In the classroom scene, the teacher is shown wiping the board and rubbing out a section of the cursive alphabet. In the next shot, the part she just rubbed out has reappeared again, and is then shown erased again in the next. (07:30).
When Dahmer is holding the drugged boy, Konerak Sinthasomphone and talking about his contact lenses, Dahmer says that the movie on the television is "Return of the Jedi". However, the music playing is Gustav Holst's "Mars, the Bringer of War", which is not featured in any Star Wars film. But the composer, John Williams, has acknowledged Holst as one of his musical influences.