in the days after 9/11, british police discovered the video during a raid on bayoumi's u.k.. they also seized bayoumi's handwritten address book that the lawyers for the 9/11 families say was filled with numerous phone numbers of numerous senior saudi officials who were in the government at the time. and when bayoumi filmed the washington video, he was often with two saudi diplomats who the fbi says had ties to al qaeda, a finding the saudi government disputes. >> well, it is another very large brick in a massive wall of evidence that at this point indicates the saudi government was complicit in the 9/11 attacks. >> reporter: ken williams is a retired fbi agent who led the 9/11 investigation in phoenix, where one of the hijackers attended flight school. he's also a consultant on the case filed by the 9/11 families. in terms of all the revelations that have come out as part of this 9/11 lawsuit, where does this video rank? >> i think it ranks right at the top of the pile. >> reporter: the government of saudi arabia says, nothing to see here, this is a tourist video. this is a

in the days after 9/11, british police discovered the video in a raid on bayoumi's apartment.y also seized bayoumi's handwritten address book that the lawyers for the 9/11 families say was filled with numerous phone numbers of senior saudi officials who are in the government at the time. and when bayoumi filmed the washington video, he was often with two saudi diplomats with the fbi says had ties to al qaeda, a finding the saudi government disputes. >> well, it is another very large brick in a massive wall of evidence that at this point indicates the saudi government was complicit in the 9/11 attacks. >> reporter: ken williams is a retired fbi agent who led the 9/11 investigation in phoenix, where one of the hijackers attended flight school. he's also a consultant on the case filed by the 9/11 families. in terms of all the revelations that have come out as part of this 9/11 lawsuit, where does this video rank? >> i think it ranks right up at top of the pie albeit >> reporter: the government of saudi arabia says nothing to see here, this is a tourist video. this is a guy out lo

it's saudi national omar al bayoumi walking the capitol in 1999.rs were deciding on 9/11 targets according to the fbi. at the time you were at the cia. we know now the fbi identified this man, al bayoumi as an intelligence operative with close ties to two of the 9/11 hijackers, but in that 9/11 commission report it said there was no credible evidence that he was a violent extremist or aided extremists. now that you have seen this video, what do you think it reveals? >> no doubt in my mind that it is a casing video, that it is a casing video for some sort of terrorist attack. number one. number two, pretty clear to me that al bayoumi was either working for al qaeda or was al qaeda. did he know about the 9/11 attacks? probably not. did he know that the two individuals he was interacting with were 9/11 hijackers? probably not, but no doubt in my mind that al qaeda tasked him to do this casing video. the video is chilling. it's chilling in terms of what he was -- what he was videotaping. his narration over the top of it which is part -- which tells you