19-year-old Genaro Mendoza, of West Salem, Oregon, broke into a house in Independence, Oregon. He took several items, left the house and hide them, then left the scene. He returned later with a stolen truck, retrieved the hidden items and went back into the house in order to steal an AR-15 assault rifle and a shotgun. He put the guns with their butts on the floorboard and their barrels pointed upward, toward the driver's seat.
While driving away on the bumpy farm road, the shotgun apparently fell against the AR-15, discharging the rifle and firing one shot that struck Mendoza and exited through the roof.
Police arrived to find Mendoza dead inside the truck.