Deaths of Giuseppe Pinelli and Luigi Calabresi

The Piazza Fontana bombing was initially attributed to anarchists. After over 80 arrests were made, suspect Giuseppe Pinelli (born in 1928), an anarchist railway worker, died after falling from the fourth floor window of the police station where he was being held. Serious discrepancies existed in the police account, which initially maintained that Pinelli had committed suicide by leaping from the window during a routine interrogation session. Murder charges against Luigi Calabresi (1937–72), one of the officers on duty at the time, and other police officials were dropped by the prosecutor (giudice istruttore) for lack of evidence; he decided that Pinelli's fall had been caused by loss of consciousness ("malore").

In 1972 Calabresi was murdered by left-wing militants in revenge. Adriano Sofri and Giorgio Pietrostefani, former leaders of the far-left Lotta Continua, were sentenced for organizing, and members Ovidio Bompressi and Leonardo Marino were sentenced for carrying out Calabresi's assassination.

Official investigations and trials

Anarchist Pietro Valpreda was also arrested after a taxi driver identified him as the suspicious-looking client he had taken to the bank that day. After his alibi was judged insufficient, he was held for three years in preventive detention before being sentenced for the crime. Sixteen years later on appeal, he was eventually exonerated after several miscarried trials.

The far-right Neo-fascist organization Ordine Nuovo, founded by Pino Rauti, came under suspicion. On March 3, 1972, Franco Freda, Giovanni Ventura and Rauti were arrested and charged with planning the terrorist attacks of April 25, 1969 at the Trade Fair and Railway Station in Milan, and the August 8 and August 9, 1969 bombings of several trains, followed by the Piazza Fontana bombing. They were acquitted and no one was ever successfully prosecuted.[2]

Several elements brought the investigators to the theory that members of extreme right-wing groups were responsible for the bombings:

• The composition of the bombs used in Piazza Fontana was identical to that of the explosives that Ventura hid in a friend's home a few days after the attacks.
• The timers were traced to a stock of 50 Diehl Junghans timers bought on September 22, 1969 by Franco Freda in a Bologna store. Freda later explained that he bought the timers for Mohamed Selin Hamid, an alleged agent of Algerian secret services (whose existence has been denied by Algerian authorities), for the Palestinian resistance. Israel secret services declared that no timer of that kind has ever been used by Palestinian groups.
• The bags where the bombs were hidden had been bought a couple of days before the attacks in a shop in Padua, the city where Freda lived.

In 1974 the trial was moved from Milan to Catanzaro. On October 4, 1978 the police discovered that Freda had disappeared from his Catanzaro apartment. On February 23, 1979 he was pronounced guilty in absentia for the Piazza Fontana bombing, and the court sentenced him to life imprisonment. On August 23, 1979 Freda was captured in Costa Rica and extradited to Italy, after which several trials followed. He was convicted and sentenced to 15 years of jail for "subversive association" on March 20, 1981, then acquitted on August 1, 1985 for lack of evidence.

In 1989, Stefano Delle Chiaie was arrested in Caracas, Venezuela and extradited to Italy to stand trial for his role in the bombing. He was acquitted by the Assise Court in Catanzaro in 1989, along with fellow suspect Massimiliano Fachini.

In 1998, Milan judge Guido Salvini indicted U.S. Navy officer David Carrett on charges of political and military espionage for his participation in the Piazza Fontana bombing et al. Salvini also opened up a case against Sergio Minetto, an Italian official of the U.S.-NATO intelligence network, and "collaboratore di giustizia" Carlo Di Giglio (Uncle Otto), who served as CIA coordinator in Northeastern Italy in the sixties and seventies. The newspaper La Repubblica reported that Carlo Rocchi, CIA's man in Milan was discovered in 1995 searching for information concerning Operation Gladio.

On June 20, 2001 Italian right wing Ordine Nuovo members Carlo Maria Maggi (a physician), Delfo Zorzi and Giancarlo Rognoni were all convicted, but their convictions were overturned in March 2004. Carlo Di Giglio received immunity from prosecution in exchange for his information.

On May 3, 2005 the last trial ended with no one found guilty of the bombing.

Red Brigades

The Red Brigades conducted its own inquiry into the events. The results of this (and other) inquiries were found in a Red Brigades hideout in Robbiano di Mediglia (Italy) after a firefight with the Italian police (Carabinieri) on October 15, 1974. The records were kept secret until 2000, when the "Commissione Stragi" of the Italian Parliament, investigating terrorism during the presidency of Giovanni Pellegrino, uncovered it.

The Red Brigades concluded that Pinelli had committed suicide because he had been somehow involved in handling the explosive material which was used for the bombing.

Political theories of responsibility for the bombing

A 2000 parliamentary report published by the center-left Olive Tree coalition claimed that "U.S. intelligence agents were informed in advance about several right-wing terrorist bombings, including the December 1969 Piazza Fontana bombing in Milan and the Piazza della Loggia bombing in Brescia five years later, but did nothing to alert the Italian authorities or to prevent the attacks from taking place." It also alleged that Pino Rauti (current leader of the MSI Fiamma-Tricolore party), a journalist and founder of the far-right Ordine Nuovo (New Order) subversive organization, received regular funding from a press officer at the U.S. embassy in Rome. "So even before the 'stabilising' plans that Atlantic circles had prepared for Italy became operational through the bombings, one of the leading members of the subversive right was literally in the pay of the American embassy in Rome", the report says.

Paolo Emilio Taviani, the Christian Democrat co-founder of Gladio (NATO's stay-behind anti-Communist organization in Italy), told investigators that the SID military intelligence service was about to send a senior officer from Rome to Milan to prevent the bombing, but decided to send a different officer from Padua in order to put the blame on left-wing anarchists. Taviani also alleged in an August 2000 interview to Il Secolo XIX newspaper: "It seems to me certain, however, that agents of the CIA were among those who supplied the materials and who muddied the waters of the investigation."