                      FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                    No. 15-50096
              Plaintiff-Appellee,               D.C. No.
                                          3:13-cr-1128-BEN-3
                 v.
                                                OPINION
 ROBERT RODRIGUEZ,
       Defendant-Appellant.


        Appeal from the United States District Court
           for the Southern District of California
         Roger T. Benitez, District Judge, Presiding

          Argued and Submitted December 9, 2016
                   Pasadena, California

                      Filed March 14, 2017

Before: A. Wallace Tashima and Richard A. Paez, Circuit
     Judges, and Paul L. Friedman, * District Judge.

                  Opinion by Judge Friedman


    *
      The Honorable Paul L. Friedman, United States District Judge for
the District of Columbia, sitting by designation.
2                UNITED STATES V. RODRIGUEZ

                          SUMMARY **


                          Criminal Law

    The panel affirmed a conviction on three drug-related
charges, vacated the sentence, and remanded for
resentencing.

    The panel held that when considering a motion to
suppress wiretap evidence, a reviewing district court judge
should apply the Ninth Circuit’s two-step approach: (1)
review de novo whether the application for a wiretap
contains a full and complete statement as to whether or not
other investigative procedures have been tried and failed or
why they reasonably appear to be unlikely to succeed if tried
or be too dangerous; and (2) if the application meets those
requirements, review for abuse of discretion the issuing
judge’s conclusion that the wiretap was necessary. The
panel held that the district court, which focused on the fact
that other judges had reviewed the wiretap applications,
erred by considering evidence beyond the statements in the
supporting affidavits.

    The panel held that the affidavits adequately explained
why the interception of wire communications was necessary
to investigate this conspiracy and the target subjects, and that
they contained a full and complete statement of facts to
establish necessity under 18 U.S.C. § 2518(1)(c). The panel
held that the district court did not abuse its discretion in
finding necessity.

**
   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. RODRIGUEZ                    3

     The panel held that the district court’s application of 21
U.S.C. § 851 to enhance the defendant’s sentence did not
violate his Sixth Amendment rights. The panel held that the
district court failed to comply with 21 U.S.C. § 851(b) when
it did not ask the defendant if he affirmed or denied the prior
convictions and did not inform him that he had to raise any
challenge to a prior conviction before the sentence was
imposed.      The panel concluded that the error was not
harmless. The panel wrote that two additional procedural
defects warrant remand: the district court appears to have
been uncertain of its responsibilities under § 851 as the
sentencing hearing unfolded, and it is unclear whether the
district court used the appropriate standard when ruling on
the merits of the § 851 issues.

    The panel held that the district court did not violate the
defendant’s constitutional rights by applying an upward
adjustment under U.S.S.G. § 3B1.1 without submitting to a
jury the issue of whether the defendant was a leader of
criminal activity, nor clearly err in denying the defendant a
downward adjustment under U.S.S.G. § 3E1.1(a) for
acceptance of responsibility.


                         COUNSEL

Jack J. Boltax (argued), Law Office of Jack J. Boltax, San
Diego, California; Leif Harrison Kleven, Law Office of Leif
Kleven, San Diego, California; for Defendant-Appellant.

Mark R. Rehe (argued), Assistant United States Attorney;
Laura E. Duffy, United States Attorney; Peter Ko, Assistant
United States Attorney, Chief, Appellate Section, Criminal
Division; United States Attorney’s Office, San Diego,
California; for Plaintiff-Appellee.
4             UNITED STATES V. RODRIGUEZ

                        OPINION

FRIEDMAN, District Judge:

     Robert Rodriguez appeals from his conviction after a
jury trial on three drug-related charges: (1) conspiracy to
distribute methamphetamine, in violation of 21 U.S.C.
§§ 841(a)(1),     846;    (2)    conspiracy      to    import
methamphetamine, in violation of 21 U.S.C. § 952; and (3)
distribution of methamphetamine, in violation of 21 U.S.C.
§ 841(a)(1), and his sentence of 600 months in prison,
followed by a lifetime of supervised release. He argues that
the district court erred because it applied the incorrect
standard of review when deciding his motion to suppress and
that the government’s wiretap application did not include a
full and complete statement of facts as required by 18 U.S.C.
§ 2518(1)(c). Rodriguez also argues that the district court
erred when it (1) enhanced Rodriguez’s sentence under 21
U.S.C. § 851 after finding three prior convictions,
(2) applied an organizer/leader upward adjustment under
United States Sentencing Guidelines (U.S.S.G.) § 3B1.1,
and (3) denied a downward adjustment for acceptance of
responsibility under U.S.S.G. § 3E1.1. He also maintains
that his sentence of 600 months is substantively
unreasonable.

    We have jurisdiction under 28 U.S.C. § 1291; we affirm
Rodriguez’s conviction, vacate his sentence, and remand for
resentencing.

I. FACTUAL AND PROCEDURAL BACKGROUND

   This case arises from an investigation in North San
Diego County called “Operation Corridor,” in which state
and federal officers jointly investigated extortion and drug
              UNITED STATES V. RODRIGUEZ                  5

trafficking by local street gangs and the Mexican Mafia, the
largest prison gang in the United States. The Mexican Mafia
is a violent organization that requires street gangs to pay
“taxes” in the form of cash, drugs, or other property. If a
gang pays the “tax,” the Mexican Mafia will allow that gang
to operate in and sell drugs in their neighborhoods. Those
who do not pay taxes experience robbery and violence at the
hands of Mexican Mafia members and its associates.

    Rodriguez is a self-identified member of the Tri-City
Thunder Hills Gang, which law enforcement officers
believed was closely associated with and “answered to” the
Mexican Mafia. Rodriguez also led a conspiracy involving
the importation of methamphetamine from Mexico and its
distribution in San Diego County and in South Carolina.
Rodriguez’s associates included, among others, his wife
Carrie Brown-Rodriguez and his codefendant at trial, Travis
Job. Rodriguez hired Job to “cut” methamphetamine, a
process by which another product is added to pure
methamphetamine to increase its weight and thus increase
the quantity available for resale.

