I found a website where you can become penpals with people that are incarcerated. I am sure it can be incredibly lonely in prison, and I think communication with the outside world, creating friendships and experiencing positive relationships must all help towards rehabilitation. So today I sent an initial email to someone whose contact details were on the website, and hopefully we can begin mutual correspondence in the near future.
https://www.facebook.com/letters.to.inmates – the website with inmates contact details
http://www.nytimes.com/roomfordebate/2012/12/18/prison-could-be-productive/punishment-fails-rehabilitation-works – an interesting article about rehabilitation