Twenty years ago, post-conviction DNA testing was first used to prove that an American prisoner had been wrongfully convicted and imprisoned for a crime he did not commit. Since that time, more than 235 American inmates have been proven innocent through DNA testing, with the number growing almost weekly. We know that this number is just the tip of the iceburg, however, because the vast majority of inmates claiming innocence--perhaps 95%--do not have probative DNA available for testing in their cases.
The recent wave of DNA exonerations has spurred social scientists to study the causes of wrongful conviction. Studies have revealed, among other things, that eyewitness identfication is not nearly as reliable as once believed, that innocent citizens confess to crimes they did not commit more readily than we previously believed, and that our system is not nearly as competent at separating the innocent from the guilty as we have always assumed. The information gained from the DNA era can be a great learning moment for our criminal justice system, and for our classrooms, if we are ready to listen, learn, and reform.