MILAN, ITALY - MAY 23:  A sign is displayed in memory of magristrates Giovanni Falcone and Paolo Borsellino on the 20th Anniversary of Capaci Mafia attack on May 23, 2012 in Milan, Italy.  The Capaci Mafia attack, a revenge attack carried out in the wake of Maxi Trial, claimed the lives of magistrates Giovanni Falcone and Paolo Borsellino. A half-ton bomb, placed under the motorway between Palermo International Airport and the city of Palermo by the Sicilian Mafia, also killed Falcone's wife Francesca Morvillo and body guards Rocco Dicillo, Antonio Montinaro and Vito Schifani. (Photo by Pier Marco Tacca/Getty Images)