I understand what you mean, I don't agree, but hay-ho. Death penalty for those convicted of child rape or murder and if a small percentage of people are actually innocent, that's a price worth paying, even if those people happened to be you or one of your own family.
I think a consequence of the death penalty would be fewer convictions though. I think plenty of jury members would be too scared for convict, knowing the person would be executed, just in case they were wrong.