The characters of Trish and Lucy were originally written for Jeffrey Thomas and his son Colin Thomas, friends of director
Jason Torrey, and the characters were male. The Lucy character, even as the alternative male version, was written as autistic because Thomas's son Colin is autistic. The subject of autism interests
Jason Torrey quite a bit, one of his three daughters was diagnosed as autistic in 2008. He explains, "I wanted to have a character that sees the killer in the act, but doesn't quite know how to articulate what was seen, but knows full well that danger is near and she and her mother must get somewhere safe. Having an autistic child myself I knew that I could write this in, make it plausible and have it work on both and intellectual and emotional level." The parts eventually went to a mother and daughter pair of local actors, this is why the characters were made female. But the two actresses ended up leaving the film before production began. The part of Lucy went to
Popi Kapiris, who met the director at a cast and crew meet and greet they held on July 4th, 2010 (the day before principal photography began) and the part of Patricia was given to
Sherrie Lemire.