Mr. Brockmeyer, 70, was keeping other Municipal Court positions in St. Louis County: as a judge in Breckenridge Hills and a prosecutor in Vinita Park and Florissant. The St. Louis Post-Dispatch reported that he had also resigned, however, as a prosecutor in Dellwood.

Last week, the Department of Justice issued a scathing report that accused Ferguson officials of using the city’s police and court system to generate revenue, rather than to protect public safety and mete out justice.

Mr. Brockmeyer was among the officials who received particular scrutiny for practices like fixing traffic tickets for colleagues and himself, punishing defendants who challenged him, and instituting new fees, many of which were “widely considered abusive and may be unlawful,” the Justice Department said.

“The Municipal Court does not act as a neutral arbiter of the law or a check on unlawful police conduct,” the department report said. “Instead, the court primarily uses its judicial authority as the means to compel the payment of fines and fees that advance the city’s financial interests.”

Judge Roy L. Richter of the Missouri Court of Appeals will take over Ferguson’s cases, according to a news release from the Missouri Supreme Court, which said it had the authority to take such action under Article 5 of the State Constitution.