Physical evidence when collected properly is pretty hard to defend against. It's not complicated. I take the death penalty seriously. I support it. But when it is used, I want there to be no question whatsoever about the guilt of the man being put to death. The day we execute a man who is later found to be innocent will be a bad day for the death penalty in this country.
Oh, OK, I was lumping physical evidence with circumstantial as “non-eyewitness”. I was thinking “what’s left?”