I heard the Break Thru came when the Man that had both legs blown up work up from surgery asked for a pen and note pad and wrote that knew who the bomber was and could identify him, the bomber looked right into his eyes before he placed the bag pack down, thats how the FBI was able to make the connnection, until then they were still going after the Muslim kids in black and blue.
with all the cameras, all the Undercover agents , it took them 2 days to identify who it was until that guy came thru for them, if it wasnt for him, i dont think they would of ever found them