Interesting. There is so many photos and videos that it will only be a matter of time until this is solved.
Check it out:

A man took the images from his office above Boylston Street and they show the moments right after one of the explosions.

You can see almost everyone is frozen, a many crouching on the ground, stunned or injured. But one man is acting very differently from everyone else. You can see he is running away from the scene.

Investigators talked to the man who took the pictures.

“One after another, you see this individual really fleeing from the scene, which is either for one or two reasons. So either he was badly burned and panicked, and fleeing, or he was fleeing for some other reason,” said the man who took the photos.

WHDH-TV 7News Boston

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