FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                        No. 09-50253
                Plaintiff-Appellee,
               v.                                  D.C. No.
                                               5:08-cr-00257-RT-1
TRAMELL D. DENTON,
                                                    OPINION
             Defendant-Appellant.
                                          
         Appeal from the United States District Court
            for the Central District of California
          Robert J. Timlin, District Judge, Presiding

                 Submitted November 3, 2009*
                     Pasadena, California

                      Filed March 24, 2010

Before: Ronald M. Gould and Carlos T. Bea, Circuit Judges,
         and Donald W. Molloy,** District Judge.

                      Opinion by Judge Bea




   *The panel unanimously finds this case suitable for decision without
oral argument. See Fed. R. App. P. 34(a)(2).
   **The Honorable Donald W. Molloy, United States District Judge for
the District of Montana, sitting by designation.

                                4733
4736               UNITED STATES v. DENTON


                         COUNSEL

Michael Tanaka, Deputy Federal Public Defender, FPDCA —
Federal Public Defender’s Office, Los Angeles, California,
for the appellant.

Jayne Kim, Assistant U.S. Attorney, and Michael J. Raphael,
Assistant U.S. Attorney, Office of the U.S Attorney, Los
Angeles, California, for the appellee.


                         OPINION

BEA, Circuit Judge:

   Tramell Denton appeals a federal district court order revok-
ing his supervised release and sentencing him to nine months
in prison. The district court found Denton physically abused
his girlfriend while he was on supervised release from a prior
                        UNITED STATES v. DENTON                         4737
conviction. Although the state authorities did not charge1
Denton with domestic abuse, the district court found that Den-
ton’s conduct could have been charged under California Penal
Code section 273.5. A violation of that section is punishable
as either a felony or a misdemeanor; it is known as a “wob-
bler,” or “alternative felony/misdemeanor,” under California
law. The district court held Denton’s conduct was a Grade A
violation under the Sentencing Guidelines because wobbler
offenses are presumptively considered felonies, punishable by
more than one year in prison.2

   In this case, we must decide whether a defendant’s
uncharged conduct, which would be chargeable as a wobbler
offense—an offense that may be charged as either a misde-
meanor or a felony—is presumptively a felony, punishable by
more than one year in prison, for the purposes of calculating
whether the defendant committed a Grade A, B, or C violation
of his supervised release. We hold that the presumption that
  1
    “Charge,” as used here, means to commence criminal proceedings in
court, by Complaint or Information, following the return of an Indictment
or a Preliminary Hearing holding order.
  2
    United States Sentencing Guidelines section 7B1.1 states:
      (a) There are three grades of probation and supervised release
      violations:
      (1) Grade A Violations—conduct constituting (A) a federal, state,
      or local offense punishable by a term of imprisonment exceeding
      one year that (i) is a crime of violence, (ii) is a controlled sub-
      stance offense, or (iii) involves possession of a firearm or
      destructive device of a type described in 26 U.S.C. § 5845(a); or
      (B) any other federal, state, or local offense punishable by a term
      of imprisonment exceeding twenty years;
      (2) Grade B Violations—conduct constituting any other federal,
      state, or local offense punishable by a term of imprisonment
      exceeding one year;
      (3) Grade C Violations—conduct constituting (A) a federal, state,
      or local offense punishable by a term of imprisonment of one
      year or less; or (B) a violation of any other condition of supervi-
      sion.
4738                   UNITED STATES v. DENTON
a charged offense under a wobbler statute is a felony does not
apply to uncharged conduct. We reverse and remand to the
district court to exercise its discretion in deciding whether the
defendant’s conduct was felonious.

                         Factual Background

   In 1994, the United States District Court for the Southern
District of Mississippi convicted Denton of possession of
cocaine base with intent to distribute, in violation of 21
U.S.C. §§ 841(a)(1). The district court sentenced Denton to
160 months’ imprisonment and imposed a five-year term of
supervised release. The conditions of Denton’s supervised
release required Denton to refrain from drug use and to refrain
from committing another federal, state, or local crime while
on supervised release. Denton began serving his supervised
release in June 2005.

