From Wikipedia:
Ronnie Bullock spent over 10 years in prison for the kidnapping and rape of a 9-year-old girl and a 12-year-old girl. DNA testing revealed that he was not the culprit.
Joseph Burrows spent nearly five years on death row until Zellner persuaded the real killer to confess at a post-conviction hearing.
Billy Wardell spent over 10 years in prison for robbery and sexual assault. He was exonerated in 1997 when Zellner convinced prosecutors to agree to DNA testing. It cleared him as the perpetrator.
Omar Saunders, Marcellius Bradford, Larry Ollins, and Calvin Ollins were convicted of the kidnapping, rape, and murder of Lori Roscetti , 23-year-old medical student. Bradford served six years in prison following a plea deal, but Saunders and the Ollins cousins had served nearly 15 years in prison before DNA testing was conducted that cleared all four men of the crimes.
Kevin Fox was imprisoned for eight months for the murder of his daughter, Riley. Zellner represented Fox until he was cleared by DNA evidence. He won a $15.5 million civil verdict against the government, which was reduced to $8.1 million on appeal.
Harold Hill and Dan Young were convicted of the 1990 rape and murder of Kathy Morgan. DNA testing performed in 2004 led to the release of both Hill and Young in 2005.
Alprentiss Nash spent more than 17 years in prison for the murder of Leon Stroud. In 2010, Zellner convinced the Illinois Court of Appeals to order DNA testing of the ski mask worn by the perpetrator. This testing led to Nash's exoneration. It matched the real killer, who was already serving time for an unrelated drug crime. A federal civil rights lawsuit against the city of Chicago is pending.
Cesar Munoz was convicted of the 1997 murder of his girlfriend, Magdaliz Rosario. Zellner's firm represented Munoz and won his acquittal in June 2013 after the fourth trial. (The first trial resulted in a hung jury, and the second two resulted in convictions but were reversed on appeal.)
Lathierial Boyd served 23 years in prison for the murder of Michael Fleming and the attempted murder of Ricky Warner. His conviction was vacated in 2013 based on evidence of his innocence and prosecutors withholding exculpatory evidence. A $20 million civil rights lawsuit against the city of Chicago and several police officers is pending in federal court.
Ryan Ferguson was arrested in 2004 for the 2001 murder of Columbia Tribune sports editor Kent Heitholt. He was convicted and sentenced to prison. He was released in November 2013 after Zellner and her firm convinced the only two witnesses against Ferguson, Charles Erickson and Jerry Trump, to admit that they had lied at trial. A $100 million civil rights lawsuit against Boone County, Missouri, the prosecutor, police officers, and others is pending in federal court.
Jerry Hobbs spent five years in jail for the murder of his young daughter and her friend. In 2010, DNA testing led to the apprehension of the real killer. After obtaining his release, Zellner filed a civil rights lawsuit on his behalf, which settled for $7.75 million.
James Edwards was convicted of two murders as the result of a false confession. He was exonerated for the murder of Fred Reckling after Zellner filed a motion for DNA testing; the results cleared Edwards as the murderer. Zellner is challenging his other murder conviction, as it was based on the same confession shown to be false because the DNA evidence excluded him as the perpetrator.
Mario Casciaro was released in September of 2015 after serving four years for the murder of a teenager. The Illinois Second District Appellate Court reversed Casciaro's conviction for intimidation murder. The court ruled that the state had failed to prove the elements of intimidation and that none of the forensic evidence matched the state's theory presented to the jury at Casciaro's second trial. The first trial had resulted in a hung jury.
ETA: Looks like maybe three cases could be argued to have not been conclusive:
Munoz (won acquittal after 4th trial);
Boyd (conviction vacated due to evidence of innocence and prosecution withholding exculpatory evidence);
Casciaro (lack of evidence and evidence didn't match state's theory in second trial).
