Tom Arnold plays a child molester. In real life, Arnold is a survivor of childhood sexual abuse.
Tom Arnold based his performance on the babysitter who sexually abused him from the ages of four to seven, even wearing the same outfit.
In an interview with Filmmaker Magazine director Damien Harris said that since they couldn't tell the child actors what the story was actually about, they came up with an alternative story. It was that Alex (Tom Arnold) had been left by his wife and so he was living alone with Frank (Kevin Zegers), his good buddy, and he wanted a family so these two kids would become his children. There was not going to be a mother, because the mother had left. Frank was now jealous because he thought that he wasn't Alex's favorite anymore, so that's why he was being mean. Then for the specific scenes with Leslie (Ryan Simpkins), they came up with a scenario that fitted emotionally where she had to be, so they didn't have to tell her anything beyond that. Harris came up with that version of the story with the Ryan Simpkin's mother.
In one scene where Gillian Jacobs' character was supposed to really break down and have a very emotional moment. Then, John Malkovich (who was off-camera) basically started improvising everything that had happened to Jacobs' character with given circumstances, and everything that she'd gone through her life as Jacobs wasn't there as a performer, emotionally. In the end, Malkovich really brought her to that place and she was able to do the scene.
The homeless shelter that the adult Leslie visits is located in the Little Italy section of downtown San Diego. In real life it is not a homeless shelter, but as of March of 2010 the building is home to a local car rental business.