An American author and screenwriter, he is best known for his two biographies of screen legend James Dean. His script for The Legend of Lizzie Borden (a television movie starring Elizabeth Montgomery) earned him the Mystery Writers of America's Edgar Allan Poe Award.
He studied theater at the University of California-Los Angeles. He began his career by writing scripts for The Aldrich Family, an NBC sitcom.
His 1977 television adaptation of The Man in the Iron Mask received two Emmy nominations.
He was the son of Gilbert Bast and Bernice Fleischmann. He was born in Milwaukee, Wisconsin, and he moved to Los Angeles, California during his college years.
He had a close relationship with James Dean; the two were roommates and occasional lovers.