When is it o.k to murder? Is it ever o.k?

I am for the death penalty. So, I believe there are many times when euthanization is in order or even torture. I believe convicted criminals should be subjected to the same punishment in which they inflicted. Eye for an eye. If someone were to harm my daughter I think that I would avenge her. Child molesters, rapists, serial killers, and other violent criminals should all be put to death. Just my opinion agree with it or not...