Feds sue Colorado over ban on certain firearm magazines

The lawsuit comes one day after the DOJ filed a separate lawsuit against the city of Denver for its decades-old “assault weapons” ban policy.

The Colorado law, passed in 2013 in the wake of the Aurora movie theater shooting, bans so-called “large-capacity” magazines, which it defines as any detachable magazine holding more than 15 rounds. The standard capacity magazines for commonly-owned AR-15 semiautomatic rifles are manufactured to hold 30 rounds.

“[Colorado] has already admitted that magazines like those it has banned are in common use by law-abiding Americans for lawful purposes, including self-defense,” the lawsuit states. “Therefore, the Magazine Ban — which makes it a crime to sell, transfer, or possess such a magazine — violates the Second Amendment.”

Assistant Attorney General Harmeet Dhillon, who heads the DOJ’s Civil Rights Division, in a written statement called Colorado’s ban “political virtue signaling at the expense of Americans’ constitutional right to keep and bear arms.”

“Under my direction, the Division’s Second Amendment Section will continue to defend law-abiding Americans’ rights against unconstitutional restrictions on their right to possess arms which are owned by tens of millions of their fellow citizens,” she added.

Colorado Attorney General Phil Weiser responded to the lawsuit Wednesday morning in a written statement defending the state law as “common-sense.”

“Using federal civil rights law to put Coloradans at greater risk of gun violence is a dangerous overreach by the Justice Department, and this lawsuit turns the mission of the DOJ’s Civil Rights Division on its head,” he said. “Large-capacity magazine laws are responsible policies that satisfy Second Amendment protections, decrease the deadly impacts of mass shootings and save lives.”

“The state has a duty to protect Colorado residents from gun violence, and I will vigorously defend our state large-capacity magazine limit law from this attack by the Trump Justice Department,” Weiser added.

The DOJ’s Civil Rights Division on Tuesday filed another lawsuit challenging the city of Denver’s so-called “assault rifles” ban that has been in effect since 1989. The ban applies to semiautomatic pistols or rifles that “have a fixed or detachable magazine with a capacity of more than” 15 rounds.

“When the City banned AR-15 style rifles with standard capacity magazines, it banned an arm in common use for lawful purposes by law-abiding citizens,” the lawsuit filed on Tuesday said. “Therefore, the Ordinance violates the Second Amendment, and the United States brings this action to vindicate the rights of Denver citizens whose rights have been — and are continuing to be — violated by Defendants.”

Denver Mayor Mike Johnston was defiant in a statement Tuesday, saying the lawsuit marks “a sweeping overreach of the federal government.”

"Our first job is to keep Denverites safe, and we will not be intimidated out of doing it," Johnston said. "Denver's law has stood for 37 years because it works, it saves lives, and it reflects the values of our community. No demand or lawsuit from Washington is going to change that."

A recent Pew Research Center analysis of national gun deaths found that rifles, which include “assault weapons,” were reportedly involved in 3% of deaths in 2024.