   In November 2008, the Rialto Police Department filed a
police report which related that Denton had physically abused
his live-in girlfriend. According to the police report, Denton
slapped his girlfriend across the face, choked her, and dragged
her by her hair. California state police arrested Denton two
days later, but the State of California, for whatever reasons,
ultimately declined to charge him with domestic violence
under California Penal Code section 273.5.3

  The next month, the United States Probation Office for the
Central District of California (“USPO”) filed a Petition on
Probation and Supervised Release (the “Petition”) in district
  3
    California Penal Code section 273.5 states, in relevant part: “Any per-
son who willfully inflicts upon a person who is his or her spouse, former
spouse, cohabitant, former cohabitant, or the mother or father of his or her
child, corporal injury resulting in a traumatic condition, is guilty of a fel-
ony, and upon conviction thereof shall be punished by imprisonment in the
state prison for two, three, or four years, or in a county jail for not more
than one year, or by a fine of up to six thousand dollars ($6,000) or by
both that fine and imprisonment.”
                       UNITED STATES v. DENTON                        4739
court. The Petition alleged Denton violated the terms of his
supervised release because Denton had (1) tested positive five
times for marijuana use; (2) “inflicted corporal injury on a
cohabitant,” in violation of California Penal Code section
273.5; and (3) failed to notify the USPO that the California
state police had arrested him for physically abusing his live-in
girlfriend in November 2008.

   The district court held a hearing, where Denton admitted he
had tested positive three times for marijuana use, and admit-
ted he had failed to notify the USPO of his November 2008
arrest. However, Denton denied he had physically abused his
live-in girlfriend, and denied the other two allegations of mar-
ijuana use.

   The court held a further hearing, and the government
moved to dismiss the marijuana allegations that Denton dis-
puted, but declined to dismiss the domestic violence allega-
tion. The government introduced into evidence a police report
that related Denton’s assault on his girlfriend in November
2008. Denton declined to object to the police report or to con-
test the facts stated in the report.4

  The district court found Denton violated the terms of his
supervised release. Specifically, the court found by a prepon-
derance of the evidence that Denton inflicted corporal injury
on a cohabitant, in violation of California Penal Code section
273.5.5
  4
     At the hearing, Denton’s counsel stated Denton would not admit to the
domestic violence offense, but would not contest the facts of the incident
as related in the police report. The defense attorney explained that if Den-
ton admitted he had physically abused his girlfriend, state prosecutors
could still formally charge Denton with domestic violence because the
statute of limitations on that charge had not yet run. Nonetheless, accord-
ing to his counsel, Denton’s “intention [was] not to contest” the domestic
violence allegation.
   5
     The court also found Denton used marijuana three times during his
supervised release and Denton failed to notify the USPO of his arrest.
4740                   UNITED STATES v. DENTON
   The district court found that, because a domestic abuse
offense is punishable by up to four years’ imprisonment, the
domestic abuse offense is a Grade A violation of Denton’s
supervised release.6 The court then calculated Denton’s sen-
tencing range under the Guidelines as 24-30 months’ impris-
onment for violating his supervised release, based in part on
the court’s finding that Denton committed a Grade A violation.7
After reviewing the 28 U.S.C. § 3553(a) sentencing factors,
the court departed downward and sentenced Denton to nine
months’ imprisonment.8 Denton timely appealed.

                         Standard of Review

   This court reviews de novo claims of error in a district
court’s order interpreting the Sentencing Guidelines and
reviews for abuse of discretion the district court’s application
of the Guidelines to the facts of a case. United States v. Mar-
ler, 

, 876-77 (9th Cir. 2008).

