Puzo had been covering the Bonanno and first Colombo war as a journalist, and turned what stories he heard or his investigation revealed about the Italian criminals, and put them as characters in his book. Luca Brasi was based off Gaspario Magaddino, AL Neri was based off a former NYPD cop who became a driver and bodyguard to a Capo in the Genovese crime family after Appalachian.