The notorious Unabomber — a reclusive “twisted genius” who ran a 17-year bombing spree in the United States — has been found dead, age 81, in a prison cell.
Theodore ‘Ted’ Kaczynski delivered handmade bombs to targets across the country, killing three people and injuring two dozen more.
From 1978 until 1995, he sowed fear and panic by mailing or hand-delivering increasingly sophisticated bombs — even threatening to blow up airliners in flight.
The Harvard-trained mathematician was dubbed the Unabomber because his early targets appeared to be universities and airlines.
Prison guards found Kaczynski dead around 8am on Saturday (local time) at a federal prison in North Carolina. A cause of death was not immediately known.
“Responding staff immediately initiated life-saving measures,” a prison spokesperson told the BBC.
Kaczynski was then transported to a local hospital and “subsequently pronounced deceased by hospital personnel”.
He had been moved to the federal prison medical facility in North Carolina after suffering declining health.
Before that he spent two decades in a federal Supermax prison in Colorado.
For nearly two decades the FBI hunted the elusive lone wolf who left false clues to throw off his pursuers.
He was eventually tracked down to a primitive cabin in the mountains of western Montana and was tried and sentenced to life without parole in 1998.
He pleaded guilty to setting 16 explosions that killed three people and injured 23 others in various parts of the country.
The FBI’s website states that 150 full-time investigators were involved in the case to uncover and track down the Unabomber who took pains to leave no forensic evidence.
Their “big break” came in 1995 when the Unabomber sent the FBI a 35,000-word essay claiming to explain his motives and views of the ills of modern society.
The FBI approved the manifesto’s publication in The Washington Post and thousands of readers suggested possible suspects.
“One stood out: David Kaczynski described his troubled brother Ted,” the FBI’s website states.
“Most importantly, David provided letters and documents written by his brother.
“Our linguistic analysis determined that the author of those papers and the manifesto were almost certainly the same.
“When combined with facts gleaned from the bombings and Kaczynski’s life, that analysis provided the basis for a search warrant.”
On April 3, 1996, investigators arrested Kaczynski and combed his cabin.
They found bomb components, 40,000 handwritten journal pages that included bomb-making experiments and descriptions of Unabomber crimes; and one live bomb, ready for mailing.
