If the goal of your prison system is rehabilitation, then the fair thing to do is assuming they changed. Possibly even if the only purpose of imprisonment was punishment.
This depends on risk of course. You and society shouldn't be exposed to undue risk because of that assumption. But limitations on the offenders freedom to - for instance - perform certain jobs after their release should be decided by a court, not the general population.
> And people will disagree on how many are
necessary.
I think you've hit the nail on the head, there is unwritten large variance timeframes that people "need to have met" for atonement, it isnt an easy solution.
The radiation continues to affect, long after the nuclear explosion.
This depends on risk of course. You and society shouldn't be exposed to undue risk because of that assumption. But limitations on the offenders freedom to - for instance - perform certain jobs after their release should be decided by a court, not the general population.