According to the FBI 7 page Maguire statement, of the 85 confirmed tapes seized, only the one released yesterday shows the impact. How unlikely is it that out of another 84 confirmed surveillance tapes directed at the building, none of them captured anything?
After determining that only 13 of the 85 had footage of the crash site, the FBI states that 12 of these only show footage AFTER the impact of flight 77.