But his real name, according to friends and others familiar with his case, is Mohammed Emwazi, a Briton from a well-to-do family who grew up in West London and graduated from college with a degree in computer programming. He is believed to have traveled to Syria around 2012 and to have later joined the Islamic State, the group whose barbarity he has come to symbolize.
“I have no doubt that Mohammed is Jihadi John,” said one of Emwazi’s close friends who identified him in an interview with The Washington Post. “He was like a brother to me. . . . I am sure it is him.”
A representative of a British human rights group who had been in contact with Emwazi before he left for Syria also said he believed Emwazi was Jihadi John, a moniker given to him by some of the hostages he once held.
“There was an extremely strong resemblance,” Asim Qureshi, research director at the rights group, CAGE, said after watching one of the videos. “This is making me feel fairly certain that this is the same person.”
Authorities have used a variety of investigative techniques, including voice analysis and interviews with former hostages, to try to identify Jihadi John. James B. Comey, the director of the FBI, said in September — only a month after the Briton was seen in a video killing American journalist James Foley — that officials believed they had succeeded.
Nevertheless, the identity of Jihadi John has remained shrouded in secrecy. Since Foley’s killing, he has appeared in a series of videos documenting the gruesome killings of other hostages, including four other Westerners, some of whom he personally beheaded.
In each, he is dressed in all black, a balaclava covering all but his eyes and the ridge of his nose. He wears a holster under his left arm.
A spokeswoman for the British Embassy in Washington said: “Our prime minister has been clear that we want all those who have committed murder on behalf of ISIL to face justice for the appalling acts carried out. There is an ongoing police investigation into the murder of hostages by ISIL in Syria. It is not appropriate for the government to comment on any part of it while this continues.” ISIL is another name for the Islamic State.
U.S. officials declined to comment for this report. Emwazi’s family declined a request for an interview, citing legal advice.
The Kuwaiti-born Emwazi, in his mid-20s, appears to have left little trail on social media or elsewhere online. Those who knew him say he was polite and had a penchant for wearing stylish clothes while adhering to the tenets of his Islamic faith. He had a beard and was mindful of making eye contact with women, friends said.
He was raised in a middle-class neighborhood in London and on occasion prayed at a mosque in Greenwich.
The friends, who spoke on the condition of anonymity because of the sensitivity of the investigation, believe that Emwazi started to radicalize after a planned safari in Tanzania following his graduation from the University of Westminster.
Emwazi and two friends — a German convert to Islam named Omar and another man, Abu Talib — never made it on the trip. Once they landed in Dar es Salaam, in May 2009, they were detained by police and held overnight. It’s unclear whether the reason for the detention was made clear to the three, but they were eventually deported.
Emwazi flew to Amsterdam, where he claimed that an officer from MI5, Britain’s domestic security agency, accused him of trying to reach Somalia, where the militant group al-Shabab operates in the southern part of the country, according to e-mails that he sent to Qureshi and that were provided to The Post.
Emwazi denied the accusation and claimed that MI5 representatives had tried to recruit him. But a former hostage said Jihadi John was obsessed with Somalia and made his captives watch videos about al-Shabab, which is allied with al-Qaeda.
The episode was described in the Independent, a British newspaper, which identified Emwazi as Muhammad ibn Muazzam.
Emwazi and his friends were allowed to return to Britain, where he met with Qureshi in the fall of 2009 to discuss what had happened. “Mohammed was quite incensed by his treatment, that he had been very unfairly treated,” Qureshi said.
Shortly afterward, Emwazi decided to move to his birthplace, Kuwait, where he landed a job working for a computer company, according to the e-mails he wrote to Qureshi. He came back to London twice, the second time to finalize his wedding plans to a woman in Kuwait.
In June 2010, however, counterterrorism officials in Britain detained him again — this time fingerprinting him and searching his belongings. When he tried to fly back to Kuwait the next day, he was prevented from doing so.
“I had a job waiting for me and marriage to get started,” he wrote in a June 2010 e-mail to Qureshi. But now “I feel like a prisoner, only not in a cage, in London. A person imprisoned & controlled by security service men, stopping me from living my new life in my birthplace & country, Kuwait.”
Nearly four months later, when a court in New York sentenced Aafia Siddiqui, an al-Qaeda operative convicted for the attempted murder of U.S. personnel in Afghanistan, Emwazi expressed sympathy for her, saying he had “heard the upsetting news regarding our sister. . . . This should only keep us firmer towards fighting for freedom and justice!!!”
In the interview, Qureshi said he last heard from Emwazi in January 2012, when Emwazi sent him an e-mail seeking advice.
“This is a young man who was ready to exhaust every single kind of avenue within the machinery of the state to bring a change for his personal situation,” Qureshi said. In the end, he felt “actions were taken to criminalize him and he had no way to do something against these actions.”
Close friends of Emwazi’s also said his situation in London had made him desperate to leave the country. It’s unclear exactly when he reached Syria or how.
One friend said he believed Emwazi wanted to travel to Saudi Arabia to teach English in 2012 but was unsuccessful. Soon afterward, the friend said, he was gone.
“He was upset and wanted to start a life elsewhere,” one of the friends said. “He at some stage reached the point where he was really just trying to find another way to get out.”
Once in Syria, Emwazi contacted his family and at least one of his friends. It’s unclear what he told them about his activities there.
A former hostage who was debriefed by officials upon release said that Jihadi John was part of a team guarding Western captives at a prison in Idlib, Syria, in 2013. The hostages nicknamed the facility “the box.” Emwazi was joined by two other men with British accents, including one who was dubbed “George.” A former hostage said Emwazi participated in the waterboarding of four Western hostages.
Former hostages described George as the leader of the trio. Jihadi John, they said, was quiet and intelligent. “He was the most deliberate,” a former hostage said.
Beginning in early 2014, the hostages were moved to a prison in the Syrian city of Raqqa, the Islamic State’s de facto capital, where they were visited often by the trio. They appeared to have taken on more powerful roles within the Islamic State.
About the same time, Qureshi said, he sent an e-mail to Emwazi.
“I was wondering if you could send me your number,” he wrote. “Inshallah [God willing] it will be good to catch up.”
There was no response.