States Attorney’s Office, San
Francisco, California; for Plaintiff-Appellee/Cross-
Appellant.


                        OPINION

TALLMAN, Circuit Judge:

    Valentino Johnson was convicted as a felon in
possession of a firearm, in violation of 18 U.S.C.
§§ 922(g)(1) & 924(e), after an emergency 911 call reporting
4               UNITED STATES V. JOHNSON

an attempted suicide led San Francisco police to discover a
handgun at the apartment where Johnson was temporarily
staying while on parole. Johnson challenges the denial of
two motions to suppress evidence gathered during the
warrantless search of the residence and a subsequent
warrantless search of his cell phone, which revealed
incriminating evidence tying him to the gun. Johnson also
appeals the admission of witness testimony on hearsay
grounds, and he claims a violation of his Confrontation
Clause rights at trial. Finally, Johnson challenges the denial
of his Daubert motion to exclude expert ballistics testimony
further linking him to the weapon found by the police.

    The government cross-appeals the district court’s
determination at sentencing that Johnson’s prior conviction
for armed robbery under California Penal Code (“CPC”)
§ 211(a) did not qualify as a “crime of violence” for
purposes of establishing Johnson’s base offense level.
U.S.S.G. §§ 2K2.1, 4B1.2. We affirm the district court on
all issues raised in Johnson’s direct appeal, but vacate
Johnson’s sentence based on the government’s cross-appeal
and remand with instructions that a conviction under CPC
§ 211(a) qualifies as a crime of violence, warranting a base
offense level of 24 under U.S.S.G. § 2K2.1(a)(2).

                              I

    On February 2, 2014, Valentino Johnson’s ex-girlfriend
called 911 from Emeryville, California, to report that
Johnson had threatened to kill himself with a gun. The caller
informed the dispatcher that Johnson was at the home of his
                   UNITED STATES V. JOHNSON                           5

aunt, Luana McAlpine, 1 in San Francisco, and that she had
received a “hysterical” call from McAlpine alleging Johnson
had shot himself.

    San Francisco Police Department (“SFPD”) officers
were dispatched to McAlpine’s apartment in a Bayview
District public housing project. Before they arrived,
responding officers received additional information about
Johnson. Dispatch informed the officers that Johnson did
not live at the Bayview District apartment. Mobile data
terminal readouts from patrol car computers showed that
Johnson’s address on file with the California Department of
Motor Vehicles was in Emeryville, across the bay, in
Alameda County. But the readouts also showed that a
domestic violence temporary restraining order had been
issued on January 29, commanding that Johnson move out
from the Emeryville address. Four days earlier, SFPD
officers in the Bayview area, where McAlpine resided, had
also received an All-Points Bulletin (“APB”) advising that
Johnson was a suspect in a recent armed burglary involving
a damaged 9mm handgun. According to the APB, Johnson
was currently on mandatory parole supervision and had prior
arrests for murder, attempted murder, assault, kidnapping,
false imprisonment, domestic violence, carjacking, and
robbery.

    Arriving officers discovered the 911 call had been a false
alarm. They saw Johnson—alive and unharmed—peering
down from an upstairs window, and officers asked to speak
with Johnson and McAlpine outside. Johnson and McAlpine
complied, but the parties dispute what happened next. We

    1
       McAlpine later explained that she is not actually Johnson’s blood
relative, but rather that they are close friends who were at one time
romantically involved.
6               UNITED STATES V. JOHNSON

credit the testimony admitted by the district court at the
evidentiary hearing, after which the district judge made
express credibility findings as to whose stories the fact-
finder believed. SFPD Officer Wise testified that both
McAlpine and Johnson stated that Johnson lived at the San
Francisco residence. On direct examination, McAlpine
testified she told police only she and her daughter, Norrisha
Rivers, lived there. But on cross-examination, McAlpine
testified she may have told officers that Johnson was either
living or paroled there (and that Johnson had provided his
parole officer with that address). The district court credited
the officers’ testimony.

    McAlpine said that within minutes, more than a dozen
officers had arrived at the scene. None had guns drawn.
According to Officers Cader and Wise, they asked McAlpine
if officers could check inside the apartment to ensure no one
had been hurt, and McAlpine consented. McAlpine, on the
other hand, testified that she assumed the officers were
conducting a parole search (pursuant to a condition of
Johnson’s parole status, about which she previously knew),
and therefore she felt she could not refuse entry to the
officers. Wise testified he did not inform McAlpine that the
search was a parole search. The search did not begin until
McAlpine consented. The officers then proceeded to search
the apartment without a warrant.

