A gun used by a man suspected of shooting and killing 10 people at a Boulder King Soopers would have been illegal under the city’s assault weapon ban that was recently blocked by a judge, though nobody ever had been cited under the ban while it was active.
The suspect purchased a Ruger AR-556 pistol on March 16, six days before the mass killing, according to his arrest affidavit. Police recovered a rifle and a handgun inside the grocery store next to the tactical vest believed to be worn by the suspect, according to the affidavit, though it’s not clear whether the Ruger gun is the handgun or the rifle referenced in the document.
The Ruger AR-556 pistol is not technically a rifle, though many features of its design echo a rifle’s set-up.
“It’s not a sporting rifle, it’s not a hunting rifle,” said Joseph Vince, a professor at Mount St. Mary’s University who worked as a Bureau of Alcohol, Tobacco, Firearms and Explosives agent for more than 30 years. “It’s made for the military and short-range combat.”
The gun comes in two barrel lengths — either 9.5 or 10.5 inches — that are both shorter than the 12-inch definition of a handgun under Colorado law. The gun also has a brace on the back, which allows users to hold the gun against their shoulder for stabilization. Users can also equip a scope and, unlike many other pistols, ammunition is fed to the gun through a detachable magazine that is separate from the pistol’s grip.