                                Analysis

  Denton does not appeal the district court’s holding that he
violated the terms of his supervised release by physically
abusing his live-in girlfriend. He appeals only the district
court’s characterization of his offense as a Grade A violation
of his supervised release.
  6
     The district court also found Denton’s marijuana use and failure to
notify the USPO of his arrest were Grade C violations.
   7
     The parties agree that if the district court had found the domestic vio-
lence offense was a Grade C violation of Denton’s supervised release, the
correct Guidelines sentencing range would have been three-to-nine
months’ imprisonment.
   8
     In departing downward, the district court cited in support: Denton’s
age, his prior employment, his financial support for his daughter, his sup-
port and care for his mother, his willingness to engage in anger manage-
ment, and his willingness to work with the USPO to overcome his drug
problems.
                     UNITED STATES v. DENTON                     4741
   [1] Courts may revoke a term of supervised release and
require the defendant to serve in prison all or part of the term
of supervised release “if the court . . . finds by a preponder-
ance of the evidence that the defendant violated a condition
of supervised release.” 18 U.S.C. § 3583(e)(3). In determining
whether a defendant violated the conditions of his supervised
release, a court may consider the defendant’s commission of
a crime even if the government ultimately did not prosecute
the defendant for that crime. U.S.S.G. § 7B1.1, cmt. 1; United
States v. Jolibois, 

, 1114 (9th Cir. 2002) (“A
[supervised release] violation . . . may be found whether [the
defendant] was ever indicted or convicted of [the] particular
offense.”).

   When sentencing a defendant for violating the conditions of
his supervised release, a court must determine the applicable
advisory sentencing range under the Guidelines. See United
States v. Carty, 

, 991 (9th Cir. 2008) (en banc)
(“All sentencing proceedings are to begin by determining the
applicable Guidelines range.”). A failure to calculate the cor-
rect advisory range constitutes procedural error. 

We reverse sentence determinations when a district court has
committed a significant procedural error. 

calculate the correct Guidelines sentencing range
for a violation of a defendant’s supervised release, the sen-
tencing court must determine whether the violation is a Grade
A, Grade B, or Grade C violation.9 U.S.S.G. § 7B1.1. The rel-
evant portion of the Sentencing Guidelines defines a Grade A
violation as conduct constituting “a federal, state, or local
offense punishable by a term of imprisonment exceeding one
year that . . . is a crime of violence.” U.S.S.G. § 7B1.1(a)(1).
The relevant portion of the Sentencing Guidelines defines a
Grade C violation as conduct constituting “a federal, state, or
  9
   Neither party contends the domestic violence offense at issue is a
Grade B violation. Thus, we will discuss Grade A and Grade C violations
only.
4742                UNITED STATES v. DENTON
local offense punishable by a term of imprisonment of one
year or less.” U.S.S.G. § 7B1.1(a)(3).

   [3] Whether a defendant has committed a Grade A or
Grade C violation of his supervised release depends on the
potential punishment for the underlying offense. See 

. Under California law, a person who com-
mits a domestic violence offense “is guilty of a felony, and
upon conviction thereof shall be punished by imprisonment in
the state prison for two, three or four years, or in a county jail
for not more than one year.” Cal. Penal Code § 273.5.
Although the California Penal Code refers to domestic abuse
as a felony, under the Guidelines, it may be either a Grade A
violation or a Grade C violation depending on the length of
the defendant’s sentence. See, e.g., United States v. Bridge-
forth, 

, 871-72 (9th Cir. 2006). As the Supreme
Court has held in another context, the California domestic
abuse statute is a “wobbler,” in which an offense under the
statute can be punished either as a felony or as a misdemea-
nor. See Ewing v. California, 

, 16 (2003) (inter-
preting California law).

   [4] Under California law, a “wobbler” statute “is presump-
tively a felony and ‘remains a felony except when the discre-
tion is actually exercised’ to make the crime a misdemeanor.”

