The late 1980s and 1990s saw further efforts by the FBI to prosecute Chicago's public crime syndicates. Operation Incubator obtained about a dozen convictions or guilty pleas, including those from five members of the City Council and an aide to former Mayor Harold Washington. Later Operation Gambat brought a wide range of charges against a Chicago judge, a state senator, an alderman, and two others relating to corruption in the Cook County Circuit Court, the Illinois Senate, and the Chicago City Council. Four were convicted and a fifth died during trial. The most extensive operation by the FBI of the 1990s, Operation Silver Shovel, sought to uncover corruption within Chicago labor unions, organized crime, and other city government officials. Operation Silver Shovel resulted in the conviction of 6 Chicago Alderman and a dozen other local officials on a wide range of corruption related charges.