The Seattle Police Department apologized Wednesday after a resident snapped a picture of an assault rifle left unattended on the trunk of a patrol car.

Nick Gonzales took the picture around 9 p.m. Monday when he says no officer was in sight of the car, according to 9 News.

A woman also reported seeing an officer later drive away with the rifle still on the trunk.

“It is unacceptable that a rifle was left unattended on a patrol car and people should expect more from their police department,” SPD Office of Professional Accountability said in a statement.

Watch this video from 9 News, broadcast June 29, 2011.