Did you read my comment wherein I specifically reject the notion that we need to perpetuate in Prison Industrial Complex? It's an incredible burden on our civilization and must be dismantled.
I think the problem is you have people who grow up in violence and only know violence. If we have a society that successfully educated people, kept people from falling through the cracks and provided them with opportunities, violence wouldn't be necessary. But for how many generations has our society failed people? How many generations have the failed, neglected people in our society grown up only knowing violence as something to be respected? Two? Three? Four generations? The question in my mind is whether even violence will deter people, which I am not certain of. But certainly prison doesn't deter anybody.
The only real answer, obviously, is education. But education is almost beyond repair at this time.