mario valencia took a rifle from a walmart in tuscon , arizona on february 19 and was able to start firing it as soon as he left .
the stolen weapon should have still been locked and police chasing the men were told he could not fire the loaded gun .
he was later taken out by an officer who hit him with his vehicle .
the gun was found to be locked with loose wire that was not wrapped enough when police recovered it from the scene .
walmart claims the wire could have been knocked loose because of the impact from the car .