My google-fu is failing me. I remember the title went something like "south park..." and more word. It has nothing to do with the comedy central "south park" series.

Here is another clue - it was some sort of a psychodrama revolving around students [most likely high school] getting revenge on teachers. In one particular sequence late in the movie, the main character and friends come about information about a murder that involved a teacher but the MC begins to have some second thoughts. Ultimately the the information does get passed around as rumor but the teacher elaborates details the rumor explaining that the murder was in fact a terrible accident that involved him and his son.

Do you know the name of this movie?