( CNN ) His voice became hauntingly familiar as the masked man with a British accent who appeared repeatedly in brutal beheading videos from ISIS . But the identity of `` Jihadi John '' remained a mystery -- until Thursday , when two U.S. officials and two U.S. congressional sources confirmed it . The man , the officials said , is Mohammed Emwazi , a Kuwaiti-born Londoner . The officials , who 've been briefed on the matter , spoke to CNN after a Washington Post report first revealed Emwazi 's identity . Emwazi is believed to have traveled to Syria in 2012 , according to the newspaper , and later to have joined ISIS there . Even with a name and face for the man behind the mask , uncertainty still swirled Thursday . London police and British officials declined to confirm his identity . Officials from a London-based human rights and Muslim advocacy organization who 've interacted with Emwazi said they could n't be 100 % certain it was him . And a key question remained unanswered : What inspired him to join ISIS ? The answer depends on who you ask . Some terrorism experts said Emwazi 's history shows someone who 'd been on a path toward extremism for years . But CAGE , the London advocacy group that worked with him , said if he is the man who 's appeared in ISIS videos , it 's a sign that British authorities ' tactics pushed him to radicalize . Emwazi was born in Kuwait in 1988 and moved to the United Kingdom when he was 6 years old , CAGE said on its website . He studied at the University of Westminster in London and graduated in 2009 with a degree in computer programming , the group said . Emwazi , according to CAGE , `` hoped that with this degree , he could build a successful career in Arab countries , as he was fluent in Arabic , English and had a British accent . '' Did something change to send him on a different path ? According to the Washington Post , friends of Emwazi said they believed his path to radicalization began when he went on a trip to the East African nation of Tanzania in 2009 . He was supposed to be going on safari there , but was reportedly detained on arrival , held overnight and then deported . He was also detained by counterterrorism officials in Britain in 2010 , the Post said . Authorities have n't provided any reasons behind those reported detentions . London police declined to confirm the reported identity . `` We have previously asked media outlets not to speculate about the details of our investigation on the basis that life is at risk , '' said Cmdr . Richard Walton of the Metropolitan Police 's Counter Terrorism Command . `` We are not going to confirm the identity of anyone at this stage or give an update on the progress of this live counter-terrorism investigation . '' A UK Foreign Office spokeswoman told CNN : `` We will neither confirm nor deny the current reporting as to the identity of Jihadi John . '' There are `` striking similarities '' between Emwazi and the man known as `` Jihadi John , '' according to Asim Qureshi , CAGE 's research director . Qureshi told reporters Thursday that he could n't be 100 % certain that Emwazi is Jihadi John because the man 's face is covered in the videos . But Qureshi said the man he knew was very different than the merciless figure from ISIS videos . Emwazi was a `` polite '' and `` beautiful young man '' who would drop into the CAGE office with treats to thank the group for helping him . Emwazi came to CAGE in 2009 looking for support when he felt that British authorities were -- in Qureshi 's words -- `` harassing '' him . If Emwazi is indeed Jihadi John , Qureshi said , that makes him sad . But in some ways , he said , it 's not surprising . `` It 's hard to imagine the trajectory , but it 's not a trajectory that 's unfamiliar , '' he said . Many Muslims feel alienated in their society , like Emwazi did , he said . `` When are we going to finally learn if we treat people as if they 're outsiders ... they will look for belonging elsewhere ? '' Qureshi said . `` Our entire national security strategy for the last 13 years has only increased alienation . '' The Washington Post 's report includes emails Emwazi purportedly wrote after British counterterrorism officials detained him and stopped him from flying to Kuwait . `` I had a job waiting for me and marriage to get started , '' he wrote in a June 2010 email to Qureshi , the Post reported . 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 , '' the email said . CAGE points the finger at British security services , who they say have `` systematically engaged in the harassment of young Muslims , rendering their lives impossible and leaving them with no legal avenue to redress their situation . '' Haras Rafiq , managing director of the Quilliam Foundation , a UK-based counter-extremism think tank , said the advocacy group was pointing the finger in the wrong direction . It 's clear Emwazi had been radicalized before 2010 , he said . And , according to Rafiq , intelligence agencies who stopped Emwazi traveling to Tanzania believed there was evidence that he intended to join the extremist group Al-Shabaab in Somalia . Haras added that it was `` very upsetting that an organization like CAGE would spin this in the way that they 've done , '' by blaming intelligence agencies . Former CIA counterterrorism analyst Philip Mudd told CNN that blaming radicalization on alienation was oversimplifying Emwazi 's story . `` We 're only seeing half of this story , '' he said . `` The government does n't spend the resources and take the risk , the legal risk of pulling somebody aside , preventing them from traveling , searching through their luggage , just because somebody looks funny . There is something else going on here in terms of whatever triggered the government to undertake this investigation that we 're missing here . '' The masked , black-clad figure believed to be Jihadi John appeared to be the ISIS militant shown in a video last month demanding a $ 200 million ransom to spare the lives of two Japanese journalists . A similar figure appeared in at least five previous hostage videos . U.S. and British officials have previously said they believed they knew who the man was , but were n't disclosing the information publicly . That could be because Western intelligence agencies believed they had more to gain from keeping quiet , Aki Peritz , a former CIA officer , told CNN last month . `` They can put pressure on his family , put pressure on his friends , '' he told CNN . `` Maybe they have a line to him . Maybe they know who his cousins are who are going to Syria who can identify him . However , if you publicly tell everybody who he is , his real identity , then maybe he 'll go to ground and he 'll disappear . '' The man 's reported background gives some clues as to why he might have been recruited , said Sajjan Gohel , director of international security at the Asia Pacific Foundation . `` We know that ISIS recruits a lot of Westerners who are skilled in new media , understanding of the Internet , because they use that as their platform as an oxygen of publicity , '' he said . But by not revealing his name for operational reasons , one expert said , officials may have created another problem . `` It created more speculation in the media , '' he said . `` In some ways , the nom de guerre of Jihadi John gave this individual a form of notorious celebrity . '' Opinion : Why 'Jihadi John ' is so worrying . CNN 's Evan Perez , Pamela Brown , Dana Bash and Alexander Felton and Damien Ward contributed to this report .
Officials : - The first time the player is killed, they will be respawned at a random location in the same map as where they died. Advocacy group CAGE says it had contact with Emwazi . London 's Metropolitan Police declines to confirm his reported identity .