The masked executioner in the Islamic State beheading videos has been identified. U.S. intelligence confirmed on Thursday that the man known as "Jihadi John" is a Londoner named Mohammed Emwazi, according to NBC News.

Emwazi, although a Briton, was born in Kuwait and is known to intelligence services, according to the BBC. Hostages that had been released told the BBC that Emwazi was one of three British jihadists. The trio was given the nicknames "John," "Paul" and "Ringo" - and known collectively as "the Beatles" - by the Westerners behind held captive.

Emwazi grew up as part of a wealthy family in West London. He graduated from college with a degree in computer programming. He left for Syria in 2012 and joined ISIS, according to The Washington Post.

"I have no doubt that Mohammed is Jihadi John," one of Emwazi's close friends told The Washington Post. "He was like a brother to me ... I am sure it is him."

Metropolitan Police in London and government officials in England would not comment, according to NBC News.