It gets tough when you look at entire systems. On one hand, you've got some brave dedicated people who work with asshole criminals. We need a carrot of freedom and parole to keep those people somewhat safe. On the other, if prisons make people worse, that carrot of freedom is dangerous to everyone else. When I look at recidivism rates, I don't think that North American prisons make people better so what the heck do we do??
I know that sounds cynical but in the last year, the 'shining lights' of my city's youth offender program 'quit' for sexually harassing the young people they were charged with. That's Canada's Young Offender system and that is one heavily scrutinized system. If that kind of evil can hide for a decade in our young offender system, we're passed the point of draining the swamp and need to bring in heavy earth movers.
In the case of armed robbery with accompanying multiple murders, I'm much more concerned for the victims than the perpetrators (beyond taking steps as needed to ensure they won’t do it again in free society).