'Unabomber' Ted Kaczynski, who terrorised US for nearly 20 years, found dead in prison

Bombing campaign killed three people and injured more than 20 between 1978 and 1995

Ted Kaczynski, better known as the Unabomber, is escorted from a courthouse by US federal agents in 1996. AP

Ted Kaczynski, who came to be known as the “Unabomber” after a campaign of sporadic, anonymous bombings in the US from 1978 to 1995, died in prison on Saturday, authorities said.

Kaczynski, 81, whose attacks killed three people and injured two dozen, was found unresponsive at 12.25am at a federal prison medical centre in Butner, North Carolina, the Federal Bureau of Prisons said.

He was taken to the hospital, where he was officially pronounced dead later in the morning.

The reclusive Harvard-educated mathematician, whose targets ranged from academics to random civilians, had a self-professed goal of halting the advance of modern technology and society, mounting his campaign of violence from a shack in rural Montana.

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.

Targets included an advertising executive, an airline president and a computer scientist. But in some cases, his bombs ended up injuring those unlucky enough to accidentally be on the receiving end of a concealed explosive.

In September 1995, The Washington Post published his 35,000-word anti-modernity manifesto, part of a joint effort with the New York Times, based on a promise that he would stop his bombing campaign if it were printed. Federal authorities at the time urged the papers to go through with the move.

Upon reading it, his estranged brother David thought he might know the author, and alerted the FBI to his suspicions.

After his 1996 arrest, Kaczynski was sentenced 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.

Kaczynski was for a long time held in a high-security prison in Colorado nicknamed the “Alcatraz of the Rockies” – one that has also held the likes of drug kingpin Joaquin “El Chapo” Guzman and would-be Al Qaeda suicide pilot Zacarias Moussaoui. He was transferred in 2021 to the health centre in North Carolina.

Born in Chicago and raised in a bookish household, the fact that Kaczynski was a loner was not surprising to those who knew him. But his revelation as a killer shocked his family.

“What could I have done to keep him out of the wilderness?” his mother, Wanda Kaczynski, said in an interview in June 1996.

“What could I have done to give him a happier life? I just don't know.”