Abstract: Door locks, door locking and unlocking methods, and door security and communications devices are provided, and can include an exterior module mountable on an exterior surface of a door; an interior module mountable on an interior surface of a door; a deadbolt movable between an unlocked position allowing opening of the door from a closed state and a locked position preventing opening of the door from the closed state; a camera and/or a microphone provided on the exterior module; and a wireless communication device configured to communicate images from the camera and/or sound from the microphone to a smart phone or computer of an authorized user for remote observation of an area adjacent the exterior surface of the door.