intelligence, james clapper, he gives new information about the number of americans who actually tried to travel to syria. >> reporter: he did. he raised that number to 180 and keep in mind so this figure as you say, it's people who have either gone to syria and iraq successfully including the group such as isis or have tried to go some of them killed there. so it's a broad number. it's an estimate but the estimate has jumped. last year that number was around 50. it creeped up to the 70s. it creeped up to 100. a short time ago, it was 150. it is growing and partly it's growing because more people are attracted and also growing, anderson, because they're making a better effort to keep track of these people but, you know, that's a worrisome sign. it's not to the level you see in european countries, several hundred in the u.k. and in france et cetera. but still, that's a significant number and that's already a difficult group of people for u.s. authorities to follow. >> yeah. jim sciutto, appreciate the update. thanks jim. >> yeah. the killer in question grew up in a city in london that was