   Inside the apartment, Officer Cader discovered a Taurus
PT-92 semi-automatic 9mm pistol in a box in an upstairs
bedroom used by Norissha Rivers. The magazine of the gun
was missing, and part of the gun’s heel was damaged.
Officers also discovered 68 rounds of various types of
ammunition in a dry bag on a second-floor balcony outside
Rivers’s bedroom. In Rivers’s bedroom, they also found
Johnson’s clothing, mail, and three prescription bottles in his
                UNITED STATES V. JOHNSON                   7

name, as well as clothing belonging to Rivers’s boyfriend,
Jakieth Martin.

    Outside the apartment, Sergeant Plantinga asked
McAlpine in a recorded conversation about the gun’s
ownership. McAlpine responded, “I know it’s not mine, I
know it’s not my daughter’s, and there’s only one other
person it could’ve been, and that is Valentino Johnson.”
Plantinga had McAlpine sign a written consent form
authorizing the search. McAlpine testified that, around the
time of her conversation with Sergeant Plantinga, another
officer threatened that she could lose her public housing if
she was not honest and truthful. The officers denied that
threat, stating that only after the gun was found did
McAlpine become upset because it could cause her problems
with the housing authority. The district court explicitly
found that the testimony of the several officers was more
credible than that of McAlpine.

     During the search, officers handcuffed Johnson outside
the apartment. Lieutenant Braconi explained to Johnson that
SFPD was responding to a 911 call from his ex-girlfriend
about an attempted suicide. Johnson told Lieutenant Braconi
to check the call logs and text messages on his cell phone to
prove he had not contacted his ex-girlfriend or threatened to
kill himself. Braconi verified that no calls were made from
Johnson’s cell phone around the time of the 911 call.

    After the gun was discovered, Johnson was taken into
custody. During an interview with Sergeants Jonas and
Plantinga at the Bayview police station, Johnson said he had
been staying with McAlpine because he had fought with his
ex-girlfriend and later had been served with a restraining
order. He told Jonas and Plantinga to again “look at the text
messages on [his] phone” to verify that he had tried to
reconcile with his ex-girlfriend around January 21, 2014.
8                   UNITED STATES V. JOHNSON

After the interview, Johnson remained in custody and his
phone was given to Sergeant Jonas for forensic analysis.

     Three days later, on February 5, 2014, SFPD’s
multimedia forensics unit reported to Jonas that they were
unable to make a digital copy of the phone’s contents
because the phone was too new for the unit’s software.
Instead, Jonas searched the phone by hand without first
obtaining a warrant. Sergeant Jonas scrolled through old text
messages sent from Johnson’s phone, making screen shots
of relevant information. He found an incriminating text sent
on January 28, 2014, that read: “Who you know that has 9-
mm clips? I just busted mine. It’s a PT-92 Taurus. . . . So
how do I get it?” One year later, on February 2, 2015, after
Johnson had been indicted on federal charges but before
trial, the Bureau of Alcohol, Tobacco, Firearms &
Explosives (“ATF”) obtained a search warrant for the phone,
and the text message was admitted at trial.

                                     II

    On July 31, 2014, a federal grand jury indicted Johnson
on a single count of being a felon in possession of the
handgun, in violation of 18 U.S.C. §§ 922(g)(1) & 924(e). 2
Before trial, Johnson moved to suppress the handgun and
text messages found on his cell phone as the products of
illegal searches. After conducting an evidentiary hearing to
establish the facts, the district court denied the motions on
the grounds that McAlpine had consented to the search of

    2
        The grand jury later returned a superseding indictment, adding an
additional count of obstruction of justice, 18 U.S.C. § 1512(c)(2), after
Johnson was recorded on jail telephones suborning perjury from
McAlpine as to who owned the gun. The district court severed that count
before trial on the gun charge, and the government voluntarily dismissed
it after the jury returned a guilty verdict on the felon in possession charge.
                UNITED STATES V. JOHNSON                    9

her apartment and that the warrant requirement does not
apply to searches of parolees’ cell phones. The court also
allowed into evidence at trial, over objection, testimony from
Jonas regarding McAlpine’s statement to Sergeant Plantinga
that the gun must have belonged to Johnson. Additionally,
the court denied Johnson’s motion to exclude expert
testimony from SFPD’s ballistics expert, Mark Proia. After
a five-day trial, the jury returned a guilty verdict.

    Johnson was sentenced on April 4, 2016. When
calculating Johnson’s base offense level, the district court
declined to classify Johnson’s prior armed robbery
conviction under CPC § 211(a) as a crime of violence for
purposes of the career-offender enhancement. See U.S.S.G.
§ 2K.1(a)(2). The court therefore assumed Johnson had only
one prior conviction for a crime of violence, a 1994
conviction for assault with a firearm, and calculated the base
offense level as 20. See U.S.S.G. § 2K.1(a)(4)(A). The
court applied a two-level enhancement for the attempted
obstruction of justice. See U.S.S.G. § 3C1.1. With a
criminal history category of V, the court calculated the
Guidelines range as 77 to 96 months, and imposed a sentence
of 96 months in prison. The district court entered final
judgment, and Johnson timely appealed. The government
cross-appealed the district court’s sentencing determination.
We have jurisdiction under 28 U.S.C. § 1291.

