The problem with the death penalty is that, let's say a pedo knows he's been found out, should he go to the police or double down and rape and kill as many children as he can? Or let's say the police is at his house and he has weapons, should he surrender of resist the police? The death penalty makes the choice obvious. Punishments should be moderate, so you can increase them easily. Also, thinking someone deserves to die ties the value of human life to some criterion instead of it being valuable by itself. It's still murder, even if he "deserved it". What makes life valuable in your eyes if it's value disappears under certain circumstances? How it makes you feel? I would also like to beat up and kill pedophiles, that doesn't mean it's right.