65 ILCS 5/10-2.1-25

The municipal attorney, in the event there is a separate attorney designated as a prosecutor for such municipality, shall represent the board unless the board is authorized by the municipality to employ its own attorney, and such attorney shall handle prosecutions before the board, but in the event that the municipal attorney shall both represent the municipality and be prosecutor in such municipality, then and in such event the governing body is hereby authorized to employ an attorney of its own choosing to represent said board.