What if the person would prefer to have his life ended instead of spending life in prison? Would that fall out of the scope of the question?
In my opinion life imprisonment seems like a lose-lose situation; you can never leave the place and you know you're going to die there. Others outside don't get anything out of it either. It just seems like needless torture, though of course if said inmates would be willing to help contribute to society then I don't see a problem. Unfortunately that's not how it works, is it?