11-year-old henry, 6 jeerld jane and 12-year-old martin. and now dzokhar raises a phone to his ear. the plan is now in motion. >> what the hell was that? >> tamerlan detonates the first bomb. >> oh, my god, something blew up. >> in the ensuing chaos, dzokhar walks quickly away from his backpack. he leaves it on the ground, right near 8-year-old martin richard. behind the richards in a blue sweater is 23-year-old lingzi lieu. >> she walked into frame just before the bomb goes off. you see he turn to look toward the finish line where the first