    Seeking to gain more information about Rodriguez’s
operation and his association with the Mexican Mafia, law
enforcement officers applied for authorization to wiretap
Rodriguez’s phone, along with the phones of three other
individuals suspected of working with the Mexican Mafia or
distributing drugs. Officer John McKean submitted a 43-
page affidavit in support of his application for electronic
surveillance. Law enforcement officers later submitted a
second wiretap application, requesting wiretaps for two
phone numbers listed to Carrie Brown-Rodriguez and used
by Rodriguez. Officer McKean submitted a 40-page
affidavit in support of the second application. The district
court authorized both wiretaps. At the time the government
6              UNITED STATES V. RODRIGUEZ

applied for these wiretaps, Rodriguez was subject to a Fourth
Amendment search waiver as a condition of parole in an
unrelated case. This fact was not included in either affidavit.
The record does not contain the exact language of
Rodriguez’s Fourth Amendment search waiver.

    A grand jury indicted Rodriguez on three counts:
(1) conspiracy to distribute methamphetamine, in violation
of 21 U.S.C. §§ 841(a)(1), 846; (2) conspiracy to import
methamphetamine, in violation of 21 U.S.C. § 952; and
(3) distribution of methamphetamine, in violation of
21 U.S.C. § 841(a)(1). Before trial, the government filed an
information pursuant to 21 U.S.C. § 851 seeking enhanced
penalties, including a 20-year mandatory minimum, because
Rodriguez committed the offenses for which he was indicted
after three prior felony convictions. Rodriguez filed a
motion to suppress the wiretap evidence, which the district
court denied following a suppression hearing. A jury
convicted Rodriguez on all counts.

     At sentencing, the district court calculated Rodriguez’s
guidelines sentencing range by applying a two-level increase
to Rodriguez’s base offense level for the importation of
methamphetamine under U.S.S.G. § 2D1.1(b)(5), which
Rodriguez does not contest, and a four-level upward
adjustment based on the conclusion that he was the manager,
leader, or recruiter of a criminal activity under U.S.S.G.
§ 3B1.1(a). The district court denied Rodriguez’s request
for a two-level downward adjustment for acceptance of
responsibility under U.S.S.G. § 3E1.1. The court also
concluded that Rodriguez was subject to a 20-year
mandatory minimum under 21 U.S.C. § 851.                After
calculating a guidelines sentencing range of 360 months to
life, the district court sentenced Rodriguez to 600 months in
prison and supervised release for life.
              UNITED STATES V. RODRIGUEZ                   7

          II. WIRETAP AFFIDAVIT ISSUES

    A. Standard of Review for Motions to Suppress
                   Wiretap Evidence

    Title III of the Omnibus Crime Control and Safe
Streets Act allows law enforcement officers to use
wiretapping in limited situations.          See 18 U.S.C.
§§ 2510–2522. “To obtain a wiretap, a law enforcement
official must apply to a [U.S. District Court] judge for an
order permitting the surveillance.” United States v.
Carneiro, 861 F.2d 1171, 1176 (9th Cir. 1988) (citing
18 U.S.C. § 2518(1)). Each wiretap application must meet
several statutory requirements. 18 U.S.C. § 2518(1). One
of those requirements dictates that each application include
a “full and complete statement as to whether or not other
investigative procedures have been tried and failed or why
they reasonably appear to be unlikely to succeed if tried or
to be too dangerous.” § 2518(1)(c). A law enforcement
officer typically includes this statement of facts in a sworn
affidavit in support of the wiretap application. See United
States v. Christie, 825 F.3d 1048, 1066 (9th Cir. 2016). The
issuing judge may conclude that the application satisfies the
necessity requirement if he or she determines that “normal
investigative procedures have been tried and have failed or
reasonably appear to be unlikely to succeed if tried or to be
too dangerous.” 18 U.S.C. § 2518(3)(c); see Christie, 825
F.3d at 1066. “Taken together, §§ 2518(1)(c) and (3)(c)
require a showing of necessity before a district court can
issue a wiretap order.” Carneiro, 861 F.2d at 1176. The
wiretap statute also includes its own exclusionary rule,
requiring suppression of wiretap evidence that the
government obtains in violation of Title III. 18 U.S.C.
§ 2515; see United States v. Giordano, 416 U.S. 505, 524–
25 (1974). A different district court judge must decide any
8              UNITED STATES V. RODRIGUEZ

motion to suppress wiretap evidence, creating a second level
of review in the district court.

    On appeal, Rodriguez argues that the district court erred
by deciding his motion to suppress under an abuse of
discretion standard and improperly deferring to the issuing
judge, rather than conducting its own independent review of
whether the wiretap affidavits contained a full and complete
statement of facts sufficient to satisfy 18 U.S.C.
§ 2518(1)(c).

    1. Proper Standard for District Court Considering a
            Motion to Suppress Wiretap Evidence

    When we review a district court’s decision on a motion
to suppress wiretap evidence, we determine de novo whether
the information in an affiant’s application for a wiretap
amounts to “a full and complete statement as to whether or
not other investigative procedures have been tried and failed
or why they reasonably appear to be unlikely to succeed if
tried or to be too dangerous.” Christie, 825 F.3d at 1066
(quoting 18 U.S.C. § 2518(1)(c)). If the wiretap application
meets the requirements of § 2518(1)(c), then the Court
reviews for abuse of discretion the issuing court’s finding
that the wiretap was necessary under § 2518(3)(c) and its
decision to grant the wiretap. Id.; see also United States v.
Lynch, 437 F.3d 902, 912 (9th Cir. 2006) (en banc); United
States v. Canales Gomez, 358 F.3d 1221, 1225 (9th Cir.
2004). We, however, have not explicitly stated whether a
district court must apply this same two-step approach when
considering a motion to suppress wiretap evidence. Some
district court judges in the Ninth Circuit have reviewed
wiretap orders issued by another district court judge solely
under an abuse of discretion standard. See, e.g., United
States v. Ai Le, 255 F. Supp. 2d 1132, 1134 (E.D. Cal. 2003);
United States v. Sotelo, No. 13cr4514-BEN, 2015 WL
               UNITED STATES V. RODRIGUEZ                   9

468397, *4 (S.D. Cal. Feb. 3, 2015). Other district court
judges have adopted this Court’s two-step approach when
deciding a motion to suppress wiretap evidence. See, e.g.,
United States v. Alvarez, No. 14-cr-00120-EMC-1, 2016 WL
69901, *6–10 (N.D. Cal. Jan. 6, 2016); United States v. Yim,
No. CR11-131MJP, 2012 WL 395791, *5 (W.D. Wash. Feb.
7, 2012). The district court judge in this case applied only
an abuse of discretion standard when he ruled on the motion
at the suppression hearing.

