There was also pressure on Mr. Sisi, who had just signed a contract to exploit a huge offshore gas field with the Italian state-controlled energy giant, Eni. He immediately agreed to a joint investigation into the killing. Weeks later, Egyptian police officers killed four men they accused of abducting Mr. Regeni, but which later appeared to be a bungled cover-up.
As the investigation progressed, some facts pointed to the involvement of Egypt’s security forces in the killing. Egyptian officials admitted that Mr. Regeni was being monitored by Egyptian intelligence weeks before his death. A videotape was produced showing that a union leader who had befriended by Mr. Regeni had secretly filmed one of their meetings.
In recent months, Italian officials have identified nine Egyptian security officials they believe were connected to Mr. Regeni’s death, and sent a 70-page file on them to Egypt. The Egyptians interrogated the suspects, some repeatedly, but there has been no sign of prosecutions.
Handing over the damaged metro footage was delayed as Egyptian and Italian officials debated how to try to recover the erased data.
A German company was hired to try to retrieve it, then let go. The Italians offered to pay, then the Egyptians insisted they would. Finally, in recent weeks, a Russian engineer working alongside a team of Italian policemen retrieved what he could.
In a letter to an Italian newspaper in January, Rome’s chief prosecutor, Giuseppe Pignatone, acknowledged the difficulty of an investigation that he called “one of a kind.” “It hasn’t always been easy to enter into the Arab mind-set,” he wrote.
In Egypt, Mr. Regeni’s case has resulted in a sharp reduction in foreign students coming to do research. “The Regeni case was a turning point for a lot of people,” said Laurie A. Brand, chair of the Committee on Academic Freedom at the Middle East Studies Association. “It made clear that as scholars we didn’t know where the red lines were any more.”