George Ralph DiCenzo (April 21, 1940 – August 9, 2010) was an American actor and one-time associate producer of Dark Shadows. He was in show business for over 30 years, in film, TV, stage, and commercials. DiCenzo played Marty's grandfather Sam Baines in the film Back to the Future. He also had a minor role in William Peter Blatty's The Exorcist III. (Via Wikipedia)