The death penalty doesn't solve anything and is far too often proven to kill the innocent. Go for a life sentence instead. It's mentally nastier. The death penalty only gives them the easy way out.
I remember the British Moors murderer Ian Brady. In an attempt to destroy the evidence of child rape, he and his impressionable girlfriend killed the kids and buried them where they hoped they wouldn't be found. (Though he may have enjoyed that anyway as a psychopath.) If you introduce the death penalty for rape, all you will do is make that more likely because why not kill them? The punishment will be the same.
Then the UK abolished the death penalty for murder before they were caught and he ended up with what he was trying to avoid. He spent his last years begging to be allowed to starve himself to death rather than live out his life pointlessly and was always told "no you don't, you will serve the sentence as laid down".
I can also refer you to the case of Fred and Rose West. They enjoyed raping and torturing girls. Fred committed suicide before the trial, no doubt knowing that the judge would hand down a sentence of life without parole. Which Is what he did do to Rose.
As far as the USA is concerned, much of the time it doesn't actually execute people anyway, so if that's where you're asking about, what difference does it make to impose a life sentence in the first place? The death sentence actually was a real threat in the UK because of how it was done. Traditionally 3 weeks were allowed before execution to allow 3 clear Sundays to make peace with God, and a maximum of 3 more weeks for the only 3 appeals allowed. If all those failed, you hanged. Which is why the UK never had a death row - nobody was ever on it long enough. If you're going to execute people, stop faffing around and do it the British way.