                     FOR PUBLICATION

    UNITED STATES COURT OF APPEALS
         FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                       No. 12-50597
               Plaintiff-Appellee,
                                                   D.C. No.
                    v.                        3:11-cr-02734-H-1

 JORGE AGUILERA-RIOS,
            Defendant-Appellant.                 ORDER AND
                                                  AMENDED
                                                   OPINION


        Appeal from the United States District Court
          for the Southern District of California
         Marilyn L. Huff, District Judge, Presiding

                   Argued and Submitted
           February 7, 2014—Pasadena, California

                    Filed June 17, 2014
                 Amended September 29, 2014

       Before: Harry Pregerson, Michael R. Murphy*,
          and Marsha S. Berzon, Circuit Judges.

                            Order;
                   Opinion by Judge Berzon

 *
   The Honorable Michael R. Murphy, Senior Circuit Judge for the U.S.
Court of Appeals for the Tenth Circuit, sitting by designation.
2              UNITED STATES V. AGUILERA-RIOS

                           SUMMARY**


                           Criminal Law

    The panel filed a superseding amended opinion reversing
a conviction for illegal reentry in a case in which the
defendant contended that, after Moncrieffe v. Holder, 133 S.
Ct. 1678 (2013), his prior removal order was invalid because
it was based on a conviction for unlawful firearms possession
under California Penal Code § 12021(c)(1), which lacked an
antique firearms exception and thus was not a categorical
match for the Immigration and Nationality Act’s firearms
offense described in 8 U.S.C. § 1227(a)(2)(C).

    The panel found that the defendant showed good cause to
excuse his failure to raise his Moncrieffe argument in the
district court, and therefore declined to find the argument
waived. The panel rejected the government’s argument that
this court cannot retroactively consider Moncrieffe in
evaluating whether the defendant was removable as charged.

    The panel held that because § 12021(c)(1) does not have
an antique firearms exception, and California prosecutes
offenses involving antique firearms, a conviction under that
statute is not a categorical match for the firearms offense
described in § 1227(a)(2)(C), and the underlying removal
order was invalid.




  **
     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. AGUILERA-RIOS                   3

                         COUNSEL

Kara Hartzler, Federal Defenders of San Diego, Inc., San
Diego, California, for Defendant-Appellant.

Mark R. Rehe (argued) and Bruce R. Castetter, Assistant
United States Attorneys, San Diego, California, for Plaintiff-
Appellee.


                           ORDER

    The opinion filed on June 17, 2014, is hereby amended.
The superseding amended opinion will be filed concurrently
with this order. No further petitions for rehearing or petitions
for rehearing en banc will be entertained.



                          OPINION

BERZON, Circuit Judge:

    Jorge Aguilera-Rios (“Aguilera”), a citizen of Mexico,
was convicted of a California firearms offense, removed from
the United States on the basis of that conviction, and, when
he returned to the country, tried and convicted of illegal
reentry under 8 U.S.C. § 1326. He contends that his prior
removal order was invalid because his conviction under
California Penal Code § 12021(c)(1) was not a categorical
match for the Immigration and Nationality Act’s (“INA”)
firearms offense. We agree that he was not originally
removable as charged, and so could not be convicted of
4              UNITED STATES V. AGUILERA-RIOS

illegal reentry.      We therefore reverse the judgment of
conviction.

                                   I.

    Aguilera entered the United States without inspection at
the age of five to live with his parents, who were lawful
permanent residents. He became a lawful permanent resident
in 2000. Two years later, he was convicted of unlawful
firearms possession in violation of California Penal Code
§ 12021(c)(1).1

    In 2005, Aguilera was served with a Notice to Appear,
alleging that he had been convicted of a crime involving
moral turpitude, 8 U.S.C. § 1227(a)(2)(A)(i), and a firearms
offense, 8 U.S.C. § 1227(a)(2)(C), and so was subject to
removal. One week later, Aguilera appeared before an
Immigration Judge (“IJ”). He admitted that he had been
convicted of unlawful firearms activity in violation of
California Penal Code § 12021(c)(1), but did not concede
removability. The IJ nonetheless held Aguilera “subject to
removal as charged,” and denied him any relief from
removal. Aguilera was removed to Mexico.

