Mohammed Emwazi, the man believed to be the ISIS executioner known as "Jihadi John," escaped from Britain in the back of a truck because he believed authorities had placed him on a watch list, U.K. security sources told NBC News. Once Emwazi, 26, had escaped the U.K., he managed to travel across Europe and into Turkey unhindered, sources said. Media reports unmasked "Jihadi John" as Emwazi last week.
