of, and an 8-year-old girl were killed at an ariana grande concert. i want to bring in cnn terrorism analyst paul kruk shank and paul, let me start with you. isis has claimed responsibility but they haven't offered any proof. >> they haven't offered any proof whatsoever describing him as a soldier of the caliphate, and i've just been in touch with a british counterterrorism official that says so far british investigators have uncovered no evidence of any link to an established terrorist group, overseas a terrorist group like isis. it's obviously early on in the investigation. one of the key focuses is on the forensic at the scene of the attack, trying to figure out how sophisticated this device was, what kind of bomb chemicals were in the device and so on, and to try and figure out, well, could