A day after being charged with a federal felony and resigning as D.C. Council chairman, Kwame R. Brown was accused of violating District laws in his 2008 campaign for an at-large council seat.

The misdemeanor charge, filed in D.C. Superior Court, carries a maximum term of six months in jail. Brown, 41, is expected to plead guilty Friday to that charge and to a count of felony bank fraud in separate appearances in superior and federal court.

The government’s investigation into the former chairman’s finances and campaign started more than a year ago as prosecutors and agents began scrutinizing Brown’s 2008 reelection bid for an at-large council seat. Brown raised nearly $1 million and drew the scrutiny of the D.C. Office of Campaign Finance, which audited the campaign’s books and found that the raising and spending of more than $270,000 had not been reported.

The audit also determined that $239,000 had been passed along to a now-defunct consulting firm run by Brown’s brother Che. The campaign also failed to register a $60,000 bank account that Che Brown controlled, the audit found.

In charging papers filed in D.C. Superior Court, Brown was accused of facilitating an illegal campaign expenditure greater than $50 in cash. Under D.C. law, it is illegal to spend more than $50 in cash on a campaign expense.

Prosecutors wrote that Brown allowed a relative to become a signatory on his campaign account at Industrial Bank. That person opened a second account there, called the “side account,” court papers say. The relative is not identified in court papers, but a city audit shows that the person is Che Brown.

Prosecutors wrote that Kwame Brown knew his brother would be making “individual cash campaign expenditures in excess of $50” from a committee bank account. And on Sept. 11, 2009, prosecutors allege, Che Brown paid a person more than $50 in cash for a campaign expense. The specific amount and the reason for the purchase were not detailed in the document.

Kwame Brown’s attorney, Frederick D. Cooke Jr., declined to comment. Sources familiar with the case said Brown is expected to plead guilty to the misdemeanor Friday, although the former chairman could decide to contest the charge in a bench trial.

A hearing in the misdemeanor case is scheduled for 1:30 p.m. Friday before D.C. Superior Court Judge Juliet J. McKenna.

Che Brown has not been charged with a crime and could not be reached to comment. His attorney, A. Scott Bolden, said he “had no comment whatsoever.”

The investigation into the 2008 campaign is continuing, federal law enforcement officials have said.

As investigators delved into the campaign, they began to probe Brown’s troubled finances; in 2010, he was at least $700,000 in debt. They also examined a series of loans that were secured by a home he bought in 2002 in the Southeast Washington neighborhood of Hillcrest.

Investigators determined that Brown falsified records to obtain loans. In court papers, prosecutors allege that he committed bank fraud by overstating his income by “tens of thousands of dollars” to Industrial Bank in order to obtain a home-equity loan and buy a $50,000 powerboat, named “Bullet Proof.”

Brown was charged Wednesday with bank fraud in a “criminal information,” a document that can be filed only with a defendant’s consent and usually signals that a plea deal has been reached. He is scheduled to attend a plea hearing in that case at 11 a.m. Friday before U.S. District Judge Richard J. Leon.

Shortly after being charged in federal court Wednesday, Brown resigned from office, saying in a letter that he was compelled to step down because “I simply will not hold this body, and its important work hostage to the resolution of my personal indiscretions.”

Sources familiar with the case said Cooke and Brown were presented with prosecutors’ evidence just before Memorial Day and soon began discussions on a potential plea deal. Brown signed the plea document Tuesday, according to a source privy to the negotiations.

The plea deal states that under advisory federal sentencing guidelines, Brown could face up to six months behind bars, although the judge has the authority to exceed that term.

The loan in question appears to have been for $166,200, and it was recorded in October 2005. It was paid back five years later, according to D.C. records. The fact that the loan was repaid may help explain why the guideline sentencing range is relatively lenient, former prosecutors said.

“Bank fraud is an extremely serious felony,” said Thomas Zeno, a former federal prosecutor who is now a lawyer at the firm of Squires Sanders. “Guidelines are mostly driven by the loss, and where the bank loan is repaid, the guidelines give a lower sentence than they would if the bank loan had gone into default and there was loss.”

The charges against Brown have ended, for now, what once seemed a promising political career.

The son of a well-known and sharp-knuckled D.C. political operative, Brown was elected council chairman in 2010 at just 40. Six years earlier, Brown upset a four-term incumbent to win an at-large council seat, becoming the first council member living east of the Anacostia River to be elected citywide.

Although his term as chairman had a rocky start — there was an uproar over his requesting a city-leased, fully loaded sport-utility vehicle — Brown worked hard to project the image of a leader, recently negotiating a 2013 budget that included no new taxes but still managed to fund new parks and set aside $18 million for affordable housing.

Staff writers Keith L. Alexander, Tim Craig and Mike DeBonis contributed to this report.