    We conclude that district courts should apply the Ninth
Circuit’s two-step approach when considering a motion to
suppress wiretap evidence. Therefore, a reviewing district
court judge must review de novo whether the application for
a wiretap contains a full and complete statement as to
whether or not other investigative procedures have been tried
and failed or why they reasonably appear to be unlikely to
succeed if tried or to be too dangerous. Christie, 825 F.3d at
1066 (citing United States v. Rivera, 527 F.3d 891, 898 (9th
Cir. 2008)). If the wiretap application meets these
requirements of 18 U.S.C. § 2518(1)(c), then the district
court judge should review for “abuse of discretion the
issuing judge’s conclusion that the wiretap was necessary.”
Rivera, 527 F.3d at 898 (citing Lynch, 437 F.3d at 912); see
also Christie, 825 F.3d at 1066. In other words, the district
court reviews de novo whether a full and complete statement
of facts was submitted to the issuing judge under
§ 2518(1)(c), but “review[s] the issuing court’s ultimate
decision to authorize a wiretap [under § 2518(3)(c)] for an
abuse of discretion.” United States v. Gonzalez, Inc., 412
F.3d 1102, 1111–12 (9th Cir. 2005); see also Lynch, 437
F.3d at 912.

   A de novo review of whether the affidavit includes a full
and complete statement of facts is critical at the motion to
10             UNITED STATES V. RODRIGUEZ

suppress stage. A hearing on a motion to suppress is the first
time when the necessity determination is reviewed in an
adversarial proceeding, with defense counsel having his or
her first opportunity to challenge the factual underpinnings
of the issuing judge’s finding of necessity and the steps law
enforcement officers took or failed to take before seeking
authorization for wiretapping. The reviewing district court
judge sits in the best position for such a fact-intensive
inquiry. This de novo review would also provide a fuller
record for appellate review, where any factual findings
would be reviewed for clear error. Gonzalez, Inc., 412 F.3d
at 1115. Our conclusion is also consistent with our
precedent, approving of district court judges who conduct an
independent review of whether wiretap affidavits satisfy 18
U.S.C. § 2518(1)(c). See United States v. Reed, 575 F.3d
900, 907 (9th Cir. 2009); Carneiro, 861 F.2d at 1176.

    In this case, as we have noted, the district court judge
applied an abuse of discretion standard to both
determinations made by the issuing judge — whether the
affidavit contained a full and complete statement of facts
under 18 U.S.C. § 2518(1)(c), and the ultimate decision that
it was necessary to authorize the wiretap under § 2518(3)(c).
Although we conclude this was error, we need not reverse
on this ground because we must do our own de novo review
of the statement of facts under 18 U.S.C. § 2518(1)(c).

 2. District Court’s Review Limited to Information in
                       the Affidavit

    Before reviewing the affidavits, we address an additional
problem with the way in which the district court applied the
abuse of discretion standard in this case — considering
evidence beyond the supporting affidavits.             At the
suppression hearing, the district court specifically noted that
the two judges who approved the wiretap applications
                 UNITED STATES V. RODRIGUEZ                         11

involved in this investigation had “half a century of judicial
experience between them,” and that they had “reviewed
hundreds of wiretap applications in their careers.” In
response to Rodriguez’s request for an independent review
of the affidavits, the district court stated that it could not
ignore the fact that two other judges had reviewed the
wiretap applications and that it could not look at the
affidavits “with a fresh face as if, in fact, this was all in a
vacuum.” The district court cited no evidence from the
affidavits themselves at the hearing. Instead, it focused on
the fact that other judges had reviewed the wiretap
applications and deferred to them. This was error.

     When deciding a motion to suppress evidence, the
district court must examine each wiretap application
separately and may look only to information in the relevant
affidavit to determine whether it contains a full and complete
statement of facts under § 2518(1)(c). See Carneiro, 861
F.2d at 1176. “Each wiretap application, standing alone,
must satisfy the necessity requirement.” Id. (emphasis in
original). On that basis, the reviewing judge must decide
first whether the statement of facts in each affidavit was
sufficient under § 2518(1)(c), and then whether the issuing
judge abused her discretion in finding necessity and issuing
the wiretap order. 1


    1
       This rule applies unless the defendant alleges that the wiretap
application contains material misstatements or inaccuracies. As noted in
our prior opinions, “[i]f an application contains inaccuracies or
significant omissions, the court must determine the facts relying on
credible evidence produced at the suppression hearing to determine
whether a ‘reasonable [issuing] judge could have denied the application
because necessity for the wiretap had not been shown.’” United States
v. Blackmon, 273 F.3d 1204, 1209 (9th Cir. 2001) (citing United States
12               UNITED STATES V. RODRIGUEZ

    Although we conclude that the district court judge
impermissibly reviewed the wiretap orders under only an
abuse of discretion standard and considered evidence
beyond the statements in the affidavits, we decline to remand
the case in order to have the district court conduct a de novo
review of the statement of facts set forth in the affidavits.
Because we must conduct that same inquiry on appeal, a
remand to the district court would be superfluous.

     B. General Challenges to the Wiretap Affidavits

    Before turning to our de novo review of each wiretap
affidavit, we first consider two general arguments that
Rodriguez makes regarding the necessity requirement itself.
First, Rodriguez argues that there was insufficient evidence
in the affidavits of particularized necessity, that is, necessity
with respect to him alone. He contends that any affidavit
must show particularized necessity as to him and that any
statements pertaining to the Mexican Mafia, other members
of the conspiracy, or the conspiracy in general cannot be
used to establish necessity for the wiretap.

    We have said that an affidavit must include “specific
facts relevant to the particular circumstances” of the case and
not just boilerplate conclusions. United States v. Blackmon,
273 F.3d 1204, 1210 (9th Cir. 2001). Under this reasoning,
statements pertaining to the conspiracy in general can be
used to show why an investigative technique would be too
dangerous or unproductive in regard to all of the target
subjects listed in a single wiretap application, so long as they
are supported by facts specific to the case. While the “the

v. Ippolito, 774 F.2d 1482, 1486 (9th Cir. 1985)); see also Carneiro, 861
F.2d at 1176. Here, Rodriguez only alleged that the facts submitted in
the affidavit did not establish necessity under 18 U.S.C. § 2518(1)(c).
               UNITED STATES V. RODRIGUEZ                   13

government is not free to transfer a statutory showing of
necessity from one [wiretap] application to another — even
within the same investigation,” that is not what happened
here. Gonzalez, Inc., 412 F.3d at 1115. Officer McKean
appropriately explained in the affidavits why certain
techniques would be unproductive or too dangerous in
regard to all of the target subjects, including Rodriguez, due
to alleged associations with the Mexican Mafia. That is
sufficient under our precedent.

