The Sleeper (2012) on Netflix

It's 1981 and the girls of Alpha Gamma Theta sorority are having a party. As the new pledges arrive, so does an uninvited guest. Little do the sisters know someone is watching them in the shadows. As the girls shower, study, eat and sleep the stalker studies the girls. One by one he finds the girls at their most vulnerable and murders them. The police hunt for the missing girls and their killer, but will they find them in time? Or will the girls be forced to fight for their lives...