St. Andrew's Girls (2003)

A small town is struck by scandal when Jennifer Walsh, a troubled teenager takes her own life.
But things aren't always what they seem.
In the weeks before her death, Jennifer is thrown into detention with a twisted trio of "bad girls," the moral rejects of an oppressive educational system at St. Andrew's Catholic High School.
These outcasts quickly form a strange bond, but the delicate balance of their friendship is threatened after Jennifer uncovers one of the girl's criminal activities.
When the girl learns that Jennifer has a secret of her own, all Hell breaks loose.