Less than 24 hours after Denver Mayor Mike Johnston publicly pushed back on a U.S. Department of Justice demand to repeal the city’s longstanding ban on assault weapons, the DOJ followed through with its threat to take the matter to court. On Tuesday, the DOJ filed a lawsuit in federal court alleging that Denver’s longstanding ban on assault style weapons unconstitutionally bans certain constitutionally protected semi-automatic rifles and infringes on the “Second Amendment rights of law-abiding citizens to keep and bear arms in common use for lawful purposes,” according to a statement from the agency. “Our answer is hell no,” Mayor Mike Johnston told members of the press, along with public safety leaders gathered at City Hall on Monday. “No, we will not roll back a common-sense policy that has kept weapons of war off of these city streets for 37 years. No, we will not put first responders at greater risk every time they respond to a dangerous incident.…