Cop Leaves Assault Rifle

Our cops may get accused of beating people up but at least they know how to keep track of their equipment. It seems a sheriffs deputy back east has trouble keeping track of his goodies. The deputy was cleaning the trunk of his unit out and left the gun, case and ammo on the ground when he was distracted by "trespassers". When he came back to his unit, he got in and drove off, leaving the firearm behind. Of  course, the first question is, what was he doing cleaning his trunk out away from the station? The second question has already been asked: will he come under investigation? Yes.