THE LETTERS urging U.S. District Judge John D. Bates to be lenient in sentencing former D.C. Council member Harry Thomas Jr. (D-Ward 5) are replete with examples of how he advocated for seniors, helped young athletes and secured resources for his ward. That the disgraced Mr. Thomas may have done some good deeds in his career gets no argument. But that doesn’t earn him a pass for robbing the city of its money and the public of its trust.

Indeed, as federal prosecutors argued in urging the maximum sentence under Mr. Thomas’s plea agreement, it militates against leniency that he used his elected office to facilitate his shameful scheme to defraud the government.

U.S. Attorney Ronald C. Machen Jr. is seeking 46 months in prison for Mr. Thomas for his theft of more than $350,000 in city funds intended for youth sports programs. Mr. Thomas, the first elected D.C. official to be guilty of a felony, is set to be sentenced Thursday, and his attorneys are asking for a sentence of 18 months. Accompanying the request for a lighter sentence is a letter from Mr. Thomas saying he is “truly sorry” and “taking full responsibility,” as well as testimonials from friends, families, constituents and other supporters. “I know he has committed a crime. But I hope you will consider all the good that he has done,” was a refrain typical of the 92 letters.

Mr. Machen’s blistering court filing anticipated such an argument. It pointed out that it was Mr. Thomas’s job — for which he received a generous salary — to deal with constituents and help his ward. It noted how, throughout Mr. Thomas’s life, his public service was mixed with personal ambitions and financial benefits. It detailed how his participation in local youth events helped facilitate his crimes by providing a veneer of altruism that concealed the thefts. And it highlighted the outrage of Mr. Thomas stealing money for an extravagant lifestyle that included luxury vehicles and exotic shoes (three pairs for $1,374!) while the needs of children in his ward were unmet.

“Thomas breached the public trust by stealing money from the very people he was elected to serve,” Mr. Machen wrote, “Even worse, as Thomas secretly stole money earmarked for youth-enrichment programs, he publicly portrayed himself as a champion of underprivileged children. His corrupt conduct tarnished the reputation of the Council of the District of Columbia and posed a serious distraction to the operations of the city government.”

The only thing Mr. Thomas gets credit for in Mr. Machen’s book is pleading guilty early in the proceedings, thus sparing the government the cost of going to trial. But that’s small change when compared with the price the District and its people have had to pay for Mr. Thomas’s villainy.