Our team has a locked supply closet with only about 5 or 6 keys... only given to adults, and only certain kids are allowed in there under supervision. We also have a computer room, and before there really hasn't been much to steal, but we just got almost new laptops with docking stations (
) and we are watching those like they're gold. We also have sign in/out sheet so we know who was at which meeting, times etc. and adults have to intial you out, so its kinda hard to steal stuff since they see you, it's also really noticeable if you open the door at the facility. We have had stealing issues in the past, and that's when we got the locked closet, plus i don't think there's a place that the adults can't see, so it would be difficult. The computer room also has an adult in it most of the time.
Hope this helps