The Ninth Circuit Court of Appeals ruled in Nordyke v. King that the Second Amendment, which protects the right to bear arms, does not apply to state and local governments.

[12] Judge Roger Benitez was nominated to the court by President George W. Bush and confirmed by the Senate with 98 votes in favor and one against, despite overwhelming opposition by a committee of the American Bar Association.

[12] On August 15, 2019, James Miller, a board member of the San Diego County Gun Owners, sued Attorney General Xavier Becerra and the Director of the California Bureau of Firearms,[8][16] alleging that the ban was an unconstitutional restriction of Second Amendment rights.

The plaintiffs argued that the definition of "assault weapon" is politically motivated and prevents law-abiding citizens from obtaining and using firearms for self-defense, hunting, and other legal purposes.

On June 4, 2021, Benitez ruled in favor of the plaintiffs, declaring the AWCA to be unconstitutional and issuing a permanent injunction against enforcing specific provisions of the law.

[10][16] On June 21, a three-judge panel of the Ninth Circuit – Barry G. Silverman, Jacqueline Nguyen, and Ryan D. Nelson – granted their request to extend the stay as appeals are litigated.

[15] On June 23, 2022, the U.S. Supreme Court decided New York State Rifle & Pistol Association, Inc. v. Bruen, broadly rejecting any "means-end tests" such as the strict or intermediate scrutiny the Ninth Circuit had applied in upholding the constitutionality of various gun regulations.

This newly clarified "text as informed by history" standard is widely expected to significantly affect how gun control cases such as Miller and Rupp are decided.

[29] State officials, including Governor Gavin Newsom and Attorney General Rob Bonta, issued strongly worded statements opposing Judge Benitez's ruling.

[7][8][23] In December 2021, Governor Newsom again cited Judge Benitez's Swiss Army knife comparison in response to the U.S. Supreme Court's decision in Whole Woman's Health v. Jackson that effectively upheld enforcement of the Texas Heartbeat Act.