So I'm watching "Serpico" yesterday and towards the end of the movie when Frank is in the hospital and there are a bunch of cops milling around outside his room, there was one cop who looked suspiciously like Judd Hirsch. He had no lines. I waited until all the credits were done, but his name never came up.
I checked HERE and, sure as shit, he was in it (uncredited). Please do not ask me why this has any importance in your life whatsoever because, clearly, it doesn't.