WASHINGTON » A Justice Department investigation found sweeping patterns of racial bias within the Ferguson, Missouri, police department, with officers routinely discriminating against blacks by using excessive force, issuing petty citations and making baseless traffic stops, according to law enforcement officials familiar with its findings.

The report, which Ferguson city officials said would be released Wednesday, marks the culmination of a months-long investigation into a police department that federal officials have described as troubled and that commanded national attention after one of its officers shot and killed an unarmed black man, 18-year-old Michael Brown, last summer.

It chronicles discriminatory practices across the city’s criminal justice system, detailing problems from initial encounters with patrol officers to treatment in the municipal court and jail. Federal law enforcement officials described its contents on condition of anonymity because they were not authorized to speak publicly before the report is released.

The full report could serve as a roadmap for significant changes by the department, if city officials accept its findings. Past federal investigations of local police departments have encouraged overhauls of fundamental police procedures such as traffic stops and the use of service weapons. The Justice Department maintains the right to sue police departments that resist making changes.

The city of Ferguson released a statement acknowledging that Justice Department officials supplied a copy of the report to the mayor, city manager, police chief and city attorney during a private meeting Tuesday in downtown St. Louis. The statement offered no details about the report, which the city said it was reviewing and would discuss Wednesday after the Justice Department makes it public.

The investigation, which began weeks after Brown’s killing last August, is being released as Attorney General Eric Holder prepares to leave his job following a six-year tenure that focused largely on civil rights. The findings are based on interviews with police leaders and residents, a review of more than 35,000 pages of police records and analysis of data on stops, searches and arrests.

Federal officials found that black motorists from 2012 to 2014 were more than twice as likely as whites to be searched during traffic stops, even though they were 26 percent less likely to be found carrying contraband, according to a summary of the findings.

The review also found that blacks were 68 percent less likely than others to have their cases dismissed by a municipal court judge. And from April to September of last year, 95 percent of people kept at the city jail for more than two days were black, it found.

Of the cases in which the police department documented the use of force, 88 percent involved blacks, and of the 14 dog bites for which racial information is available, all 14 victims were black.

Overall, African-Americans make up 67 percent of the population of Ferguson, about 10 miles north of downtown St. Louis. The police department has been criticized as racially imbalanced and not reflective of the community’s demographic makeup. At the time of the shooting, just three of 53 officers were black, though the mayor has said he’s trying to create a more diverse police force.

Brown’s killing set off weeks of protests and initiated a national dialogue about police officers’ use of force and their relations with minority communities. A separate report to be issued soon is expected to clear Darren Wilson, the officer who shot Brown, of federal civil rights charges. A state grand jury declined to indict Wilson in November, and he resigned from the department.

Benjamin Crump, the attorney for the Brown family, said that if the reports about the findings are true, they "confirm what Michael Brown’s family has believed all along — and that is that the tragic killing of an unarmed 18-year-old black teenager was part of a systemic pattern of inappropriate policing of African-American citizens in the Ferguson community."

The report says there is direct evidence of racial bias among police officers and court workers, and details a criminal justice system that issues citations for petty infractions such as walking in the middle of the street, putting the raising of revenue from fines ahead of public safety. The physical tussle that led to Brown’s death began after Wilson told him and a friend to move from the street to the sidewalk.

The practice hits poor people especially hard, sometimes leading to jail time when they can’t pay, the report says, and has contributed to a cynicism about the police on the part of citizens.

Among the report’s findings was a racially tinged 2008 message in a municipal email account stating that President Barack Obama would not be president for very long because "what black man holds a steady job for four years."

The department has conducted roughly 20 broad civil rights investigations of police departments during Holder’s tenure, including Cleveland, Newark, New Jersey, and Albuquerque, New Mexico. Most such investigations end with police departments agreeing to change their practices.

Several messages seeking comment from Ferguson Police Chief Tom Jackson and Mayor James Knowles III were not returned. A secretary for Jackson said he is not doing media interviews, and Jackson left the police department Tuesday afternoon without comment. Knowles has previously said the city is attracting a large pool of applicants to police jobs, including minority candidates seeking the position left vacant by Wilson’s resignation.

John Gaskin III, a St. Louis community activist, praised the findings, saying, "Ferguson police have to see the light in how they deal with people of color.

"It’s quite evident that change is coming down the pike. This is encouraging," he said. "It’s so unfortunate that Michael Brown had to be killed. But in spite of that, I feel justice is coming."

Associated Press writers Jim Salter and Jim Suhr in St. Louis and Alan Scher Zagier in Ferguson contributed to this report.