ST. LOUIS >> In the aftermath of Michael Brown’s death, legal activists suggested that some of the raw anger that erupted in suburban St. Louis had its roots in an unlikely place — traffic court.

It was there, they said, that low-income drivers sometimes saw their lives upended by minor infractions that led to larger problems. If left unpaid, a $75 ticket for driving with expired tags could eventually bring an arrest warrant and even jail time.

So courts began an experimental amnesty program designed to give offenders a second chance by waiving those warrants. But the effort is attracting relatively few participants, despite a renewed emphasis on municipal court reform after Brown’s death last summer in Ferguson.

St. Louis County’s jumble of more than 80 municipal courts has been targeted by some public-interest lawyers who say the courts are virtual debtor’s prisons, extracting fines and fees from poor drivers and using the money to fund local governments, which in some cases serve just a few hundred residents.

“They make people poor, and they keep people poor,” said Thomas Harvey of the nonprofit legal clinic ArchCity Defenders, which is suing Ferguson and six other small cities, alleging they collect illegal municipal court fees.

Missouri’s auditor is reviewing the finances of several such courts statewide, including Ferguson, and some legislators want to limit the amount of money small cities can collect from traffic violations.

Critics of the traffic courts describe prolonged legal nightmares that can begin with tickets for driving with a suspended license or without proof of required inspections, what Harvey called “crimes of poverty.”

Defendants unable to pay those fines or hire an attorney to negotiate a plea deal may then miss their court dates or fail to sign up for installment-payment plans. Judges issue failure-to-appear warrants, which can lead to larger fines and court costs and even jail time on top of the original penalties, not to mention time missed from work or school.

Robert Lamont Douglas, 39, was recently issued five citations in the village of Bel-Ridge for traffic violations that included driving without insurance and failing to register his car.

“The main question was, ‘Am I wanted or do I have drugs in the car,'” Douglas said. “I was singled out because I was black. The assumption is I must have warrants, drugs or guns.”

A 2013 report by the Missouri attorney general’s office found that Ferguson police stopped and arrested black drivers nearly twice as frequently as white motorists but were also less likely to find contraband among black drivers.

The amnesty program in the city of St. Louis allows defendants who face arrest for failing to appear in municipal court to reschedule those hearings without penalty. But it has attracted fewer than 4,000 participants out of 75,000 who are eligible, despite an aggressive outreach campaign.

The story is similar in St. Louis County, where just a few hundred people have opted for an amnesty program that requires a $100 payment to wipe out traffic-court arrest warrants. Both efforts continue through the end of the year.

In Ferguson, the city no longer issues failure-to-appear warrants and is dismissing the charge in pending cases. Elected officials in September voted to cap municipal court revenues at 15 percent of revenue, eliminated a fee for towing cars and forgave warrants for nearly 600 defendants.

Municipal courts in St. Louis and St. Louis County collected nearly half of the $132 million in fines and fees paid statewide, despite the area being home to fewer than 1 in 4 Missourians, according to an October study by the nonprofit group Better Together.

More than $45 million — or 34 percent — of that amount came from the county’s municipal courts, even though their combined population represents just 11 percent of the statewide total.

Fourteen of those cities — including Vinita Terrace, population 277, and Bellerive, population 188 — depend on traffic-court fees and fines as their largest source of revenue, eclipsing sales and property taxes. Each lies in the predominantly black inner suburbs known as North County.

In Calverton Park, a seven-officer police force helped generate $484,000 in fines in the 2013-2014 fiscal year. That’s almost 65 percent of the annual revenue for a city with fewer than 1,300 residents, some 40 percent of whom are black.

Without revenue from fines and fees, the communities could not afford to operate, the study concluded. “The municipal courts in many areas of St Louis have lost the faith of their communities,” it said.

Among the recommended changes to Missouri’s municipal courts is a rule that would limit them to providing 10 percent of the revenue for local government, compared with the current limit of 30 percent — a threshold that is rarely enforced. The Missouri Municipal League says such a limit would bankrupt many of its smaller members.

Vestiges of a court system unaccustomed to outside scrutiny persist.

On Monday, court officials and St. Louis marshals ordered an Associated Press reporter to leave the municipal courthouse during an open court docket, despite state laws that generally allow for public access to legal proceedings with limited exceptions.

Slay spokeswoman Maggie Crane later said the exclusion was a mistake