Tyrone and Kareem are inmates at the Fishkill Correctional Facility in New York, serving time for violent crimes. They're also volunteers with Puppies Behind Bars, training dogs to help the disabled (and helping themselves in the process). [PBB, Time]
Other prison programs I've heard of simply raise shelter dogs - preventing them from being killed, training them, and then adopt them back out to the (approved by the organization) pubilc. The waiting lists to get one of these amazingly well trained dogs is extensive. The prisoners have the time, energy, and it seems love, to repair some severely damaged animals. I love it.