booby-traps at his northern nevada residence, that's why a s.w.a.t. team is there right now. let's bring in phil mudd, our cnn analyst. phil, ammonium nitrate reminds me of the ammonium used in the bombs at the federal office building in oklahoma city. why would he have it in significant quantities in his vehicle in las vegas? >> we've got a lot of clues here, wolf. there's one bottom line, and that is this is an open criminal investigation. we're not just looking at what happened. we've got to have questions about whether somebody else knew. ammonium nitrate, that's fertilizer readily available. it's not explosive by itself, but if you combine with fuel oil, something common in basic improvised or homemade terrorist devices, we've seen around the world in terrorism one of the basic questions, did they find a laptop in the house and was this man researching how to build an improvised explosive device with