'Unabomber' Ted Kaczynski has died in federal prison at age 81

Theodore "Ted" Kaczynski, the man known as the "Unabomber," has died in custody at a federal prison medical center in Butner, North Carolina, at age 81.

He was found unresponsive Saturday shortly after midnight. Staff performed life-saving measures, and he was transported to a hospital, the Bureau of Prisons said. Kaczynski was pronounced dead at about 8 a.m., Kristie Breshears, a spokesperson for the Bureau of Prisons confirmed to USA TODAY. A cause of death was not immediately known. 

He was serving a life sentence after sending a series of homemade bombs by mail around the country. He pleaded guilty to setting 16 explosions that killed three people and injured 23 others.

Kaczynski had been transferred from supermax prison in Colorado to a federal prison medical facility in North Carolina in December 2021. Officials didn't say why he was moved at the time.

USA's most prolific bomber

The FBI spent nearly two decades trying to hunt down Kaczynski, who became known as America's most prolific bomber.

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His first bomb, which the FBI described as "primitive" went off at a Chicago university in 1978. He went on to send 15 more bombs by mail that mostly targeted scientists. His bombs advanced in their sophistication over the years, authorities said.

Kaczynski killed computer rental store owner Hugh Scrutton, advertising executive Thomas Mosser and timber industry lobbyist Gilbert Murray. California geneticist Charles Epstein and Yale University computer expert David Gelernter were maimed by bombs two days apart in June 1993. A dozen people suffered smoke inhalation from a bomb he placed on an airplane in 1979.

The "Unabomber" moniker came from a task force's name of the case – UNABOM, because of the "UNiversity and Airline BOMbing" cases investigated. The task force included over 150 members assigned to track him down.

In 1995, Kaczynski sent authorities a 35,000-word manifesto that he also pressured The Washington Post and The New York Times into publishing. The Times noted that federal officials recommended publishing.

The tirade, called, "Industrial Society and Its Future,” claimed modern society and technology was leading to a sense of powerlessness and alienation.

His brother sent in a tip after recognizing the writing, which led investigators to his ultimate arrest on April 3, 1996, at a dingy shack in the Montana wilderness.

Unabomber changed US mail, airplanes

Kaczynski grew up in Chicago and was a Harvard-trained math professor who once taught at the University of California, Berkeley – where he placed two of his bombs. He targeted universities, scientists, airlines and a timber industry lobbyist he blamed for drowning the world in technology and destroying the environment.

Years before the Sept. 11 and the anthrax mailing attacks, the Unabomber’s deadly homemade bombs changed the way Americans mailed packages and boarded airplanes, even virtually shutting down air travel on the West Coast in July 1995.

Though he was diagnosed with paranoid schizophrenia by a psychiatrist while in prison, Kaczynski hated being depicted as mentally ill and pleaded guilty rather than let his defense team proceed with an insanity defense.

The bombing spree was borne out of Kaczynski's drive for vengeance, investigators concluded based on his writings.

Contributing: The Associated Press