Nearly all the traffic cameras in Tehran had been hacked for years. And when the senior Iranian officials came to work near Pasteur Street in Tehran – where Ayatollah Ali Khamenei was killed in a US-Israeli air strike on Saturday – the Israelis were watching, according to a Financial Times report.

One camera had an angle that proved particularly useful, the British daily said, providing Israel a window into the workings of a mundane part of the closely guarded compound.

Complex algorithms added details to dossiers on members of these security guards that included their addresses, hours of duty, routes they took to work and, most importantly, who they were usually assigned to protect and transport – building what intelligence officers call a “pattern of life”, the report detailed.

The effort was a part of a years-long intelligence campaign that helped pave the way for the 86-year-old Ayatollah’s assassination.

Tracking this real-time traffic data was one of the ways Israel and the CIA were able to determine exactly what time the supreme leader would be in his offices on Saturday morning and who would be joining him.

Israeli intelligence detected a meeting at the leadership compound in the heart of Tehran on Saturday morning and the strikes were moved forward, Reuters had earlier reported.

Crucially, the CIA learned that the supreme leader would be at the site.

Israel was also able to disrupt single components of roughly a dozen or so mobile phone towers near Pasteur Street, the report said, making the phones seem as if they were busy when called and stopping Khamenei’s protection detail from receiving possible warnings.

The intelligence picture of the arch-enemy’s capital was the result of laborious data collection, made possible by Israel’s sophisticated signals intelligence Unit 8200, the human assets recruited by its foreign intelligence agency Mossad and the mountains of data digested by military intelligence into daily briefs, the report said.

Israel, the report said, used a mathematical method known as social network analysis to parse billions of data points.

The country’s intelligence superiority was on full display in the 12-day war last June, when more than a dozen Iranian nuclear scientists and high-ranking military officials were assassinated within minutes in an opening salvo.

“We took their eyes first,” the report said, quoting an intelligence official. Both in the June war and now, Israeli pilots have used a specific kind of missile called the Sparrow, variants of which are able to hit a target as small as a dining table from more than 1,000km away – far from Iran and the reach of any of its aerial defence systems, the report elaborated.

Killing Khamenei, only the second supreme leader of the cleric-run state after Ayatollah Ruhollah Khomeini, was a political decision, not simply a technological achievement, the British daily said, which interviewed more than half a dozen current and former Israeli intelligence officials for the story.

Not all of the details of the latest operation are known. Some may never be made public, in order to protect sources.

Khamenei, unlike his ally Hezbollah leader Hassan Nasrallah, did not live in hiding. 

Nasrallah had spent years of his life in underground bunkers, dodging several Israeli assassination attempts until September 2024, when Israeli fighter jets dropped as many as 80 bombs over his hide-out in Beirut, killing him.

Instead, Khamenei, whose image is plastered on billboards in public spaces and his photograph is ubiquitous in shops, had mused in public about the possibility of being killed, dismissing his own life as inconsequential to the fate of the Islamic republic.

When the CIA and Israel determined that Khamenei would be holding a meeting on Saturday morning at his offices near Pasteur Street, the chance to kill him, along with much of Iran’s senior leadership, was real.

They assessed that hunting them down after a war had properly begun, the report said, would have been much harder, since the Iranians would quickly embark on evasive practices, including heading underground to bunkers immune to Israeli bombs.

While Donald Trump had repeatedly threatened to attack Iran in recent weeks, building up an “armada” off its shores, negotiations between the US and Iran over the Islamic republic’s nuclear programme were meant to continue this week.

The mediator Oman said Iran was willing to make concessions that might help stave off a war and described the most recent meeting last Thursday as fruitful.

The attack on Iran had been planned for months but officials adjusted their operation after the US and Israeli intelligence confirmed that Khamenei and his senior officials would be meeting in his compound in Tehran on Saturday morning.

Israeli intelligence had information from signals intelligence, such as the hacked traffic cameras and deeply penetrated mobile phone networks, the report said. The meeting with Khamenei was on schedule, with senior officials heading to the location, the report said.

But the Americans had something even more concrete – a human source, the report said.

The vital information provided a window of opportunity for the two countries to go in for the kill. And they did.

Trump unleashed the attack shortly after midnight in Washington — and daytime in Iran — two days after inconclusive negotiations in Geneva facilitated by Oman.

The US military cleared the path for Israeli fighter jets to bomb Khamenei’s compound by launching cyber attacks “disrupting, degrading and blinding Iran’s ability to see, communicate and respond”, according to General Dan Caine, chair of the US joint chiefs of staff.

“He [Khamenei] was unable to avoid our Intelligence and Highly Sophisticated Tracking Systems and, working closely with Israel, there was not a thing he, or the other leaders that have been killed along with him, could do,” Trump posted on Truth Social.

The Israel Defense Forces (IDF) said approximately 200 fighter jets completed “the largest ever military flyover in the history of the Israeli Air Force”, targeting approximately 500 objectives.

The Iranians were meeting for breakfast when they were killed, Trump told Fox News.

Iranian state television confirmed the news of Khamenei’s death in the early hours of Sunday, broadcasting archive images with a black banner.