A British Man
The Islamic State executioner known as "Jihadi John" who has appeared in the various snuff videos put out by the terrorist organization has been identified.
The man is Mohammed Emwazi, a young British man from West London who was known to British security services.
He is a computing graduate from Queen’s Park in West London, who traveled to Syria in 2012 and later joined the Islamic State (IS, formerly ISIS).
['Jihadi John identified: ISIS killer named as Mohammed Emwazi from West London, Russia Today, February 26, 2015]
So the intelligence agencies knew about Mr. Emwazi but for whatever reason couldn't or didn't do anything about him. He appears to have received a good (taxpayer-funded) education but, contra State Department spokesbimbo Marie Harf, that doesn't seem to have turned him away from terrorism.
Obviously, what is needed is a larger police crackdown on the "far Right" and more education.