with this bolt. and there. was >> the thing that made it exceptionally clear was that the bull still had some fishing string attached just under the head of the boat, which is how it was depicted in the diagrams. >> so it would've been hanging? >> yes >> we as a wait? >> yes. >> it was clear that that bolt was part of our device that was described in the letters. >> and we're fragments of a plastic soda bottle. black paint still clinging to them. again just like the diagram. >> so it's a spring that was similar to a rat trap spring, there was gasoline on the victims clothing. and then we recovered pieces of a nine volt battery that we were able to determine had no business being in the panel. >> so if you found the writer of those letters you had found the killer? >> that was our opinion, yes. >> along with a diagram was a second letter, in which the bomber repeated his earlier claim that he was a reluctant