I’d seen him in a few movies earlier, but I really started paying attention to him when he was on CSI. He had a recurring role as Catherine’s father, a sketchy casino owner named Sam Braun. Later I saw him in In Cold Blood (1967) as one of the murderers, Dick Hickock. I was absolutely blown away by his performance. I honestly thought he deserved at least an Oscar nomination for that role, which was only his second film gig ever. Most people probably remember him for The Walking Dead, but I gave up on that show before he became part of the cast.
In my opinion, he was a great actor, very much underappreciated. I can’t define screen presence, but whatever it is, he had it.