BOULDER, Colo. (AP) – Police have identified a 21-year-old man as the suspect who opened fire inside a crowded Colorado supermarket. The attack Monday in Boulder killed 10 people, including an officer, and sent terrorized shoppers and employees scrambling for cover. Authorities say Ahmad Al Aliwi Alissa was from the Denver suburb of Arvada and that he engaged in a shootout with police inside the store. The suspect was expected to be booked into the county jail later in the day on murder charges. Investigators have not established a motive. 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.