Many Chicago residents are enraged over the number of officer-involved shootings in their city, and now some are demanding that Mayor Rahm Emanuel step down. (Reuters)

For four years, Officer Raoul Mosqueda offered the same account of the January night when he shot and killed a man during a traffic stop on Chicago’s South Side.

Mosqueda and his partner, Gildardo Sierra, heard over their police car radio that officers were looking for an Oldsmobile Aurora involved in a shooting. A gun could be inside the car, the dispatcher warned. They saw a similar vehicle and instructed it to pull over; then the officers approached the two men inside, guns drawn. There was a confrontation, the car backed up and began to drive away, and Mosqueda opened fire, killing driver Darius Pinex.

For four years, the evidence that could have verified or refuted that account — a recording of the dispatch from that night — was nowhere to be found. Attorneys for the city said the recording didn’t exist, even as a wrongful-death lawsuit brought by Pinex’s family went to trial.

Then, in late February, too late for attorneys for the Pinex family to adjust their case, it emerged that an attorney for the city had the recording after all but waited more than a week before telling the Pinex family. A federal jury ultimately found that Mosqueda and Sierra were justified in the shooting.

But on Monday, a federal judge ruled that the lawyer, senior attorney for the city Jordan Marsh, intentionally hid evidence that could have changed the outcome of the case. The Oldsmobile described by the dispatcher had a different temporary license plate number than the one driven by Pinex. And the dispatcher in the recording made no mention of a shooting or a gun in the vehicle — the reason Mosqueda gave for approaching the car with his gun drawn.

“After hiding that information, despite there being numerous times when the circumstances dictated he say something about it, Marsh said nothing and even made misleading statements to the Court when the issue arose,” U.S. District Judge Edmond Chang wrote, reversing the federal jury’s decision and calling for a new trial in the case brought by Pinex’s family.

Marsh resigned just hours later, according to the Associated Press.

[In Chicago, distrust toward mayor has turned ‘personal’]

Chang’s ruling comes as the administration of Mayor Rahm Emanuel is roiled by outrage over its handling of the fatal police shooting of 17-year-old Laquan McDonald in October 2014. For more than a year, the administration resisted efforts to have dash-cam video of the confrontation released. Meanwhile, emails between the mayor’s office, police and the group that investigates police shootings that were released last week show close coordination between the agencies over how to deal with the public relations problem posed by the graphic footage, according to the Associated Press.

Emanuel has apologized for the shooting and fired Police Superintendent Garry F. McCarthy after video of the McDonald shooting was released. Emanuel also pledged to eliminate the “cone of silence” around police conduct.

“No officer should be allowed to behave as if they are above the law just because they are responsible for upholding the law,” he told the Chicago City Council in December. “Permitting and protecting even the smallest acts of abuse by a tiny fraction of our officers leads to a culture where extreme acts of abuse are more likely, just like what happened to Laquan McDonald.”

Even so, Emanuel and other city officials are now facing accusations of a coverup and calls for Emanuel to resign.

Corporation Counsel Stephen Patton — Chicago’s top legal officer who handles civil claims against the city — told the Chicago Tribune on Monday that the city is doubling down on its efforts to train lawyers on producing records. He also challenged the notion that there are widespread accountability or transparency problems in how the city deals with such cases.

“To say this is a practice, a systemic abuse or part of a coverup, there’s just no evidence of that,” Patton said. “There’s nothing in the ruling to support it.”

But the ruling in the Pinex case is yet another blow to public trust in the city as it copes with the fallout from a series of fatal police shootings.

[Chicago police superintendent fired by mayor amid outcry over video of shooting]

Marsh had admitted in the middle of the trial, away from a jury, that he failed to turn over a recording of the dispatch that the officers heard, according to Chang’s ruling. He also gave conflicting stories to a judge about when he first learned of the recording’s existence and why he didn’t tell the plaintiffs about it sooner.

In addition to overturning the February decision in the case, Chang imposed sanctions against Marsh and the city, ordering that they pay the plaintiffs’ legal fees.

“Attorneys who might be tempted to bury late-surfacing information need to know that, if discovered, any verdict they win will be forfeit and their clients will pay the price,” Chang wrote. “They need to know it is not worth it.”

Chang also found that Marsh’s co-counsel, city attorney Thomas Aumann, failed to make a reasonable effort to find the dispatch recording; he blamed the law department, which defends city employees who are accused of wrongdoing, of poor oversight and lax training that contributes to problems like the one in case about Pinex’s fatal shooting.

The law department announced that Marsh would be resigning Monday, saying that it “does not tolerate any action that would call into question the integrity of the lawyers who serve” Chicago and that it would be reviewing its training and evidence gathering procedures, according to the Associated Press.

The city has spent $460,000 on outside lawyers since the issue first came up, according to the Tribune.

This is the second time in the past year that Chang has sanctioned Chicago’s law department for its handling of a police-misconduct case. In May, he ordered a new trial for Jonathan Hadnott, who alleged that plainclothes police officers falsely arrested him and illegally searched his parents’ home in 2006. Officers said they had no recollection of stopping Hadnott and hadn’t filled out a “contact card” about the incident, according to Salon.com. There was evidence that police had run Hadnott’s name through a database that day, but city lawyers said it would have taken too long to do that and search his parents’ home in the time described.

“It is physically — it is impossible in a space and time continuum to do this,” city lawyers argued, accusing Hadnott of engaging in “outrageous lies,” according to Salon.

But after Hadnott’s trial, city lawyers revealed that it takes only a few seconds to search the police database, undermining their own argument in the case. Hadnott was granted a new trial.

Speaking to the Chicago Tribune about the Pinex case, Steve Greenberg, an attorney representing the slain man’s family, said the ruling raises questions about how Chicago police officers are held accountable by the city.

“There’s just a total disregard for the truth, and it runs to the highest levels,” Greenberg said. “There is a culture to cover up and win at all costs”

In his ruling, Chang said that he understood that the law department was pressed for time and resources to deal with discovery requests. But that’s all the more reason to develop better policies for training lawyers on how to find and interpret records preserved by police, he said.

“Failing to do so will cost even more in the long run,” Chang wrote. “Not just in dollars.”