Since District Attorney Larry Krasner took office in 2018, the Conviction Integrity Unit he created has become one of the largest and most active in the country. It’s produced 21 exonerations and has 88 more active investigations. And it has developed a police-misconduct database that has led prosecutors to decline 447 cases, and crafted office-wide policies including an open-file discovery protocol — a first for the city — that could help prevent the errors of the past from being repeated.

It has also been a source of extraordinary friction within the city’s criminal justice system, facing opposition from the courts, the police, and even from within the district attorney’s own office.

That’s according to a self-assessment from the District Attorney’s Office, titled “Overturning Convictions — and an Era,” released Tuesday on the CIU’s work during Krasner’s first term. To underscore the point, the report was unveiled at a City Hall press conference concluding with a march to the site where the statue of law-and-order Mayor Frank Rizzo was removed last summer.

“We anticipated that we would uncover many cases where misconduct caused innocent people to go to prison. What we saw, however, has taken our breath away,” Krasner wrote in the report’s introduction, which took prior district attorneys and police to task for “horrendous abuses of power.”

“In 20 [of the 21] cases, prosecutors withheld evidence they were ethically and constitutionally required to disclose. In 15 cases, police committed egregious misconduct.”

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CIU Chief Patricia Cummings said the report was an important move toward transparency. “What we’ve had in the criminal justice system, not just in Philadelphia but across the country, is we’ve had it operate in the dark,” she said.

The report details the exonerations — and offers a window into barriers to the CIU’s work.

“We have faced lawsuits by the local police union, the hostility of some judges to our fundamental mission, and the intensity of conflict even within our own office,” Cummings wrote in the report, which criticizes judges who “remain unclear on the prosecutor’s actual role.”

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Cummings, who takes a collaborative approach, has weathered excoriating, on-the-record criticism by federal and Philadelphia Common Pleas judges who accused her and her team of abandoning their adversarial role or even failing in their duty of candor.

The report also alleges that the Police Department changed a longstanding file-sharing policy just as the CIU’s work was beginning in May 2018, in order to prevent the District Attorney’s Office from taking possession of police files. It allowed review on site, but then put in place added restrictions including police supervision during file review. The CIU finally won permission to take custody of files for review in April 2021.

In an interview this May, Homicide Capt. Jason Smith acknowledged the recent policy change, but said the department has been “more than accommodating in providing those case files.”

He also expressed frustration with learning of exonerations only by reading the news, and said he had written to the CIU asking to be included in the case-review process.

“I would like the opportunity to learn from the mistakes of the past,” he said.

Cummings said she agreed more collaboration is needed, particularly if any wrongful conviction is to be corrected with not only an exoneration but the arrest of the true perpetrator. So far that has not happened, in part because of the many logistical challenges to reopening cold cases but also, according to Cummings, a lack of will. She said some detectives declined because they believed they’d gotten it right the first time.

In the case of the murder of 4-year-old Barbara Jean Horn, of which Walter Ogrod was exonerated in 2020, “what they specifically said was ‘we don’t have the manpower or the resources to even think about investigating that case,’ ” Cummings said.

In a section called “Setbacks,” the report also calls out three cases where judges denied relief despite the CIU’s agreement that serious injustices had occurred. In one case, prosecutors had reneged on an agreement to resentence Salvatore Chimenti in a 1986 murder case, resulting in his lifelong incarceration. The named plaintiff in a lawsuit that forced the Department of Corrections to provide life-saving hepatitis C treatment, Chimenti is now terminally ill, according to the report, and his petitions have been denied as untimely.

Other startling details include a study on the review of Detective Philip Nordo’s work, which so far has included four exonerations. He faces criminal charges on accusations of raping and coercing witnesses. The CIU has declined action on another 33 Nordo cases, but is actively reviewing 34 more, the report notes.

The report also addresses funding shortages — currently, there are 12 attorneys staring down a backlog of 1,165 cases — and outlined novel solutions including the new Pro Se Review Project, in collaboration with the nonprofit law office Phillips Black, to help vet cases by self-represented petitioners and connect them with legal representation.

One of the more notable reforms outlined, though, is forward-looking. That’s the District Attorney’s Office’s file-sharing policy, which was dated October 2020 but on which staff are being trained this month. It adds disclosure requirements, which, under Krasner, already included revealing the misconduct histories of police officers expected to testify.

“There’s been a real sea change,” said lawyer David Rudovsky, citing the CIU’s openness with files in post-conviction cases. It’s in those files that lawyers have found much of the evidence leading to recent exonerations. He praised the new policy for following the American Bar Association model rules for post-convictions disclosures, which have guided disclosure laws in some states but not Pennsylvania.

In lieu of statewide legislation, said Temple University law professor Jules Epstein, “Having this on paper is an unbelievably important statement.”

He raised concerns that the policy leaves unclear whether defense is entitled to the entire police case file, as well as the district attorney’s file.

But, if fully implemented, it could prevent another generation of wrongful convictions, he said. “This is part of a ‘do it once, do it right’ approach that says we’re not going to be litigating cases for mistakes for 30 years.”