Until the advent of DNA technology, wrongful convictions were thought to be extremely rare. But as the number of DNA exonerations rises—at least 281 as of this writing—we confront the uncomfortable truth that the number of innocent people behind bars is far higher than we realize. The vast majority of DNA exonerations are in rape cases. In many felony cases—robberies, shootings, murders, drug-related crimes—there is no DNA to test. Even in rape cases, forensic evidence often is lost or destroyed.