Abstract: A dead bolt type door lock including a combined dead bolt member and latch which engages a common locking recess in a door jamb around a door in which the lock is mounted. The door lock utilizes a standard keyed lock assembly in combination with a latch fitted in sliding relationship within a channel shaped dead bolt member so that when the dead bolt member is retracted into the door the latch functions in a conventional manner and when the dead bolt is extended over the latch into the door jamb opening the door is secured against the normal techniques of unauthorized entry commonly accomplished by the use of credit cards and the like. The lock includes linkage and latch assemblies for manipulating and holding the latch and dead bolt sleeve at the various operating positions at which the lock is locked and released. The dead bolt sleeve is selectively operable from both the interior and exterior sides of the door.