On Friday a Colorado state district court struck down a Boulder, Colorado, ban on the sale, possession, and transfer of certain commonly-owned semi-automatic pistols, rifles, and shotguns—which the city derisively labeled “assault weapons”—and standard capacity magazines that could accept more than 10 rounds of ammunition. The district court struck down Boulder’s ban based on Colorado state preemption grounds.

The court found that Boulder’s ban on “assault weapons” is completely preempted by state law, and that Boulder’s magazine ban is operationally preempted because the ordinance “materially impedes the state’s interest in consistent firearms regulation as it directly forbids what state law authorizes and encourages a patchwork of regulations affecting possession of firearms.”
The Court concluded: “[T]he Court declares that the provisions of the Ordinance prohibiting the sale, possession, and transfer of assault weapons and [magazines] is preempted by state law, are thus invalid, and enjoins their enforcement.”
“We are very encouraged that a Colorado court has recognized Boulder’s residents’ right to keep and bear arms as citizens of Colorado and as protected by the Colorado legislature,” said Cody J. Wisniewski, Director of Mountain States Legal Foundation’s Center to Keep and Bear Arms. “The fight for Coloradans’ rights is far from over, but this is a huge victory along the way.”
MSLF’s Center to Keep and Bear Arms is currently litigating against Boulder’s Ordinances, including not only the firearm and magazine ban, but also Boulder’s prohibition on firearm ownership based on age and Boulder’s registration requirements. That case, Caldara v. City of Boulder, is still pending in federal court. We will be monitoring Boulder’s reaction to this state decision to determine next steps in our federal lawsuit.

