Continuity mistake: When the killer has hanged Damon in the tree and smashes the front window of the car, the girl in the car is backing, and when she does that the killer falls off the car, and then you can, if you listen carefully, hear a mans voice "say" something like "uff". The killer is a girl but the stuntman is a man.
Continuity mistake: Brenda is showing Natalie a slideshow using a projector to show her how her boyfriend was killed; she firstly shows a photo, then a newspaper article. The article is left projected for the whole scene. That is until Brenda is shot out of the window, and now it is the photo that is back to being projected.