The scene where Emily smacks Jack in the dream sequence had to be filmed five times because the camera man, Justin Axelrode, kept deleting the takes so he could watch Emily (Emma Pfister) smack Jack (Noah Pfister) again.
Throughout the film, a ring can be seen on the finger of both Emily and Jack. It's the same ring, but when Emily died, Jack took it and wore it as a sign of remembrance for his dead sister.
Production originally began in November with a different actor playing Jack. But director, Noah Pfister, had a hard time keeping the actor and the camera man from laughing non stop. Thus the role was recast.
The murder scene was filmed in an abandoned parking lot near a movie theatre. The crew was nervous that the police would be called on them, so they got the scene filmed fast and then got out of there. Ironically, as the crew left, four police cars arrived at the parking lot.
Noah Pfister wrote the role of Lynda with Felise in mind.