Goofs

Berkowitz removes the ticket from his car, yet he is caught because he is seen driving away with a ticket on his windshield.

When Vinny is looking at the bodies in the car, he reaches his arm in and touches one. His arm is subsequently in/out of the car between shots.

When Detectives Petrocelli and Atwater sit down at the restaurant their veal portions flip around from sauce to no sauce to back again.

In the film the British rock band, The Who are repeatedly referred to as a punk rock band. This is wildly incorrect. The Who was founded in 1964 and were part of the trailing edge of the British Invasion. The only thing that related to the violent attitude of hard-core punk bands was the fact that on a couple of occasions the drummer and guitarist (Keith Moon and Pete Townshend) smashed their instruments (which began at the Monterey Pop Festival in 1967, in response to Jimi Hendrix' burning his guitar). By the time of the Son of Sam murders, the Who had already been hard rockers for nearly a decade and had been using synthesizers for over half that time--something that no punk band would ever do, up until the Clash released Bankrobber in 1980.

When Berkowitz is shown shooting the second pair, he fires his weapon eight times. The Charter Arms .44 Special "Bulldog" holds only five rounds.

When the guys come to get Vinny to help them with Richie, Vinny picks up the phone to call the police. When the phone is ripped off the wall, you can see that there is no phone line or place to plug in the phone on the wall.

Phil Rizzuto's name is spelled incorrectly in the end credits. His last name is RIZZUTO. In the end credits, it's spelled RIZUTO.

During the shooting sequence where Phil Rizzuto is doing the play by play for a Yankee game, you can clearly see blood mechanically squirt out after both victims are not moving and no more shots are being fired.

At about minute 31, right after the Beelzebub blocks, when 'Son of Sam' unloads his gun, there are no primers in the bullet cases, meaning they are impossible to fire.

At the beginning of the movie, set in the summer of 1977, characters are seen dancing in a disco to the song "There But For the Grace of God Go I" by Machine. The song wasn't recorded until 1979.

One of the punks in front of CBGBs is wearing an "Organ Grinder" T-shirt which is a punk rock puzzle magazine that won't exist for more than 20 years after 1977.

Many of the punks in the film are sporting early 1980's Southern California Hardcore fashion, and are completely out of place in New York in 1977.

The knife Richie uses in the sex show was not invented until the 1990s.

In shots of CBGBs, many of the punk extras have piercings in their tongues etc. Tongue piercings were first performed by Gauntlet in San Francisco, and not popularized until the '80s. Similar stories are true of eyebrow piercings and many others. During the late 70s and most of the '80s, piercings as featured in the movie had little to do with the punk scene, but were embraced by the gay/S&M scene.