critical. when you see a video like that, if you went to a din e e party tonight and somebody started showings like that, wouldn't you say something is wrong here? it's the classic see something say something. what were these people thinking and why didn't they do anything? i need to foe that. >> and we know investigators are looking into the suspect's time in saudi arabia. apparently went home and returned back to the u.s. what are they looking for? >> this gets really tough when you're dealing with a single individual if there are other conspirators. if you have two or three people involved, you typically are going to see things like an e-mail trail where you can start to see them talking and therefore understand motive. what they're look iing at when u have just one person is whether somebody says he started getting more religious and radical. tried to get inside the united states when we doesn't have a coconspirator. they're trying to understand a