My Super Psycho Sweet 16: Part 3(2012)

Overview:

As she leaves for art school in New York, Skye gets a phone call from Alex. Skye hasn't heard from Alex in two years, but before she can move on with her life she needs to tie up some loose ends. Unfortunately, someone else has the same idea, and they're stalking and slashing their way through Alex's Sweet 16 party at her grandparents' isolated estate.