THE FEDERAL probe into the secret “shadow campaign” that helped clinch Mayor Vincent C. Gray’s electoral victory in 2010 has reached the mayor’s inner circle. One of his closest friends and longtime advisers, Vernon Hawkins, described as the field marshal who ran the lavishly funded, off-the-books parallel campaign, pleaded guilty Tuesday to misleading FBI investigators.

Mr. Hawkins has been a top operative for Mr. Gray, a Democrat, for nearly a decade and a kitchen cabinet confidant for longer. In 2010, he directed for the Gray campaign an independent get-out-the-vote effort, allegedly funded by Jeffrey E. Thompson, the moneyman who made millions as a former city government contractor.

In 2011, Mr. Hawkins gave $8,000 to a key campaign worker so he would leave town and remain inaccessible to federal agents who wanted to interview him about the secret campaign. Mr. Hawkins’s guilty plea Tuesday stemmed from lying about it last summer to FBI agents.

Mr. Hawkins said that the cash, which he slipped to the operative in a Southeast grocery store parking lot, had been given to him by Jeanne Clarke Harris. Ms. Harris pleaded guilty last year to funneling money to various local campaigns from an unnamed D.C. businessman thought to be Mr. Thompson.

Is it plausible that Mr. Gray, who for so long has touted himself as a detail-oriented manager, had no idea what one of his closest campaign aides was up to? Is it plausible that he had no grasp that his campaign’s ambitious canvassing operation, under the direction of Mr. Hawkins, was paid for by separate funds that were never declared, as required by law? Is it possible that the mayor, who would have had frequent contact with Mr. Hawkins at his campaign headquarters, was ignorant of what was happening almost under his nose?

In court papers and under questioning in court Tuesday by U.S. District Judge Colleen Kollar- Kotelly, Mr. Hawkins gave no indication that the mayor knew about the scheme that illegally funneled hundreds of thousands of dollars to his campaign. Mr. Gray has denied any wrongdoing.

Nonetheless, U.S. Attorney Ronald C. Machen Jr., the District’s top prosecutor, said Mr. Hawkins’s guilty plea “takes us one step closer to understanding the extent of the deception that tainted the 2010 campaign.”

As usual, Mr. Gray has nothing of substance to say about the investigation that has revealed the rot at the heart of his successful primary challenge to then-Mayor Adrian M. Fenty. As Mr. Hawkins pleaded guilty to lying to cover up wrongdoing on his behalf, the mayor, his longtime friend, would allow only that “it’s unfortunate to have to see something like this.”

What’s really unfortunate is that the mayor of the District of Columbia doesn’t have the spine to level with his constituents about a campaign, and a tawdry chapter in the city’s political history, that Mr. Machen has called “corrupted by a massive infusion of cash that was illegally concealed.”