The state should not have the authority to execute its citizens, no matter how heinous the crime may be. One innocent person being executed is too many.
I have to disagree. There are some mutts who are just too dangerous to be allowed to live.
This one is an example:
Anders Behring Breivik - Wikipedia
en.wikipedia.org
He killed 77 people, mostly children. He single-handedly wiped out the next generation of Norway's leftist leadership. His crime was brilliant, well-planned, well-considered, and wildly successful. He was coldly logical about it and when he gets out of prison in another seven years or so I expect he'll kill again.
Executing this guy is not retaliatory it is preventative.
A truly civilized society will protect its children from monsters like this. And this guy is a monster because he is perfectly sane and rational in his abominable acts.