ATLANTA — In her courtroom in Brunswick, Ga., Judge Amanda F. Williams told lawyers to “sit down and shut up.” She once jailed a defendant for using the words “baby momma.” And she detained offenders “indefinitely” without access to lawyers, state judicial investigators say.

But on Monday, Judge Williams, the chief judge of the Superior Court of the Brunswick Judicial Circuit — a powerful, controversial figure who gained national exposure when the public radio program “This American Life” devoted an hourlong episode to her — announced that she was leaving the bench after 21 years.

Judge Williams, 64, who said she would resign on Jan. 2., faced wide-ranging misconduct accusations. She vowed not to seek another judgeship, and, as a result, those complaints will be dropped, the Georgia Judicial Qualifications Commission said. She could still face criminal charges related to her conduct.

She was first elected in 1990 to the court, which handles cases in five southeast Georgia counties. For more than a decade, she also ran the state’s largest drug court.