Barry Van Dyke (born July 31, 1951) is an American actor and the second son of actor and entertainer Dick Van Dyke and Margie Willett, and nephew of Jerry Van Dyke. He has often worked with his father. He is best known to audiences as Lieutenant Detective Steve Sloan, a homicide detective and the son of Dr. Mark Sloan (played by Dick Van Dyke) on Diagnosis: Murder. In the show, the characters' relatives were frequently played by real-life family members.