Karla is a 2006 American psychological thriller film. The film is based on the true story of Canada's two most notorious serial killers, Paul Bernardo and Karla Homolka, though the names of the victims were changed, with the exception of Karla's sister. The film starts with a framing device of psychologist Dr. Arnold (Patrick Bauchau) in a session with Karla Homolka (Laura Prepon) at Canada's Regional Psychiatric Centre in Saskatoon, Saskatchewan. Dr. Arnold's evaluation will determine Karla's eligibility for parole. During the session, Dr. Arnold shows Karla a photo album of herself and her husband Paul Bernardo (Misha Collins) in happier times, and Karla has a memory of how they first met. However, when Dr. Arnold introduces the subject of Karla's sister Tammy, Karla becomes uncooperative. Over the following weeks, Dr. Arnold probes Karla about her knowledge of Paul's secret life as a serial rapist, and it is revealed that shortly before their marriage Paul began to rape women.