    In further support for this conclusion, we note that
“[i]nvestigations of criminal conspiracies present unique law
enforcement problems and pose a greater threat to society
than individual action toward the same end.” Canales
Gomez, 358 F.3d at 1226 (citation and internal quotation
marks omitted). Thus, the “government is entitled to more
leeway in its investigative methods when it pursues a
conspiracy.” United States v. McGuire, 307 F.3d 1192, 1198
(9th Cir. 2002). Citing the first affidavit, Rodriguez begins
by disputing that the government was even investigating a
conspiracy and sought to identify unknown individuals in
that conspiracy; he asserts that the investigation’s true
purpose was to “develop information regarding
[Rodriguez’s] distribution of drugs.” From the affidavits,
however, it is clear that the government sought a wiretap for
Rodriguez’s phone to understand his role in a larger
extortion and drug conspiracy associated with the Mexican
Mafia. The first affidavit, for example, states that the
wiretap is necessary to “develop information regarding
[Rodriguez’s] distribution of drugs” and “to determin[e]
whether the Tri-City Hills gang [of which Rodriguez was a
member] is collecting and/or paying taxes to various
Mexican Mafia associates like similarly situated gangs.”
Contrary to the particularity argument Rodriguez makes
here, “[t]he necessity for the wiretap is evaluated in light of
14               UNITED STATES V. RODRIGUEZ

the government’s need not merely to collect some evidence,
but to develop an effective case against those involved in the
conspiracy.” United States v. Decoud, 456 F.3d 996, 1007
(9th Cir. 2006) (citation and internal quotation marks
omitted). Given the “leeway” we give the government when
it is investigating a conspiracy, Canales Gomez, 358 F.3d at
1226, we may consider general statements about the
conspiracy so long as they are specific to the case and are
not impermissible boilerplate conclusions about the inherent
limitations of a particular investigative technique.

    Second, Rodriguez contends that this Court cannot
conclude that the affidavits contain a full and complete
statement of facts because the affidavits did not include the
fact that Rodriguez was subject to a Fourth Amendment
search waiver. 2 As a preliminary matter, we note that
Rodriguez has not sufficiently established in the record that
the government was aware that Rodriguez was subject to a
search waiver when it submitted the wiretap applications to
the issuing judge. Rodriguez simply argues that the
government must have been aware of the search waiver
because the police conducted a physical search of his
residence, pursuant to the waiver, nearly two months after
the police submitted the wiretap applications.




     2
      As previously noted, the record does not contain the exact language
of Rodriguez’s Fourth Amendment search waiver. These search waivers
are commonly included as a condition for probation and require the
individual to subject his person, property, and residence to search and
seizure without the standard level of cause. See United States v. Lara,
815 F.3d 605, 607 (9th Cir. 2016). We note, however, that the exact
language used in search waivers is not uniform and varies depending on
the probation condition.
                 UNITED STATES V. RODRIGUEZ                          15

    A search waiver is relevant to the necessity
determination under 18 U.S.C. § 2518(1)(c) because the
waiver allows law enforcement officers to conduct a more
extensive search than a search pursuant to a search warrant,
which would be limited in scope and particularity. The
government argues, however, that knowledge of the Fourth
Amendment search waiver would not have affected the
issuing judge’s determination here because the affidavit
already explained that any searches would have been
impractical and largely unproductive. See United States v.
Ippolito, 774 F.2d 1482, 1485–86 (9th Cir. 1985). This
rationale, the government argues, extends to searches
pursuant to Fourth Amendment search waivers where the
same type of limited evidence would have been discovered.
We agree.

    In the context of this case, the government sought
evidence to identify and prove relationships between certain
subjects and determine the extent of the subjects’
involvement with the Mexican Mafia. The affidavits explain
that this type of evidence is “rarely ‘stored’ in locations that
can be searched or even kept in a tangible form capable of
being physically seized.” Because it follows that a search
conducted pursuant to a Fourth Amendment search waiver
would have been similarly unproductive, the omission of the
search waiver from the statement of facts does not tip the
balance and lead to a conclusion that the affidavits did not
include a full and complete statement of facts under 18
U.S.C. § 2518(1)(c) or that the issuing judge abused her
discretion in issuing the wiretap orders. 3


    3
      Although the search waiver and a potential search warrant are
equivalent in terms of necessity for a wiretap application here, that may
16               UNITED STATES V. RODRIGUEZ

          C. Statutory Requirement of Necessity

    As noted, in reviewing a district court’s decision on a
motion to suppress wiretap evidence, we review de novo
whether the application for the wiretap contained “a full and
complete statement as to whether or not other investigative
procedures have been tried and failed or why they
reasonably appear to be unlikely to succeed if tried or to be
too dangerous.” 18 U.S.C. § 2518(1)(c); see Christie, 825
F.3d at 1066; Rivera, 527 F.3d at 898. The application must
include more than “boilerplate conclusions that merely
describe inherent limitations of normal investigative
procedures.” Christie, 825 F.3d at 1068 (citing Blackmon,
273 F.3d at 1210). If the wiretap application meets the
requirements of 18 U.S.C. § 2518(1)(c), we then review the
decision to authorize the wiretap for abuse of discretion. Id.
at 1066. We review each wiretap independently. Gonzalez,
Inc., 412 F.3d at 1115.

 1. Whether the Affidavits Contain a Full and Compete
                    Statement of Facts

    We first turn to a de novo review of the statements in the
wiretap affidavits purporting to show necessity under 18
U.S.C. § 2518(1)(c). Each affidavit includes information
about confidential sources, undercover officers, physical
surveillance, stationary surveillance, pen registers, toll
analysis, grand jury subpoenas, trash searches, search
warrants, interviews with associates, mail covers, and
vehicle tracking devices. The second affidavit is not an
impermissible “carbon copy” of the first, Blackmon, 273

not always be the case. Here, law enforcement officers sought evidence
that would likely not be produced from a search pursuant to a search
warrant or a search waiver.
               UNITED STATES V. RODRIGUEZ                   17

F.3d at 1208, because it explains the developments in the
case since the authorization of the first wiretap and the need
for new wiretaps on phone numbers listed to Carrie Brown-
Rodriguez. Specifically, law enforcement officers sought a
wiretap for phone numbers associated with Rodriguez’s wife
because Rodriguez was no longer using the phone that was
wiretapped as a result of the first wiretap authorization.

