device that is used to maim or kill. >> for almost two decades, he skillfully evaded identification and capture. >> we had literal hi hundreds and hundreds of suspects. >> dropped out of sight for six years. >> people thought he was dead. >> he was obsessed about leaving fingerprint evidence. >> nobody has ever seen anybody like theodore ka zin ski. >> the hunt for the unabomber next. ♪ >> reporter: a simple sketch was almost all investigators had to go on. the facial features were distinct but the head was cloaked by a hood. and the eyes, obscured by aviator sunglasses. for more than 17 years, he