The Justice Department has filed a lawsuit against Colorado over a state law banning high-capacity ammunition magazines.
The legal action follows a separate suit the agency brought against the city of Denver on Tuesday.
The lawsuit challenges Colorado’s prohibition on magazines that hold more than 15 rounds.
Federal officials argue the state law conflicts with the Second Amendment and federal firearm regulations.
Colorado enacted the ban in 2013 after a mass shooting in Aurora killed 12 people.
Supporters of the law say limiting magazine capacity helps reduce the potential for mass casualties.
Opponents contend the restriction infringes on lawful gun ownership and self-defense rights.
The Justice Department’s move marks an escalation in federal efforts to contest state-level gun restrictions.
Legal experts expect the case to test the boundaries of state authority over firearm regulations.
The outcome could set a precedent for similar laws in other states across the country.
