He attracted attention as a young man in such films as Splendour in the Grass 1961, then produced and starred as gangster Clyde Barrow in the hugely successful Bonnie and Clyde 1967. Later, he directed Reds 1981, Dick Tracy 1990, and co-produced Bugsy 1992, in which he played the gangster Bugsy Siegel. He is the brother of actress Shirley MacLaine.