                             III

    Johnson first argues that the warrantless searches of his
cell phone violated his Fourth Amendment rights. He asks
us to find that Riley v. California, 134 S. Ct. 2473 (2014),
and our decision in United States v. Lara, 815 F.3d 605 (9th
Cir. 2016), apply to parolees. Riley held that warrantless
searches of cell phones incident to arrest violate the Fourth
Amendment, 134 S. Ct. at 2485, while Lara held that the
10              UNITED STATES V. JOHNSON

same principle applied to suspicionless searches of
probationers’ cell phones, 815 F.3d at 612. Johnson further
contends that his Fourth Amendment rights were violated
because the searches of his cell phone were unreasonably
delayed.

     The government responds that Riley and Lara do not
apply in the parolee search context because the balance of
privacy interests and factual circumstances in this context
are different. Alternatively, the government argues that,
even if the Constitution normally requires warrants for
searches of parolees’ cell phones, no constitutional violation
occurred here, because: (1) Johnson consented to a search
of his phone; (2) any constitutional error was cured by the
later-obtained federal warrant; and (3) the searching
officers’ conduct falls under the good-faith exception to the
exclusionary rule given the state of the law at the time of the
trial. Because Johnson’s status as a parolee significantly
diminishes his privacy interests compared to the defendants
in Riley and Lara, we affirm the district court’s ruling. 3

                              A

    We review the denial of Johnson’s suppression motion
de novo, and “the district court’s factual findings for clear
error.” United States v. Sullivan, 797 F.3d 623, 632–33 (9th
Cir. 2015). “[T]he ultimate touchstone of the Fourth
Amendment is reasonableness.” Riley, 134 S. Ct. at 2482
(quoting Brigham City v. Stuart, 547 U.S. 398, 403 (2006)).
Determining the reasonableness of a particular search
involves balancing “on the one hand, the degree to which
[the search] intrudes upon an individual’s privacy, and on

    3
      Because we affirm on this ground, we do not reach the
government’s alternate arguments.
                   UNITED STATES V. JOHNSON                           11

the other, the degree to which [the search] is needed for the
promotion of legitimate governmental interests.” Lara,
815 F.3d at 610 (alterations in original) (quoting United
States v. Knights, 534 U.S. 112, 119 (2001)).

    We have repeatedly recognized that status as a parolee 4
significantly diminishes one’s privacy interests as compared
to the average citizen. See Samson v. California, 547 U.S.
843, 850 (2006). “[P]arole is an established variation on
imprisonment of convicted criminals” and granted only “on
the condition that the prisoner abide by certain rules during
the balance of the sentence.” Id. (quoting Morrissey v.
Brewer, 408 U.S. 471, 477 (1972)). Parolees are thus subject
to various state-imposed intrusions on their privacy,
including mandatory drug tests, meetings with parole
officers, and travel restrictions. Id. at 851. California law
also specifically provides that all parolees shall be “subject
to search or seizure by a probation or parole officer or other
peace officer at any time of the day or night, with or without
a search warrant or with or without cause.” Cal. Penal Code
§ 3067(b)(3).

   “[R]estrictions on a parolee’s liberty are not
unqualified,” however, and parolees still enjoy limited




    4
      Although Johnson was classified as being under “mandatory
supervision” by a parole officer under CPC § 1170(h)(5)(B), we have
previously held that “the State’s interest in supervising offenders placed
on mandatory supervision is comparable to its interest in supervising
parolees.” See United States v. Cervantes, 859 F.3d 1175, 1181 (9th Cir.
2017), as amended, __ F.3d __ (Sept. 12, 2017). Therefore, we conduct
our analysis and refer to Johnson as a “parolee.”
12                UNITED STATES V. JOHNSON

Fourth Amendment rights. 5 Samson, 547 U.S. at 850 n.2.
Recent case law emphasizes that even offenders with
otherwise reduced privacy expectations—arrestees in Riley,
and probationers in Lara—have a right to be free from
unreasonable searches of their cell phones. In Riley, the
Supreme Court reasoned that because cell phones store vast
quantities of sensitive data, and because cell phones have
become ubiquitous, the privacy interests implicated in cell
phone searches are particularly acute. See 134 S. Ct. at
2489–91. Unlike other types of searches, the search of a
person’s cell phone can “typically expose . . . far more than
the most exhaustive search of a house,” as modern cell
phones contain “[t]he sum of an individual’s private life.”
Id. at 2489, 2491. The unique features of cell phones led the
Court to conclude that

         [c]ell phones differ in both a quantitative and
         a qualitative sense from other objects that
         might be kept on an arrestee’s person. The
         term “cell phone” is itself misleading
         shorthand; many of these devices are in fact
         minicomputers that also happen to have the
         capacity to be used as a telephone. They
         could just as easily be called cameras, video
         players, rolodexes, calendars, tape recorders,
         libraries, diaries, albums, televisions, maps,
         or newspapers.

