He played the role of McCoy who would eventually become District Attorney through the series finale in 2010 and has reprised the role throughout the Law and Order universe. Kaplan again in the episode "Road to Rhode Island" but he is not credited in any other episode in which the character appears. Early life
Waterston the third of four siblings (Roberta George and Ellen) was born in Cambridge Massachusetts.
Samuel Atkinson "Sam" Waterston (born November 15 1940) is an American actor producer and director. He has been nominated for multiple Golden Globe Screen Actors Guild BAFTA and Emmy awards having starred in over eighty film and television productions during his forty-five-year career. Among other roles he is noted for his Academy Award-nominated portrayal of Sydney Schanberg in 1984's The Killing Fields and his Golden Globe-nominated and Screen Actors Guild Award-winning portrayal of Jack McCoy on the NBC television series Law & Order.