A D.C. Superior Court judge has ordered a Washington woman to pay the city $400 after the Public Defender Service incorrectly gave her son free legal counsel.

Judge Peter H. Wolf called the judgment of the public defender supervisor who granted free counsel to a youth whose mother had a $15,854 yearly income "careless, erroneous, incomplete and insufficiently skeptical."

The woman's 16-year-old son was arrested May 5, his ninth arrest since 1976. He had always been represented by the Public Defender Service and asked to keep that attorney although his mother had hired a private attorney for him, according to Judge Wolf. The opinion contains no names because the case involves a juvenile offender.

The Corporation Counsel, the city government's lawyer, asked for a hearing on the woman's finances to determine whether her son was eligible for the free legal advice, the judge wrote.

"Despite the court's distaste for subjecting [the woman's] finances to the scrutiny of a contested hearing, it is crucially important to make optimum use of a Public Defender Service that limits its intake and to protect severely limited [Public Defender Service] funds," Wolf wrote.

The hearing revealed several errors by the Public Defender Service supervisor, according to Wolf.

The supervisor deducted monthly expenses for an individual and two dependents rather than an individual and one dependent, an error of $128 a month. "This was pure carelessness of a misunderstanding of [deductions] table," the opinion said.

The supervisor incorrectly computed the woman's monthly income to be $614. The correct figure was $851, the opinion said. The woman was given four months to repay the city.