    The affidavits contain some boilerplate conclusions as to
the effectiveness of certain techniques, particularly
regarding pen registers, pole cameras, grand jury subpoenas,
search warrants, and interviews with associates and targets.
For example, the second affidavit explains that search
warrants would be unproductive because the “execution of
such search warrants would likely cause certain Target
Subjects to cease use of their respective telephones and take
additional steps to conceal their activities.”           Some
boilerplate language, however, is not fatal as we evaluate
“‘the level of detail in the affidavit as a whole,’ rather than
piecemeal.” Christie, 825 F.3d at 1068 (quoting Rivera, 527
F.3d at 899) (emphasis in original).

     Each affidavit includes information on why a particular
technique would not be effective in this particular
investigation. Both affidavits explain that the effectiveness
of undercover agents, confidential sources, interviews, and
grand jury subpoenas is limited due to the extreme violence
that the Mexican Mafia uses in its everyday operation. The
first affidavit notes that the Mexican Mafia “ruthlessly
punishes law enforcement cooperators,” and the
organization’s reputation “has caused and will continue to
cause potential cooperators . . . to resist recruitment by law
enforcement.” As noted above, Rodriguez asserts that these
explanations cannot be used to show necessity as to him. In
United States v. McGuire, however, we accepted an affidavit
18             UNITED STATES V. RODRIGUEZ

with similar explanations regarding a “close-knit” group
with a “known violent propensity.” 307 F.3d at 1197. Here,
it is logical to conclude that these statements may extend to
Rodriguez as a gang member allegedly associated with the
Mexican Mafia.

    In regard to undercover agents, both affidavits explain
that the insular and violent nature of the Mexican Mafia and
its associated street gangs would make the insertion of an
undercover agent into this investigation unproductive or too
dangerous. The first affidavit notes that it would not be
possible to create an undercover identity “that includes
serving time in prison, because, any claim of prison time
would be rapidly disproved by the Mexican Mafia’s inmate
network.” Both affidavits note that the Mexican Mafia relies
on its 200 members and street gang members who “are from
the same neighborhoods and often grow up together.” The
Mexican Mafia members and its associated street gangs rely
on close connections of individuals they already know,
which sufficiently explains why the use of undercover agents
would not be a successful investigative technique. Although
Rodriguez asserts that these statements offer no information
on why the government could not use an undercover agent
in the investigation of him, as we noted above, it is fair to
infer that these statements are relevant to Rodriguez, among
others, because the government was investigating his
association with the Mexican Mafia.

    With respect to stationary surveillance, the first affidavit
explains that pole cameras would not be productive because
Rodriguez lives in a community apartment building.
Rodriguez argues that this “blanket assertion” that the value
of stationary surveillance would be limited because
Rodriguez lived in an apartment building is insufficient. We
disagree. Rodriguez incorrectly states that the first affidavit
               UNITED STATES V. RODRIGUEZ                   19

includes no information about the “layout of the apartment
building that would make stationary surveillance
impractical.” The first affidavit notes that pole cameras
could not be installed in any location that could observe
Rodriguez’s apartment, and that agents therefore would be
unable to differentiate individuals visiting Rodriguez from
those who are “visiting or returning to other apartments in
the building.” The second affidavit explains that agents
placed pole cameras outside two residences associated with
Rodriguez and Brown-Rodriguez other than the apartment
listed in the first affidavit. The affidavit states that while
these cameras would be helpful to see if any of the target
subjects visit those residences, they would provide no
information about the substance of any communications
between target subjects regarding criminal activity.

    Rodriguez also contends that because law enforcement
officers did not attempt trash searches, the government has
not established necessity. We, however, do not require law
enforcement officers to “exhaust every conceivable
alternative before obtaining a wiretap.” Christie, 825 F.3d
at 1068 (citing Rivera, 527 F.3d at 903). The affidavit need
only explain why a particular investigative procedure
reasonably appears “unlikely to succeed.” 18 U.S.C.
§ 2518(1)(c). The first affidavit adequately explains that
trash searches would be unproductive because Rodriguez
lives in an apartment building, and law enforcement officers
would not be able to separate his trash from the trash of other
residents. Similarly, the second affidavit states that trash
searches would be unlikely to produce the kinds of evidence
sought in this investigation, such as “the disposition of tax
proceeds collected from gang members,” “the manner and
timing of the importation of narcotics,” and “the location of
additional stash houses.”
20             UNITED STATES V. RODRIGUEZ

    According to Rodriguez, the first affidavit also
insufficiently explains the need for a wiretap in light of the
success in the investigation through a confidential source
(“CS-1”). The first affidavit shows that CS-1 was successful
in providing the government with information on Rodriguez
and other subjects through controlled buys during the first
two months of the investigation. We, however, have
acknowledged that “the mere attainment of some degree of
success during law enforcement’s use of traditional
investigative methods does not alone serve to extinguish the
need for a wiretap.” United States v. Bennett, 219 F.3d 1117,
1122 (9th Cir. 2000). The first affidavit also explains that
the evidence that CS-1 could provide was limited because he
could not inquire about Rodriguez’s relationship to other
subjects “without raising suspicion,” and perhaps putting
himself at great risk. See Canales Gomez, 358 F.3d at 1226
(quoting United States v. Bernal-Obseo, 989 F.2d 331, 333
(9th Cir. 1993)) (“[T]he use of informants to investigate and
prosecute persons engaged in clandestine criminal activity is
fraught with peril.”).

      The second affidavit states that CS-1 is no longer an
available source because he was involved in unsanctioned
illegal activity. These explanations do not explicitly “recite
the inherent limitations of using confidential informants” but
explain “in reasonable detail why each confidential source
. . . was unable or unlikely to succeed in achieving the goals
of the [particular] investigation.” See Rivera, 527 F.3d at
899. They are more than sufficient.

    Based on a de novo review of both affidavits, we
conclude that they adequately explained why the
interception of wire communications was necessary to
investigate this conspiracy and the target subjects, and that
they contained a full and complete statement of facts to
               UNITED STATES V. RODRIGUEZ                  21

establish necessity under 18 U.S.C. § 2518(1)(c).         See
Canales Gomez, 358 F.3d at 1225.

