Kim Taggart and Antonio Mastrantonio star in this horror movie about a serial killer who terrorizes the unsuspecting citizens of a small American town. Two detectives attempt to crack the complex case after a group of high school kids encounter the deranged murderer-with grisly results. As the case unravels fingers start to point at a high school loner who is seen acting suspiciously, but KNOCK, KNOCK has a few surprises in store as the bloodshed escalates and the film builds towards a dramatic finale. Director Joseph Ariola Star Kim Taggart, Antonio Mastrantonio Special Features: Widescreen Audio: Dolby Digital 5.1 - English Subtitles - English, Spanish Additional Release Material: Featurettes - 1. RICO, BEHIND THE MASK 2. Music and the Sounds 3. Special Makeup and Effects Trailers - Trailer Gallery Runtime: 92 minutes.