The condemnation theory of punishment seems harsh, but perhaps it can be implemented as follows.
A serial criminal, after society has had enough ot letting him in and out through the revolving door or prisons, is given a life sentence but with a possibility of parole after just 1 year and every year thereafter.
If the committee of psychologists or whoever is in charge of evaluating eligibility for parole feels the guy has been rehabilitated, as least partially, then they’ll let him out quickly.
If he seems evil, he stays locked up.
Might this salvage our theory?