The door viewport with cross-door locking bar laterally spans the door frame with a viewport exterior lip on the door and an interior face plate near an interior of the door forming, in one instance, a mid-bar capture channel. Alternatively, the viewport has an interior extension coacting with a complementary interlocking element on the cross-bar's midpoint. Either construct holds the cross-door locking bar substantially at its mid-point. Cross-bar terminal end mounts removably attach the cross-bar to the door frame. One type of mount is an L-bracket. Another type of mount is a controllable transverse extension member forcing a door frame plate against the door frame. A user-controlled extension means forces the cross-door locking bar away from the door frame plate, with either a screw drive system or a grooved rod with spring loaded lever control.