Stalker (2015)

Stalker is an 2015 slasher film starring Britt Robertson, Emma Stone, Emma Roberts, Brooke Shields and Matthew Broderick.

Summary
A mysterious stalker (who wears a paper-mache mask and hood) puts a viral video on YouTube which Emily (Emma Stone) becames embarrassed after her mother (Andrea Martin)'s death.

Cast

 * Emma Stone as Emily Crosby, the main character in the film and a student on Winsdor College
 * Britt Robertson as Lizzy Cameron, she is Emily's friend and one of the murders of Ohio Killing Spree
 * Emma Roberts as Kimberly Crosby, Emily's twin sister and the main killer
 * Brooke Shields as Melissa Cameron (in the ending, she is now Adams), a reporter and Lizzy's older sister and the main tritagonist
 * Matthew Broderick as Deputy Sheriff Steve Adams, the film's main deuteragonist