There's no doubt it has, which is why I only support the death penalty in cases where it's obvious beyond all doubt that the victim is guilty as sin. (IE the OJ Simpson case)
It's best to err on the side of caution than to excecute an innocent person.
Instead of applying the death penalty, why not have the person locked forever on some place, working as a slave planting something or producing something? Wouldn't that be more productive?
That is an alternative I suggested. But quite honestly, I am not sure how well it would work, and it is very unlikely they would be able to support themselves fully. So very likely they would still be sucking up tax dollars. Even if you had them working a 8 hour work day, you can bet people are going to be crying out foul for making them preform slave labor, or at the very least might say that the prisoner should get his money sent to his own family or transfered into a private bank account rather than going to the prison system.
If we could lock them away in some obscure location where they could work in something like "sweat shops" producing cheap labor for companies to profit from, then this could be a very interesting alternative. But you know there will be constant protests against the use of prisoner labor, even if it is only reserved for extreme death penalty level cases.
The only problem I see with trying to lock them away forever or making them work it off, other than the tax money they suck out of our government, would be the fact that there will always be the chance that they could break out and have the opportunity to murder or rape again. Whereas, when you put them to death, there is no chance that they could victimize anyone ever again. This has occured, review the Texas Seven and even in the UK. The most notable person to be cited would have to Kenneth Allen Mcduff, anyone who reads that and does not think our justice system is screwed, needs a head examination. Kenneth McDuff is the apitomy of why we need the death sentence and why it should be used. If this bastard hadbeen put to death in the 60's, at least four women would be with thier famlies today.