The five main girls were all named after female musicians Cindy (Lauper), Darcy (Wretzky), Zia (McCabe), Kim (Gordon), and Kim (Deal).
Producer Colin Lamb broke his finger during the stunt where the killer punches through the wooden door, which was the final shot of principal photography.
Filmed over a single weekend in October 2007.
No single person played the killer. She was portrayed by three separate stand-ins to give her a more mysterious, asexual appearance.
A stunt involving a fake leg consisting of meat, blood bags, and bone being blown apart with a shotgun was filmed but eventually cut from the final version.