Born at Misilmeri, Chinnici graduated in law at the University of Palermo in 1947 and started working as a magistrate in 1952 in Trapani.

In November 1979, he became head of the Examining Office at the Palermo Court, following the murder of his predecessor, Cesare Terranova, by the Mafia.

Chinnici created the Antimafia Pool, a group of investigating magistrates who closely worked together sharing information to diffuse responsibility and to prevent one person from becoming the sole institutional memory and solitary target.

He frequently spoke out against the Mafia in public appearances and schools at a time when judges had avoided the word for many years.

[1] On 29 July 1983, a car bomb explosion in Palermo killed Chinnici, two of his bodyguards, Mario Trapassi and Salvatore Bartolotta, and the concierge of his apartment block, Stefano Li Sacchi, as he left the house to go to work.