Visible crew/equipment: Before we first see the marching band, and Kevin Bacon finds out what his daughter's name is, there is a shot looking at him in his car and he drives off screen. As the car goes out of the shot to the left, check out the reflection of the camera man in the rear driver's side window.
Continuity mistake: In the scene where Kevin Bacon and Laurence Fishburne go to Tim Robbins' house to speak to him about being in the bar on the night of the murder, they all walk down the street together, as Dave is walking his son to school. In one shot, following the men from behind, it shows them walking past a red brick building, then a blue cape cod style building. When they are about halfway past this blue building, it cuts to a shot taken from in front of them (showing their faces), in which we can see them walking past the red brick building and then the blue building again.
Factual error: In the first scene the boys are playing street hockey using sticks that have plastic blades made with holes in them for better aerodynamics. These blades were not available in the mid-70's. We know this scene is taking place in the mid-70's because Dave tells his son he was in high school from 1978-82. The scene takes place when Dave is 11, too young to have been in high school.
Other mistake: On the tape of the 911 call regarding the murder a boy says "They want to know her name" to a supposed accomplice. However one of the two boys who are accused of the phone call and murder at the end of the film is deaf, and the two boys communicate with sign language - the boy who could talk would never say anything to the other.