are taking this as a terror attack until they have evidence to the contrary. some are saying the way this was orchestrated with the vehicle, plowing into a crowd, that is the type of thing that isis does. former fbi assistant director ron hofstra. what do you make of that? >> isis has done that, isis has called for it. those that have aspired to connect themselves to isis have done this low intensity deadly attack repeatedly in the past. so i think your prior guest was right, that it seems strangely normal now and that citizens, whether it's in europe, great britain or here in america ought to be thinking proactively about what their response would be if it happens near then. >> ron huber reminded me in the past. but this idea of crude but effective terror method. in this case, a knife, something