How did Mohammed Emwazi become 'Jihadi John'?

Aired: 2/26/2015 | 0:04:31 | Clip
A day after the U.S. arrest of three men attempting to join the Islamic State, officials identified the man known as “Jihadi John,” an IS militant who has been seen in brutal videos executing hostages. What motivated Mohammed Emwazi, a British citizen, to embrace extremism? Judy Woodruff talks to Peter Neumann of King's College London about Westerners who may be drawn to terrorism.