If any of you want to learn more about forensic evidence and how innocent people are often put in jail, I strongly recommend you watch this:
http://www.pbs.org/wgbh/pages/frontline/real-csi/
Basically people in jail often don't belong there. There are many innocents there and the ignorant belief that everyone in jail deserves to be there is stupid. Forensic evidence and "expert" testimony is shaky at best.
It doesn't help that the past few decades we've been trying to crack down and be tough on crime. It hasn't worked. Our jails are overcrowded, filled with mostly non violent drug offenders. Privatization is a huge problem. We're spending more on them than schools. The death penalty has not been proven to deter crime. Rehabilitation would be so much more useful. We isolate people, take away their humanity, treat them like animals, we release them and we wonder why they act like animals and go back to a life of crime.
The stigma attached to this is unbelievable, they can't get jobs and they need money so they resort to going back to deviance.
Politicians need to learn to listen to experts like criminologists and not give in to the fear of the people that demand we crack down on crime. They want votes, obviously, but the best way to change things is to speak on this subject and educate the people.
Of course, as long as people are ignorant enough to believe Fox News, they'll believe all criminals are evil people out to harm they and they should be forever isolated from society. We've come a long way from the Middle Ages, but we have a long road ahead of us to catch up with the rest of the industrial world, i.e. Europe.