oversees the fbi labs analyzed the shoe bomb 17 years ago. >> that told us that that device was built by someone other than richard reid. >> while reid failed to light the detonator, the fbi team showed a jury the explosive potential. >> we took a sheet of aluminum, put the shoe, our recreation of the shoe with the exact amount of explosions on that detonated it to educate the court. >> jeager explained the forensics on the al qaeda influenced 2013 boston marathon bombing. pressure cookers killed three and injured several hundred. >> that is fragments of the pressure cooker. copper kettle steel shot and b bs and small nailed a fragmentation for them to be lethal. graphite where one of the backpack was situated. when beam are fleeing for their life they are leaving behind purses, backpacks and other items. every one of those things becomes another potential device that has to be cleared. >> inside this mask fbi