He was a recluse who spread terror through the mail for 18 years. Two men died and more than a dozen were injured , but Ted Kaczynski wasn't known as the Unabomber until his brother tipped off the FBI. Kaczynski's Manifesto, published in major newspapers, set off a flurry of activity for the FBI: writing analysis and comparisons, DNA gleaned from a single postage stamp and finally, Kaczynski's arrest at his tiny cabin. The agents collected enough evidence, including the Manifesto itself, to convict Kaczynski. He is serving four life sentences plus 30 years with no chance of parole.