Born Merle Johnson, Jr., he became a teen idol in the 1959 film, A Summer Place, and played a role in The Godfather Part II. He also played roles in Deadly Prey, Nudity Required, Sounds of Silence, and The Platinum Triangle.
He was a journalism major at Columbia University.
After he acted in My Blood Runs Cold, Warner Bros. ended his contract, which led him down a self-destructive path until he appeared in The Godfather Part II.
Prior to his death, he was engaged to mezzo-soprano singer Zheng Cao.
His agent also tested the pseudonym Troy on Rory Calhoun.