There are several. First let me explain if you haven't seen this movie, it is about the investigation and subsequent apprehension of John Wayne Gacy so the time period is around 1976. Now if you watch at just about any time you will see people, even the main characters driving vehicles that are from at least the mid 80's. Also when the detectives are talking to one of the missing victims parents in his bedroom, there is a poster of Ryne Sandberg in his cubs uniform with the word RYNO on it on the wall(he wasn't even in baseball until the 80's and that was with the Phillies at first). You can't miss it. The worst one though is when Gacy has a kid in his house and is doing the handcuff trick; the kid has a big Air Jordan logo on his shirt. I mean come on, who made this movie?