Attorney General Bonta: States Must Have the Ability to Protect Residents from Assault Rifles Commonly Used in Mass Shooting Attacks

OAKLAND - California Attorney General Rob Bonta today, as part of a coalition of 19 attorneys general, filed an amicus brief in the U.S. Supreme Court in support of laws enacted in Connecticut and Cook County, Illinois, restricting the sale, manufacture, and possession of certain uniquely dangerous assault rifles. The brief, filed in Viramontes v. County of Cook, urges the U.S. Supreme Court to uphold appellate court rulings that affirmed that these challenged assault weapon laws are consistent with the Second Amendment and the nation's strong historical tradition of regulating weapons that are uniquely dangerous.

"The California Department of Justice will continue to aggressively defend life-saving safety measures and support local leaders with the tools necessary to keep people safe. Assault weapon laws restrict a small and uniquely dangerous category of weapons that have proven to be mass shooters' weapon of choice for a reason," said Attorney General Bonta. "California enacted the nation's first state-level assault weapons restriction almost four decades ago to protect our residents from uniquely dangerous weapons with battlefield features that facilitate indiscriminate mass killing. The Supreme Court has the opportunity to affirm what many appellate courts have already found: these commonsense protections are reasonable and constitutional. A mass shooter with an assault weapon demonstrably can inflict more deaths and injuries compared to those using other weapons, and three-quarters of mass shootings of 10 or more victims from 2012 to 2022 involved the use of an assault weapon. Protecting our communities from mass shootings and gun violence is a core responsibility of state and local government."

The coalition's amicus brief explains that the AR-15 platform and similar semiautomatic rifles are uniquely dangerous because their features facilitate assaultive mass killing and are poorly designed for self-defense purposes. The brief also explains that the U.S. has a long historical tradition of regulating uniquely dangerous weapons. It also urges the Supreme Court to reject petitioners' argument that the Second Amendment prohibits laws restricting any weapon, regardless of dangerousness, once it has reached some arbitrary popularity threshold. The brief argues this would be a dangerous, illogical, and ahistorical outcome that is contrary to the Supreme Court's Second Amendment caselaw , and would also encourage firearms manufacturers to flood communities with new dangerous weapons before a legislature manages to institute restrictions to prevent them from proliferating in shootings and other criminal activity.

California has been a leader among states that have enacted effective firearm safety laws. Republican Governor George Deukmejian signed California's initial bipartisan assault weapons restriction into law in 1989 following a hate-motivated school shooting at Cleveland Elementary School in Stockton, California, in which a gunman wielding an AK 47-style semiautomatic assault rifle with detachable 30-round and 75-round large-capacity magazines fired over 100 times in about three minutes - murdering five young children and injuring 30 other students and a teacher. A 2026 report from the California Department of Justice's Office of Gun Violence Prevention showed that California's mass shooting victimization rate for 2023-2025 fell to 38% below the rate for the rest of the U.S. on average. Today, 10 other states and several cities generally restrict the sale, manufacture, and possession of assault rifles, including the AK-47 and AR-15.

Connecticut enacted its initial assault weapons law in 1993 and expanded that law in 2013 following the December 2012 Sandy Hook elementary school shooting in which a gunman armed with an AR-15 style rifle and large capacity magazines fired over 150 rounds and murdered 20 children and six educators in under five minutes.

Attorney General Bonta joins the attorneys general of Arizona, Colorado, Delaware, the District of Columbia, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, and Washington s in filing the brief.

A copy of the brief can be found here.