Id. at 2489. Riley’s emphasis on the almost sui generis
nature of cell phones weighed heavily in Lara. In that case,
despite the defendant’s status as a probationer, and even

     5
       For example, California courts have held that parole searches
violate the Fourth Amendment if they are “arbitrary, capricious, or
harassing.” People v. Reyes, 968 P.2d 445, 450 (Cal. 1998).
                UNITED STATES V. JOHNSON                   13

though he agreed to “submit [his] person and property,
including any residence, premises, container or vehicle
under [his] control to search and seizure” as a term of his
probation, we ultimately concluded that the defendant’s
privacy interest “was substantial in light of the broad amount
of data contained in, or accessible through, his cell phone.”
Lara, 815 F.3d at 611–12. Under Riley and Lara, therefore,
Johnson’s claim of an enhanced privacy interest in the
contents of his cell phone appears weighty.

    As previously noted, however, the government’s interest
in supervising parolees is “substantial.” Samson, 547 U.S.
at 853. Those interests include combating recidivism,
promoting reintegration, and effectively detecting parole
violations. Id. at 853–54. Requiring officers to obtain a
warrant before searching a parolee’s cell phone would often
undermine the state’s ability to supervise effectively
thousands of parolees and prevent concealment of criminal
conduct as in the case here. See id. at 854. Lara held that
these governmental interests were ultimately insufficient to
overcome a probationer’s substantial privacy interest in his
cell phone, although the government’s interests were
reduced when the suspected probation violation (missing an
appointment with the probation officer) was not a serious or
violent crime. See 815 F.3d at 612.

    Despite these significant competing interests, we hold
that the warrantless searches of Johnson’s cell phone were
constitutionally reasonable, given Johnson’s status as a
parolee. Johnson’s parolee status may be of even greater
concern here due to his lengthy and serious criminal history
involving violent offenses. But most persons released on
parole supervision are completing a sentence that involved
incarceration for serious offenses. We do not think a
workable rule can be fashioned for officers on the street
14               UNITED STATES V. JOHNSON

based on an argument that police should first examine the
severity of the parolee’s prior criminal record in determining
whether or not they may conduct a warrantless search of a
parolee or his cell phone when the parolee is subject to a
search condition. 6

    While privacy interests in cell phones are significant,
Johnson’s parole status alone distinguishes our case from
Lara and Riley. It is well established that parolees have
reduced privacy interests compared to probationers, see, e.g.,
Samson, 547 U.S. at 850; Lara, 815 F.3d at 610, and even
more so compared to those persons who have been arrested
but not convicted. Indeed, “[o]n the ‘continuum’ of state-
imposed punishments,” parolees appear to hold the most
limited privacy interests among people convicted of a crime
but are not actually imprisoned. See Samson, 547 U.S. at
850 (explaining that “parole is more akin to imprisonment”
than probation, and that “parole is an established variation
on imprisonment of convicted criminals” (quoting
Morrissey, 408 U.S. at 477)). Moreover, as a parolee,
Johnson knew that under CPC § 3067, he could be searched
“at any time of the day or night, with or without a search
warrant or with or without cause.” (emphasis added). This
search condition sweeps more broadly than the probation
search condition at issue in Lara, which we held did not
apply to cell phone searches because the search condition in
Lara referred specifically to searches of “containers” and
“property.” 815 F.3d at 610–11.

     6
      Before commencing parole, the parolee is informed and must
acknowledge in writing that he and his property are subject to the
warrantless search condition under CPC § 3067(b)(3). Both McAlpine
and Johnson admitted they were aware of this condition of Johnson’s
mandatory parole supervision before police arrived at the Bayview
apartment.
                UNITED STATES V. JOHNSON                   15

    The government’s interests in searching Johnson’s cell
phone were also weightier than the governmental interests at
stake in Lara, where the cell phone search occurred after the
defendant missed a probation meeting. Accordingly, we
held that this violation was “worlds away from the suspected
crimes”—such as arson and homicide—that had justified
warrantless searches of probationers’ homes in other cases.
Id. at 612 (distinguishing Knights, 534 U.S. at 112, and
United States v. King, 736 F.3d 805, 806 (9th Cir. 2013)).
Here, at the time of the cell phone search, officers knew
Johnson had a violent criminal history, and had reason to
believe his cell phone contained evidence of serious parole
violations, including possession and use of a firearm in a
residential burglary. As such, there was no evidence
showing that the officer’s purpose in trying to determine
what had happened was “arbitrary, capricious, or harassing.”
Therefore, because Johnson was a parolee, subject to CPC
§ 3067(b)(3), and under the Fourth Amendment he had a
reduced expectation of privacy, we affirm the district court’s
finding that the search of Johnson’s cell phone did not
violate his Fourth Amendment rights.

