absorbed most of the impact. right here, this is where they believe the bomb went off. the forensic agents, the fbi and atf were here, and picking up physical pieces of evidence. this is a brand new concrete that's been laid down here. they removed that, and they're going to -- they're testing things, the blast pattern, bringing shrapnel out of pieces of stone and concrete. back here, you can see the windows are still blown out. all of that is going to be analyzed so investigators can understand how this device work. they still don't know how exactly the device worked, how it was put together. and the impact of the shrapnel. here a somber mood, people reflecting and realizing that tamerlan was standing pretty much where i am. >> we're learning more about his widow, katie russell. more information about her, she said through her attorney that