    Six years later, Aguilera was charged with attempted
entry after deportation, in violation of 8 U.S.C. § 1326(a) and
(b). Aguilera moved to dismiss the indictment under
§ 1326(d), arguing that, during the 2005 removal
proceedings, the IJ did not meaningfully advise him of his
opportunity to apply for voluntary departure. The district


    1
   This section was replaced by California Penal Code § 29805, effective
January 1, 2012. For clarity, we refer to the statute as California Penal
Code § 12021(c)(1).
             UNITED STATES V. AGUILERA-RIOS                    5

court denied the motion, and Aguilera was found guilty of
illegal reentry. Aguilera was sentenced to time served, and
has since been removed to Mexico.

    On April 23, 2013, after Aguilera filed his opening brief
in this case, the Supreme Court issued its decision in
Moncrieffe v. Holder, 133 S. Ct. 1678 (2013), concerning
application of the categorical approach in immigration cases.
Although that case involved a marijuana conviction, the
majority opinion addressed an argument by the Solicitor
General that, under the Court’s analysis, “a conviction under
any state firearms law that lacks . . . an exception [for antique
firearms present in the federal firearms statute] will be
deemed to fail the categorical inquiry.” Id. at 1693. Aguilera
moved to file a substitute opening brief in this case, arguing
that, after Moncrieffe, his 2005 removal order was invalid for
a second reason (in addition to the previously asserted due
process violation): Aguilera was never deportable as charged
because the California statute of conviction lacked an antique
firearms exception. We accepted the substitute brief, and the
government responded to Aguilera’s arguments in its
answering brief.

   We review Aguilera’s collateral attack on his 2005
removal order de novo. See United States v. Lopez-
Velasquez, 629 F.3d 894, 896 (9th Cir. 2010) (en banc).

                               II.

    “A defendant charged with illegal reentry pursuant to
8 U.S.C. § 1326 has a due process right to bring a collateral
attack challenging the validity of his underlying deportation
order because it serves as a predicate element of his
conviction.” United States v. Melendez-Castro, 671 F.3d
6            UNITED STATES V. AGUILERA-RIOS

950, 953 (9th Cir. 2012) (per curiam) (citation omitted).
Section 1326(d) expressly provides for such collateral attacks
on an underlying deportation order, but establishes limits on
them. A defendant must demonstrate that: (1) he exhausted
all administrative remedies available to appeal his prior
removal order; (2) the prior removal proceedings “improperly
deprived [him] of the opportunity for judicial review;” and
(3) the entry of the prior removal order was “fundamentally
unfair.” 8 U.S.C. § 1326(d).

   The government recognizes that the first two elements of
§ 1326(d) have been met. It maintains, however, that
Aguilera “cannot meet the last element, i.e., ‘fundamental
unfairness.’”

     “An underlying removal order is ‘fundamentally unfair’
if (1) an alien’s ‘due process rights were violated by defects
in the underlying deportation proceeding,’ and (2) ‘he
suffered prejudice as a result of the defects.’” United States
v. Pallares-Galan, 359 F.3d 1088, 1095 (9th Cir. 2004)
(citation omitted). If Aguilera “was removed when he should
not have been,” his 2005 removal was fundamentally unfair,
and he may not be convicted of reentry after deportation.
United States v. Camacho-Lopez, 450 F.3d 928, 930 (9th Cir.
2006).

                              III.

    Aguilera’s central contention is that the generic “federal
definition of a ‘firearm’ specifically exempts antique
firearms, while the California definition of a firearm does not.
Thus, a person may be convicted under Cal[infornia] Penal
Code § 12021 for conduct that does not fall within the
firearms ground of removal.” The government asks us not to
             UNITED STATES V. AGUILERA-RIOS                   7

reach this argument on the ground that Aguilera waived it by
failing to raise it in the district court. In addition, the
government argues that Moncrieffe cannot be retroactively
applied to invalidate a removal that was proper under the law
at the time it was ordered. We address each of these points in
turn.

                              A.

