Israel says it killed the Hamas mastermind behind October 7. Here’s what we know

More than a year after Hamas’ devastating October 7 attacks on Israel, the country’s military said Thursday it had killed the man it considers to have been the chief architect of that cross-border massacre – raising questions about the future of the war and of the militant group itself, which has faced blow after blow in recent months.

The death of Hamas leader Yahya Sinwar could pose a rare opportunity to strike a ceasefire, US officials say – with Israel having killed several other top Hamas commanders including Ismail Haniyeh, the group’s former political leader, as well as leaders of militant group Hezbollah in Lebanon.

Hamas and Hezbollah are both part of an axis of militant groups backed by Iran.

But both sides in the Gaza conflict have indicated fighting will continue. In a recorded video message Thursday, Israeli Prime Minister Benjamin Netanyahu said Sinwar’s death marked “the beginning of the day after Hamas,” but “the task before us is not yet complete.”

Hamas confirmed Sinwar’s death, but a senior official, Khalil Al Hayya, said the group would not release Israeli hostages until “aggression on our people in Gaza stops,”

Here’s what you need to know.

After the October 7 attacks, Israel poured resources into a fierce manhunt for Sinwar, declaring him the most-wanted man in Gaza and a “dead man walking.” At one point, an Israeli military spokesperson said their hunt would “not stop until he is captured, dead or alive.”

US officials believed the Israeli military got close a few times, at one point even obtaining a video that purportedly showed Sinwar with several family members inside a Gaza tunnel – but he continued slipping away. The Israeli military previously surrounded Sinwar’s house and carried out an intensive assault on his hometown of Khan Younis in central Gaza, but could not find him.

That year-long search finally came to an unexpected end on Wednesday in Rafah, southern Gaza. Israeli forces had been in the area during a routine military operation when they came under fire near a building, according to two Israeli sources familiar with the matter.

The troops returned fire with a tank, then flew a drone into the heavily damaged building, according to the Israeli military. The video, shared by the military, shows what seem to be Sinwar’s final moments: he sits alone in a chair, surrounded by dust and rubble, appearing to look directly at the camera. He holds a piece of wood in his hand, and throws it at the drone before the video ends.

It was only then, and when troops inspected the rubble, that they realized Sinwar was among the bodies, according to the Israeli military.

When Israeli forces found a body resembling Sinwar’s on Wednesday, his finger was cut off and sent for DNA testing in order to identify him, the pathologist who examined him in Israel told CNN on Friday.

“After the laboratory made the profile, we compared it with the profile that Sinwar had in the term that he was serving here as a prisoner, so then we could identify him finally by his DNA,” Chen Kugel, chief pathologist at Israel National Center of Forensic Medicine in Tel Aviv said.

Sinwar spent more than two decades in Israeli prisons before he was released in 2011 as part of a prisoner swap for an Israeli soldier.

On Saturday, Israel released new video footage it says shows Sinwar underground in Hamas tunnels “just hours before the October 7 massacre.”

Talking over the images of what the IDF says are Sinwar and his children, Israeli military spokesperson Daniel Hagari said that the Hamas leader was hiding alone with his family all night in tunnels below Khan Younis and that the footage showed he had “prioritized himself” over the people of Gaza.

Hamas rejected Israel’s portrayal of Sinwar in his final year, accusing the IDF of “blatant lies” and “a failed theatrical performance.” The group said Sinwar was killed while “engaging in the battlefield” after having spent the past year “moving across various combat fronts in the Gaza Strip, at the forefront of our brave people’s resistance.”

Sinwar had been trying to escape to the north when he was killed, said another Israeli military spokesperson on Thursday. He was found with a gun and more than $10,000 in Israeli shekels, the spokesperson said.

Sinwar had long been a key player in Hamas, joining the militant group in the late 1980s and quickly rising through the ranks.

He was born in a refugee camp in Gaza, after his family was displaced from the Palestinian village of Al-Majdal – now part of the Israeli city Ashkelon – during the Arab-Israeli war.

As a student, Sinwar became an anti-occupation activist, but he was imprisoned in Israel on several life sentences after being accused of orchestrating murder. He served 23 years before being released as part of a prisoner swap in 2011.

Sinwar returned to Gaza and quickly established his name in Hamas. He founded the group’s feared international intelligence security branch, the Majd, and was known for employing brutal violence against anyone suspected of collaborating with Israel.

