Chancellor Jim Petro, whose long career in public service has included 12 years as state auditor and attorney general, is retiring. The 64-year-old Petro planned to announce Monday that he'll end his run in February after two years as Chancellor of the Ohio Board of Regents. Petro, a Republican from outside Cleveland, sought the governor's seat in 2006 but lost a GOP primary among three sitting statewide officeholders. In 2005, he became the first state attorney general in the nation to intervene for the use of DNA evidence on behalf of a wrongly convicted inmate. His work helped exonerate Clarence Elkins, an Ohio man wrongly accused of rape and murder. He and wife Nancy wrote a book on the experience, which will be the center of an international tour after he retires.