Hello,
@Harrybrigham - this thread wakes up every couple of years. Glad to see a new member take interest in side issues as well as the tech part of the forum!
I agree with you that anyone convicted of murder, released, and arrested for a new murder should take a long jump with a short rope around his neck. But as you also point out, we must be sure beyond even the remotest shadow of doubt that the rope is on the right neck. And therein lies the problem. Modern forensics can be pretty good these days, but people are more clever about not leaving as much evidence. It is always a battle between better science and more clever perpetrators.
IF we are going to use the awesome (legal) power of a government to terminate just one person's life, we owe that person (and by implication, every other person) the maximum effort to get it right. The USA "due process of law" concept is the short way of saying that we must dot every "i" and cross every "t" in our quest to assure that justice falls on the proper person. Recent U.S. Supreme Court decisions have clarified that we must in ALL such cases be able to convince a jury of the person's guilt UNANIMOUSLY. If we can't do that, we screwed up.
I have to clarify that I am not so much FOR the death penalty as that I am not AGAINST it when it is correctly handled through proper legal processes. In this forum we have seen all sorts of complaints that the state should not kill someone for killing someone else, because that seems to be an inherent contradiction. But the ultimate question is, can there ever be a justified killing? If the answer is no, you just shot down all sorts of self-defense cases. And there, I have to draw a line.
Now magnify that a million times. When England went to war with Germany in WW II, or when we went to war with Japan, we were in essence pronouncing a death sentence on any German or Japanese soldier who didn't surrender. Is war EVER justified? Including the case where you were not the original aggressor? Because that is self-defense on the largest scale we have.