(quoting People v. Williams, 

, 229
(1945)). This Circuit has not decided whether this “wobbler
presumption” applies to uncharged conduct. We observe that
California courts have stated the wobbler presumption applies
to charged conduct. See, e.g., People v. Mincey, 

, 453 (1998) (holding the felony statute of limitations
applies to a wobbler offense initially charged as felony, with-
out regard to the ultimate reduction to a misdemeanor); Peo-
ple v. McElroy, 

, 880 (2005) (“A
wobbler offense charged as a felony is regarded as a felony
for all purposes until imposition of sentence or judgment.”).
We have not found any authority, state or federal, holding the
wobbler presumption applies to uncharged conduct.
                        UNITED STATES v. DENTON                          4743
   [5] We hold that when a district court finds that a defen-
dant has committed a wobbler offense, but the offense is
uncharged, no presumption applies as to whether the offense
is punishable as a felony (more than one year’s imprisonment)
or a misdemeanor (less than one year’s imprisonment).10
Because no presumption applies, the district court must exer-
cise its discretion to decide whether the offense was punish-
able by more than one year’s imprisonment.

   [6] To decide whether an offense was punishable by more
than one year’s imprisonment, the court should determine first
whether, assuming the offense had been charged, a California
prosecutor would have charged the offense as a misdemeanor
or a felony. If the district court finds a prosecutor would have
charged the offense as a felony, the district court must deter-
mine, second, whether a trial court would have “impose[d] a
punishment other than imprisonment in a state prison,” under
the process set forth in California Penal Code section 17(b).
For the purpose of this inquiry, the district court should fol-
low the factors identified in People v. Superior Court (Alva-
rez), 

, 978 (1997): “[T]he nature and
circumstances of the offense, the defendant’s appreciation of
and attitude toward the offense, or his traits of character as
evidenced by his behavior and demeanor at the trial . . . [and]
the general objectives of sentencing.”11
  10
      As a note of caution, we do not hold that uncharged offenses are pre-
sumptively misdemeanors. When an offense is uncharged, no presumption
applies.
   11
      In Alvarez, the police discovered methamphetamine and drug para-
phernalia during a consensual search of Alvarez’s 

.
The prosecution charged Alvarez with a felony violation of California
Health and Safety Code section 11377, subdivision (a). 

charged Alvarez with four prior serious felony convictions. 

trial, he moved to have the instant charge declared a misdemeanor, which
the trial court took on submission and granted after the jury returned a
guilty verdict. 

On a petition for a writ, the Court of Appeal
held the trial court abused its discretion by failing sufficiently to take into
account Alvarez’s criminal past and for substituting its views for the Leg-
islature’s three-strikes policy. 

Supreme Court reversed
the Court of Appeal’s decision, holding that California’s three strikes law
did not modify trial courts’ discretion to reduce a wobbler offense from
a felony to a misdemeanor.
4744                   UNITED STATES v. DENTON
   [7] To aid the district court, the parties should submit evi-
dence, such as affidavits from prosecutors and defense attor-
neys in the relevant jurisdiction, as to whether the defendant’s
offense was more similar to offenses charged and sentenced
as felonies, or, whether the defendant’s offense was more
similar to offenses charged or sentenced as misdemeanors, as
well as any other conduct, characteristics, or circumstances
that might have affected a prosecutor’s decision about how to
charge Denton or a court’s decision about how to exercise its
discretion under California Penal Code section 17(b).12 The
district court should evaluate the parties’s evidence and
decide the appropriate Grade of the sentencing violation based
on a preponderance of the evidence.

