The foreign casualties in Somalia included Bilal al-Berjawi and Mohamed Sakr, members of a close-knit circle to which Emwazi belonged while growing up in north-west London.
The three men knew Habib Ghani, the partner of Samantha Lewthwaite, the so-called "White Widow" of one of the 7/7 London bombers, along with Omar Hammami, an American jihadist. Emwazi was also an associate of Ali Adorus, now in prison in Ethiopia, whose family still lives in north London.
The men's deaths were accompanied by claims in Islamist circles of vicious internal strife within al-Shabaab, with enemies being eliminated in collusion with Western intelligence services.
The so-called "London Boys" raised funds and disseminated propaganda for al-Shabaab; six of them underwent military training in Somalia as early as 2006. One of them was involved with a cell which attempted to carry out bombings in London in 2005, two weeks before the suicide bombing by Lewthwaite's husband, Germaine Lindsay.
Emwazi had repeatedly claimed he was being hounded by MI5, which he said was trying to recruit him, after a thwarted attempt to reach Somalia alongside Adorus, a former security guard, five years ago. He had become convinced that al-Shabaab had been infiltrated by Western intelligence agencies.
"He told me that he tried to warn some of them, but it was too late," recalled Ayman, a 29-year-old Syrian who asked that only his first name be used. "His view was that if they [the intelligence agencies] could not prevent people from going to Somalia, they had them killed there instead. He was full of suspicion about spies. It was his ambition to go to help al-Shabaab, but he couldn't, so he was frustrated."
Sitting at a cafe in a town across the Turkish border, Ayman described his encounter with Emwazi at Manbij in northern Syria. They met in spring last year just after Isis had taken over the town from Jabhat al-Nusra, an al-Qaeda affiliate, in the first stages of a vicious struggle between the two hardline groups - both of which were fighting the Syrian regime of Bashar al-Assad.
Ayman, a slim man with restless eyes, insisted that he just carried out "some office jobs" in Manbij while al-Nusra and Isis took control and was never a member of either group. He fled to Turkey, he said, as soon as he could after ensuring that his family got to safety. "We had to work, otherwise Nusra and Daesh (Isis) would accuse us of being sympathetic to Bashar".
Ayman could not explain why Emwazi should choose to confide in him. "We knew some people in common. The first time I saw him he was with some foreigners - Chechens, Tunisians, Yemenis - hanging around. I thought he was a Yemeni. It was only after speaking to him that I realised he was from England. I never knew his family name, some called him al-Brittani like the other British here.
"He wasn't a commander, no one famous, and I only remember the conversation because it was an important time in our war, with Daesh (Isis) fighting Nusra. But this man, he wanted to talk about Somalia: it was big on his mind and he was following news from there when he could."
Ayman added: "Mohammed was not seen much in public in Raqaa [Isis 'capital' in Syria]. We heard that he was really trusted by the Daesh leadership, and he was becoming haughty." He said he did not know Emwazi was to be involved in beheading captives. "It was a shock to us all," he said.
Emwazi's known killing spree began in August 2014 with the decapitation of American photojournalist James Foley. This was followed by videos of similar murders of Steven Sotloff, another American journalist; Peter Kassig, a US soldier who had become an aid worker; and David Haines and Alan Henning, British aid workers. Two Japanese hostages, Haruna Yukawa and Kenji Goto, were also killed, as was a group of Syrian soldiers.
Previous testimony gave a brief glimpse of Emwazi's focus on Somalia even after he had joined Isis. A former hostage told The Washington Post newspaper that the man known as "Jihadi John" was obsessed by al-Shabaab and forced captives to watch videos of fighting in Somalia.
Emwazi, Adorus and a German Muslim convert called Marcel Schrödl were sent back to Europe after landing at Dar es Salaam in 2009. Emwazi claimed that an MI5 officer attempted to recruit him at Amsterdam's Schiphol airport on his way back.
Former "London Boys" Berjawi and Sakr were similarly stopped and deported from Kenya on their way to Somalia at around the same time as Emwazi's travels. They managed to get through in a second attempt later that year. Both were subsequently killed in US drone strikes.
In an attempt to counter claims of a "set-up" over these and other deaths, al-Shabaab produced a captured "informant" who confessed to supplying a foreign intelligence service with the information leading to the air strikes.
Lewthwaite's Pakistani-born partner Ghani and the American Hammami were shot dead in a village 200 miles from Mogadishu in 2013. The killings were supposedly carried out on the orders of Ahmed Abdi Godane, who had become the head of al-Shabaab in an internal coup.
Ayman said very little was known about Emwazi inside Syria. "He just appears in these videos, before that he was a no-one. Perhaps the British should be sorry they did not let him go to Somalia, he would probably be dead by now like his friends," he reflected with a smile.
- The Independent
