A top staffer for Mississippi's only Democratic member of Congress faces charges of tax evasion.

Prosecutors filed a five-count misdemeanor criminal charge against Isaac Lanier Avant Monday in federal court in Alexandria, Virginia.

Avant is chief of staff for U.S. Rep. Bennie Thompson. The congressman didn't immediately respond Tuesday to a request for comment. It's unclear if Avant has a lawyer to speak for him.

An IRS agent says Avant wrongly claimed in May 2005 that he was exempt from federal income taxes and that none was withheld from his paycheck until January 2013.

Avant has been charged, not indicted. Such criminal charges sometimes precede a defendant pleading guilty. Avant is scheduled to appear in court on Sept. 13.

Avant faces up to five years in prison if convicted.