Abstract: An improved security storage assembly (9) that is lockable, that can store many different items, and that can warn the owner or user thereof if someone is attempting to break into it is disclosed. The assembly (9) includes a container (10) having walls (11,12), a closed bottom (16) and a cover (19) hingedly connected to the top (T) of a wall. A lock assembly (40) is disposed in the cover (19) for interconnecting the cover (19) to a wall (11). A motion-detecting alarm member (50) having a sensing mechanism for detecting a greater than threshold amount of motion and having a coupled alarm element therein for emitting an alarm signal when said greater than threshold amount of motion has been detected is removably mounted within the container (10). A fastening element (61) is fixedly secured to the motion-detecting alarm member (50) and a plurality of cooperating fastening receiving elements (60) are spaced apart on and fixedly secured to the upper portion of the interior of the walls (11,12 ).