Australia With Enough Space and Time...

Australia's model of social establishment failed in one key aspect: There were already people on Australia who quite resented being pushed aside for a bunch of white usurpers and their rabbits and wild dogs. But, space is larger than Australia. Send the criminals into space. Place them in colonization capsules, with the Garden of Eden Creation Kits installed, and no way of coming home. Shoot them out into the stars towards habitable planets in cryogenic sleep, with no way of knowing how to get home. In two hundred years, three hundred, seventeen-thousand years, these ragged, outcast, throwaway men and women will stand on the naked rock of a new world, and carve their own society out from mineral and starlight. 

People did this once, and they'll do it again. Send them all to Australia. Make them work in Australia. Let them find their fortunes far from this civilized place.

The grand social experiment of modern justice requires that bad people must go away. Get those criminals. Get them locked up. Remove them from society like bad seeds.

Be tough on crime. Send our neighbors' sons and daughters to the stars with no way back. Let them carve their Australia out there, and if they're smart they'll figure out what we were trying to teach them all along about civil society. 

At least it's better than a lethal injection, or expensive life imprisonment, and it's just as effective for us on the ground. Why bother curing the criminally-insane, when we can just send them off to fend for themselves somewhere beyond far, far away?