A man has murdered someone and has been executed legally in the US. If I could go back in time and kill the killer before he committed his crime, thus saving the life of his intended victim, would this make me a murderer, or his executioner, as I would be killing him before he had committed his crime?
This question is from Anthony Roddy-Burns in Rochdale, England.
One's tempted to say that if the man has indeed murdered someone in the past, then if you were to travel back in time you could not kill him before the murder. The past is past and, contrary to Hollywood lore, it cannot be changed. For more on this, see Question 242 .