Authorities identified a 21-year-old man as the suspect who opened fire inside a supermarket on Monday in an attack that killed ten people, including an officer.
Authorities said Ahmad Al Aliwi Alissa was from the Denver suburb of Arvada and that he engaged in a shootout with police Monday afternoon inside the Boulder store. The suspect was being treated at a hospital and was expected to be booked into the county jail later in the day on murder charges.
Investigators have not established a motive, but authorities believe he was the only shooter, Boulder County District Attorney Michael Dougherty said.
A law enforcement official briefed on the shooting told The Associated Press that the gunman used an AR-15 rifle, a lightweight semi-automatic rifle. Officials were trying to trace the weapon. The official was not authorized to speak publicly and spoke to AP on condition of anonymity.
Hundreds of police officers from throughout the Denver area responded to the attack, converging on a King Soopers supermarket in a busy shopping plaza in southern Boulder.
SWAT officers carrying ballistic shields slowly approached the store as others escorted frightened people away from the building, which had some of its windows shattered. Customers and employees fled through a back loading dock to safety. Others took refuge in nearby shops.
“This is a tragedy and a nightmare for Boulder County,” Dougherty said. “These were people going about their day, doing their shopping. I promise the victims and the people of the state of Colorado that we will secure justice.”