    As to waiver, the government contends that Aguilera’s
failure to raise his new Moncrieffe argument “before trial” as
part of his motion to dismiss the indictment effected a waiver
pursuant to Federal Rule of Criminal Procedure 12(b)(3)(B).
That rule provides that “a motion alleging a defect in the
indictment or information” “must be raised before trial.” Fed.
R. Crim. P. 12(b)(3)(B).

    We decline to find such a waiver here. Rule 12(e) sets
forth specifically the circumstances under which an argument
is waived. It provides that “[a] party waives any Rule
12(b)(3) defense, objection, or request not raised by the
deadline the court sets [for pretrial motions].” Fed. R. Crim.
P. 12(e). But Rule 12(e) further indicates that “[f]or good
cause, the court may grant relief from the waiver.” Id. On
appeal, we have held that “‘even issues that are deemed
waived [in the district court] under Rule 12 may be addressed
by this court and relief may be granted’ where good cause is
shown for the party’s failure to raise the argument earlier.”
United States v. Anderson, 472 F.3d 662, 669 (9th Cir. 2006)
(quoting United States v. Murillo, 288 F.3d 1126, 1135 (9th
Cir. 2002)) (internal quotation marks omitted) (emphasis and
alteration in original). We find good cause to excuse
Aguilera’s failure to raise this argument in the district court.
8            UNITED STATES V. AGUILERA-RIOS

    Prior to Moncrieffe, Aguilera would have had no reason
to challenge whether he was properly removed for a “firearms
offense.” As we explain below, this Court’s caselaw prior to
Moncrieffe foreclosed the argument he now makes. See Gil
v. Holder, 651 F.3d 1000, 1005–06 (9th Cir. 2011). We have
previously (albeit not explicitly in the Rule 12 context)
“elect[ed] to entertain [an] issue [raised for the first time on
appeal] because of a change in the intervening law that
brought the issue into focus.” In re Skywalkers, Inc., 49 F.3d
546, 548 n.4 (9th Cir. 1995) (citing Romain v. Shear,
799 F.2d 1416, 1419 (9th Cir. 1986) (holding that a change in
the law during the pendency of an appeal permits
entertainment of an issue not previously raised), cert. denied,
481 U.S. 1050 (1987)); cf. United States v. Tekle, 329 F.3d
1108, 1112 (9th Cir. 2003) (affirming finding of “‘no good
cause’” to excuse a Rule 12 waiver “‘because . . . United
States v. Gantt, 194 F.3d 987 (9th Cir. 1999) . . . did not
change the law. In fact, the Gantt court acknowledged as
much.’”).

    Moreover, Aguilera demonstrated diligence by moving in
this Court within a month after Moncrieffe was decided to
substitute his opening brief. And the government had a full
opportunity to respond in written briefing and at oral
argument to this purely legal issue. Aguilera has therefore
shown “good cause” to excuse his failure to raise this
argument in the district court. We decline to find it waived.

                              B.

    The government next contends that Moncrieffe cannot be
retroactively applied to invalidate Aguilera’s 2005 removal
order. It cites United States v. Vidal-Mendoza, 705 F.3d 1012
(9th Cir. 2013), for the proposition that on collateral review,
             UNITED STATES V. AGUILERA-RIOS                   9

a removal is to be judged “under the applicable law at the
time of [the] removal hearing,” id. at 1013, not “post-removal
precedent,” id. at 1016.

    Vidal-Mendoza concerned the scope of an IJ’s duty to
advise a noncitizen of his eligibility for discretionary relief.
It held that a noncitizen’s due process rights are not violated
if an IJ informs him, based on controlling law at the time of
the removal hearing, that he is ineligible for relief, even if
post-removal changes in the law would have altered that
analysis. Id. at 1016–17. Noting that “an IJ need not
anticipate future ‘change[s] in law,’” Vidal-Mendoza
suggested that applying post-removal precedent on collateral
review would violate “our long-stated principle that ‘IJs are
not expected to be clairvoyant’ when discharging their duty
to inform.” Id. at 1017 (quoting Lopez-Velasquez, 629 F.3d
at 900–01) (alteration in original).

    Vidal-Mendoza and its predecessor, Lopez-Velasquez, do
not apply here. Those cases asked what law applies when
evaluating whether an IJ violated its duty to inform the
noncitizen of potential avenues for relief. This case concerns
not the duty to inform the noncitizen of his eligibility for
relief in a removal proceeding, but whether he was removable
at all.

