CNN CNN Newsroom April 17, 2013 13:10:00
What that person was using as a guide or if they had a specific teacher show them how to do it. that's a very important -- that's how the investigation is similar to after an airplane crash when they reconstruct the plane to see exactly where the explosion happened and the parts that were closest to it. that's a very important feature, often, surprisingly, you can have something as part of the explosive device and yet still have the bombmaker's dna, hair, skin particles or some other fluid on there that can yield later the evidence you need to convict a specific person of having been the one t...
Source: archive.org