I disagree.
97% of federal convictions and 94% of state convictions are the result of plea bargains. At least 4% of death sentences are erroneous. In 2007 there were 2.4 million prisoners in the United States.
I'm guessing death row convictions receive much more attention than normal convictions, especially convictions from plea bargains. In this case, we can conservatively guess that the rate of false conviction is higher for plea bargains.. let's say it's 6%. Extrapolate that to the entire prison population, and that's 144,000 people who are wrongfully locked up. That number is far, far too high no matter how you look at it, and I'm guessing it's even worse than that in reality. The way our system abuses the plea bargaining system is morally reprehensible. This alone should be enough to warrant reform.
> people are capable of really heinous stuff.
People who were raised in shitty circumstances tend to do shitty things. 68% of prisoners don't have a high school diploma. I think that's pretty telling on its own.
The real question is: what is the point of prison? Is it a place wherein troubled individuals can receive treatment and be corrected so that they may be reintegrated at some point and become functioning and productive members of society? Or is simply a place that we punish people indiscriminately?
Recidivism rates tell the story. In California, 60% of the formerly incarcerated end up back in prison. Prison is obviously not a place for treatment or healing or anything that might improve the lives of the people who enter it. It is a place that society simply locks the people up that it doesn't like - for the most part, poor black people.
But there is hope. When I see things like this: http://sacramento.cbslocal.com/2014/05/13/rehab-program-boas... , it gives me hope that people will realize that the way we're handling 'corrections' produces more criminals than it stops. Our system currently doesn't work if the goal is to reduce crime in the long run. I wonder how many criminals we have created because of false convictions. Or because of the war on drugs, since the number of federal prisoners has jumped 790% since 1980 (do you really think people have been committing 790% more crime since then?)