On written request, a correctional officer may have expunged from any file the record of a formal complaint made against the correctional officer if: the internal investigation unit that investigated the complaint: exonerated the correctional officer of all charges in the complaint; or determined that the charges were unsustained or unfounded; or a hearing board acquitted the correctional officer, dismissed the action, or made a finding of not guilty; and at least 3 years have passed since the final disposition by the correctional facility or hearing board.