                              B

    Independent of the warrantless searches of his cell
phone, Johnson alleges that his Fourth Amendment rights
were violated because the cell phone searches conducted on
February 5, 2014, and February 2, 2015, unconstitutionally
prolonged the seizure of his phone. “An unreasonable delay
between the seizure of a package and obtaining a search
warrant may violate [a] defendant’s Fourth Amendment
rights.” Sullivan, 797 F.3d at 633. “The touchstone is
reasonableness.” Id.

    We hold the delays in searching Johnson’s phone were
not unreasonable. Johnson had reduced privacy interests in
16               UNITED STATES V. JOHNSON

his phone given his parolee status, and Johnson never sought
return of his phone while he was in continuous custody since
he was arrested on February 2, 2014. See id. at 633–34
(holding that a 21-day delay before the search of a parolee’s
laptop was reasonable). The government obtained the phone
lawfully, and there is no evidence the delays were the result
of dilatory tactics by the state. See United States v. Mulder,
889 F.2d 239, 241 (9th Cir. 1989) (finding a one-year delay
reasonable, where the defendant’s pills were not obtained
“as the result of an unlawful search,” the defendant “never
made a motion for the return of the pills,” and “the time lapse
was the result of the judicial appeal process rather than any
dilatory tactics”); see also United States v. Burnette,
698 F.2d 1038, 1049 (9th Cir. 1983) (“[O]nce an item . . .
has been lawfully seized and searched, subsequent searches
of that item, so long as it remains in the legitimate
uninterrupted possession of the police, may be conducted
without a warrant.”). Furthermore, the initial three-day
delay occurred because SFPD’s multimedia unit was
unsuccessful in attempting to download the contents of the
phone, which was too new for the unit’s imaging software.
And the February 2, 2015, search was conducted under
authority of a search warrant for which there was ample
probable cause. Under the totality of the circumstances, the
delays were reasonable and did not render the searches
“arbitrary, capricious, or harassing.” See Reyes, 968 P.2d at
450.

                              IV

    Johnson next argues that the district court erred in
finding (1) that McAlpine gave valid consent to the search
of her apartment, or (2) in the alternative, that the responding
officers conducted a lawful parole search. Accordingly, he
argues that the handgun discovered during the search of
                 UNITED STATES V. JOHNSON                    17

McAlpine’s residence should have been suppressed. The
factual findings of the district court resolve the issue.
Despite the conflicting testimony of the witnesses reflected
in the record, we hold that the district court did not clearly
err in finding that McAlpine gave valid verbal consent for
the search because the district court credited the officers’
testimony and not that of the defense witnesses.

    We review a district court’s factual determination of
valid consent to a search for clear error. United States v.
Washington, 490 F.3d 765, 769 (9th Cir. 2007). The
government bears “the burden of proving that the consent
was, in fact, freely and voluntarily given.” Bumper v. North
Carolina, 391 U.S. 543, 548 (1968). “Whether consent to
search was voluntarily given or not is ‘to be determined from
the totality of all the circumstances.’” United States v. Chan-
Jimenez, 125 F.3d 1324, 1327 (9th Cir. 1997) (quoting
Schneckloth v. Bustamonte, 412 U.S. 218, 227 (1973)). We
consider five factors to assess whether consent was
voluntary:

       (1) whether defendant was in custody; (2)
       whether the arresting officers have their guns
       drawn; (3) whether Miranda warnings have
       been given; (4) whether the defendant was
       told he has a right not to consent; and
       (5) whether defendant was told a search
       warrant could be obtained.

United States v. Russell, 664 F.3d 1279, 1281 (9th Cir. 2012)
(quoting United States v. Morning, 64 F.3d 531, 533 (9th
Cir. 1995)). The rule is that failing to object to police entry,
when no request for permission to enter was made, does not
constitute effective consent. United States v. Shaibu,
920 F.2d 1423, 1428 (9th Cir. 1990).
18              UNITED STATES V. JOHNSON

      Here, it is undisputed that McAlpine was not in custody
when she was questioned, and officers did not have their
weapons drawn. No Miranda warnings were given, but “[i]t
would . . . make little sense to require that Miranda warnings
. . . be given by police before requesting consent.” Russell,
664 F.3d at 1281 (quoting United States v. Vongxay,
594 F.3d 1111, 1120 (9th Cir. 2010)). Nothing in the record
establishes that McAlpine was told she had a right not to
consent, so the fourth factor weighs in Johnson’s favor.
There is no evidence that McAlpine was told that a search
warrant could be obtained, so as to imply that her refusal to
consent would be fruitless, though she said she knew
Johnson was subject to a warrantless search condition
because he was on parole. The Russell factors, therefore,
weigh in favor of upholding the district court’s finding that
McAlpine’s consent was freely given.

