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Duncan v. Becerra


Defending California’s prohibition on large-capacity magazines.

Courts: Southern District of California; Ninth Circuit

Issue At Stake: Large-capacity magazines

Summary: On November 22, 2017, Everytown filed an amicus brief in the United States Court of Appeals for the Ninth Circuit in defense of California’s prohibition on large-capacity magazines. This brief corrects the District Court’s misinterpretation of research on mass shootings conducted by Mayors Against Illegal Guns. This brief details the long history of regulating especially dangerous weapons, including a century of restrictions on semiautomatic firearms capable of firing a large number of rounds without reloading. It also demonstrates the circularity and illogic of the “common use” test argued for by plaintiffs, based upon nationwide sales and manufacturing figures, which cannot be reconciled with either the Supreme Court’s decision in District of Columbia v. Heller or common sense, and is inconsistent with core principles of federalism. And, relying on Everytown’s own research, this brief further explains the substantial relationship between regulating large-capacity magazines and California’s undeniably important interest in preventing and mitigating both mass shootings and day-to-day gun violence.

On August 14, 2020, a divided three-judge panel of the United States Court of Appeals for the Ninth Circuit issued a ruling striking down under the Second Amendment California’s prohibition on the possession, sale, manufacture, and transport of large-capacity ammunition magazines, like those used in the deadliest mass shootings. Everytown for Gun Safety jointly filed an amicus brief with other gun-violence-prevention groups to urge the Ninth Circuit to rehear the case before a larger, eleven-judge panel — and to reverse this erroneous, dangerous, and out-of-step decision. The brief presents two main arguments in support of rehearing. First, it explains how the three-judge panel’s ruling, by thwarting the will of millions who support magazine limitations, would impede the critical ability that Americans, including those from historically underrepresented communities, must have to address gun violence through the democratic political process. Second, the brief rebuts the panel’s incorrect historical analysis and its market-driven definition of a weapon’s commonality, both of which contradict binding Supreme Court and Ninth Circuit precedent. 

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