Illinois led the nation in exonerations of wrongfully convicted people, with 49 people clearing crimes off their records in 2018, according to a report issued Tuesday by the National Registry of Exonerations.

Padding the innocence statistics for Illinois were 31 convictions vacated in Cook County of defendants framed by former corrupt Chicago Police Sgt. Ronald Watts. Watts was arrested on federal charges in 2012 for shaking down residents in the Ida B. Wells housing projects. Most the defendants exonerated in cases tied to Watts or officers under his command had already served out their prison sentences, mostly for drug offenses.

The 18 non-Watts exonerations in Illinois still led the nation, ahead of New York state, which tallied 16 overturned convictions last year. All but five of the exonerations — which the organization classifies as when a convicted defendant wins acquittal in a new trial or prosecutors’ drop charges against them based on new evidence — were in cases in Cook County.

Illinois typically ranks high on the list of exonerations, according to Barbara O’Brien, editor of the Registry, though the reasons for each overturned conviction is unique. Generally, Cook County has several elements that will keep it high on the list: several law schools with robust “innocence organizations” to research cases; a large volume of criminal defendants; several long-running law enforcement scandals; and, a Conviction Integrity Unit within the State’s attorney’s office that reviews suspect cases.

“I think it is a good thing” to rank high on the list of exonerations, O’Brien said. “It shows there’s a willingness to revisit these cases, a willingness to admit error, and to try to fix it.”