Night Visitor (1989)

The compulsive liar teenager Billy Colton witnesses the murder of his sexy and prostitute neighbor Lisa Grace by his history teacher Willard. Willard is an unknown Satanist wanted by the police for killing prostitutes with his brother. Like in the fairy-tale, nobody but his girlfriend believes in Billy. He looks for help with the former friend of his deceased father, the retired Detective Devereaux, and they two decide to investigate his teacher's house. But his snoopy girlfriend Dolan has had the same idea and is captured by the twisted brothers.