The conclusion by the Justice Department that the Baltimore Police Department routinely violated people's civil rights is expected to launch a reform process that is likely to take years and cost tens of millions of dollars.
Dozens of similar reviews around the country suggest a road map for the city.
In some cases, senior police officials have found that the threat of court action has helped prod officers' unions to accept changes and persuade local officials to pay for improvements. But in others, court oversight has continued for a decade or more as departments have struggled to meet the targets laid out by the Justice Department.
Samuel Walker, a professor emeritus of criminal justice at the University of Nebraska, has studied police departments that have been reviewed by the Justice Department. He said the conclusion of the investigation is only a first step.
"It's the beginning of a reform process that hopefully will change how the Baltimore police operate with some new professional standards that hopefully will result in lawful, constitutional policing," Walker said.
City and federal officials now are expected to negotiate a settlement to be presented to a federal judge. That document — it could be a memorandum of understanding or a consent decree — could spell out more than a hundred targets for the police department to meet.
The Justice Department report says the city has reached an "Agreement in Principle" with federal authorities. Vanita Gupta, head of the DOJ Civil Rights Division, said the agreement provides a framework for developing a final consent decree and includes a timeline for the process.
"Because the relationship has been very cooperative, we're anticipating that we will be able to get to an agreement pretty expeditiously," she said.
During the negotiations for the final consent decree, Gupta said her office will talk to local community members and law enforcement officials to get their feedback on what fixes might solve the problems laid bare in the report's findings.
"There's going to be a lot of folks with a lot of ideas about what needs to happen now in the community and in law enforcement, and it's been really important to us to be able to hear directly from community members," she said.
The agreement says officials intend for negotiations to be completed by November. If the talks break down, the Justice Department could sue the city to force changes.
David Harris, a law professor at the University of Pittsburgh who studies policing, said it's typically unwise for cities to battle the Justice Department in court.
"Most jurisdictions are not going to completely push back," he said.
Police in Cleveland entered an agreement with the Justice Department in May 2015. The 110-page document covers improving relations between the police department and the community, how police use force, how officers deal with mentally ill suspects and combating racism.
Typically, an independent monitor is appointed to make sure the department is meeting its targets. The monitor, often an experienced lawyer, is tasked with reporting back to the court.
"They're very important sources of information about what is going on," Walker said.
Cities have found that making changes is not cheap. Cleveland officials estimated that implementing the consent decree will cost $45 million over five years. The Seattle Police Department reported spending $12.8 million in its first two years working to meet the terms of a Justice Department civil rights settlement.
Mayor Stephanie Rawlings-Blake estimated the cost of implementing reforms in Baltimore would be $5 million to $10 million a year.
Senior officials surveyed by the Police Executive Research Forum in 2013 were generally positive about the results of Justice Department reviews of their departments. But some described clashes with their court-appointed monitors and expressed concerns about the cost of implementing changes.
"PERF has been aware for some time that DOJ's role in monitoring local police is a complex, controversial issue," Chuck Wexler, the organization's chief executive wrote.
Baltimore Sun reporter Yvonne Wenger and Kevin Rector contributed to this article.
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