    Johnson argues the record establishes that the search of
McAlpine’s residence was conducted as a parole search, and
the government has tried post hoc to justify the warrantless
search as a consent search. He relies on McAlpine’s
testimony that one of the officers told her they would
conduct a parole search, and therefore she felt she “had no
other choice” but to allow the officers entry. He also points
to the testimony of Officers Vannuchi, Ortiz, Basurto,
Plantinga, and Cader, who all testified they understood they
were conducting a parole search. Johnson further asserts that
McAlpine could not give valid consent because she felt
pressured by the number of officers present, and she was
threatened with having her public housing taken away.
Johnson also contends that racial dynamics played a role.

   Although there is evidence to support Johnson’s
contention that later-arriving officers believed they were
conducting a parole search, the officers who first
                   UNITED STATES V. JOHNSON                         19

interviewed McAlpine—Wise and Cader—testified
otherwise. They both said that they asked McAlpine if she
would permit officers to check the apartment to make sure
no one was hurt and to secure any weapon, and she agreed.
Wise’s incident report reflects this account. Wise also
testified that he did not hear any officer tell McAlpine that
they were conducting a parole search. Sergeant Plantinga
testified he thought it was both a parole search and a consent
search. Regarding the alleged threat to McAlpine’s
continued public housing eligibility, the district court
credited evidence that McAlpine became upset about losing
her housing after the gun was discovered, not before the
search occurred. Prior to that development, officers testified
that relations with McAlpine were cordial and polite when
she gave consent.

    Given this conflicting testimony and the district court’s
conclusion that the officers testified more credibly, we hold
that the district court did not clearly err in finding McAlpine
gave valid verbal consent for the search. 7 The record does
not compel the conclusion that McAlpine could not validly
consent because the officers told her they were conducting a
parole search. Even if later-arriving officers assumed they
were conducting a parole search, the record supports the
court’s factual finding that McAlpine first verbally
consented to the search after Wise and Cader asked if they
could enter the residence to ensure that everyone inside was
safe.


    7
       The district court properly concluded that McAlpine’s written
consent, provided after the search had already occurred, did not
retroactively establish valid consent. United States v. Howard, 828 F.2d
552, 556 (9th Cir. 1987). It is, however, corroborative of the officers’
testimony that she had earlier consented orally to the search.
20              UNITED STATES V. JOHNSON

                              V

     Johnson also challenges the admission of testimony at
trial from Sergeant Jonas about McAlpine’s out-of-court
statements to Plantinga in a recorded interview. Jonas
testified, “[McAlpine] said there was only one person [the
gun] could belong to, and that was Valentino Johnson.”
Johnson contends that Jonas’s testimony was hearsay and
violated Johnson’s Confrontation Clause rights.           But
Johnson’s defense theory offered to the jury was that the gun
belonged to his cousin, Jakieth Martin.           Given the
government’s need to rebut Johnson’s third-party culpability
defense, we hold that McAlpine’s statements were not
hearsay and did not violate his constitutional rights. See
Tennessee v. Street, 471 U.S. 409, 414 (1985) (permitting
evidence as nonhearsay when used to rebut the defense
theory).

    We review the interpretation of the rule against hearsay
de novo, United States v. Mitchell, 502 F.3d 931, 964 (9th
Cir. 2007), and the admission of evidence under a hearsay
exception for abuse of discretion, United States v. Molina,
596 F.3d 1166, 1168 (9th Cir. 2010). Generally, we review
whether the admission of evidence violated the
Confrontation Clause de novo, but if the defendant failed to
raise a Confrontation Clause objection at trial, we review for
plain error. United States v. Matus-Zayas, 655 F.3d 1092,
1098 (9th Cir. 2011).

    Hearsay is an out-of-court statement offered for the truth
of the matter asserted. Fed. R. Evid. 801(c). The
Confrontation Clause forbids “admission of testimonial
statements of a witness who did not appear at trial unless he
was unavailable to testify, and the defendant had had a prior
opportunity for cross-examination.”            Crawford v.
Washington, 541 U.S. 36, 53–54 (2004). “Crawford applies
                 UNITED STATES V. JOHNSON                      21

only to testimonial hearsay, and ‘does not bar the use of
testimonial statements for purposes other than establishing
the truth of the matter asserted.’” United States v.
Wahchumwah, 710 F.3d 862, 871 (9th Cir. 2013) (quoting
Crawford, 541 U.S. at 59).

