As of early 1996, researchers had identified 28 such cases, all of which involved sexual assault or sexual assault coupled with other crimes. In each case, DNA test results obtained subsequent to trial proved that, on the basis of DNA evidence, convicted persons could not have committed the crimes for which they were incarcerated. All but one of the released defendants had been convicted in jury trials and sentenced to long prison terms. Prior to exoneration, they had served an average of 7 years in prison. In a sample of 40 DNA laboratories, the study determined about 30 percent of suspects were excluded through DNA testing. Researchers noted, however, that findings did not identify what happened to these suspects after being excluded through the analysis of DNA evidence--whether they were released or simply prosecuted with other existing evidence and testimony. Consideration is paid to the reliability of DNA evidence, the competence and reliability of DNA laboratory procedures, the preservation of evidence for DNA testing, training in DNA forensic uses, multiple defendant crimes, post-trial relief, and future DNA forensic uses. 19 notes