If a politically motivated prosecutor can convince a jury of twelve people that Bill killed Dave, by using his psychic brain powers, or, alternatively, by sticking pins into a voodoo doll, or some other form of non-scientific witchcraft, Bill is going to hang.

The hypothetical gullibility of juries doesn't mean that we shouldn't have laws against murder, juries, or prosecutors.

The line between mistake and negligence is a lot blurrier than the line between killed and didn’t kill.