An institutional door lock mechanism for retrofitting existing installations with a remotely controllable/monitorable door lock and open/close position indicator is described. A hollow vertical door strike jamb extends along an outside surface of the door frame opposite a hollow vertical columnar striker plate mechanism mounted on a fronting plate of the door. A hollow vertical housing also on the fronting plate contains a first component part of a proximity/alignment detection mechanism including a magnetic reed switch. The door strike jamb is configured as a vertical riser for housing a wiring harness for the catch-extension/retraction mechanism and for the proximity/alignment detection mechanism. The catch-extension/retraction mechanism includes a motor for extending/retracting the catch, the motor being operable by a securely coded manual key placed adjacent a switch mechanism or within a keyway operatively coupled with the switch mechanism. The catch-extension/retraction mechanism operates in a fail-safe lock-down mode of operation in the event of power interruption or failure.