Gaffes

Getting partially dressed and leaving the apartment, after the first bat, he neglects to put on his socks. When they exit the building, he is clearly wearing two socks. Later in the office, he is again shown sans socks.

The blood patterns/stains on Peter Loew's shirt vary after he kills the girl in the night club.

The film portrays Peter shooting himself in the mouth, then remaining unharmed because the gun is loaded with blanks. However, this action would actually cause severe injury or death, since a gun loaded with blanks will fire compressed gas with the force of a bullet.

Several times the viewer sees close up the fangs of Jennifer Beals's character (Rachel), and moreover, also sees at least two (2) times that the width of the bite mark under Peter's neck adhesive bandage is far narrower.

During both sex scenes with Rachel and Peter in Peter's bed, the flesh colored pad covering Jennifer Beals' nipple is clearly visible.

During the sex scenes between Rachel and Peter in Peter's bed, they are both wearing exactly the same clothes (underwear), indicating that both scenes were filmed at the same time.

Alva's address on the index card is listed as Grand Concourse, the Bronx's main drag. However, when Peter arrives at her house, it is on a quiet side street.

It is mentioned in the film that Alva lives in Pelham Bay in the Bronx and she is seen taking the 6 train home. However, when Peter looks up Alva's address in his Rolodex, it is listed as 712 Grand Concourse. This address is located in the South Bronx and in the complete opposite end of the borough as Pelham Bay. The appearance of Alva's home and neighborhood in the film more closely resemble Pelham Bay than the South Bronx address listed.