Abstract: A three point lock mechanism includes a lower deadbolt which respectively engage the threshold and lintel of a door or other hinged panel, in addition to the central jamb deadbolt. The mechanism utilizes a conventional deadbolt lock set for the central jamb deadbolt, with a generally circular plate being attached to the lock set to rotate therewith when the lock is turned to lock or unlock the door. An upper and a lower deadbolt actuation rod extend from the plate, and serve to actuate respectively the upper and lower deadbolts of the system by a pivoting actuator at each deadbolt. The two rods are pivotally secured to the plate 135 degrees from one another, in order to provide an overcenter weight bias of the rods to urge the upper and lower deadbolts to a retracted position when retracted, and to an extended position when extended.