Transference - S2.E6

Steven Romero, an old patient of Rachels who was convicted of five murders and sent to Headlands Correctional Medical Facility, a place for the criminally insane, kills two men and escapes. He has always 'loved' Rachel and she is worried that he may be planning to come looking for her. Visiting his cell Rachel and derek discover that he has been studying pagan rituals involving death and ritual sacrifice.