Let's end this with a picture instead, says more than thousand words or something:

This is the message we send out right now. In EU, it's even worse.
EDIT!
I just realized that there is an institution that will provide way better numbers in rehabilitated vs. not scale, works same way as imprisonment (i.e. uses taxpayer money), but provides results.
It's called military. Why gladiators vs poor lions, when lawbreakers can actually serve the country and pay the dues to society?
We need military all the time, everywhere. It should be separated unit, something like French Foreign Legion, but I think it would work. Far better than hotel "barbed wire" anyway... Plus, teach prisoners alot about taking really care of themselves and provide instant job with honest life once term is served. And get the adrenaline out where needed.

This is the message we send out right now. In EU, it's even worse.
EDIT!
I just realized that there is an institution that will provide way better numbers in rehabilitated vs. not scale, works same way as imprisonment (i.e. uses taxpayer money), but provides results.
It's called military. Why gladiators vs poor lions, when lawbreakers can actually serve the country and pay the dues to society?
We need military all the time, everywhere. It should be separated unit, something like French Foreign Legion, but I think it would work. Far better than hotel "barbed wire" anyway... Plus, teach prisoners alot about taking really care of themselves and provide instant job with honest life once term is served. And get the adrenaline out where needed.