WASHINGTON, Pa. (AP) -- Police believe they know the identity of a man who allegedly threatened to shoot up a southwestern Pennsylvania Wal-Mart during a phone call in which he was reportedly angry about the store's return policy. Officers from South Strabane Township and three neighboring municipalities responded to the store at Trinity Point shopping center about 9 a.m. Tuesday. That's about 20 miles southwest of Pittsburgh. Wal-Mart officials haven't commented, though the store remained open. Police were patrolling the parking lot and watching the store's entrances while they worked to locate the 24-year-old Washington man they believe made the call. The Associated Press is not reporting the man's name because he's not been charged with a crime. Police believe the threat has been quelled, but they want to locate the man to be sure.