(Thornton Police Department via AP)Ostrem was handcuffed at a crowded intersection about 14 hours after the shooting that sent dozens of shoppers and workers fleeing in panic from the busy store.Police spokesman Victor Avila declined to say whether Ostrem had a weapon.
He called Ostrem a quiet worker who was skilled at making metal flashing for roofs.
Killed were Pamela Marques, 52, Carlos Moreno, 66, and Victor Vasquez, 26, the coroner said.
None were Walmart employees, and all were Hispanic. Police offered no possible motive for the shooting other than to say there was nothing to suggest it was related to terrorism.
“We believe as of right now that the shooting was random,” Avila said.
Video from CNN affiliates showed a Walmart Supercenter parking lot filled with emergency vehicles.