CSI: Crime Scene Investigation (2000 - Present): Go to Hell

The CSIs stumble upon a grisly multiple murder related to a girl who has been through an exorcism. The victims are parents of Amy, a 12-year-old wild child, and they had attempted to rein her in when they discovered that she was in a relationship with a 23-year-old man. Eventually the parents became convinced that their daughter was possessed, and sought the help of a fly-by-night exorcist. Unfortunately for them, the exorcism failed, and they end up murdered. Amy is still missing.