In 1982 Jerry Miller, then 22, was convicted of kidnapping, robbing, and raping a woman in Chicago. He was imprisoned until 2006, when he was released but required to register as a sex offender and wear an electronic monitoring device. In April 2007, DNA tests demonstrated that semen preserved from the rape couldn't have been Miller's.
Miller is the 200th wrongfully convicted person to be exonerated with the help of the Innocence Project, an organization founded by attorneys Barry Sheck and Peter Neufeld at Yeshiva University's Cardozo School of Law in 1992. The group reports that in the cases where it has helped win exonerations, eyewitness testimony contributed to 77 percent of the wrongful convictions, while forensics errors, such as lab mistakes and testimony by frauds posing as experts, contributed to 63 percent. Remarkably, in 25 percent of the exonerations, the defendant at one time confessed to committing the crime, suggesting problems with overcharging, plea bargaining, and/or coercive interrogation techniques.
You can expect more exonerations in the future. Dallas County, Texas, alone has more than 400 convicts awaiting DNA testing. That county decided in the early 1980s to preserve evidence from all violent crimes, but such policies are rare. In many jurisdictions, innocent people in prison won't have the opportunity to clear their names.