During the movie, Early Grayce sports a chipped tooth. Brad Pitt visited a dentist to have the tooth chipped for the role.
The locations where the serial killer events take place are related to the names of the actors in the movie: Lewiston Ranch, Mt. Juliet, Texas (Juliette Lewis); Forbes, Tennessee (Michelle Forbes; Davidson Mine, Dew Cove, Nevada (David Duchovny); and Bradbury Textile Warehouse in Pittsburgh, Pennsylvania (Brad Pitt).
This is the second of two films in which Brad Pitt and Juliette Lewis co-starred together playing a criminal couple. The first was the made-for-TV film Too Young to Die? (1990). They started dating while shooting "Too Young to Die?" in 1989, when Lewis was 16 and Pitt was 26. The relationship ended in 1993, shortly after "Kalifornia" was released. Director Dominic Sena didn't know that Lewis and Pitt were a couple when he cast them. He was looking for someone to play Adele when he saw Lewis in "Too Young to Die?", and immediately wanted her for his film. While searching for an actor to play Early Grayce, Sena noticed Pitt in "Thelma & Louise".
Michelle Forbes' photographer character is a reference to the controversial photographer Andres Serrano, specifically his series "History of Sex" and "The Klan" (from the early 1990s).
Michelle Forbes' debut.