That's a total misrepresentation of what I said. Serious punishment for sex crimes is not only permissable, but it's mandatory. Nothing I said detracts from that simple truth.
Rather, I said that the when a sex crimes carries the ULTIMATE punishment, there is no reason for the actor to not go ahead and commit the ultimate crime. Quite the contrary, the actor would have instead have a genuine incentive to kill his victim because dead witnesses never come forward on their own.
Serious punishment does not equal the ultimate punishment. There can be only one crime that merits the ultimate punishment, and that's the taking of human life. When any other crime, save possibly treason, can command the ultimte penalty, then life itself is cheapened.
We'll just have to agree to disagree, then. I do not believe the death penalty being on the table will encourage perps to kill, nor do I think it will stop them from killing. However, once it's been enforced, we know for sure they won't hurt, or kill, again.