Student Bodies (1981)

This is a famous horror film: the predecessor of screaming, a small number of black comedies in the early 1980s, with a parody style, a very interesting youth horror film, the plot is also narrated on Halloween night, high school students are killed one by one, what they have in common is that they are all killed while making out, and the heroine Toby is a high school student, because her old friends are dead one by one. The arrow also points to Toby's involvement is a major suspect, how can she come forward and catch the real killer according to the clue? It was definitely done by someone in the school! Is it the principal? The principal's secretary? Teacher? Co-workers? Nurse? Or a psychiatrist?