that emwazi has been publicly identified? >> reporter: it's possible. isis is a a horrific group. so -- it's possible to expect any kind of reaction from them. what people who watch isis are wondering is will his next video, and undoubtedly there will be a next video, will he continue to be masked? will he show his face in the future videos and will showing his face demystify -- he seemed something of a monster. he called himself the nightmare of obama. he didn't like to call him president obama. just i guess he thought he was on a first-name basis with the u.s. president. now when you have a 27-year-old from a middle-class family in london, will he appear so threatening, or will he appear just to be another murderer? >> richard engel in istanbul. thank you so much. good to see you. back in the states the big worry is about homegrown