verify but not necessarily ahead of time. >> that is right. but it could also about used in other ways because if you know dna then you could test other people to understand the family relationship and get closer to that individual. >> seth, you've covered isis extensively and out a book calmed "after isis, america, iran and the strug of for the middle east." big credit to the special operators and the secretary of defense and president trump for this operation being such a success. put into perspective, how big of a blow the death of al baghdadi and the death of his potential successor? >> look, i think symbolically it is very important that he's been killed. it is like the bin laden raid. we know there is something like 14,000 isis fighters at large. so there is certainly a lot of isis people out there and that means that in iraq and syria, even iffer not swearing