   Our holding is consistent with the commentary to the Sen-
tencing Guidelines, which urges courts to determine the grade
of a defendant’s violation based on the defendant’s actual
conduct. U.S.S.G. § 7B1.1, cmt. 1 (“The grade of violation
does not depend upon the conduct that is the subject of crimi-
nal charges or of which the defendant is convicted in a crimi-
nal proceeding. Rather, the grade of the violation is to be
  12
     Here, there were aspects of Denton’s conduct on both sides of the
issue whether a prosecutor would have charged him with a felony or mis-
demeanor, and how severely a court would have sentenced him. On the
one hand, the district court had before it evidence of the assault against the
victim. The described abuse was violent: “Denton straddled the victim and
began to choke her by squeezing her neck with both hands . . . Denton
then slapped the victim across her face. Denton then began to choke her
again . . . Denton pulled the victim into the living room by her hair.” Den-
ton then released his live-in girlfriend and “walked outside and began to
beat and kick his dog.” Although Denton’s live-in girlfriend did not seek
medical attention, the abuse resulted in a “traumatic condition,” a bruise
on her leg. On the other hand, there were considerations in Denton’s favor:
He cared for his aged mother, paid child support for his daughter, held
down a job for much of the time, had made progress on his drug usage
problem, and in general garnered more support than fear from his live-in
girlfriend who was the victim of his prior abuse. These circumstances in
total might have invited a decision in either direction and deserve the dis-
trict court’s exercise of a sound discretion.
                   UNITED STATES v. DENTON                4745
based on the defendant’s actual conduct.”). A district court
should evaluate the seriousness of the defendant’s uncharged
conduct to decide whether that conduct would be punishable
by more than one year’s imprisonment.

   [8] Furthermore, a defendant charged under a wobbler stat-
ute has several opportunities to challenge the characterization
of his offense as a felony. See Cal. Penal Code § 17(b). The
defendant may convince the prosecutor to charge the offense
as a misdemeanor, or the defendant may convince the court
to either impose a punishment other than imprisonment in a
state prison, such as “diversion,” or grant probation to the
defendant without imposing a sentence and declare the
offense a misdemeanor. 

law, trial courts
have longstanding authority to reduce an offense from a fel-
ony to a misdemeanor for a wobbler, without having to over-
come a presumption that an offense is a felony. See People v.
Perez, 

, 363 (1995). When a defendant’s
conduct is not charged, however, the defendant’s first oppor-
tunity to convince a court that his offense is merely a misde-
meanor is at his revocation hearing. The defendant should not
be subject to a higher standard for proving his offense was a
misdemeanor than the defendant would have to meet before
a state trial court if his conduct was actually prosecuted.

   Finally, the Government’s reliance on United States v.
Bridgeforth, 

(9th Cir. 2006), and United States
v. Robinson, 

(9th Cir. 1992), is misplaced
because neither case involved uncharged conduct. In Robin-
son, the state sentencing court suspended imposition of the
defendant’s sentence and placed the defendant on probation
with nine months in county 

. In Bridge-
forth, the defendant was convicted and sentenced to 365 days
in county 

. The Government has not
raised any authority regarding uncharged conduct.

  [9] Accordingly, the district court committed a significant
procedural error. United States v. Hammons, 

,
4746               UNITED STATES v. DENTON
1106 (9th Cir. 2009) (holding that a court that calculates
incorrectly the Guidelines range commits reversible error
even if the actual sentence is within the correct Guidelines
range). The district court did not exercise its discretion to
determine whether Denton’s uncharged offense was punish-
able by more or less than one year. The district court instead
applied a presumption that the uncharged offense was a fel-
ony and therefore a Grade A violation.

   [10] Although we use the term “significant procedural
error,” we hasten to add that the district court did nothing
unreasonable. To the contrary, the district court seems pre-
scient of our opinion and departed downward from the Guide-
lines’ range to issue a sentence within the range that would
apply if the district court determined that Denton’s offense
was a Grade C violation. We remand only because the record
suggests the district court felt compelled to consider Denton’s
offense a Grade A violation. Instead, on remand, the district
court should exercise its discretion to decide whether Den-
ton’s conduct constituted an offense punishable by more than
one year, in which case the offense is a Grade A violation, or
one year or less, in which case the offense is a Grade C viola-
tion.

  REVERSED AND REMANDED.