CHICAGO (Reuters) - Chicago police routinely violated the civil rights of people in one of America’s largest cities, the U.S. Justice Department said in a report released on Friday, citing excessive force, racially discriminatory conduct and a “code of silence” to thwart investigations into police misconduct.

A Chicago police officer attends a news conference announcing the department's plan to hire nearly 1,000 new police officers in Chicago, Illinois, U.S., September 21, 2016. REUTERS/Jim Young

The report said excessive force falls “heaviest on black and Latino communities,” with police using force almost 10 times more often against blacks than whites.

The Justice Department began a civil rights investigation in December 2015 after the release under court order of a video showing the Oct. 20, 2014, shooting of Laquan McDonald, a black teenager, by white officer Jason Van Dyke. The video was released more than a year after the shooting.

The video sparked several days of protests and led to the ouster of Chicago’s police chief and calls for Mayor Rahm Emanuel to resign.

The McDonald shooting was one of many high-profile incidents that thrust Chicago and other U.S. cities into a national debate over the use of excessive by police against minorities.

“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,” U.S. Attorney General Loretta Lynch told a news conference.

The 161-page report said use of excessive force by Chicago police included officers shooting at fleeing suspects and using Tasers on children.

Earlier this week Baltimore agreed with the Justice Department to change how officers use force and transport prisoners, almost two years after the death of a black man while in police custody.

Chicago and federal officials have signed an agreement in principle to create a court-enforced consent decree addressing the issues revealed by the probe. Chicago’s compliance with the decree would be reviewed by an independent monitor.

The consent decree must be negotiated, then approved by a federal judge.

Emanuel’s decision to sign the agreement was reached too quickly, Chicago police union president Dean Angelo, Sr. said in a telephone interview.

Angelo said that he had not read the entire report, but agreed with findings about a lack of training and equipment for officers.

The Justice Department completed the review as confirmation hearings were underway for positions in President-elect Donald Trump’s administration, including his nominee for U.S. Attorney General, Jeff Sessions.

“We need to be sure that when we criticize law officers it is narrowly focused on the right basis of criticism,” Sessions said during Tuesday’s hearing. “To smear whole departments places officers at greater risk, and we are seeing an increase in the murder of law officers up 10 percent last year.”

President Barack Obama’s administration opened 25 civil rights investigations into law enforcement agencies as part of efforts to re-examine and improve police practices in the United States, particularly in minority communities.

“Some of the findings in the report are difficult to read,” Police Superintendent Eddie Johnson said at the news conference. “Quite simply, as a department, we need to do better.”

Many of the Chicago police department’s problems stemmed from deficient training and accountability, Lynch said.

Investigations into police misconduct were often thwarted by “a code of silence among Chicago police officers ... extending to lying and affirmative efforts to conceal evidence,” the report said.

The report also found “profoundly low morale” among many members of the department.

Chicago’s mayor, Emanuel, enacted a number of police reforms over the past year, including a body-camera program and a new use of force policy, efforts that were recognized by Lynch.