Mark Shera (born Mark Shapiro; July 10, 1949, Bayonne, New Jersey) is an American actor, who is perhaps best known for his role as J.R. in the popular television series Barnaby Jones His brother is CBS Evening News director Eric Shapiro.Shera was well known in the television series S.W.A.T. as he played Officer Dominic Luca in 1975 through 1976. He was a guest star on The Love Boat in 1978 with Janis Paige and Monty Hall as his parents.