WHEN ASKED several weeks ago whether he had any idea why the mayor might have asked the city's inspector general to audit the HIV/AIDS prevention office where he worked, Michael W. Martin, son-in-law of former Washington Teachers' Union executive assistant Gwendolyn M. Hemphill, said, "I don't have any clue whatsoever." Today, Mr. Martin is probably no longer clueless, inasmuch as federal prosecutors charged him on Wednesday with conspiracy to launder $487,000 in union money through a phony company that he set up and managed. With those charges, which include using a front company to send false invoices to the union, Mr. Martin joins former union chauffeur Leroy Holmes, who was charged in January with unlawfully cashing $1.2 million in union checks and pocketing the money for himself and others.

We have no idea what the inspector general will find in his probe of the D.C. Health Department's HIV/AIDS prevention office, where Mr. Martin once worked as a supervisory programs analyst. But federal prosecutors claim they found that he had used an unspecified amount of union cash to pay for his "home mortgage, credit card bills, car notes, vehicle maintenance, home improvement projects . . . personal trips and lavish parties." When he wasn't allegedly feathering his own nest, the charges suggest, Mr. Martin transported then-union President Barbara A. Bullock and Ms. Hemphill "to engage in spending sprees using WTU funds and credit cards, and would and did make orders of clothing, art and other items for WTU's President's personal use that were unlawfully obtained by using union funds." On top of that, Mr. Martin was also Ms. Bullock's hairdresser and fashion consultant.

Charges against Mr. Martin, as with Mr. Holmes, were contained in a criminal information, a document that, according to Post writer Neely Tucker, can be filed in felony cases only with the defendant's consent. Mr. Holmes subsequently pleaded guilty and agreed to aid prosecutors. Has Mr. Martin agreed to follow suit? And if so, what does that mean for others involved in a case that may involve as much as $5 million in misspent dues? Obviously the investigation cannot stop with Mr. Martin and Mr. Holmes. While many of the items bought with union money reportedly have been recovered by the FBI in raids on the homes of former union officials, a substantial amount of cash is unaccounted for. So there is every reason to expect more to come from the federal prosecutors. And more people making their way to the bar of justice.