BUTNER - Ted Kaczynski, known as the "Unabomber," who terrorized Americans from 1978 to 1995 with his sporadic, anonymous bombing campaign, died in prison Saturday, US authorities said.
Kaczynski (81), whose attacks killed three people and injured two dozen, was found unresponsive at a federal prison medical centre in Butner, North Carolina, said the Federal Bureau of Prisons. He was taken to the hospital, where he was officially pronounced dead later in the morning.
His bombs were either hand delivered or mailed over nearly two decades, confounding investigators looking to bring him to justice.
It was only after Kaczynski's capture and the revelation of his identity that the FBI uncovered his previous life -- one where he scored 167 on an IQ test and entered university at just 16.
The nickname of "Unabomber" came from his targeting of a university and an airline company, leading the FBI to dub him the "University and Airline Bomber."
The seemingly random nature of Kaczynski's bombings put the nation on edge, and at one point brought a halt to air travel on the West Coast in July 1995.
But it would turn out that while Kaczynski picked his victims without knowing them, he selected them using extreme anti-technology views to justify the attacks.
After his 1996 arrest, Kaczynski was convicted to life in prison in 1998. When his lawyers tried to enter a plea of insanity, Kaczynski asked the court to dismiss them, and rejected a diagnosis that he was a paranoid schizophrenic.
Kaczynski pleaded guilty, which helped him avoid the death penalty -- and put a stop to any insanity plea.
He was given four life sentences, plus 30 years in a case prosecuted by Merrick Garland, who now serves as the US attorney general.