       2. Whether the Wiretaps Were Necessary

    We turn next to the question of whether the issuing judge
appropriately determined “on the basis of the facts submitted
by the applicant [in the affidavits] that . . . normal
investigative procedures have been tried and have failed or
reasonably appear to be unlikely to succeed if tried or to be
too dangerous.” 18 U.S.C. § 2518(3)(c). As we have said,
we review for an abuse of discretion the issuing judge’s
decision to issue the wiretap order once she has found that
the wiretap was necessary in the circumstances. Lynch, 437
F.3d at 912; Canales Gomez, 358 F.3d at 1225.

    In undertaking this review, we use “a ‘common sense
approach’ to evaluate the reasonableness of the
government’s good faith efforts to use traditional
investigative tactics or its decision to forego such tactics
based on the unlikelihood of their success.” Christie, 825
F.3d at 1068 (quoting Gonzalez, Inc., 412 F.3d at 1112).
Rodriguez argues that individual subjects were not
surveilled long enough to justify a finding of necessity for
the wiretaps. The government applied for the first wiretap
after two and a half months of investigation. We have never
stated a minimum number of days of investigation required
before the government may apply for a wiretap
authorization, but the length of the investigation is a factor
in the analysis. Given the wide range of traditional
techniques used in the first two months of investigation, it
does not appear in this case that the government sought “‘to
use the wiretap as the initial step’ in its investigation.”
Christie, 825 F.3d at 1068 (citing Rivera, 527 F.3d at 902).
22             UNITED STATES V. RODRIGUEZ

     We have always accorded the issuing judge
“considerable discretion in finding necessity, particularly
when the case involves the investigation of a conspiracy,”
Reed, 575 F.3d at 909, so our standard of review is
deferential, McGuire, 307 F.3d at 1197. The affidavits here
show that the government used a range of traditional
techniques including confidential sources, pen registers,
physical surveillance, and grand jury subpoenas before
seeking authorization for electronic surveillance. The
affidavits also explain why other techniques such as search
warrants, undercover agents, trash searches, stationary
surveillance, and interviews with witnesses would be
unproductive or dangerous given specific facts about the
Mexican Mafia and the particular case. In this case, law
enforcement officers specifically sought to gain evidence
and knowledge of how the Mexican Mafia and associated
gangs were operating through extortion and drug trafficking.
In addition, we have “consistently upheld findings of
necessity where traditional investigative techniques lead
only to apprehension and prosecution of the main
conspirators, but not to apprehension and prosecution of . . .
other satellite conspirators.” Rivera, 527 F.3d at 902 (citing
McGuire, 307 F.3d at 1198).

    After reviewing the factual statements in the affidavits,
which include the purpose of the investigation and the
information sought, we cannot say that the issuing judge
abused her discretion in finding necessity in the
circumstances presented here.

               III. SENTENCING ISSUES

     A. Sentencing Enhancement under 21 U.S.C. § 851

   Rodriguez makes two arguments to attack his sentence
enhancement under 21 U.S.C. § 851. First, he contends that
              UNITED STATES V. RODRIGUEZ                  23

the statutory scheme under § 851 violates Rodriguez’s Sixth
Amendment right to a jury trial. Second, he argues that the
district court erred in applying the sentencing enhancement
because the government failed to prove his identity in the
three prior convictions that were the basis for the
enhancement.

    Rodriguez’s first argument lacks merit. Relying on
Alleyne v. United States, Rodriguez argues that the sentence
enhancement scheme under § 851, which increases an
individual’s mandatory minimum sentence, violates the
Sixth Amendment because “facts that increase mandatory
minimum sentences must be submitted to the jury.” 133
S. Ct. 2151, 2163 (2013).          The Supreme Court in
Almendarez-Torres v. United States held that the fact of a
prior conviction used to enhance a sentence is a sentencing
factor and not an element of the offense that must be decided
by a jury. 523 U.S. 224, 247 (1998). We have “repeatedly
held . . . that Almendarez-Torres is binding unless it is
expressly overruled by the Supreme Court.” United States
v. Leyva-Martinez, 632 F.3d 568, 569 (9th Cir. 2011); see
also United States v. Vallejos, 742 F.3d 902, 906 (9th Cir.
2014). We therefore conclude that the district court’s
application of § 851 to enhance Rodriguez’s sentence did not
violate his Sixth Amendment rights.

    Rodriguez’s second argument requires fuller discussion.
A grand jury indicted Rodriguez for violating 21 U.S.C.
§ 841(a)(1). Section 841 allows the government to seek
increased penalties if the individual commits the violation
after a prior felony drug conviction has become final. 21
U.S.C. § 841(b)(1)(A)(viii). Pursuant to the procedures set
forth in § 851, the government filed an information seeking
enhanced penalties to increase Rodriguez’s potential
mandatory minimum from 10 years to 20 years. § 851(a).
24             UNITED STATES V. RODRIGUEZ

Rodriguez filed a written response challenging the prior
convictions on the grounds that (1) the statutory scheme
under 21 U.S.C. § 851 is unconstitutional, and (2) two of the
three prior convictions were not controlled-substance
offenses that could serve as a basis for the enhancement —
an issue he does not raise on appeal.

     At a hearing before sentencing, the government
presented certified copies of three prior convictions to
support the sentence enhancement under § 851. After the
prosecution finished presenting its evidence of the prior
convictions, Rodriguez’s counsel raised a new argument that
there was “[n]othing to show that [his] client is the individual
who is listed here as Robert Rodriguez in these documents.”
In other words, he argued that the government failed to prove
with sufficient evidence that he was the “Robert Rodriguez”
named in the convictions. After the government noted that
this argument was not included in Rodriguez’s written
response, the district court asked defense counsel if “as an
officer of the court” he had “a good faith belief that these
[were] not [his] client’s convictions.” Defense counsel
responded that he would prefer not to answer unless ordered
to do so by the court. After the district court ordered him to
respond, defense counsel said, “I believe these are my
client’s convictions.” Significantly, the district court made
no such inquiry personally of Rodriguez. After further
discussion, the district court concluded that the certified
copies of the convictions proffered by the government were
“reasonably reliable information that these are convictions
suffered by the defendant,” and that the government had met
its burden of proving the prior convictions under § 851.

