Question: Who was the first Mafia boss to turn informant ("pentito") and explain the inner workings of the organisation, who told  that Geraci took care of the fugitive Riina while he stayed in Partinico?
Sentence (from "Nenè Geraci"): Antonio Geraci (Partinico, January 2, 1917 – Partinico, February 6, 2007), better known as Nenè or "il vecchio" (the old one), is the historical boss of the Mafia in Partinico, in the province of Palermo.
Relevant evidence: No