World May 6, 2026 06:47 PM

Justice Department Files Suit to Overturn Colorado’s 15-Round Magazine Ban

DOJ contends the decade-old restriction infringes Second Amendment protections; Colorado pledges to defend its firearm safety laws enacted after the Aurora theater shooting

By Leila Farooq

The U.S. Department of Justice filed a lawsuit seeking to invalidate Colorado’s 2013 prohibition on large-capacity ammunition magazines that hold more than 15 rounds. The complaint, brought by the DOJ’s civil rights division, argues the ban restricts access to widely owned firearms and therefore violates the Second Amendment; Colorado officials say they will defend the law as a responsible public-safety measure.

Justice Department Files Suit to Overturn Colorado’s 15-Round Magazine Ban

Key Points

  • The DOJ filed an 11-page complaint seeking to invalidate Colorado’s 2013 ban on ammunition magazines that hold more than 15 rounds, arguing it violates the Second Amendment.
  • The suit contends such magazines are standard equipment on many popular firearms and are in "tens of millions" of lawfully owned semi-automatic firearms in the U.S., and thus are "in common use."
  • Colorado has vowed to defend the ban as responsible public-safety policy; prior litigation over the law was dismissed by the 10th U.S. Circuit Court of Appeals in 2016 for lack of plaintiff standing.

The U.S. Department of Justice sued the state of Colorado on Wednesday aiming to overturn a law enacted in 2013 that bans ammunition magazines capable of holding more than 15 rounds.

The complaint asserts that Colorado’s restriction on large-capacity magazines - adopted after a mass shooting at an Aurora movie theater that killed 12 people and wounded 58 others - infringes on rights protected by the Second Amendment to the U.S. Constitution.

The lawsuit, filed by the DOJ’s civil rights division, cites the U.S. Supreme Court’s 2008 ruling in District of Columbia v. Heller, saying that the Second Amendment safeguards the rights of law-abiding citizens to possess firearms commonly used for lawful purposes. The DOJ’s court filing is 11 pages long and centers on the prevalence of magazines holding more than 15 rounds with many of the nation’s most popular firearms.

Among the assertions in the complaint is the contention that such magazines "come standard with many of the most popular firearms in the U.S., including AR-15-style rifles and some semi-automatic pistols." The filing adds: "The number of lawfully owned semi-automatic firearms in the United States that utilize a magazine like the ones banned by the state is in the tens of millions."

The DOJ argues that by outlawing these large-capacity magazines, Colorado is effectively restricting individuals’ access to weapons that are "in common use." The complaint also states these weapons are "used for multiple lawful purposes," including recreational target shooting, collecting and self-defense.

The remedy sought by the lawsuit is a court order preventing enforcement of Colorado’s statute banning the magazines.


Colorado’s attorney general, Phil Weiser, responded to the filing by saying the state will defend its gun-safety measures. In a statement he accused the lawsuit of subverting the mission of the DOJ division that initiated it, saying it "turns the mission of the DOJ’s civil rights division on its head."

"Large-capacity magazine laws are responsible policies that satisfy Second Amendment protections, decrease impacts of mass shootings and save lives," Weiser said. "The state has a duty to protect Colorado residents from gun violence."

The DOJ action in Colorado follows closely on another challenge the department filed a day earlier, in which it contested a long-standing Denver ordinance that bans semi-automatic rifles the city defines as assault weapons.

The complaint comes after a prior legal challenge to Colorado’s 2013 measures. In 2016, a three-judge panel of the 10th U.S. Circuit Court of Appeals dismissed a case brought by county sheriffs, gun shops, outfitters and shooting ranges that had challenged both the large-capacity magazine ban and a separate measure requiring universal background checks for gun buyers. The appeals court found those plaintiffs lacked legal standing, concluding they had not shown they would be personally harmed by the laws.

With the new lawsuit, the Justice Department is directly contesting the constitutionality of the magazine restriction under the framework set by Heller. The outcome will hinge on how the courts reconcile the DOJ’s interpretation of what constitutes arms "in common use" and the state’s interest in measures intended to limit harm from mass shootings.

As the litigation proceeds, Colorado officials have signaled they will continue to defend the statute as part of the state’s effort to prevent and reduce gun violence. The DOJ and Colorado are now on a collision course in federal court over the legal boundaries of firearm regulation under the Second Amendment.

Risks

  • Uncertainty over the legal outcome - a court decision overturning the ban could affect state-level restrictions and reshape regulatory expectations for the firearms industry.
  • The question of legal standing and constitutional interpretation - lower and appellate courts may differ on how Heller applies to magazine capacity limits, creating prolonged litigation and regulatory uncertainty for manufacturers and retailers.
  • Potential enforcement limbo - while litigation proceeds, enforcement and compliance costs for state and local governments as well as for sellers and owners of affected firearms could be unclear.

More from World

Renewed U.S.-China Trade Confrontation Ahead of Presidential Visit May 6, 2026 Journalists Killed or Abducted in Mexico Nearly Double in 2025, Report Finds May 6, 2026 Cuban leaders condemn U.S. statements on possible military intervention amid crippling fuel shortages May 6, 2026 Macron Presses Iran on Keeping Strait of Hormuz Open for Shipping May 6, 2026 Sheinbaum Faces Internal Morena Rift After U.S. Indictment of Mexican Officials May 6, 2026