but they can't tell us what they've collected because it would, you know, misdirect the investigation. >> james, the trip wire, that concerned you as well. obviously it's all concerning, but in terms of an evolution of tactics. >> absolutely. we talked in the early segment about how this is not the unabomber 2.0. this appears much more like the d.c. sniper case, anderson, in 2002, in the month of october for three weeks two snipers paralyzed parts of maryland and virginia. this seems similar in this instance. if, and it's a big if, these seven devices can be linked together. and that link analysis is critical here. if. even the fact that this last device was an insend areay device, let's not make that out to be something benign. we haven't seen it. we don't have details yet. but incendiary device is combustible. it is flammable. it's something designed to cause fire. there are three ways that cause fatalities in bombings. the most onerous one is the overpressure. meaning the pressure that comes out that basically crushes organs and soft tissue.