It wouldn't take that much to work out the details of something along the lines of the American '3 strike' system. Founf guilty of three serious or violent crimes and it's an immediate 25 years to whole life imprisonment without the possibility of parole. Build a special high security prison for these animals somewhere in the middle of nowhere and keep them away from the public.
I'm all for 'three strikes'....
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But in the 'States they extended it to drug crimes and the prisons simply overflowed with drug users/dealers...
I'd go for pretty much all crime
providing there was a serious attempt at training/rehabilitation after the first crime.
So basically, you commit a crime, you are punished and returned to society with some chance of living a normal life... so you have received some life skills/training/qualifications or whatever and if you can't find a job one would be found for you - even if it is painting coal white.
Thereafter you are just punished for increasingly long periods.