    In a similar case, the Tenth Circuit concluded that
“[d]ecisions of statutory interpretation are fully retroactive
because they do not change the law, but rather explain what
the law has always meant.” United States v. Rivera-Nevarez,
418 F.3d 1104, 1107 (10th Cir. 2005) (citing Rivers v.
Roadway Express Inc., 511 U.S. 298, 312–13 (1994) (“A
judicial construction of a statute is an authoritative statement
of what the statute meant before as well as after the decision
10           UNITED STATES V. AGUILERA-RIOS

of the case giving rise to that construction.”)).
Rivera-Nevarez concerned whether the Supreme Court
decision in Leocal v. Ashcroft, 543 U.S. 1 (2004), which held
that a Florida driving under the influence of alcohol offense
did not constitute a “crime of violence,” would apply
retroactively to invalidate a defendant’s 1999 removal order.
Rivera-Nevarez, 418 F.3d at 1107. The court held that
“[b]ecause Leocal involves a question of statutory
construction, its holding is retroactively applicable to the time
of Rivera-Nevarez’s removal hearing.” Id. As Leocal merely
“explain[ed] what the law has always meant,” Rivera-Nevarez
noted that it “provides the correct interpretation of the law as
it stood in 1999 when Rivera-Nevarez was deported.” Id.

    We reached the same conclusion as the Tenth Circuit in
Camacho-Lopez. Like Rivera-Nevarez, Camacho-Lopez
concerned a pre-Leocal removal that was invalid after Leocal.
Camacho-Lopez retroactively applied Leocal, explaining that
“the government concedes that Leocal—a substantive
interpretation of ‘crime of violence’ under 18 U.S.C.
§ 16—applies to Camacho’s 1998 deportation hearing[,]” that
“Camacho’s Notice to Appear charged him as removable only
for having committed an aggravated felony[,]” and that after
Leocal, “Camacho’s prior conviction did not fit that
definition[.]” Camacho-Lopez, 450 F.3d at 930 (emphasis
omitted). We therefore reversed his § 1326 conviction as
having been premised on an invalid removal order. Id.

    Camacho-Lopez has since been cited by district courts
within the Ninth Circuit for the proposition that any post-
removal substantive interpretation of a “crime of violence” or
“aggravated felony” provision is fully retroactive on
collateral review. See, e.g., United States v. Dominguez, No.
CR12-879 CAS, 2013 WL 2237786, at *3 n.2 (C.D. Cal. May
               UNITED STATES V. AGUILERA-RIOS                        11

20, 2013); United States v. Rodriguez Garcia, No.
CR-09-6093-EFS, 2010 WL 996409, at *2 (E.D. Wash. Mar.
15, 2010). Our recent precedent, however, counsels a more
restrictive reading of Camacho-Lopez. See United States v.
Gomez, ___ F.3d ___, 2014 WL 1623725 (9th Cir. Apr. 24,
2014).

    Unlike Vidal-Mendoza and Lopez-Velasquez, Gomez did
not concern the IJ’s duty to inform. Gomez nonetheless
considered only the federal law “at the time [Gomez] was
ordered deported in January 2006” in determining “whether
[the] alien was eligible for relief from deportation.” Id. at
*10 (emphasis added). Gomez did not, however, involve
application of post-removal precedent on collateral review
where that precedent would render a noncitizen not
removable; Camacho-Lopez did. Indeed, Gomez specifically
distinguished Camacho-Lopez, noting that “[i]t concerned
whether [Leocal] was nonetheless applicable on collateral
review to determine whether he was subject to removal as
charged—not, as in this case, whether, although removable,
he was entitled to discretionary relief.” Id. at *10 n.12
(distinguishing “relief from removal” from “removability”).

