Roy Thinnes

Roy Thinnes (; born April 6, 1938) is an American former television and film actor best known for his portrayal of lonely hero David Vincent in the ABC 1967–68 television series The Invaders.
He starred in the 1969 British science fiction film Doppelgänger (a.k.a. Journey to the Far Side of the Sun outside Britain), and also played Manhattan District Attorney Alfred Wentworth in the pilot episode of Law & Order.

Biography fallback source: Wikipedia