Knock, Knock [Unrated Director's Cut]

When a group of popular high school students cross the path of a deranged serial killer, the bloody aftermath causes the local residents to lock their doors and cower in fear. Slaughter has come to a small town America, but who could be responsible for such a horrific atrocity? As two detectives attempt to catch a madman responsible for the mayhem, suspicions quickly begin to fall on the school recluse. When the teenage misfit is seen wandering the streets after dark, the locals become convinced that he's the killer. Now, as darkness falls over these suburban streets, the sound of fear is a gentle knock at the front door.