    Moreover, whether or not one regards Camacho-Lopez as
binding precedent on that point,2 there is good reason to
distinguish between discretionary relief, as in Gomez, and

 2
   Camacho-Lopez mentioned that the government “concede[d]” Leocal’s
retroactive application. 450 F.3d at 930. To say that something was
conceded is ordinarily to indicate that it is so. To note a concession is
different from stating, as we often do, that a legal argument was not
raised, or that we are assuming, but not deciding, a particular legal
standard. See, e.g., In re Pac. Pictures Corp., 679 F.3d 1121, 1126 n.2
(9th Cir. 2012). Still, we shall assume for purposes of this opinion that
Camacho-Lopez is not a definitive holding on the issue we here decide.
12           UNITED STATES V. AGUILERA-RIOS

grounds for removability for purposes of collateral review of
removal proceedings. Section 1326 is concerned with
whether a noncitizen has reentered after being “denied
admission, excluded, deported, or removed.” 8 U.S.C.
§ 1326(a). Where a noncitizen is in fact removable, the
denial of an opportunity to apply for a voluntary departure,
the discretionary relief at issue in Gomez, does not implicate
the propriety of a removal in the same fundamental a way as
does an IJ’s legal determination that a noncitizen is
removable on the basis of precedent we now know to have
been erroneous.

    Where relief is discretionary, it may not have been
accorded, requiring an after-the-fact inquiry comparing the
equities in a particular case to those in similar cases. See,
e.g., United States v. Rojas-Pedroza, 716 F.3d 1253, 1263
(9th Cir. 2013) (describing the process of determining
whether a noncitizen was prejudiced by an IJ’s failure to
advise him of his eligibility for discretionary relief, including
the “focus on whether aliens with similar circumstances
received relief”). And where relief was not available at the
time, there are no comparable cases with which to conduct
the required analysis. Moreover, the relevant facts tending to
show whether an IJ would have granted discretionary relief
to a particular noncitizen would often have to be
reconstructed, because there would have been no reason to
develop them if the noncitizen was categorically ineligible for
relief from removal at the time. Finally, most forms of relief
from removal are matters of grace as to someone already
determined to be removable. See, e.g., Tovar-Landin v.
Ashcroft, 361 F.3d 1164, 1167 (9th Cir. 2004) (describing
voluntary departure, the form of relief also at issue in
Gomez). Failing to obtain such discretionary relief is quite
different than the situation here, where Aguilera would have
               UNITED STATES V. AGUILERA-RIOS                        13

had the right to be in the United States, as a lawful permanent
resident, but for the IJ’s determination that he was removable
— a determination we now know to be legally erroneous after
Moncrieffe, as we explain below.

    Where that is the question, the usual rule that statutory
interpretation decisions are fully retroactive should apply.
Otherwise, an individual who had the right to remain here as
a legal resident — and to return to this country if he leaves —
but was removed as a result of a legal error, would be subject
to criminal conviction and incarcerated for returning. Such
an individual is in effect being criminally punished for the
government’s legal mistake. To maintain via enforcement
proceedings the finality of an otherwise proper removal order
is one thing; to impose criminal sanctions under these
circumstances is quite another.3

   We therefore reject the government’s position that we
cannot consider Moncrieffe in evaluating whether Aguilera
was removable as charged. We proceed to consider
Aguilera’s challenge on the merits.

                                  IV.

   Federal law makes deportable “[a]ny alien who at any
time after admission is convicted under any law of
purchasing, selling, offering for sale, exchanging, using,
owning, possessing, or carrying . . . any . . . firearm or


 3
   We note that a determination by this Court on collateral review that a
noncitizen’s conviction was not for a federal aggravated felony offense
would not affect the finality of the prior removal. See 8 C.F.R.
§ 1003.23(b)(1). It could, however, have other immigration consequences.
See, e.g., 8 U.S.C. § 1182(h).
14           UNITED STATES V. AGUILERA-RIOS

destructive device (as defined in section 921(a) of Title 18) in
violation of any law.” 8 U.S.C. § 1227(a)(2)(C). Section
921(a)(3) defines the term “firearm,” stating, inter alia, that
“[s]uch term does not include an antique firearm.” 18 U.S.C.
§ 921(a)(3).

    Aguilera asserts that after Moncrieffe, any conviction
under a state firearms statute lacking an exception for antique
firearms is not a categorical match for the federal firearms
ground of removal. We agree. And because Moncrieffe is
“clearly irreconcilable” with this Court’s prior case law,
particularly in Gil, we must follow Moncrieffe not Gil. See
Miller v. Gammie, 335 F.3d 889, 900 (9th Cir. 2003).

