In 1978, he was appointed Chief Prosecutor of Palermo. His arrival was not welcomed by everyone. Within the judicial environment, he was labeled as a “political prosecutor,” and his appointment was delayed. From the very beginning, he understood that he would be working in a hostile environment, not only outside but also within the institutions. Despite this, he moved forward. During his time in Palermo, he launched highly sensitive investigations aimed at uncovering the financial networks of the Mafia. He secretly entrusted the Guardia di Finanza with deep investigations into economic and business interests connected to powerful figures like Rosario Spatola.

To avoid leaks, he and Rocco Chinnici would meet inside an elevator, stopped midway, to speak without being overheard. It was a sign of the climate in which they were operating: a battle not only against the Mafia, but against silence and resistance. The pressure around him grew. Officers involved in the investigations were threatened and transferred. Obstacles appeared from different directions. Yet Costa continued, maintaining a clear and uncompromising position.

| He knew he was alone — but he also knew that stepping back would have meant surrendering the State itself.

At a certain point, he made a decision that would seal his fate. Faced with arrest warrants against members of the Spatola clan, when other magistrates refused to sign them, Costa signed them himself. It was an act of responsibility, but also one of isolation. From that moment, he became an exposed target. On August 6, 1980, in the early evening, he was walking alone near his home in Palermo. He stopped at a street bookstall, flipping through books. It was a simple, ordinary moment. Then, from behind, two killers approached and shot him multiple times.

He died on the pavement, alone.

Despite the importance of his role, his funeral was attended by few people, and even fewer magistrates. It was a silence that spoke louder than any words. For years, no one was definitively held responsible for his murder. Investigations and trials failed to deliver full justice, leaving behind a sense of unresolved truth. His death was linked not only to his investigations, but also to a broader and more complex environment, where Mafia, business, and power intersected. Many tried to forget him. But his story did not end there.

His work was carried forward by figures like Giovanni Falcone and Rocco Chinnici, who understood the importance of his investigations and continued along that path. The case he had worked on would later become one of the first major successes in the fight against Mafia drug trafficking.

Gaetano Costa was not a man of speeches or public recognition.

He was a magistrate who chose to act, even when it meant standing completely alone.