It won't be swift or simple, particularly if the same police chief is in charge and many of the same officers are on the beat. Some residents and civic leaders want to see wholesale changes in leadership or even complete dissolution of the department.
At the very least, experts said Thursday, Ferguson must move quickly, and publicly, to prove it is serious about regaining public trust.
The Justice Department on Wednesday cleared Darren Wilson, the white former Ferguson officer who shot Michael Brown, of federal civil rights charges in the death of the 18-year-old, who was black and unarmed.
But a separate report released simultaneously found patterns of racial profiling, bigotry and profit-driven law enforcement and court practices in the St. Louis County suburb that has come to represent the tension between minorities and American police nationwide. Most of Ferguson's police officers and city leaders are white, but two-thirds of the 21,000 residents are black.
Meanwhile, attorneys for Brown's parents on Thursday announced plans for a wrongful-death lawsuit against the city and Wilson. They did not say specifically when the complaint would be filed. Brown's parents attended the news conference announcing the case but did not speak or take questions.
Attorney Anthony Gray said the lawsuit will offer a "more accurate picture" of the fatal confrontation between Brown and the officer.
"He had other options to him," Gray said of Wilson. "He chose deadly force as his option." Gray called that choice "unreasonable and unnecessary."
The Justice Department found that black drivers were more than twice as likely as others to be searched during routine traffic stops. Minority residents bear the burden of fines and court costs expected to generate $3 million this fiscal year. Black residents were more likely to face excessive force from police, often during unwarranted stops.
Police Chief Tom Jackson, in a reply to a texted interview request, said only, "I'm still looking into this report." Messages seeking comment from Ferguson Mayor James Knowles III and attorneys for Wilson were not returned.
The report also included seven racially tinged emails that did not result in punishment. Knowles said Wednesday that three employees were responsible for those emails. One was fired Wednesday, and the other two are on administrative leave pending an investigation, he said.
The report spurred calls from some for St. Louis County or another municipality to take over the department. Others urged Jackson to resign, or for the city to fire him.
"The chief has no credibility," said state Sen. Maria Chappelle-Nadal, a Democrat who represents Ferguson. "How in the world did the chief of police not know that there was an undercurrent of racism that existed in his police department?"
Other political leaders were more measured in their assessment but still pressed for improvements.
"Facts exposed in the Department of Justice's report on the Ferguson Police Department are deeply disturbing and demonstrate the urgent need for the reforms I have called for, some of which the General Assembly is now considering, including reforms to municipal courts," Gov. Jay Nixon said in a statement.
Criminology experts aren't sure change is possible without new leadership, but they agreed the city must move quickly in response.
"Every hour that goes by without them doing something solidifies in the minds of people in Ferguson and elsewhere that they either don't know what they're doing or that they're dismissive of the DOJ report," said Remy Cross, a criminology and sociology professor at Webster University in suburban St. Louis.
Jens David Ohlin, law professor at the Cornell Law School in Ithaca, New York, said it is vital for Ferguson leaders to embrace the findings, rather than become defensive.
"The smartest thing for them to do is to commit themselves publicly to reforming their policing and judicial practices and tell the community and the rest of the country that they are grateful to the Justice Department, and they are going to make changes as quickly as possible," Ohlin said.
At a brief news conference Wednesday, the mayor tried to show that Ferguson is serious about reform, saying the city has been working for some time to find more black officers. Only four of the current 54 commissioned officers are black.
Ferguson has also empaneled a civilian review board to consider complaints against officers and launched an "Explorer" program in a local school district, aiming to interest young people in law-enforcement careers, the mayor said.
Back in September, the city council passed a law capping municipal court revenues at 15 percent of the overall budget and made changes to ease court cost and fee burdens.
Those efforts weren't enough for the Rev. Al Sharpton, the chief eulogist at Brown's funeral. He said Knowles' remarks were "mostly evasive, insignificant and showed a total failure to address the need for a change in leadership at the police department."