According to an article in ProPublica, Roland Burris defied his own staff to continue prosecuting Rolando Cruz for the 1983 rape and murder of a 10-year-old girl in the Chicago suburbs.
Cruz was twice convicted, but by 1992 another man -- a repeat sex offender -- confessed to the crime, and in 1995 DNA evidence ruled out Cruz as the rapist and implicated the sex offender.
ProPublica, a nonprofit news outlet, reported that Burris' own deputy attorney general, Mary Brigid Kenney, pleaded with Burris to drop the case at the time. She resigned, writing in her resignation letter that Burris was ignoring evidence and that she felt she was "being asked to help execute an innocent man."
http://www.foxnews.com/politics/2009/01/02/report-burris-drew-criticism-prosecuting-innocent-man/