Yes. Everybody, even the worst criminal, deserves a chance to redeem themselves.
Even those who commit mass murder or genocide? Some people are bad enough that releasing them after a few decades doesn't seem right. Maybe if people lived for eternity, you'd have a point.
Theoretically, yes. Of course, the standard for what constitutes redemption should be proportional to the gravity of the crime, which in those cases would make it almost impossible. But the possibility exists and it ought to be preserved.