Who was on the roof when the bomb went off?

After an appeal for all amateur photographs and video of the Boston Marathon terror attack, the video below was turned over to police and the FBI.

Let's go to the videotape.



If you didn't see the people on the roof, here are some freeze frames (Hat Tip: NY Nana):




The video, shot from a room in the Lenox Hotel across the street
about two minutes after the explosion, shows what appears to