    Gil held that “in conducting the categorical analysis, we
do not consider the availability of affirmative defenses; the
fact that there may be an affirmative defense under the
federal statute, but not under the state statute of conviction,
does not mean that the state conviction does not fall
categorically within the federal statute.” 651 F.3d at 1005.
That general holding is still valid after Moncrieffe, as the
Court’s “decision said nothing about affirmative defenses.”
United States v. Albino-Loe, 747 F.3d 1206, 1212 (9th Cir.
2014). But Gil’s treatment of the antique firearms exception
of § 1227(a)(2)(C) as an affirmative defense, which need not
be considered in a categorical analysis, see 651 F.3d at 1005
n.3, rather than as an element of the definition of the criminal
offense, which must be, has been clearly overruled.

   A bit of background on Moncrieffe is necessary to
understand its effect on our case law: Moncrieffe, a lawful
permanent resident, pleaded guilty under Georgia law to
possession of marijuana with intent to distribute. Moncrieffe,
133 S. Ct. at 1683. Alleging that Moncrieffe’s conviction
             UNITED STATES V. AGUILERA-RIOS                  15

constituted an aggravated felony, the government sought to
deport him. Id. The Board of Immigration Appeals
concluded that possession with intent to distribute is an
offense under the Controlled Substances Act (“CSA”),
21 U.S.C. § 841(a), punishable by up to five years
imprisonment, id. § 841(b)(1)(D), and therefore an
aggravated felony. Moncrieffe, 133 S. Ct. at 1683. The Fifth
Circuit affirmed, rejecting Moncrieffe’s reliance upon
§ 841(b)(4), which makes distribution of a small amount of
marijuana without remuneration punishable as only a
misdemeanor. Id. The Supreme Court reversed. Id. at 1684.

    The Court considered whether Moncrieffe’s conviction
necessarily involved facts equating to the aggravated felony
of “‘illicit trafficking in a controlled substance,’” which
“encompasses all state offenses that ‘proscrib[e] conduct
punishable as a felony under [the CSA].’” Id. at 1685
(alteration in original) (citations omitted). “[T]o satisfy the
categorical approach, a state drug offense must meet two
conditions: [i]t must ‘necessarily’ proscribe conduct that is an
offense under the CSA, and the CSA must ‘necessarily’
prescribe felony punishment for that conduct.”               Id.
Moncrieffe thus reaffirmed a “core feature of the categorical
approach: its focus on the minimal conduct that would satisfy
the statutory definition of the offense of conviction.”
Albino-Loe, 747 F.3d at 1213 (emphasis in original).

    Possession with intent to distribute was clearly an offense
under the CSA, so the key question in Moncrieffe was
whether that conduct was punishable as a felony or
misdemeanor. The least culpable conduct (e.g., sharing a
small amount of marijuana for no remuneration) would result
in conviction under the Georgia statute, but trigger only
misdemeanor punishment under the CSA. “So Moncrieffe’s
16          UNITED STATES V. AGUILERA-RIOS

[state] conviction could correspond to either the CSA felony
or the CSA misdemeanor.” Moncrieffe, 133 S. Ct. at
1686–87. Moncrieffe held that “[a]mbiguity on this point
means that the conviction did not ‘necessarily’ involve facts
that correspond to an offense punishable as a felony under the
CSA. Under the categorical approach, then, Moncrieffe was
not convicted of an aggravated felony.” Id. at 1687.

   Moncrieffe’s response to an argument by the Solicitor
General in that case is of critical importance here:

       [T]he Government suggests that our
       holding will frustrate the enforcement of
       other aggravated felony provisions, like
       § 1101(a)(43)(C), which refers to a federal
       firearms statute that contains an exception for
       ‘antique firearm[s],’ 18 U.S.C. § 921(a)(3).
       The Government fears that a conviction under
       any state firearms law that lacks such an
       exception will be deemed to fail the
       categorical inquiry.        But [Gonzales v.]
       Duenas–Alvarez requires that there be “a
       realistic probability, not a theoretical
       possibility, that the State would apply its
       statute to conduct that falls outside the generic
       definition of a crime.” 549 U.S. [183,] 193
       [(2007)]. To defeat the categorical comparison
       in this manner, a noncitizen would have to
       demonstrate that the State actually prosecutes
       the relevant offense in cases involving antique
       firearms.

