Diagnosis: Murder is an American comedy-mystery-medical crime drama television series starring Dick Van Dyke as Dr. Mark Sloan, a medical doctor who solves crimes with the help of his son Steve, a homicide detective played by Van Dyke's real-life son Barry. The series began as a spin-off of Jake and the Fatman (Dr. Mark Sloan made his first appearance in episode 4.19 "It Never Entered My Mind"), became a series of three television films, and then a weekly television series that debuted on CBS on October 29, 1993.