Minneapolis citizens had already put the city’s police department on notice that Derek Chauvin, the officer charged with second-degree murder in the death of George Floyd, might be dangerous. Over his 18-year career, they lodged at least 17 complaints against him, but none resulted in meaningful discipline. Chauvin’s example mirrors a pattern seen in earlier prominent police killings — such as the murder by Jason Van Dyke of 17-year-old Laquan McDonald, in Chicago — in which officers with a history of abusive behavior were nonetheless allowed to continue interacting with the public.

Why don’t police take complaints seriously? And what can be done to make complaint systems work better?

These patterns of unconstitutional police violence are enabled and shielded by systemic deficiencies in supervision, accountability, and training, and by the code of silence within the department.

Many of the most egregious examples of police misconduct arise from tightly knit groups of officers like these. That’s no accident. Recently released data from the Chicago police department shows that misconduct spreads from officer to officer like an infectious disease. And the same behavior that leads cops to violate the rules often predicts whether they will participate in a shooting.

The data shows not only police shootings, but also thousands of regular police uses of force over more than a decade — involving an average of 10 people every day — documenting cases in which officers tackled, tased, or used other types of force on civilians, nearly 90 percent of whom were people of color. The data provides a more detailed look at the pattern of unconstitutional force discovered by the Justice Department investigation that opened shortly after the release of the McDonald video.

While more than 95 percent of all Chicago police officers never fired their gun from 2004 to 2016, 130 officers have done it more than once.

The code of silence has protected some particularly reprehensible behavior in the C.P.D., much of it directed at the city’s black population. Perhaps the most egregious was that of Jon Burge, a commander who, in the nineteen-seventies and eighties, headed a group of officers that he called the Midnight Crew. To extract confessions, the crew tortured dozens of men, most of them African-American, using electric shock, suffocation, and Russian roulette. Last May, the city agreed to a reparations agreement that included $5.5 million for the victims and an obligation to teach the episode in the public-school curriculum. According to the Better Government Association, between 2010 and 2014 there were seventy fatal shootings by the Chicago police, a higher number than in any other large city. (Phoenix, Philadelphia, and Dallas had a higher number per capita.) Between 2004 and 2014, the city spent $521 million defending the department and settling lawsuits claiming excessive force.

Last March, after a seven-year legal battle, waged by Futterman, Kalven, and two Chicago law firms—Loevy & Loevy and the People’s Law Office—to obtain records of police officers who had accumulated repeated citizen complaints, an Illinois appeals-court judge ordered the records released. They show that, of nearly twenty-nine thousand allegations of misconduct filed between 2011 and 2015, only two per cent resulted in any discipline—and, of those which did, the vast majority took the form of reprimands or suspensions of less than a week. Moreover, while African-Americans filed most of the complaints, those lodged by whites were more likely to be upheld.

By 2007, the department was engulfed in scandal over a surveillance video that showed a drunken officer, Anthony Abbate, beating a female bartender, and allegations that fellow officers covered up for him. That year, Mr. Emanuel’s predecessor, Mayor Richard M. Daley, announced the creation of the Independent Police Review Authority — run by civilians and overseen by the mayor — to replace the Office of Professional Standards.

Now the new system is accused of being little better than the old. From 2011 to 2015, 97 percent of more than 28,500 citizen complaints resulted in no officer being punished, according to data recently released by the Invisible Institute, a nonprofit journalism organization, and the Mandel Legal Aid Clinic of the University of Chicago Law School. The Police Department and the review authority have questioned the data, though Mr. Emanuel said last week that the low rates of disciplinary action “defy credibility.”

The “few bad apples” theory of police violence posits that a small portion of the police force is ill-intentioned or inclined to misconduct or violence, while the majority of officers are good cops. Until recently, this theory was difficult for civilians to investigate, but department data on complaints against officers obtained through a legal challenge shows that police misconduct in Chicago is overwhelmingly the product of a small fraction of officers and that it may be possible to identify those officers and reduce misconduct.

