The killer wears the exact same pajama pants as Ryan. This was used to deliberately throw the audience off.
Originally planned as a direct follow up to the production team's Lock In for the St. Joseph Film Society. High school scenes were shot at the same location, but omitted in later versions for pacing.
Scenes involving Ryan's school and Danielle, Chris and Ryan's sister, were eliminated in some cuts of the film. The filmmakers decided to make the film more claustrophobic and centered around Ryan and his mental state.