Exonerations, where a convicted criminal is later proven innocent, have increased significantly in recent decades. From 1973-1988 (15 years), 35 cases were exonerated; from 1989-2004, there were 81 exonerations. The most common cause was eyewitness error, from "confusion or faulty memory." Snitch testimony was typically a part of a plea bargain. "Other" primarily consisted of bad defense-lawyering and questionable/circumstantial evidence.