Continuity: 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.

Factual error: In one scene there is a POW/MIA flag being flown on a building. This type of POW flag was not flown regularly during this time period. It was first flown on National POW/MIA Recognition Day in 1988.

Factual error: Near the beginning of the movie, which is set in 1977, the song "Grace of God" is playing in a club. "Grace of God" didn't come out until 1979.

Continuity: When John Leguizamo's vigilante friends confront him in his apartment, they pull his phone off the wall when he tries to call the police.  You can see that the phone is just a prop as there is no phone jack or brackets holding it in, just one nail sticking out of the wall.

Continuity: The film is set in 1977.  There is a scene where the radio is playing 1010 WINS and the announcer comes on and says "1010 WINS, you give us 22 minutes, we'll give you the world!" When 1010 WINS first started, they used to say, "You give us 10 minutes, we'll give you the world!"  They didn't start saying 22 minutes until the 80's.

Factual error: There is a scene where John Leguizamo's character is holding a pack of Marlboro Red cigarettes in a box. On the side of the box you see Marlboro Miles. The film is based in the 70's and Marlboro Miles weren't introduced until many years later.