    To seek an enhanced penalty, the government must file,
before trial or before the entry of a plea, a written
information stating “the previous convictions to be relied
               UNITED STATES V. RODRIGUEZ                   25

upon.” 21 U.S.C. § 851(a)(1). The government did so in
this case. At some point before the sentence is imposed, the
district court must address the defendant personally and
(1) “inquire of the person with respect to whom the
information was filed whether he affirms or denies that he
has been previously convicted as alleged in the information,”
and (2) “inform him that any challenge to a prior conviction
which is not made before sentence is imposed may not
thereafter be raised to attack the sentence.” § 851(b). If a
defendant “denies any allegation of the information” or
“claims that any conviction alleged is invalid,” he must file
a written response, which triggers a hearing “to determine
any issues raised by the response.” § 851(c)(1). At the
hearing, the government has the burden of proof beyond a
reasonable doubt on any disputed issue of fact. Id. “Any
challenge to a prior conviction, not raised by response to the
information” is waived unless the person can show “good
cause” for a failure to make a timely challenge. § 851(c)(2).

    We require “strict compliance with the procedural
aspects of section 851(b).” United States v. Hamilton, 208
F.3d 1165, 1168 (9th Cir. 2000). The § 851(b) colloquy is
not merely a procedural requirement. It serves a functional
purpose “to place the procedural onus on the district court to
ensure defendants are fully aware of their rights.” United
States v. Espinal, 634 F.3d 655, 665 (2d Cir. 2011) (quoting
United States v. Baugham, 613 F.3d 291, 296 (D.C. Cir.
2010)). In this case, the district court “did not follow these
procedures meticulously.” Id. at 662. It did not ask
Rodriguez if he affirmed or denied the prior convictions nor
did it inform him that he had to raise any challenge to a prior
conviction before the sentence was imposed. The district
court thus failed to comply with § 851(b).
26             UNITED STATES V. RODRIGUEZ

     “The general rule is clear that failure to comply with
section 851(b) renders the sentence illegal.” United States
v. Housley, 907 F.2d 920, 921 (9th Cir. 1990) (citation and
internal quotation marks omitted). But “non-prejudicial
errors in complying with the procedural requirements of
§ 851” do not automatically require reversal; they sometimes
may be harmless. Espinal, 634 F.3d at 665; see also United
States v. Severino, 316 F.3d 939, 948 (9th Cir. 2003) (en
banc) (concluding that the district court’s failure to give a
§ 851(b) colloquy was not plain error where the defendant
“had no way to challenge the validity of the prior
conviction”); Housley, 907 F.2d at 921 (concluding that the
district court’s failure to give a § 851(b) colloquy was
harmless where the defendant was barred from challenging
the validity of the convictions due to § 851(e)). In this case,
however, a combination of factors — the detailed procedures
required by § 851, the district court’s failure to comply
strictly with § 851 and the resulting confusion, the lack of
clarity in the court’s ruling, and the serious impact that the
20-year statutory mandatory minimum had on the sentence
imposed — lead us to conclude that the error here was not
harmless.

    The § 851(b) colloquy notifies the defendant that he
must include all challenges to his prior convictions in the
written response, or he forever waives such challenges.
§ 851(b). Rodriguez filed a written response, but he did not
explicitly deny the convictions or argue that he was not the
individual listed in the exhibits attached to the government’s
information. It appears that Rodriguez or his attorney made
a tactical choice not to include his identity challenge in the
written response, and instead raised it orally only after the
government had concluded its presentation. We do not
condone attempts to surprise opposing counsel with an
argument that was not raised in submitted papers, and
               UNITED STATES V. RODRIGUEZ                    27

Rodriguez’s choice certainly added to the confusion at the
proceeding. Nevertheless, under the statute, Rodriguez was
not required to affirm or deny the convictions or file a written
response until addressed personally by the district court and
advised of his obligation to do so and — importantly — that
any failure to do so waived any objections. Espinal, 634
F.3d at 663–65. That Rodriguez ultimately did file a written
response does not negate the importance of a proper advisal.

    In addition to the impact on a defendant, when the court
fails to follow the procedures in § 851(b), the government
does not have a fair opportunity to present its best arguments
and evidence. See id. at 666. The procedures in the statute
anticipate that the § 851(b) colloquy and the defendant’s
written denial of the convictions or any allegation in the
information will occur before the government must produce
further evidence at the hearing. Although the government
has the burden of proving disputed facts at the hearing
beyond a reasonable doubt, “that burden is triggered only
where the defendant denies the prior felony and submits a
written response raising a [disputed] factual issue.” Id. at
664 (citing 21 U.S.C. § 851(c)).

    Two additional procedural defects warrant remand in
this case. First, the district court appears to have been
uncertain of its responsibilities under § 851 as the sentencing
hearing unfolded. At one point in the proceeding, the court
noted that the presentence investigation report set out
Rodriguez’s prior convictions, but then conflated
Rodriguez’s failure to object to the convictions set forth in
the report with his separate identity challenge. The district
court also asked “how else would we prove” these
convictions and later questioned whether § 851 required
testimony from individuals and whether a jury was required.
Section 851 explicitly answers these questions. If the
28               UNITED STATES V. RODRIGUEZ

defendant denies any allegation in the information and files
a written response, a “hearing shall be [held] before the court
without a jury and either party may introduce evidence.”
§ 851(c)(1). Furthermore, a district court may find as a
matter of fact any undisputed portion of a presentence
investigation report under Rule 32 of the Federal Rules of
Criminal Procedure, but that is not the same as the
requirement that the government prove beyond a reasonable
doubt a disputed fact, including a prior conviction under
§ 851. See Fed. R. Crim. P. 32(i)(3)(A). 4

    Second, it is unclear from the record whether the district
court used the appropriate standard when it ultimately ruled
on the merits of the § 851 issues and concluded that
Rodriguez was subject to a 20-year statutory mandatory
minimum. Initially, the district court characterized its
inquiry as whether the documents provided by the
government were “reasonably reliable information.” After
further discussion with the parties, the court then stated:

         I have reasonably reliable information that
         these are convictions suffered by the
         defendant, Mr. Rodriguez. . . . Proof beyond
         a reasonable doubt does not require proof
         beyond all doubt. It is proof using common


    4
      Although 21 U.S.C. § 851 does not state precisely when the district
court must engage in the § 851(b) colloquy, it “seem[s] preferable not to
postpone the inquiry until the scheduled sentencing date” to avoid the
kind of confusion that occurred in this case. Espinal, 634 F.3d at 662.
The district court may, however, hold the proceeding required by
§ 851(c) immediately before sentencing; it need not hold a separate
hearing on a different day. See Housley, 907 F.2d at 921.
                UNITED STATES V. RODRIGUEZ                        29

        sense that, in fact, these are Mr. Rodriguez’s
        convictions. . . . I’m satisfied that, in fact, the
        government has proved that these are the
        defendant’s prior convictions. So that is my
        ruling.

