Okay, by that famous last words you can argue to throw every criminal having harmed other people or having killed somebody, into sensory deprivation and lifelong isolation.
I have and my family has lost loved ones to idiots behaving like azzes - and despite my grumble with the courts and the lax laws and my rage for the offenders responsible, I do not feel any desire to make the offenders subjects of measures like in this case.
And if you argue that it is an eye for an eye and cruel punishement for all times and death would not be good enough - you often have taken side with Christian dogmas and beliefs in various threads, defending Christian religion in general. Now consider what Jesus said about forgivenes, and try to imagine if what you feel and say would be in conformity with what he has told people.
Is your position on this issue really that Christian at all?
Determination is enough, and fully sufficient. Cruelty beyond that is not needed.