This far-reaching data set, a product of the nonprofit Invisible Institute’s Citizens Police Data Project, comprehensively covers nearly five years of complaints against Chicago police officers. Each of the 28,588 records in the database offers a detailed account of the incident, including information on the accused officer, the complainant, the type of alleged misconduct, and whether the complaint was found legitimate by an internal investigation.

While it may seem surprising that so many complaints against one officer would be tossed out, a Huffington Post analysis of four years of city data released by the Invisible Institute, a nonprofit journalism organization, reveals that there are more than 180 city police officers with more complaints than Van Dyke who weren’t disciplined at all over that time. Most of those complaints were made by black residents, whose allegations of police misconduct are dismissed at nearly four times the rate of complaints filed by whites, HuffPost found.

Of 10,500 complaints filed by black people between 2011 and 2015, just 166 — or 1.6 percent — were sustained or led to discipline after an internal investigation. Overall, the authority sustained just 2.6 percent of all 29,000 complaints. Nationally, between 6 and 20 percent of citizen-initiated complaints are sustained, said Lou Reiter, a police consultant who trains internal affairs investigators. As HuffPost’s Ryan Reilly noted earlier this year, a lack of transparency and accountability within police departments is a phenomenon hardly limited to Chicago.

Documented misconduct of Chicago police dating back decades is not publicly available, but after police officials said they planned to destroy the records, media outlets seeking their release caught a small break from a judge’s emergency order.

On Thursday, Illinois Circuit Court Judge Peter Flynn ruled Chicago police must first contact journalist and human rights activist Jamie Kalven before disposing of hundreds of thousands of files related to complaints against officers.

The emergency order came in response to a petition by Kalven who, along with the Chicago Tribune, Sun-Times and other media organizations, is seeking a full release of the documents, some going back as far as 1967.

Mayor of Chicago Rahm Emanuel walks past a group of Chicago Police Department's newest recruits prior to their graduation ceremony in Chicago, Illinois, April 21, 2014. REUTERS/Jim Young (UNITED STATES - Tags: CRIME LAW) - RTR3M4HT

At this writing, Chicago is the latest city to erupt in protests. The impetus there is yet another gruesome video, this time of an officer named Jason Van Dyke shooting 17 year-old LaQuan McDonald 16 times as he walked away from police.

The public wouldn't know the truth even about McDonald if not for a Freedom of Information Law (FOIL) request filed by journalist Brandon Smith. We also wouldn't know that Van Dyke had over 20 abuse complaints in his past, were it not for the Citizens Police Data Project (CPDP), which is undertaken by a group called the Invisible Institute in conjunction with the Chicago Law School's Mandel Legal Aid clinic. The group used FOIL and litigation to obtain information about abuse complaints of thousands of officers.

But Chicago is the exception, while New York is closer to the rule. In the Garner case specifically, similar efforts have been undertaken to dig up the dirt, but this city has been more successful in keeping it hidden.

Emanuel’s taskforce wouldn’t be the first time the creation of a new agency or group has been offered as the bandage on Chicago’s police problems. The Independent Police Review Authority, which currently investigates and suggests action on police shootings and other misconduct, was created in 2007 to take over misconduct reviewsfor the Office for Professional Standards, an internal agency deemed largely ineffective by critics.

But the birth of IPRA failed to create the promised sea change in accountability and the Laquan McDonald shooting is seen as only the latest iteration of its failure. The agency sustains complaints against police officers at around 3% and has only twice recommended an officer involved in a shooting be fired – despite Chicago police having fatally shot 70 people over a five-year span, topping departments in the largest US cities. More broadly, in terms of concrete criminal charges, the police officer accused of killing Laquan was the first officer in 35 years to be charged with first-degree murder.