Id. at 1693 (emphasis added).
            UNITED STATES V. AGUILERA-RIOS                  17

    Aguilera argues that this analysis governs here, and that
because California does prosecute cases involving antique
firearms under California Penal Code § 12021(c)(1), his
conviction is not a categorical match for the federal firearms
offense. The description of such an offense in 8 U.S.C.
§ 1227(a)(2)(C) incorporates the same definition of firearms,
18 U.S.C. § 921(a)(3), as that alluded to in Moncrieffe with
regard to “other aggravated felony provisions.” Thus,
Aguilera’s argument is consistent with the express language
of Moncrieffe’s antique firearms discussion. It is also
consistent with that opinion’s overall analysis and holding.

    Moncrieffe requires us to presume that Aguilera was
convicted of an offense under California Penal Code
§ 12021(c)(1) using an antique firearm, because California
actually prosecutes people for such conduct. See, e.g., People
v. Charlton, No. A122842, 2011 WL 1492529, at *1, 4 (Cal.
Ct. App. Apr. 19, 2011) (affirming conviction under
California Penal Code § 12021 for possession of replica
muzzle-loading pistol); People v. Servin, No. E047394, 2010
WL 1619298, at *1 (Cal. Ct. App. Apr. 22, 2010) (affirming
conviction under California Penal Code § 12021 for “family
heirloom” replica single-shot muzzle-loading rifle incapable
of using modern ammunition); People v. Coffman, No.
C044728, 2005 WL 958409, at *1–2 (Cal. Ct. App. Apr. 26,
2005) (affirming conviction under California Penal Code
§ 12021 where the gun was described as an “antique
cowboy-style gun with a long barrel” and an “old-style cap
and ball pistol that was rusted and would only fire one shot at
a time and had to be reloaded each time to fire”); People v.
Cushman, No. C044129, 2005 WL 300024, at *1 (Cal. Ct.
App. Feb. 9, 2005) (affirming conviction under California
Penal Code § 12021 for possession of black powder,
muzzle-loading firearms). These recent examples of
18           UNITED STATES V. AGUILERA-RIOS

California prosecutions involving antique firearms meet the
“realistic probability” standard of Duenas-Alvarez. 549 U.S.
at 193. Under the express language of Moncrieffe, the
“categorical comparison” is therefore “defeat[ed].” 133 S.
Ct. at 1693.

    Moncrieffe’s overall analysis also supports the conclusion
that California Penal Code § 12021(c)(1) and the immigration
law’s firearms offense definition are not a categorical match.
As this Court recently recognized, Moncrieffe clarified that a
definitional element of a criminal offense, like the antique
firearms exception, must be considered for purposes of the
categorical approach, even if affirmative defenses are not.
See Albino-Loe, 747 F.3d at 1213–14. Moncrieffe squarely
rejected the Solicitor General’s argument in that case that
“the categorical approach is concerned only with the
‘elements’ of an offense,” not a definitional element like
§ 841(b)(4), the social marijuana sharing exception, or
§ 921(a)(3)(D), the antique firearm exception. 133 S. Ct. at
1683. “[W]hen Congress has chosen to define the generic
federal offense by reference to punishment, it may be
necessary to take account of federal sentencing factors too.”
Id. at 1687 (emphasis added). The Court therefore held that
“to qualify as an aggravated felony, a conviction . . . must
necessarily establish” “the presence . . . of certain factors that
are not themselves elements of the crime.” Id.

    In Moncrieffe, this holding meant that a state conviction
must establish that the offense did not involve social sharing
of a small quantity of marijuana to be a categorical match. In
this case, it would mean establishing that the offense did not
involve an antique firearm. As we explained in Albino-Loe,
             UNITED STATES V. AGUILERA-RIOS                    19

        the antique firearms exception appears in
        18 U.S.C. § 921, a section titled “Definitions.”
        See 18 U.S.C. § 921(a)(3) (“The term
        ‘firearm’ means (A) any weapon (including a
        starter gun) which will or is designed to or
        may readily be converted to expel a projectile
        by the action of an explosive; (B) the frame or
        receiver of any such weapon; (C) any firearm
        muffler or firearm silencer; or (D) any
        destructive device. Such term does not include
        an antique firearm.” (emphasis added)). One
        cannot know what conduct constitutes a
        firearms offense without knowing the
        definition of “firearm,” which excludes
        antique firearms.