    Here, McAlpine’s statements to Sergeant Plantinga were
clearly testimonial, because they were “[s]tatements taken
by [a] police officer[] in the course of interrogations.” See
Crawford, 541 U.S. at 52. Furthermore, although McAlpine
testified at the suppression hearing, she did not testify at trial
and the government did not show that she was unavailable.
Whether McAlpine’s out-of-court statements were hearsay
and violated the Confrontation Clause thus hinges on
whether the statements were admitted for a legitimate
nonhearsay purpose.          The government asserts that
McAlpine’s statements were not offered for their truth, but
to explain why the government focused its investigation on
Johnson rather than Jakieth Martin. The government
contends this was relevant to rebutting Johnson’s suggestion
that the gun belonged to Martin, and that SFPD’s failure to
investigate Martin was sloppy police work.

    Courts must exercise caution to ensure that out-of-court
testimonial statements, ostensibly offered to explain the
course of a police investigation, are not used as an end-run
around Crawford and hearsay rules, particularly when those
statements directly inculpate the defendant. See, e.g., United
States v. Silva, 380 F.3d 1018, 1020 (7th Cir. 2004)
(“Allowing agents to narrate the course of their
investigations, and thus spread before juries damning
information that is not subject to cross-examination, would
go far toward abrogating the defendant’s rights under the
sixth amendment and the hearsay rule.”). We previously
have rejected the government’s proffered nonhearsay
22              UNITED STATES V. JOHNSON

rationale when, for example, explaining that the course of
the police investigation was not relevant to the government’s
case. See, e.g., United States v. Dean, 980 F.2d 1286 (9th
Cir. 1992); United States v. Makhlouta, 790 F.2d 1400 (9th
Cir. 1986). In these cases, we determined the out-of-court
statements were inadmissible because they were not relevant
to prove anything other than their truth. But here,
McAlpine’s statements were relevant to rebutting Johnson’s
theory of the case: to rebut Johnson’s claim that the police
were sloppy and had no reason to investigate Johnson’s
property, rather than investigate Jakieth Martin’s.

    To ensure further that McAlpine’s out-of-court
statements would not be considered for their truth, the
district court properly and contemporaneously instructed the
jury that the statements were to be considered only for
nonhearsay purposes. The jury was again reminded of this
admonition in the final jury instructions.          And the
prosecution made no reference to McAlpine’s statements
during closing arguments. Cf. Ocampo v. Vail, 649 F.3d
1098, 1112–13 (9th Cir. 2011) (finding that the
prosecution’s reliance on out-of-court statements during
closing arguments indicated that the statements were
intended for a hearsay purpose). The district court therefore
did not abuse its discretion in admitting Jonas’s testimony
for a legitimate nonhearsay purpose.

    But even if Jonas’s testimony was inadmissible hearsay,
we find that any error was harmless and did not affect
Johnson’s substantial rights. See United States v. Blandin,
435 F.3d 1191, 1195 (9th Cir. 2006). Setting aside
McAlpine’s statements, the government presented
compelling additional evidence to link Johnson to the gun,
including the text messages on Johnson’s phone, the
                   UNITED STATES V. JOHNSON                           23

evidence from the prior armed burglary, and ballistics
evidence.

                                   VI

    Finally, Johnson appeals the denial of his Daubert
motion to exclude expert testimony from an SFPD firearms
examiner, Mark Proia, as well as a written ballistics analysis
produced by the SFPD firearms unit. 8 This evidence linked
a test bullet fired from the PT-92 Taurus found at the San
Francisco residence to a live round recovered from the scene
of a burglary to which Johnson’s brother pled guilty in 2011.
Proia’s testimony and the written report relied on the
Association of Firearm and Toolmark Examiners (“AFTE”)
methodology, which involves making feature-comparisons
of bullet markings (“striations”) to determine if different
bullets were fired from the same gun. 9 Johnson argues that
Proia misapplied the AFTE methodology and that the
methodology is inherently unreliable under the Daubert
factors. 10 We review the district court’s admission of expert

     8
       The government initially planned to offer expert testimony through
Tasha Smith, an SFPD firearms examiner trainee who authored the
ballistics report under Proia’s supervision. Johnson’s Daubert motion
thus focused on Smith’s planned testimony, even though Proia ultimately
testified at trial.
    9
      Specifically, the AFTE methodology involves identifying three
types of toolmarks: (1) class characteristics, which are features shared
by many weapons of the same type; (2) individual characteristics, which
are unique to a particular weapon; and (3) subclass characteristics, which
may be common to a small group of firearms manufactured at the same
time. United States v. Monteiro, 407 F. Supp. 2d 351, 360–61 (D. Mass.
2006) (describing the methodology in detail).
    10
       These factors are: (1) whether the method has been tested;
(2) whether the method “has been subjected to peer review and
24                  UNITED STATES V. JOHNSON

testimony for abuse of discretion. United States v. Cazares,
788 F.3d 956, 975–76 (9th Cir. 2015).

