A police officer in Vallejo, California, shot and killed 22-year-old Sean Monterrosa early Tuesday morning after mistaking a hammer in his pocket for a gun, the city’s police chief said Thursday. Monterrosa was on his knees when the unnamed officer, who told authorities he believed Monterrosa to be armed with a gun, fired at him five times through his car windshield. Monterrosa had a hammer, not a gun, in his pocket.

The officers had been responding to reports of looting at the Walgreens. Vallejo Police Chief Shawny Williams said the officer who shot Monterrosa has been on the force for 18 years. All of the officers present for the shooting have been placed on routine administrative paid leave, and the district attorney and internal affairs are investigating the matter. “He did not see Mr. Monterrosa put his hands on it in a threatening way,” said John Burris, who is representing Monterrosa’s family. “So the question here is what threat if any did he actually present.”