The indictment also charges Martin, a candidate for City Council, with giving alcohol to someone under 21, the legal drinking age in Georgia.
Stewart defeated former council member Cyndi Parham and is scheduled to be sworn into office at 6 p.m. Thursday.
The Richmond County elections board certified the vote count Saturday, although Parham had requested a recount.
"I was completely shocked," Parham told an Augusta television station. "I found out within five minutes that the polls closed that there was an investigation and I just couldn't believe it."
Parham resigned her council position to run for mayor. Martin intends to run for the seat in a May 22 special election.
Blythe is about 145 miles east of downtown Atlanta.
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