What is the point of finding nazi war criminals and putting them on trial?

Don't you think that when someone does something heinous, he or she should be accountable for those actions and punished? If someone tortured and killed your mother, or your child would you not bother wanting to see justice because that person hadn't done it recently? Prison is not just a deterrent, it's punishment. What kind of ignoramus are you? Are you in junior high or are you just a complete moron?