I've seen many criminals who go in and out of the justice system here in Sweden for quite a few years now. Many who come out and commit new crimes again within 1-2 years. Some have even committed new crimes the day they get out, or even when they're going to be released and they've been in a low-security facility and then committed crimes against visitors there.
Are some people even able to be rehabilitated, and if not, what should be done if they can't be when the sentences are time based? How many times should one be able to be sentenced for serious crimes before you actually get locked up for a longer period of time to protect society?