The collective bargaining agreement between the City of Chicago and Lodge No. 7 of the Fraternal Order of Police (FOP) is not an exciting document. Many of its 158 densely worded pages are devoted to topics like insurance subrogation and access to the mailboxes at department headquarters. In 2014, the City Council voted unanimously, 49-0, to approve the current agreement, which runs through June 30, 2017. Until recently, the next set of negotiations promised to play out the same way the last one did, the same way similar ones have, for years, in municipalities big and small, all across the country: quietly, behind closed doors, far from the eyes of the communities most affected by the outcome.

Now, as racial justice activists shine new light on the troubling consequences of police union contracting nationwide, Chicago has its own morbid reasons to scrutinize what has long been a fatally overlooked aspect of a fatally overlooked crisis. Within the pervasive system of corruption, complicity, and negligence that led to Laquan McDonald’s death and then facilitated its cover-up, Chicago’s police officers union has emerged not just as a political impediment to reform, but also as a major institutional foundation underpinning racial injustice.

It was a Chicago FOP spokesman, Pat Camden, who first breathed life into the slander that McDonald, a 17-year-old, lunged at detective Jason Van Dyck before Van Dyck shot him 16 times. The officers who allegedly erased 86 minutes of camera footage from a nearby Burger King that would have exposed this lie were presumably union members, too—as was whoever posted a bail fund for Van Dyck on the FOP’s website.

Investigators attempting to uncover the truth of McDonald’s killing would have had to contend with Section 6.2e of the FOP’s collective bargaining agreement, which allows officers present at the scene of a shooting to postpone their testimony. If the city had elected to share the details of the investigatory findings with the public, rather than spend thousands in taxpayer dollars in defense of their secrecy, Section 6.9 would have prevented officials from revealing Van Dyck’s identity. If Van Dyck somehow manages to remain on the Chicago police force once his trial for first-degree murder has concluded, the record of his paid desk suspension will eventually be expunged, along with the files on his lengthy history of prior misconduct, in accordance with Section 8.4.

Of the 14 other major U.S. cities featured on a new infographic released Wednesday as part of Campaign Zero’s Police Union Contract Project, seven have collective bargaining agreements with similar provisions delaying the interrogation of officers being investigated for use of force and erasing the resulting documentation of abuse. Thirteen have agreements that accomplish one or the other. In Austin, Houston, Louisville, and San Antonio, police union contracts go so far as to require 48-hour notice before an interview with an officer can be conducted, a precaution predicated on the utterly baseless claim that the buffer period helps preserve accurate memory. (Based on the available evidence, it’s more likely that the opposite is the case.) Before Cleveland’s recent settlement with the Justice Department, the personnel files of its police were wiped clean every two years.