diagram was a two-inch pipe bomb placed next to a one liter soda bottle full of gasoline spray painted black. a large bolt tied off with a fishing line and acting as a drop weight would fall on a rat trap causing it to strike a firing pin. kind of like a rube goldberg device. the author also said there was a second secret triggering device as backup. either way the bomb was designed to go off when roberto ayala opened the door of the electrical box. could have been almost anything. now suddenly agent parker saw how they all fit. those confusing bits and pieces he'd been poring over for the past month. >> it was almost like someone had sent us the cover of the puzzle box. >> reporter: so now they matched the bits to the diagram. >> the first thing i looked for was this bolt and there it was. >> the thing that made it exceptionally clear was the fact that the bolt still had some fishing string attached just under the head of the bolt which was how it was depicted in the diagram.