Chicago's police routinely used excessive force, tolerated racially discriminatory conduct and often maintained a "code of silence" among officers to thwart investigations into misconduct, according to a blistering report released by the federal government on Friday.
The 161-page document from the US Department of Justice details a 13-month civil rights investigation of the Chicago Police Department.
The probe began in December 2015 after several days of protests following the release of video footage showing Laquan McDonald, a black teenager, being fatally shot by Jason Van Dyke, a white police officer.
"On the basis of this exhaustive review, the Department of Justice has concluded that there is reasonable cause to believe that the Chicago Police Department engages in a pattern or practice of use of excessive force in violation of the Fourth Amendment to the Constitution," US Attorney General Loretta Lynch said at a news conference, flanked by Chicago's mayor and police chief.
The report said use of excessive force by Chicago police included officers shooting at fleeing suspects and use of Tasers on children.
It came the same week that Baltimore agreed with the Department of Justice to change how officers use force and transport prisoners, almost two years after the death of a black man while in police custody sparked a day of rioting.
Justice Department officials have pushed to wrap up ongoing investigations, including the one in Chicago, before President-elect Donald Trump is sworn in on January 20.
Republican Trump touted himself during his campaign as more friendly to law enforcement.
Chicago and federal officials have signed an agreement in principle to create a court-enforced consent decree that addresses the problems found during the probe with compliance reviewed by an independent monitor.
McDonald, 17, was shot in October 2014 but the city did not release the video of the shooting until more than a year later.