Goofs

The "Fade Away" soundtrack repeats several times during the first party sequence.

According to the movie's commentary, the blue tape on Amy's handbag disappears and reappears several times in the movie.

When Derek gets strangled to death, there's no blood on his face except for his throat and on the rope. About a minute later, when Stacy investigates his body - there's some blood lining on his face.

When Stacy goes to the locker room, she leaves her top on the overflow drain next to Derek. It disappears before he dies and she is seen wearing it in the locker room.

In some scenes, snow covers the school grounds. But in other scenes, the grounds are devoid of snow.

When the killer slashes a cop's throat, it's obvious that the makeup does not match up with the contact of the hammer and you can even see the flap of the throat makeup before the rest of the slitting.

During the dance scene at the bar, the song mentions Compact Discs which were not released until 1982.

A Bud Light sign is visible in the bar during the disco sequence. Since the movie takes place in 1981, it would've been another year before that was introduced and the name of it would've been Budweiser Light.

Though the filmmakers did well with physical props, the song that plays during the disco dancing scene - James Curd's "Live Forever" - is a contemporary techno song that sounds vaguely disco-ish. One of the lyrics mentions music on CD's, which weren't available in the US until two years after the movie takes place.

(about 1 hr. and 10 min.) Reflected on the glass door behind Detective Drake, after he enters the stairway that leads to the location of the killer's dungeon.