Report on exoneration of previously convicted defendants

The National Registry of Exonerations tracks cases of exonerated defendants, those who were found guilty but later determined to be innocent of their crimes, and indicates in recent reporting that with 891 exonerations, and 1170 mass releases of accused parties due primarily to police misconduct and fabrication of crimes, the rate of wrongful convictions in this country cannot be determined reliably - but it is certain this country imprisons people wrongfully, and it is hard to rack such a thing up to mistakes in our system. A summary report is here:  Exonerations in the United States, 1989 - 2012

The web site for the National Registry of Exonerations.