>> that sounds very much like the m.o. of what happened at ohio state in 2016. >> exactly. ohio state, berlin, and nice are the main examples that we look to. >> and each of those had at least some of those elements. >> exactly. nice, berlin, and now new york, is using the large truck. before, we've also seen with smaller cars. but in general, those are not as deadly. >> now, one of the things that i've learned from you in your coverage of isis is that isis typically does not like to claim responsibility for attacks when the attacker is still alive. particularly when the attacker is in custody. >> exactly. >> explain again why that is and how that may apply to this situation. >> the reality, rachel, is we don't know why they do this. the speculation is they don't want to do this because if they claim him now, then it complicates his case when he