Factual error: Set in the summer of 1977, serial killer David Berkowitz is seen throughout the film wearing a US Army woodland camouflage pattern field jacket. The Army did not start using these jackets nor were any ever made until the early 1980's. They were all solid green until then.
Trivia: Throughout the movie the killer is portrayed as a childish, tantrum-throwing, reclusive psychopath with no self-control, who receives orders to kill from neighbor Sam Carr's black dog that trots into his bedroom. The character portrayal is inaccurate and the scene with the dog was obviously added to be a darkly humorous moment. In real life David Berkowitz served in the army, held jobs afterward, participated in satanic cult rituals, and used hallucinogenic drugs. And when pressed for his true motives by an FBI agent after his conviction he admitted that he targeted young ladies because he harbored negative emotions toward women. The order from the dog was a story that he initially told the police to preserve the option of pleading insanity, but he would later choose to plead guilty.
Vinny: You fuckin' make me sick, you fuckin' slut.
Dionna: I am a slut? You're calling me a slut? You lowlife piece of fuckin' shit - you fucked - my - cousin! You didn't think I knew about that! I smelled her pussy juice all over your fuckin' face! You fuckin' sick bastard! How dare you? And all this time I'm thinking there's something wrong with me! You perverted sick fuck.