Police departments are provided with shops in which weapons and equipment are sold for 5 (if not 10) times lower prices than at weapon stores. Players, especially after jail, are used to run on-duty, fully equip themselves and quit the duty, thus they get armed, save up cash & time, remain civilian and get to breaking the law in no time. What I would implement is a script that keeps your service armament stored away while you're going off the duty.