atf examiner examined the extrusion mark, made during the examining process.the wire its uniform size. >> those marks will be imparted on the plastic element before it changes dramatically. >> looking at it on a comparison microscope, there was no doubt the wire from both bomb sites came from the same source. >> in fact, these were produced on the same diet, the same plant. >> they also discovered both bombs used the same glue and the same cotton string. since both bombs appeared to be made by the same individual, this eliminated jimmy morris and phil ryan. they both had solid alibis for the second bombing. but why did these boys implicate themselves in the first place? >> they offered an explanation that they were doing this because they were playing this dungeons and dragons game. >> they really spent a lot of time wasting the time of investigators. >> i thought that was an incredibly stupid thing to do. >> then a witness came forward saying she had seen a white male walking a german shepherd dog near the church parking lot a few hours before the first bombi