Question: who was the actor that played ben stone on law and order?
Answer: Michael Moriarty

Michael Moriarty ( born April 5 , 1941 ) is an American - Canadian stage and screen actor and jazz musician . He received an Emmy Award and Golden Globe Award for his first acting role on American television as a Nazi SS officer in the 1978 mini-series Holocaust , and he played Executive Assistant District Attorney Benjamin Stone for the first four seasons ( 1990 -- 1994 ) on the television show Law & Order . Moriarty is also known for his roles in films such as Bang the Drum Slowly , Who 'll Stop the Rain , Q : The Winged Serpent , The Stuff , Pale Rider , Troll , Courage Under Fire , and Shiloh .