They are accused of conspiring to submit fraudulent absentee ballots.
Small was trounced in the city's June Democratic primary by incumbent Mayor Lorenzo Langford.
The charges involve use of messenger ballots, a type of absentee ballot designed for those too sick or frail to make it to the polls. Designated messengers pick up the ballots at county election offices, take them to voters and return them to election officials once completed.
A telephone message left for Small was not immediately returned Thursday.