     First, Johnson contends that Proia misapplied the AFTE
methodology, because Proia testified that the test-fired bullet
matched a bullet recovered from the 2011 crime scene “to a
reasonable degree of ballistics certainty,” and because the
written report in no way qualified its conclusion that the two
bullets matched. He points out that the National Academy
of Sciences has sharply criticized the AFTE methodology for
failing to incorporate standardized protocols and for over-
reliance on the subjective judgments of examiners. Indeed,
in light of these flaws in the AFTE methodology, a number
of district courts have required that experts clarify that
bullets can be matched only to a “reasonable degree of
ballistics certainty”—disallowing experts from presenting
their conclusions with absolute certainty. See, e.g., United
States v. Cerna, No. CR 08-0730 WHA, 2010 WL 3448528,
at *4 (N.D. Cal. Sept. 1, 2010); United States v. Diaz, No.
CR 05-00167 WHA, 2007 WL 485967, at *11 (N.D. Cal.
Feb. 12, 2007); Monteiro, 407 F. Supp. 2d at 372; United
States v. Green, 405 F. Supp. 2d 104, 124 (D. Mass. 2005). 11
This qualification is meant to ensure that juries are not

publication;” (3) “the known or potential rate of error;” (4) whether there
are “standards controlling the technique’s operation;” and (5) the general
acceptance of the method within the relevant community. Daubert v.
Merrell Dow Pharm., Inc., 509 U.S. 579, 592–95 (1993). “[W]hether
these specific factors are ‘reasonable measures of reliability in a
particular case is a matter that the law grants the trial judge broad latitude
to determine.’” Estate of Barabin v. AstenJohnson, Inc., 740 F.3d 457,
463 (9th Cir. 2014) (quoting Kumho Tire Co. v. Carmichael, 526 U.S.
137, 150 (1999)).
     11
        At least one court did not even take this precaution. United States
v. Casey, 928 F. Supp. 2d 397, 400 (D.P.R. 2013) (“[The witness] may
testify accordingly without qualification of his degree of certainty.”).
                UNITED STATES V. JOHNSON                    25

misled about the reliability of ballistics evidence. Johnson
points to only one case in which a “reasonable degree of
ballistics certainty” was determined to be too misleading.
United States v. Glynn, 578 F. Supp. 2d 567, 574–75
(S.D.N.Y. 2008) (allowing the expert to testify it was “more
likely than not” that bullets matched).

    Here, although the written report did not qualify its test
results, Proia’s testimony made clear he could conclude only
that the test-fired bullet matched the bullet from the 2011
crime scene to a “reasonable degree of ballistics certainty.”
Proia also clarified in his live testimony that the written
report’s conclusions were not absolutely certain.
Additionally, Johnson was allowed to cross-examine Proia
on the more precise meaning of “reasonable degree of
ballistics certainty,” and to present his own ballistics expert
witness. The district court therefore provided adequate
safeguards to allow the jury properly to evaluate the
probative value of Proia’s opinion testimony and the written
report.

    Second, Johnson contends that the AFTE is inherently
unreliable and fails to satisfy the Daubert factors. The
district court cited a number of cases and scientific sources
establishing that that the AFTE methodology satisfies
Daubert. Conversely, Johnson has not cited a case in which
AFTE ballistics testimony was excluded altogether.
Because the district court has “broad latitude” to make
admissibility determinations, Estate of Barabin, 740 F.3d at
463, we hold that the district court did not abuse its
discretion in denying Johnson’s Daubert motion.

                             VII

    The government cross-appeals the district court’s
determination at sentencing that Johnson’s prior armed
26              UNITED STATES V. JOHNSON

robbery conviction under CPC § 211(a) does not qualify as
a “crime of violence” within the meaning of U.S.S.G.
§§ 2K2.1 and 4B1.2. Because the district court held that
Johnson’s prior armed robbery conviction was not a crime
of violence, it adopted the base offense level assuming that
Johnson had only one prior conviction for a crime of a
violence rather than two. As a result, Johnson’s base offense
level was 20 rather than 24.             Compare U.S.S.G.
§ 2K2.1(a)(2), with U.S.S.G. § 2K2.1(a)(4)(A).

    We recently addressed this issue in United States v.
Barragan, holding unequivocally that a prior California
robbery conviction is categorically a “crime of violence” for
purposes of the career offender sentencing provision.
871 F.3d 689, 714 (9th Cir. 2017); see also United States v.
Chavez-Cuevas, 862 F.3d 729, 740 (9th Cir. 2017)
(affirming a district court’s reliance on United States v.
Becerril-Lopez, 541 F.3d 881 (9th Cir. 2008), in classifying
CPC § 211 as a “crime of violence”). Therefore, we vacate
Johnson’s sentence and remand to the district court for
resentencing with instructions to treat Johnson’s CPC
§ 211(a) conviction as a crime of violence in determining the
applicable base offense level.

                            VIII

    We AFFIRM the district court’s ruling on each of the
issues raised in Johnson’s direct appeal; VACATE
Johnson’s sentence; and REMAND for resentencing on a
properly calculated total offense score.
