kurt yeager is the fbi chief explosive scientists come the closest analytical center in huntsville, alabama, with unprecedented access to the fbi lab, fox news obtained exclusive evidence photos including the 2001 device worden by richard reid. the shoe bomb was a game changer which is why we take shoes off airports. when you cut it open you have the explosive stuffed in the actual waffle. reporter: alice eisenberg who oversees the fbi lab analyzed the shoe bomb 17 years ago. that told us that device was built by someone other than richard reid. reporter: the field to light the detonator, the fbi changed the explosive potential. we took a sheet of aluminum, the exact amount of explosives
on that, detonated it. reporter: yeager explained forensics on the al qaeda influenced boston marathon bombing. a pressure cooker, these little thin things are small nails increasing potential to be lethal. the warehouse is home to 1 million pieces of bomb evidence. it is like a historical archive allowing investigators to identify trends and pursue criminal prosecution. reporter: were investigators some cases never seem finished like the 2003 plot the killed alleged co-conspirator brian wells. the bomb lobbed around his neck. will stick in my memory because it took 7 years of my life. it is a bank robbery plot by a sociopath. one piece out of hundreds that looked like probably part of the bomb. not going to hunt me until i retire. reporter: with the fbi in huntsville, alabama, catherine herridge, fox news. reporter: top congressional democrats being called out by the sun of a 9/11 victim for