Starred as the eponymous roles of TV's Mike Hammer on Mickey Spillane's Mike Hammer and Kolchak of Kolchak: The Night Stalker.
He was placed in three different orphanages before ending up in a boy's home on a ranch after his parents divorced.
In 1960, he starred in a TV series called Riverboat.
He married Melanie York in 1944, and together they had four children.
He has been compared with Robert Conrad for doing his own stunts.