The United States District Court for the Southern District of California recently held, in the case entitled Duncan v. Becerra[1], that California Penal Code section 32310 is unconstitutional. The statute prohibits possession of large-capacity magazines (“LCMs”), defined as those capable of holding more than ten rounds.


In November 2016, California citizens approved Proposition 63. Proposition 63 amended California Penal Code section 32310 to prohibit a citizen from acquiring and keeping a firearm magazine that is able to hold more than 10 rounds.[2]  For all firearms, California law declares acquisition and possession of a magazine able to hold more than ten rounds a crime pursuant to Section 32310.

Section 32310(c) makes simple possession of a magazine holding more than 10 rounds an infraction. Acquiring a magazine holding more than 10 rounds in California by importing, buying, borrowing, receiving, or manufacturing the magazine is now a misdemeanor or a felony under Section 32310(a).  The same provision states that “any person in this state who manufactures or causes to be manufactured, imports into the state, keeps for sale, or offers or exposes for sale, or who gives, lends, buys, or receives any large-capacity magazine is punishable by imprisonment in a county jail not exceeding one year or imprisonment pursuant to subdivision (h) of Section 1170”.  Under the subsection’s provision, punishment may be either a misdemeanor or a felony.  The District Court commented that the provision lacked any qualifying language; “all forms of possession are summarily prohibited,” whether “carrying a loaded assault rifle while walking down Main Street” or “storing large-capacity magazines in a locked safe at home.”

The State defended the prohibition on such magazines, asserting that mass shootings are an urgent problem and that restricting the size of magazines a citizen may possess is part of the solution. While the District Court acknowledged that mass shootings are tragic, the Court also explained that they are “exceedingly rare.”  Meanwhile, “robberies, rapes, and murders of individuals are common, but draw little public notice.”  The Court cited a number of California crime statistics and specific incident examples that the Court said illustrated a need for individual self-defense and the use of magazines with a capacity of more than 10 rounds.


The District Court explained that the Second Amendment protects a person’s right to keep and bear firearms. The Second Amendment provides: “A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.”  U.S. Const. amend. II. The Court stated that “[r]egardless of current popularity, neither a legislature nor voters may trench on constitutional rights. ‘An unconstitutional statute adopted by a dozen jurisdictions is no less unconstitutional by virtue of its popularity.’” (quoting Silveira v. Lockyer, 312 F.3d at 1091.)

The Court further explained that the United States Supreme Court, in the seminal case District of Columbia v. Heller,[3] established a simple Second Amendment test in “crystal clear language … a test that anyone can understand.  The right to keep and bear arms is a right enjoyed by law-abiding citizens to have arms that are not unusual ‘in common use’ ‘for lawful purposes like self-defense.’” (Id., 554 U.S. at 624.)  The Court stated Heller’s test “is a hardware test.  Is the firearm hardware commonly owned?  Is the hardware commonly owned by law-abiding citizens?  Is the hardware owned by those citizens for lawful purposes?  If the answers are ‘yes,’ the test is over.  The hardware is protected.”  Under Heller, lawful purposes include, among other purposes, self-defense within the home.[4]

The Court also noted that, because “magazines are ‘arms’ within the meaning of the Second Amendment,”[5] the same analytical approach is applied to both firearms and the ammunition magazines designed to make firearms function.

In applying the Heller test to magazines holding more than 10 rounds, the Court cited numerous federal cases declaring such magazines are in common use by law-abiding citizens for lawful purposes.  The Court observed that “these magazines number in the millions” and are lawful in at least 41 states and under federal law.  Finding therefore that LCMs were used by law-abiding citizens in common use for lawful purposes like self-defense and recreation, the Court concluded that a magazine able to hold more than 10 rounds passes the Heller test and is protected by the Second Amendment, adding that “the size limit directly impairs one’s ability to defend one’s self.”

The Court Rejects Additional Arguments to Support Section 32310

The California Attorney General argued that it was permissible to ban common handguns with LCMs because possession of firearms with other smaller magazines was allowed. The Court rejected this view, explaining that Heller states, “[i]t is no answer to say . . . that it is permissible to ban the possession of handguns so long as the possession of other firearms (i.e., long guns) is allowed.”[6]

The Court also rejected the argument that LCM use was “too lethal” to attach Second Amendment protection because LCMs used by mass shooting perpetrators caused a high number of and more severe casualties than in other shootings wherein LCMs were not used. The Court explained: “Nothing in the Second Amendment makes lethality a factor to consider because a gun’s lethality, or dangerousness, is assumed.”  Moreover, “the relative dangerousness of a weapon is irrelevant when the weapon belongs to a class of arms commonly used for lawful purposes.”[7]

The Court further determined that California’s prohibition on detachable ammunition magazines larger than 10 rounds was “a type of prohibition that has not been historically accommodated by the Second Amendment,” contrary to the Attorney General’s view.

Ninth Circuit’s Standard

Though this analysis sufficed, the Court also found Section 32310 failed the Ninth Circuit’s “tripartite binary test with a sliding scale and a reasonable fit.” Though the Court asserted that the Ninth Circuit’s test set forth “the wrong standard” to apply, the Court determined that Section 32310 “fails [this Ninth Circuit standard] anyhow.”

