Sorority Row

Sorority Row is a movie starring Briana Evigan, Rumer Willis, and Carrie Fisher. A group of sorority sisters try to cover up the death of their house-sister after a prank gone wrong, only to be stalked by a serial killer.
When five sorority girls inadvertently cause the murder of one of their sisters in a prank gone wrong, they agree to keep the matter to themselves and never speak of it again, so they can get on with their lives. This proves easier said than done, when after graduation a mysterious killer goes after the five of them and anyone who knows their secret.