Senior Regional Correspondent

Let’s all agree from the start that a bitter, fired employee who’s already admitted filing a false campaign finance report isn’t exactly a witness dripping with credibility.

So the risk that the Sulaimon Brown controversy will mean major legal trouble for Mayor Vincent Gray and two officials from his 2010 campaign probably depends in large part on whether documents, electronic records or other physical evidence support Brown’s account of what happened.

Another key factor is whether the FBI thinks that Gray’s deputies are trustworthy when they are initially questioned and, presumably, repeat their strong denials of Brown’s account.

Technically, there’s no full-scale, official inquiry yet into the incendiary allegations by Brown, a minor candidate for mayor in last year’s race. The U.S. attorney’s office and the Office of Campaign Finance are engaged only in preliminary reviews of Brown’s claims that the Gray campaign secretly promised him a job in exchange for keeping up nasty public attacks on incumbent Adrian Fenty. Brown says the Gray team also slipped him thousands of dollars in cash to support his candidacy.

If a formal criminal probe is launched, however, then the District should prepare itself for a prolonged, ugly scandal. It could distract the new administration from addressing important issues like education reform, unemployment and the budget deficit.

The wish on the mayor’s side is for Brown to say or do something that would quickly discredit him. That’s not completely unrealistic, given the emotional, volatile interviews he’s been giving and his frank acknowledgment that he wants to force Gray from office.

But enough circumstantial material has already emerged backing certain parts of Brown’s allegations that he can’t just be dismissed. Phone records show numerous calls to him from Gray’s campaign chair, Lorraine Green, and consultant Howard Brooks. Brown says he was promised a job, and he got one — though he was fired shortly afterward.

Brown also has claimed that he still has some envelopes in which cash was allegedly passed to him. That raises the possibility that fingerprints or DNA evidence could be sought.

(The Washington Post, which originally reported Brown’s allegations March 6, has not been able to independently verify any payments. Gray has denied Brown’s allegations, as have Green and Brooks.)

The key actor here is U.S. Attorney Ronald Machen, who has the resources to mount a major probe and can bring criminal charges. The Campaign Finance Office has a much smaller staff and only imposes fines for civil infractions, although it can recommend that the U.S. attorney go further.

The activity that Brown described “is certainly sleazy, but whether it’s illegal is another question,” said Joseph diGenova, a former U.S. attorney who prosecuted some of former mayor Marion Barry’s top deputies. “You never know that until you conduct a thorough investigation and you’re able to get people under oath to explain what happened.”

One key question is whether federal investigators find anything in writing to support Brown’s assertion that he had a deal with the Gray campaign. Gray has insisted that there was no “quid pro quo.” The mayor has also said that Brown, like many others, was promised only a job interview, not a job.

That’s significant, because the promise of a job in exchange for campaign activity could violate the District’s corrupt-influence statute, according to lawyers and other specialists. A person convicted under the relevant provision, section 22-704a of the D.C. Code, faces jail time of six months to five years.

“A case could be made if a prosecutor can prove that an individual, with corrupt intent, promised a position in the government as a quid pro quo for something of value in return,” said lawyer Kenneth A. Gross, leader of the political practice at the Skadden law firm.

“In proving such a case, if there’s no ‘smoking gun,’ such as written proof of a quid pro quo, then it becomes a question of credibility of witnesses before a jury,” Gross said.

Investigators are also looking into possible campaign-finance violations. If it was established that money allegedly given to Brown was a kind of campaign expense for the Gray side, then the mayor’s team could be charged with failing to properly report expenditures or with making cash expenditures in excess of $10.

That could lead to civil charges and the payment of fines. If a false report was intentionally filed, then the U.S. attorney could bring criminal charges.

Cynics in the newsroom said Gray must have set some kind of speed record by taking less than 10 weeks to get from his inauguration to a scandal involving the FBI. Sadly, if the fallout sets a record as well, it’s likely to be for longevity rather than brevity.