Killing is final. No possibility for changing and growing away from being the person who did then killing, and no chance for the truth to emerge, in the cases where an innocent perosn has been wrongly convicyed.

As for the pretty unique American system where after the person has served something like a life sentence, and perhaps has changed into someone far different from the person who did the killing, and has learnt to repent - and they take them out and ritually kill them...

Something that always puzzles me. In the USA, you've got this bit in your constitution about "cruel and unusual punishment" - and it seems to me you must have an extraordinary way of defining "cruel and unusual", for that kind of thing to be legal. Even leaving "cruel" on one side, that whole procedure is hardly "usual", outside the USA, which is just one country in a big world.