I think anyone can be redeemed regardless of what they need to improve upon in their lives, but they need to want to change themselves and make an effort to do that. People must put aside pride, past hurts, etc. and trust that they can become a better person if they work at it.
Doing that, though, doesn't necessarily come without a cost or price to pay--you may lose many things in the process, like family, relationships, jobs, money, depending on the situation, but that's your "fee" for being a jerk or a criminal, abuser--whatever.
But on the upside, there's always something to be gained from a concerted effort to improve oneself. It's just the people who refuse to see that they have a problem, are the ones that aren't necessarily on the track to "redemption", and will stay in whatever cycle they're in.