Abstract: A thief-trapping apparatus for a room having a closure permitting room ingress and egress and an object therein to be safeguarded utilizes a locking mechanism for the room closure and a cord having a frangible link. The locking mechanism includes a bolt and a bolt receptacle which are operatively mountable on the closure and the wall of the room adjacent the closure. When operatively mounted on the room wall and closure, the bolt is movable between a first position at which the bolt cooperates with the bolt receptacle to lock the closure in a closed condition and a second position at which the closure is unlocked. The locking mechanism further includes a spring for biasing the bolt from its second position to its first position, and the cord is fastened at one end to the bolt so that when the cord is pulled from its other end, the bolt moves to its second position.