What is appropriate punishment for heinous crimes by Buddhist standards?

I've been looking into this lately and am curious how should we address crime and punishment? I know all about the story of Angulimala, but we can't expect all murders, rapist etc., to experience liberation in this fashion. If capital punishment is out and so many seem opposed to excessively long prison sentences what's the practical alternative? Yes programs and such to deal with the root cause of these issues are needed but in the here and now how can we best protect society and give these individuals an opportunity to reform. Also people don't like the idea of prison as retaliation or revenge "justice", but shouldn't all social actions have social consequence other than just allowing for kamma? And maybe the social consequence of jail is your kamma.