Before he was NYC mayor, he was the U.S. attorney who prosecuted the mafia in the "pizza connection" case
In addition to 
the "Commission" case, where the heads of New York's five Mafia... [DOC] [TLE] Giuliani to Quit, Hints at Run for N.Y. Mayor : High-Profile U.S. ... [PAR] Jan 11, 1989 ... U.S. Atty.