For wrongly convicted felons, improved DNA testing has increasingly provided the means by which innocence is proved and freedom from incarceration secured. A recent study of 328 criminal cases and subsequent exonerations over the past fifteen years found that DNA evidence contributed to 145 of those exonerations, and, moreover, that DNA evidence helped free inmates in 88 percent of the rape cases in the study. Former Governor Ryan of Illinois made national headlines when he commuted the death penalty sentences of 167 inmates because new evidence revealed that many on death row were innocent of the crimes for which they were convicted. DNA testing has applicability well beyond criminal law, however. Improved genetic testing is changing how ...