From these statements, it is unclear whether the district court
applied the required proof beyond a reasonable doubt
standard or a lesser “reasonable reliability” standard. 5

    The procedures detailed in § 851 are intended to provide
clarity to all parties before a judge imposes a lengthy
mandatory minimum sentence that substantially affects a
defendant. As the Second Circuit has noted, “[c]onsidering
that a ten-year sentencing enhancement turns on the outcome
of the § 851 procedure, the failure to comply fully with the
statute’s procedural requirements should not casually be
deemed harmless error.” Espinal, 634 F.3d at 667. Given
the procedural defects here — and despite the fact that
Rodriguez’s counsel caused some of the confusion, see id. at
663 — we cannot say the error in this case was harmless.
We therefore vacate Rodriguez’s sentence and remand for
resentencing.

B. Guidelines Sentencing Adjustments Under §§ 3B1.1
                     and 3E1.1

   Although we vacate Rodriguez’s sentence for the district
court’s failure to comply with 21 U.S.C. § 851(b), we


    5
      We decline to state whether the certified copies of conviction
offered by the government proved beyond a reasonable doubt that
Rodriguez suffered these convictions, although this was not a case in
which the government produced unverified or incomplete records as
proof of prior convictions. See Espinal, 634 F.3d at 660, 663.
30             UNITED STATES V. RODRIGUEZ

address Rodriguez’s other sentencing guidelines arguments
because these issues are likely to arise again at resentencing.

    When calculating Rodriguez’s guidelines sentencing
range, the district court applied a four-level upward
adjustment under U.S.S.G. § 3B1.1(a) after finding that
Rodriguez was a leader of a criminal activity. The district
court also denied Rodriguez’s request for a two-level
downward adjustment for acceptance of responsibility under
U.S.S.G. § 3E1.1(a). Rodriguez first argues that a factual
determination by a judge that Rodriguez was a leader of a
criminal activity violates the Sixth Amendment, and that
under Alleyne, such a fact must be proven to a jury beyond a
reasonable doubt. 133 S. Ct. at 2151. Second, he maintains
that the district court erred by denying a downward
adjustment for acceptance of responsibility.

    Under U.S.S.G. § 3B1.1(a), a district court may increase
the base offense level by four levels if the court finds that the
“defendant was an organizer or leader of a criminal activity
that involved five or more participants.” In United States v.
Vallejos, we concluded that if an offense level increase under
the U.S. Sentencing Guidelines does not affect the statutory
maximum sentence or the mandatory minimum sentence,
“neither Apprendi nor Alleyne v. United States is
implicated.” 742 F.3d at 906 (citing Alleyne, 133 S. Ct. at
2163). The organizer/leader adjustment did not affect the
statutory maximum or mandatory minimum of Rodriguez’s
sentence, and therefore neither Alleyne nor Apprendi require
a jury to find that Rodriguez was an organizer or leader of a
criminal activity. Id. The district court did not violate
Rodriguez’s constitutional rights by applying an upward
adjustment under U.S.S.G. § 3B1.1(a) without submitting
the issue to a jury.
               UNITED STATES V. RODRIGUEZ                  31

    The Sentencing Guidelines allow a two-level downward
adjustment to an individual’s base offense level “if the
defendant clearly demonstrates acceptance of responsibility
for his offense.” U.S.S.G. § 3E1.1(a). “A district court’s
decision about whether a defendant has accepted
responsibility is a factual determination reviewed for clear
error.” United States v. Doe, 778 F.3d 814, 821 (9th Cir.
2015) (quoting United States v. Rosas, 615 F.3d 1058, 1066
(9th Cir. 2010)). “The determination of the sentencing judge
is entitled to great deference on review because of the
sentencing judge’s unique position to evaluate a defendant’s
acceptance of responsibility.” United States v. Nielsen, 371
F.3d 574, 582 (9th Cir. 2004) (citation and internal quotation
marks omitted). The defendant bears the burden of
demonstrating acceptance of responsibility, United States v.
Osinger, 753 F.3d 939, 948 (9th Cir. 2014), and must show
“genuine contrition for his acts,” United States v. Dhingra,
371 F.3d 557, 568 (9th Cir. 2004). We conclude that the
district court did not clearly err in denying the adjustment.

    The Sentencing Guidelines note that a downward
adjustment for acceptance of responsibility generally is not
intended to apply to a defendant, like Rodriguez, “who puts
the government to its burden of proof at trial by denying the
essential factual elements of guilt, is convicted, and only
then admits guilt and expresses remorse.” U.S.S.G. § 3E1.1
cmt. 2. But “in appropriate circumstances the [adjustment]
is also available in cases in which the defendant manifests
genuine contrition for his acts but nonetheless contests his
factual guilt at trial.” United States v. Cantrell, 433 F.3d
1269, 1285 (9th Cir. 2006) (quoting United States v.
McKinney, 15 F.3d 849, 853 (9th Cir. 1994)).

    In his presentence interview, Rodriguez expressed his
regret for involving himself in illegal activity, and he said
32             UNITED STATES V. RODRIGUEZ

how difficult his incarceration had been on his family.
Rodriguez stated that he went to trial because he was not
made a reasonable plea offer and therefore had no other
choice but to go to trial. Rodriguez chose not to speak at
sentencing and provided no other statements that
demonstrated that he had accepted responsibility for his
actions. Although Rodriguez expressed some regret for his
actions to the probation officer, these statements do not
necessarily indicate that he showed genuine contrition for his
actions, or that the district court clearly erred in denying a
downward adjustment for acceptance of responsibility. See
United States v. Martinez-Martinez, 369 F.3d 1076, 1090
(9th Cir. 2004).

C. Substantive Reasonableness of Rodriguez’s Sentence

    Rodriguez’s sentence of 600 months — or 50 years —
may be unduly harsh, and we might reasonably question
whether it was “greater than necessary” to further the
purposes of the sentencing statute. 18 U.S.C. § 3553(a); see
United States v. Crowe, 563 F.3d 969, 978 (9th Cir. 2009);
United States v. Cherer, 513 F.3d 1150, 1159 (9th Cir.
2008). Although Rodriguez had an extensive criminal
history, his sentence is longer than those for many violent
crimes. Ultimately, we need not reach Rodriguez’s
substantive unreasonableness claim because, for the reasons
previously discussed, we vacate the sentence and remand for
resentencing.

    The judgment of conviction is AFFIRMED. The
sentence is VACATED, and we REMAND for
resentencing.
