THERE ARE questions still to be answered about the federal government’s investigation of former D.C. Council chairman Kwame R. Brown (D). But whether U.S. Attorney Ronald C. Machen Jr. made the right call in requiring Mr. Brown to resign as part of the plea agreement for bank fraud and violation of city campaign finance laws is not one of them. Someone who would lie and forge documents for personal benefit — as Mr. Brown knowingly and willfully did — should not be making decisions about billions of dollars of taxpayer money.

“How would you feel if we had left him in office and a greater fraud was perpetuated?” Mr. Machen asked, when challenged at a news conference Friday about insisting that the council chairman resign. Bank fraud is a felony, punishable by up to 30 years in prison, precisely because it’s a crime that goes to the heart and stability of our financial institutions.

Those who would argue that Mr. Brown’s actions were commonplace should read prosecutors’ descriptions of the elaborate fictions he created to get a $166,000 home equity loan in 2005: forging a friend’s name on a verification of employment, fabricating a job as “vice president of strategy,” lying about earning $3,000 a month and the mythical promise of an even bigger pay raise. Deception worked so well that two years later, to get $55,335 for a powerboat, Mr. Brown altered a government tax form, changing the “3” to an “8,” so that it appeared that he earned $85,000. No, “everyone” doesn’t engage in this kind of deceit. Besides, shouldn’t we expect more from our public officials?

Mr. Machen explained how the fraud was uncovered during an investigation into irregularities in Mr. Brown’s 2008 at-large reelection campaign. Federal prosecutors were called in by the D.C. Office of Campaign Finance — at the express request of Mr. Brown’s own lawyer — so it’s hard to argue that Mr. Brown was unfairly targeted.

What is unsatisfying about the investigation is its failure to get to the bottom of the financial irregularities in Mr. Brown’s campaign finances in the 2008 election, in which he was essentially unopposed. He pleaded guilty to aiding and abetting an unlawful cash campaign expenditure, in excess of the $50 limit on individual cash transactions.

But officials provided few details about other, more serious, shortcomings uncovered by the Office of Campaign Finance. What happened to hundreds of thousands of dollars funneled to a now-defunct company run by his brother that are still unaccounted for.? Who got this money, and what was it used for? Mr. Machen said there is no evidence that Mr. Brown stole campaign funds. The investigation is continuing, and the Office of Campaign Finance has the ability to assess fines for the violations it cited. Mr. Brown’s guilty plea solves the immediate problem of his continued service in public office, but it can’t be the end of the story.