The Trump administration filed a lawsuit Tuesday against Denver and the city’s police department aimed at ending an assault-weapons ban adopted in 1989, saying the ordinance violates the Constitution’s Second Amendment right to bear arms. The case came one day after Denver officials publicly rejected the Department of Justice’s request that the city stop enforcing the long-standing local policy.
In a statement on Tuesday, acting Attorney General Todd Blanche said, “The Constitution is not a suggestion and the Second Amendment is not a second-class right,” and he argued Denver’s ban “directly violates the right to bear arms.” The administration’s suit also seeks to challenge Denver’s enforcement of the ban against semi-automatic rifles it characterizes as commonly owned, including AR-15-style rifles.
Denver’s officials had rejected the federal government’s push to abandon the ordinance, with Mayor Mike Johnston saying during a news conference Monday that the city would not negotiate away what he described as a “common sense policy.” Johnston said, “Our answer is hell no,” adding that Denver would not “roll back” a ban that he said has kept “weapons of war” out of city streets for 37 years. He also said the ordinance protects first responders and reduces fears that people will be unsafe in places such as movie theaters, grocery stores, and public elementary schools.
The lawsuit reached for a broader constitutional argument. Federal attorneys told the city that Denver’s ban includes AR-15-style rifles owned by at least 16 million people in the country, describing them as “ordinary semiautomatic rifles” used for lawful purposes, including “self-defense.” The administration said in court filings that it is pursuing the case after asking the city last week to stop enforcing the ban and enter negotiations with federal officials.
Denver’s top police official defended the ordinance by focusing on the department’s experience with weapons recovered in the city. Denver Police Chief Ron Thomas, who said he joined the department the year the assault weapons ban was adopted, said the policy has helped address gun violence. Thomas said that of 2,100 guns recovered in Denver last year, fewer than 2% were assault-style weapons.
Colorado’s gun-policy fight extends beyond Denver, according to the Trump administration’s position. The administration said it is also threatening to sue Colorado over a statewide ban on large-capacity ammunition magazines that the state’s Supreme Court upheld in 2020. Justice Department attorneys referenced the ban in an April 28 letter to state officials threatening litigation unless the state stops enforcing the law and agrees it is unconstitutional.
Assistant Attorney General Harmeet Dhillon wrote in that letter that, “Law-abiding Americans own literally hundreds of millions of magazines identical to those banned in Colorado.” Colorado Attorney General Phil Weiser responded in a statement that firearms with large-capacity magazines pose a major threat to public safety, and he said large-capacity magazine laws are “responsible policies that decrease the deadly impacts of mass shootings and save lives.”
The assault-weapons ban was enacted during a period of heightened concern about gun violence in Denver, and the federal and city arguments unfold against a wider backdrop of major shootings in Colorado in later years. Those include the 1999 Columbine High School massacre, the 2012 Aurora movie theater attack, a 2021 supermarket shooting in Boulder, and a 2022 attack at an LGBTQ nightclub in Colorado Springs that officials said killed multiple people.