747 F.3d at 1214 (final emphasis added). A state statute that
allows conviction for offenses using antique firearms would
therefore not equate to the § 1227(a)(2)(C) firearms offense.

    Moncrieffe further clarified that these definitional
elements must be considered regardless of which party would
bear the burden of proof in a criminal prosecution. In
Moncrieffe, the Solicitor General noted that in a criminal
prosecution, the government “need not negate the § 841(b)(4)
factors[;] . . . [i]nstead, the burden is on the defendant to show
that he qualifies” for misdemeanor treatment under
§ 841(b)(4). 133 S. Ct. at 1688. The Court acknowledged
that the defendant bears the burden in a criminal trial, but
concluded that the burden was irrelevant to the “‘more
focused, categorical inquiry’ . . . whether the record of
conviction of the predicate offense necessarily establishes
conduct that the CSA, on its own terms, makes punishable as
a felony.” Id. (citation omitted). “Our concern is only which
20             UNITED STATES V. AGUILERA-RIOS

facts” the generic federal definition required, rather than
“who has the burden of proving which facts in a federal
prosecution.” Id. at 1689. Thus, to the extent that Gil relied
on the fact that, in a federal criminal prosecution, a defendant
would be required to prove that the firearm was an antique,
see 651 F.3d at 1005 n.3 (citing criminal cases), it has been
overruled by Moncrieffe.4

     Moncrieffe also reiterated that in evaluating whether there
is a categorical match, “we must presume that the conviction
‘rested upon [nothing] more than the least of th[e] acts’
criminalized.” 133 S. Ct. at 1684 (alteration in original)
(citation omitted). In that case, doing so meant presuming
that the defendant had shared a small quantity of marijuana
for no remuneration — since Georgia actually prosecuted
people for such conduct. The same is true of the antique
firearm exception. Moncrieffe requires us to presume that
Aguilera was convicted of an offense under California Penal
Code § 12021(c)(1) using an antique firearm, as long as
California actually prosecutes people for such conduct —
which, as we have seen, it does.

    In sum, California Penal Code § 12021(c)(1) punishes
anyone who “owns, purchases, receives, or has in possession
or under custody or control, any firearm” within ten years of
a prior conviction for certain misdemeanors. It does not have
an antique firearms exception, and California prosecutes for
offenses involving antique firearms. A conviction under


 4
   We are not holding that Gil’s distinction between affirmative defenses
and elements of a crime is invalid for all categorical analyses. Rather, we
read Moncrieffe as applying particularly to definitional provisions, and as
holding that as to such provisions, the allocation of the burden of proof is
not relevant to a categorical analysis.
               UNITED STATES V. AGUILERA-RIOS                        21

California Penal Code § 12021(c)(1) is therefore not a
categorical match for the § 1227(a)(2)(C) firearms offense.
“Because the statute is missing an element of the[ ] generic
crime[ ], our inquiry ends here—we do not undertake a
modified categorical analysis.” Gomez, 2014 WL 1623725,
at *17.

    The government concedes that Aguilera’s conviction was
not for a “crime of moral turpitude” — the other potential
ground of removal. As a result, there was no legal basis for
his 2005 removal order. As Aguilera “was removed when he
should not have been,” he “clearly suffered prejudice.”
Camacho-Lopez, 450 F.3d at 930.

    A valid prior removal order “serves as a predicate element
of [Aguilera’s] conviction” for illegal reentry under § 1326.
Melendez-Castro, 671 F.3d at 953. As Aguilera’s 2005
removal order was invalid, we reverse his conviction.5

       REVERSED.




   5
     As we reverse Aguilera’s conviction on this basis, we need not
consider his alternative argument that the IJ violated due process by not
affording him a meaningful opportunity to apply for pre-conclusion
voluntary departure.
