I went to a college were the lab computers were all protected by a system were a fiber optic cable loop was passed through a little adapter that bolted to the case (you had to remove the fiber to access the bolt), if the loop was broken without properly disarming the system, the authorities were called automatically.
Setting up a similar system were a very loud siren is secured in a tamper proof box, with two fiber optic passthrough connectors, and the external fiber is passed through all handles, adapters, etc, a security system can be created. Fiber has the advantage of being hard to bypass without breaking the loop triggering the alarm. There is system were you can track who accesses the room and exactly when, through fingerprints, smart cards, tokens.