Continuity mistake: In the last scene, Tanya gets her arm cut on a piece of glass in the window by Charles, just before he turns to fight a cop. In the next shot the glass has disappeared from the window completely.
Continuity mistake: Towards the end of the movie, the sheriff is shooting at Charles' mother. He shoots a vase of yellow flowers. Then seconds later, he shoots the same vase.
Factual error: Ron Pearlman plays a state police captain named "Captain Soames". On his uniform he has both captain's bars on his shirt collar and sergeant's stripes on his upper shirt sleeves. He would not hold both ranks and would not keep the sergeant's stripes on if he had been promoted to captain. He also would have gone through the rank of lieutenant (one bar) prior to becoming a captain, so he would have had plenty of time to take the stripes off his uniform.
Revealing mistake: Charles is cutting a letter into his arm with a knife towards the beginning. However it's obvious the knife is fake and the blood is coming out of the top of the knife onto his skin like an ink pen on paper.
Revealing mistake: At the end, when the monster grabs the sheriff and throws him across the front yard, the sheriff lands on his back and his right arm falls into a beartrap. The trap snaps and the sheriff screams in pain, but only one jaw of the prop beartrap actually snaps into vertical position (the opposing jaw remains flat and doesn't move). A real beartrap snaps both jaws together vertically. So, the sheriff's hand doesn't get snapped at all.
Answer: Sleep Walk by Santo and Johnny.