He was also viewed as a pragmatic political leader by some: In 2017, Hamas elected Sinwar as the political chief of the Politburo, its main decision-making body in Gaza.

Sinwar was designated a global terrorist by the US Department of State and the European Union in 2015, and was sanctioned by the United Kingdom and France in recent years.

But he rose to greater prominence after the October 7 attacks as one of Israel’s key targets. Israeli officials have called him the “face of evil” and “the butcher from Khan Younis.”

He became one of Hamas’ most senior leaders in August after Ismail Haniyeh was assassinated in Iran. Sinwar had not been seen since the October 7 attacks, likely surviving Israel’s siege of Gaza by hiding in a vast network of underground tunnels.

Israel has publicly accused Sinwar of being the “mastermind” behind Hamas’ October 7 attack – though experts say he was likely one of several.

The attack was the deadliest assault on Israel in its history. Hamas and other Palestinian armed groups killed more than 1,200 people, mostly civilians, and took about 250 people into Gaza as hostages.

Sinwar was considered a vital decision-maker and likely the outside world’s main point of contact in Gaza during the intense negotiations over the hostages’ return.

The talks involved senior figures from Israel, Hamas, the United States, Qatar and Egypt.

While it’s too soon to say what may happen next or how Hamas may respond, Sinwar’s killing marks the latest blow to the group – which has seen several top leaders picked off one by one during Israel’s campaign to dismantle Hamas entirely.

Only a day after Haniyeh’s assassination, Israel confirmed it had killed Hamas’ military chief Mohammed Deif during a previous strike – another one of the reported masterminds behind October 7.

With negotiations on a ceasefire and hostage release deal to pause the war stubbornly stuck for months, senior US officials had clung to the hope that Sinwar might one day be taken out – opening a pathway to a resolution. With him now gone, officials speculate this could be one of the best chances of bringing the Israel-Hamas war to an end, but are reluctant to make any predictions about what that will ultimately mean for the volatile region.

Sinwar’s remains are currently being held in a secret location in Israel, according to local media reports. His body could be used as a “bargaining chip” in exchange for the release of Israeli hostages being held in Gaza, Israeli sources told CNN.

US President Joe Biden spoke with Netanyahu on a call Thursday, where “both leaders agreed that there is an opportunity to advance the release of the hostages and that they would work together to achieve this objective,” the prime minister’s office said in a readout.

UK Prime Minister Keir Starmer spoke with Netanyahu on Saturday, and told him that Sinwar’s death was an opportunity to stop the fighting in Gaza and get the hostages out, according to a Downing Street spokesperson.

But much remains unknown – including the fate of Sinwar’s brother.

Mohammed Sinwar recently took over as Hamas’ military commander, a senior Israeli official told CNN last month. The brothers were very close, and as recently as late August were often still together, the same official told CNN.

If Mohammed survived this week, he will likely continue his brother’s hardline negotiating tactics as Israel seeks to extract its remaining hostages from the Palestinian enclave. But until a clear picture emerges, it will be hard to know the militant group’s next move.

And even with Sinwar’s death, the wider Middle East conflict rages on – particularly as Israel prepares to retaliate against Iran’s ballistic missile attack earlier this month. CNN has previously reported that move was expected to come before the US election next month.

And another front of the conflict is ramping up across the Israel-Lebanon border, with Hezbollah announcing a “new and escalating phase” in its war with Israel on Thursday.

Hezbollah, too, has suffered significant losses in recent months – from the deadly pager and walkie-talkie attacks that killed dozens and injured thousands, many of them civilians, to the assassinations of several high-ranking commanders including their chief Hassan Nasrallah last month.

Meanwhile in Gaza, Palestinians told CNN they do not believe Sinwar’s killing will end the war – though some voiced tentative hope.

“Sinwar has died, but so many of our people have been killed, and there is no excuse now for Netanyahu to continue the war,” said 22-year-old Mumen Khalili.

CNN’s Abeer Salman, Ivana Kottasova, Mostafa Salem, Ibrahim Dahman, Kara Fox, Mathew Chance, Mia Alberti, Dana Karni, Pauline Lockwood, Sophie Tanno, Kevin Liptak, MJ Lee, Kylie Atwood, Alex Marquardt, Katie Polglase, Pallabi Munsi, Gianluca Mezzofiore, Eyad Kourdi, Jeremy Diamond and Zeena Saifi contributed reporting.