An evidence locker would be an incredibly interesting little addition.  There have been many other servers I've seen in possession of evidence lockers at the prisons, within a separate facility or usually within each HQ. Evidence doesn't have to mean all illegal contraband such as drugs, weapons, items; why not 'weapons locker' and have the ability for it to be raided. Possibly broken up into classes; One locker within the 'weapons locker' possesses 7.62's, the next locker over possesses 5.