Hmm...
In my opinion (and this does need to be stressed that this is MY opinion, and not a common one), it looks to me that in the vast majority of rape/murder/torture cases, the perpetrator have spent most of the lives as victims, theirselves. Whether it's abuse or bullying or mental health issues, most of these "cold" criminals have got reasons as to why they've gotten fucked up in the head.
For me, it would be much better if these individuals were put into secure facilities where they can undergo therapy and treatment. Try to heal their minds first, so that they can feel, for once, human, and let them have some compassion for their victims. Let them work in the prisons and have the proceeds go to either the victim/victim's estate, or charities that deal with helping victims.
In cases where they are deemed to fit to enter society by professionals, have received forgiveness from the victims/victim's estate, and have met certain arbitrary points (like 30 years, or whatever), give them partial freedom again: back outside, but with constant surveillance, mandatory "check ups", restrictions on how far they can travel, etc.
I don't think humans have any benefit for giving into our petty instincts for revenge.