 Say a president's at a fundraiser, he slugs someone in the face, knocks them down, and they bang their head and die. That's an unofficial act. He could be criminally prosecuted for negligent, I guess that would be negligent homicide in that instance. But that's a very rare, unlikely thing. By and large, most presidential actions will be immune from criminal prosecution, and it has to be that way, man. Mm-hmm.