Some people do change and I think no matter what the person did and if they had a mental illness or not us humans shouldn’t decided when someone’s last day on earth should be we all have done bad things. Whoever allows this is seeking and promoting revenge when this is allowed. All life is valuable. Also It’s not like the person will be walking out of prison so why not let them live.
I think about what if they were my own that got hurt but we must forgive and not kill the person out of anger. I would just agree to them being put in jail for life rather than something harsher than that. Every life is valuable and killing out of revenge is not the answer.
As much as you would feel hurt Revenge is not the answer. We should learn to forgive even if the person doesn’t know what they did was horrible and hopefully that persons receives help. If self defense came in the picture that would be different but the person won’t be able to walk out of that prison that should be Enough.