The most important thing to understand about the problems with the police force in Ferguson, Mo., is that they’re not unique to Ferguson.

An investigation by the Justice Department’s Civil Rights Division, launched after a police officer fatally shot Michael Brown, would be upsetting, infuriating — pick your adjective of outrage — if Ferguson were a one-off.

The 102-page report depicts a department — indeed, an entire city bureaucracy — more focused on raising revenue than protecting public safety. Ferguson used its police force and court system to make ends meet — on the backs of poor and minority residents.

As described in the report, Ferguson police, under pressure to bring in fines to boost the city’s coffers, pile on multiple, often bogus, charges for minor infractions. Then they top that up with additional charges, fines, fees and even jail time for those who fail to pay promptly and in full.

Police see residents, especially African Americans, “less as constituents to be protected than as potential offenders and sources of revenue,” the investigation found.

For example, an African American woman parked her car illegally on a single occasion in 2007, receiving two tickets and a $151 fine, plus fees. Eventually charged with seven “failure to appear” offenses for missing court dates or payments on the fines, she was arrested twice, spent six days in jail and paid $550. As of December, seven years later, she still owed $541.

Forget community policing. This is community fleecing, with an ugly racial element. African Americans are disproportionately at risk for being stopped, searched, cited and arrested. Most disturbing, Ferguson residents are at risk of being jailed not for committing crimes or posing a danger to the community if released before trial but because they can’t pay fines or post bonds on arrest warrants for offenses as minor as traffic tickets.

“There have been many cases,” the Justice report noted, “in which a person has been arrested on a warrant, detained for 72 hours or more, and released owing the same amount as before the arrest was made.” Asked why time in jail is not tracked as part of a case, “a member of court staff told us: it’s only three days anyway.”

Imagine if you were imprisoned for “only three days” over a parking ticket.

Debtors’ prisons are — or are supposed to be — illegal in the United States. In a 1983 case involving an indigent defendant whose probation was revoked after he failed to pay a fine, the Supreme Court ruled that “punishing a person for his poverty” violates the equal protection clause.

Since then, with local budgets under strain and the explosion of the private prison industry, there has been a growing tendency to use the criminal justice system as a revenue-generating tool. As Sarah Stillman detailed in the New Yorker last year, private probation companies have become particularly aggressive in milking offenders with ever-mounting court fines.

“Now, across much of America, what starts as a simple speeding ticket can, if you’re too poor to pay, mushroom into an insurmountable debt, padded by probation fees and, if you don’t appear in court, by warrant fees,” Stillman wrote in the aftermath of Ferguson. “What happens when people fall behind on their payments? Often, police show up at their doorsteps and take them to jail.”

In Montgomery, Ala., a nonprofit legal group called Equal Justice Under Law settled a case challenging the city’s practice of allowing those paying fines to “work” them off with jail time instead — $50 a day, plus $25 daily if they agreed to perform janitorial services.

The group, along with ArchCity Defenders and the St. Louis University School of Law, sued Ferguson and a nearby municipality over their practices. The Justice report says that Ferguson’s “prolonged detentions for those who cannot afford bond . . . raise considerable due process and equal protection concerns.”

Last month, it took the unusual step of filing a “statement of interest” in another lawsuit filed by Equal Justice Under Law against Clanton, Ala., which sets fixed bail amounts for those charged with offenses, regardless of ability to pay.

“The criminal justice system should not work differently for the indigent and the wealthy,” said Vanita Gupta, acting assistant attorney general of the Civil Rights Division.

Except it does — and not only in Ferguson.

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