The gunman used a semiautomatic handgun that is essentially a shortened version of an AR-15-style rifle. He had purchased it legally six days before the attack.
Investigators searching for answers after the mass shooting in Boulder, Colo., this week still do not know why a gunman shot and killed 10 people at a crowded grocery store, the police chief said on Friday. “We, too, want to know why,” the Boulder police chief, Maris Herold, said at a news conference. “Why that King Soopers? Why Boulder? Why Monday? And unfortunately, at this time, we still don’t have those answers.” The semiautomatic weapon used in the shooting was legally purchased six days earlier at a gun store in Arvada, Colo., the chief said. That weapon, a Ruger AR-556 pistol, is essentially a shortened version of an AR-15-style rifle and is considered a handgun under Colorado law. The 21-year-old suspect, Ahmad Al Aliwi Alissa, was also found with a 9-millimeter handgun, but the authorities do not believe he fired it, the chief said. Officials pledged to chase every lead and said they were working to determine whether there were any connections between the gunman and anyone in the supermarket. But they acknowledged the possibility that the gunman’s motives might never be known. It is not yet clear whether Mr. Alissa had ever been to the grocery store — which is about 15 miles north of his family’s house in Arvada — before the shooting, Chief Herold said.
