Vittorio Zambrano was one of the five heads of the Italian Mafia dons in New York City targeted to die by Carl Elias.
Zambrano acted as the liaison between HR and the mafia. He kept a detailed ledger containing the names of HR members and the payments made to them. After his death, his son found the ledger and, being an honest businessman unlike his father, called the FBI. Christopher was murdered before he could turn over Vittorio's ledger, but it was found by John Reese and Maxine Angelis and turned over to the police, minus the pages on Fusco and Simmons. (“Bury the Lede”)