Those images were taken around 11 AM. The bomb didn't go off for nearly 4 more hours. So there would have to have been a suspicious looking bag in front of the

Those images were taken around 11 AM. The bomb didn't go off for nearly 4 more hours. So there would have to have been a suspicious looking bag in front of the store there for almost 4 hours. These guys were walking away from the bomb location. We don't have access to the images being sent to the FBI, which I imagine might include a lot of personal photographs taken on phones. Deadspin's images from a few minutes before the first explosion show clearly that there were a lot of people in the vicinity actively taking pictures in all directions, so I suspect someone got a shot of the area where the bag was placed (near the intersection of the wall of the Lenscrafter's and the black railing) within 10-20 minutes of the explosion. This is all based on public photographs and poorly coordinated timestamps. There are likely 100x as many being submitted as evidence that we can't see. It'd be nice if they were all public, as the leads a mass of volunteer investigators could turn up might result in something credible, but privacy and everything.