Two figures instrumental in fighting for sunlight in the Laquan McDonald shooting, Craig Futterman of the University of Chicago Law School and Jamie Kalven of the Invisible Institute, wrote last December about an alarming pattern in Chicago … They went on to explain that “in Kalven v. Chicago, the Illinois Appellate Court held that documents bearing on allegations of police abuse are public information,” and that the Emanuel administration adopted a new transparency policy as a result—but that the Kalven decision “is limited to closed police misconduct cases; it doesn’t cover ongoing investigations,” even though public interest in police-killing investigations “is far more intense at the time of the shooting than one or two years later when the case is closed and public attention has turned elsewhere.”

t is shameful that it took a court ruling to prompt Emanuel to be honest with the public about closed cases and doubly shameful that it took another lawsuit to force this week’s release. How much better would Chicago’s police department be if the resources spent fighting to hide bad behavior had been spent on making it less frequent?

In the graphic video seen across the country Tuesday, Chicago police officer Jason Van Dyke levels his gun toward Laquan McDonald, an African American teen carrying a knife and veering away from the officer. Van Dyke shoots. McDonald spins, then falls to the ground as Van Dyke continues to fire every bullet in his clip — 16 shots in all.

The officer was charged Tuesday with first degree murder in the Oct. 20, 2014, shooting, which prosecutors say was an “improper use of deadly force.” That night protesters in Chicago streamed through downtown toward police department headquarters, chanting “16 shots.”

Van Dyke, a white 14-year veteran of Chicago’s police force, has been accused of misconduct 17 times before, according to data from the University of Chicago and the journalism non-profit Invisible Institute. The database, published less than a week before the announcement that Van Dyke would be prosecuted, details tens of thousands of complaints against Chicago police officers that weren’t previously made public. Fewer than five percent of the allegations resulted in disciplinary actions for the officers; none of the 18 complaints against Van Dyke led to a penalty.

Despite the fact that McDonald’s family did not file a lawsuit, the city paid them $5 million in April and fought to conceal the video, even after The Wall Street Journal, the Chicago Tribune and a freelance journalist all filedFOIA requests for its release. Van Dyke remains on paid desk duty as the shooting is investigated by the FBI and the United States Attorney’s Office in Chicago.

For more, we are joined by Jamie Kalven, founder of the Invisible Institute, a nonprofit journalism outlet that recently released tens of thousands of pages of civilian complaints filed against the Chicago Police Department—97 percent of which resulted in absolutely no disciplinary action. Kalven is also the freelance journalist who uncovered Laquan McDonald’s autopsy report.

But data recently obtained by the Citizens Police Data Project show that there are quite a few bad officers in the Chicago Police Department, many of whom have exhibited patterns of misconduct without punishment. University of Chicago Law School professor Craig Futterman and the Invisible Institute, a journalism nonprofit, has published visualizations of the Chicago police misconduct data, including a set that names police officers who’ve been the subject of complaints, how many complaints each has received, and how often they’ve been disciplined.

The biggest takeaway is that it appears from the data that Chicago cops are rarely punished, even when found culpable for the misconduct they’re accused of. Van Dyke was the subject of 17 citizen complaints in the years before he killed McDonald, though he was not penalized for any of them. The data profile below, also from Futterman’s project, shows another police officer, Raymond Piwincki, who’s had 68 complaints filed against him, but has only been penalized twice.

A massive database of complaints against Chicago police has been published. With 55,000 rows of data it provides an unprecedented and historic look into how the City of Chicago polices its communities and its officers. The city fought long and hard to keep the information secret.

The legal battle over the complaints started in the 1990s when Jamie Kalven, a quixotic journalist, writer and social worker, started spending time in Stateway Gardens. Kalven had an unofficial office in a ground floor apartment in the building. Now, Kalven looks at the new buildings and a park with a curving walking path and long prairie grasses. 

“This is not the community I worked in,” he says. “I wish it well but it’s something else.”