Care to cite your evidence that the death penalty deters crime?

You're straw manning. Not all crimes should have the death penalty. But severe abhorrent ones like killing, spreading of chaos (i.e. "terrorism"), or some other abhorrent obvious ones. We see that in countries that do apply the death penalty for such crimes, they have much lower of those crimes compared to those that don't. And they've done it for over 1000 years.

Asking for evidence of your claims is not a strawman. Care to cite any evidence showing any of that to be true?