I think he's referring to the case of Roy Criner. What was ridiculous is that I remember watching a documentary that focused in part about this case and they interviewed the district attorney who was denying an appeal of the case after the DNA analysis of the semen confirmed that it didn't belong to Roy Criner. The DA was adamant that he was obviously guilty because he was given a fair trial and that the DNA evidence just meant that the victim also had sex with someone else recently before she was raped and murdered by Criner.

http://www.law.northwestern.edu/legalclinic/wrongfulconvicti... http://www.pbs.org/wgbh/pages/frontline/shows/case/etc/updat...