[shhrubbery!]

What exactly do you not find convincing about the superimposed photo? The two guys' position at "ground zero," with respect to the Forum cafe's sidewalk rail, is exact. OK, I'm going to post the superimposed version here ... to see the photos separately, go to http://imgur.com/a/f2iNp

[ltc8k6]

It’s unconvincing as evidence that they did anything, even assuming it’s correct as to ground zero.

[ltc8k6]

He is still clearly wearing the backpack in this photo, where the NY Post claims it’s gone.

http://www.nypost.com/rw/nypost/2013/04/18/news/web_photos/18.1n004.boston2.C—300x300.jpg