circumstances isis in this attempt here? >> they claim credit for it. the use of tatp the main explosive material in this device, that is a substance that others have pointed out has become a hallmark of isis terror but other terror groups have used it the in past before. we saw this most effectively used in paris and brussels two years ago. the fact that we are now talking about multiple actors instead of just one, it's become kind of a cliche, really a myth in the media to describe attacks like these as lone wolf attacks. more cases than not tend to be coordinated i don't want to even say cells, but an association of people that are behind the coordination and planning of these attacks. two people have been arrested, more may be coming and doesn't surprise me in the least. >> so let's talk about the top of your answer there that isis