CHICAGO (CBS) — A prominent Chicago law professor on Wednesday urged aldermen to get it right this time when they replace the agency that investigates police conduct, and make sure it can truly do its job.

University of Chicago law professor Craig Futterman, a longtime critic of the Police Department’s disciplinary system, said testifying before two City Council committees about a plan to replace the Independent Police Review Authority with a new civilian-run police oversight agency felt like déjà vu.

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Ten years ago, Futterman testified about the failure of the Police Department’s Office of Professional Standards to effectively deal with police misconduct, even though the percentage of so-called “bad cops” was small.

“The problem wasn’t one and isn’t one of simply a few bad apples. It was that the department had allowed those abusive officers to hurt the most vulnerable among us – the most vulnerable Chicago residents – without fear of any punishment or consequence,” he said.

OPS, which was an internal unit of the Police Department, was replaced with IPRA, a separate agency that has been criticized as being equally ineffective at disciplining police officers who break the rules.

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Futterman, who was part of the team that successfully fought to force the release of the video of the fatal police shooting of Laquan McDonald, said IPRA has the same problems as OPS.

While Futterman had high praise for IPRA chief administrator Sharon Fairley, he said the deck is stacked against efforts to punish cops for wrongdoing, and the agency must be replaced.

“I think that she’s doing a damn good job under the circumstances, but one of the things that we’ve learned from our past is, as important as leadership is, even the greatest leader in the world can’t create a credible system of police oversight in Chicago if she’s dealt the same hand; the cards are still stacked,” he said.

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Futterman said public trust in the Police Department could be restored by showing there will be accountability for officer misconduct.