The Court explained that criminalization of a citizen’s acquisition and possession of magazines able to hold more than 10 rounds “hits directly at the core of the right of self-defense in the home. It is a complete ban on acquisition.  It is a complete ban on possession.  It is a ban applicable to all ordinary law-abiding responsible citizens.  It is a ban on possession that applies inside a home and outside a home.”  The Court explained that “Section 32310 strikes at the core of the Second Amendment right of self-defense and severely burdens that right, triggering strict scrutiny.  Because the statute imposes a broad prophylactic ban that is the opposite of a regulation using the least restrictive means to achieve a compelling interest, Section 32310 fails constitutional muster under the test of strict scrutiny.”  The Court observed that Section 32310 imposed such a severe restriction on the core right of self-defense of the home such that it amounted to a destruction of the right and is unconstitutional under any level of scrutiny.[8]  The Court added that, even under the more lenient standard of intermediate scrutiny, Section 32310 was “a poor fit to accomplish the State’s important interests.”


Accordingly, the Court concluded that Section 32310 directly infringed upon Second Amendment rights by “broadly prohibiting common firearms and their common magazines holding more than 10 rounds, because they are not unusual and are commonly used by responsible, law-abiding citizens for lawful purposes such as self-defense. And ‘that is all that is needed for citizens to have a right under the Second Amendment to keep such weapons.’ Friedman v. City of Highland Park, 136 S. Ct. 447, 449[](2015).”  The Court concluded that the law failed the Heller test because “it criminalizes a law-abiding citizen’s possession of a common magazine that is used for lawful purposes and prohibits its use for self-defense in and around the home.”  It also failed the strict scrutiny test because the law was not narrowly tailored because it “strikes at the core of the inalienable Constitutional right and disenfranchises approximately 39 million state residents.”  Accordingly, the Court granted Plaintiffs’ motion for summary judgment, declared Section 32310 unconstitutional and enjoined its enforcement.


Duncan v. Becerra may be headed to the Ninth Circuit to assess the legitimacy of Section 32310’s prohibition on magazines capable of holding more than ten rounds. Though the District Court’s opinion against Section 32310’s constitutionality is extensive and forceful, the Ninth Circuit may have other plans.  The law’s ultimate fate remains unclear.  In light of the broad impact of this case, agencies should keep abreast of additional developments.

In the interim, the District Court has issued the following broadly-phrased injunction: “IT IS HEREBY ORDERED that:

  1. Defendant Attorney General Xavier Becerra, and his officers, agents, servants, employees, and attorneys, and those persons in active concert or participation with him, and those duly sworn state peace officers and federal law enforcement officers who gain knowledge of this injunction order, or know of the existence of this injunction order, are enjoined from enforcing California Penal Code section 32310.
  2. Defendant Becerra shall provide, by personal service or otherwise, actual notice of this order to all law enforcement personnel who are responsible for implementing or enforcing the enjoined statute. The government shall file a declaration establishing proof of such notice.”

On April 4, 2019, the District Court issued a partial stay of its injunction concerning Section 32310. Specifically, the Court stated that “the State of California and law enforcement agencies therein will be free to re-start the enforcement of Calif. Penal Code § 32310 (a) and (b) which currently prohibits, among other things, any person in the state from manufacturing, importing into the state, offering for sale, giving, lending, buying, or receiving a firearm magazine able to hold more than 10 rounds (as defined by Calif. Penal Code § 16740).  This will continue until the appeal proceedings conclude or the stay is modified or lifted.”  The Court, however, stated that “the State of California and the law enforcement agencies therein will remain enjoined (or prevented) from enforcing Calif. Penal Code § 32310 (c) and (d) which would have criminalized the simple possession of a firearm magazine able to hold more than 10 rounds and required the disposing of such magazines.”

As noted in our prior Client Alert on this case, there currently is a dispute within the legal community concerning the ultimate effect of a broadly-worded injunction in a non-class action lawsuit filed in federal court, such as the one issued here in the Duncan case.  As such, you should consult with your legal counsel to determine your agency’s actions with respect to the District Court’s injunction concerning Section 32310.

As always, if you wish to discuss this matter in greater detail, please feel free to contact James R. Touchstone at (714) 446–1400 or via email at jrt@jones-mayer.com.

Information on www.jones-mayer.com is for general use and is not legal advice. The mailing of this Client Alert Memorandum is not intended to create, and receipt of it does

[1] 2019 U.S. Dist. LEXIS 54597 (S.D. Cal. Mar. 29, 2019).

[2] For more information on the procedural history of this case and Section 32310, see Client Alert Vol. 32 No. 17.

[3] 554 U.S. 570 (2008).

[4] McDonald v. City of Chicago, 561 U.S. 742, 780 (2010).

[5] Ass’n of N.J. Rifle & Pistol Clubs v. A.G. N.J., 910 F.3d 106, 116 (3rd Cir. 2018).

[6] Heller, 554 U.S. at 629.

[7] Caetano v. Massachusetts, 136 S. Ct. 1027, 1031 (2016)

[8] See Jackson v. City & Cty. of S.F., 746 F.3d 953, 961 (9th Cir. 2014); Heller, 554 U.S. at 629.