Ted Kaczynski, known as the Unabomber, has died in federal prison at the age of 81

Theodore “Ted” Kaczynski, the Harvard-educated mathematician who retreated to a dingy cabin in the Montana wilderness and spent 17 years conducting a bombing raid that killed three people and injured 23 others, died Saturday. He was 81.

Kaczynski was labeled an “unabomber” by the FBI and died at the medical center at the federal penitentiary in Butner, North Carolina, Kristie Breshears, a spokeswoman for the federal Department of Prisons, told The Associated Press. He was found lifeless in his cell early Saturday morning and was pronounced dead around 8am, she said. A cause of death was initially unknown.

Prior to his transfer to the prison’s medical facility, he had been held at the Supermax federal penitentiary in Florence, Colorado, since May 1998, when he was sentenced to four life terms plus 30 years for a campaign of terror that roiled universities across the country. He admitted to carrying out 16 bombings in 1978 and 1995, permanently maiming several of his victims.

Years before the 9/11 attacks and the anthrax shipments, the Unabomber’s deadly homemade bombs changed the way Americans shipped packages and boarded airplanes, and in July 1995 even virtually shut down West Coast air travel.

He forced the Washington Post, along with the New York Times, in the agonizing decision in September 1995 to publish his 35,000-word manifesto, Industrial Society and Its Future, which asserted that modern society and technology were becoming a sense of industrial society lead to impotence and alienation.

But it led to his downfall. Kaczynski’s brother David and David’s wife Linda Patrik caught the tone of the paper and tipped off the FBI, which has been searching for the Unabomber for years as part of the country’s longest and costliest manhunt.

In April 1996, authorities found him in a 10 x 14 foot (3 x 4 meter) plywood and tar paper shack outside of Lincoln, Montana, filled with diaries, an encrypted diary, explosive ingredients and two finished bombs.

An elusive criminal mastermind, the Unabomber gained many sympathizers and comparisons to Daniel Boone, Edward Abbey and Henry David Thoreau.

But when Kaczynski revealed himself to be a wild-eyed recluse with long hair and a beard who’d survived Montana winters in a one-room cabin, Kaczynski struck many as more of a pathetic loner than a romantic anti-hero.

Even in his own diaries, Kaczynski came across not as a committed revolutionary but as a vengeful recluse driven by petty grievances.

“I certainly do not claim to be an altruist or to act for the ‘good’ (whatever that is) of mankind,” he wrote on April 6, 1971. “I act solely out of a desire for revenge.”

A psychiatrist who interviewed Kaczynski in prison diagnosed him as a paranoid schizophrenic.

“Mr. Kaczynski’s delusions are mostly haunting in nature,” Sally Johnson wrote in a 47-page report. “Key issues include his belief that he is being vilified and harassed by family members and modern society.”

Kaczynski hated the idea of ​​being considered mentally ill, and when his attorneys attempted to present a defense of insanity, he attempted to have her dismissed. When that failed, he tried to hang himself with his underwear.

Kaczynski eventually pleaded guilty instead of letting his defense team continue with an insane defense.

“I’m confident in my sanity,” Kaczynski told Time magazine in 1999. “I’m not delusional and stuff like that.”

He was definitely brilliant.

Kaczynski skipped two grades to go to Harvard by age 16 and had published essays in prestigious mathematics journals. His explosives have been carefully tested and come in meticulously handcrafted wooden cases that have been sanded to remove any possible fingerprints. Later bombs were inscribed “FC” for “Freedom Club”.

The FBI dubbed him the “Unabomber” because his first targets appeared to be universities and airlines. An altitude-triggered bomb he mailed in 1979 detonated as planned aboard an American Airlines flight. A dozen people on board suffered smoke inhalation.

Kaczynski killed computer rental company owner Hugh Scrutton, advertising executive Thomas Mosser, and lumber 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.

Mosser was killed at his home in North Caldwell, New Jersey on December 10, 1994, on a day he was due to pick out a Christmas tree with his family. His wife, Susan, found him badly injured from a barrage of razor blades, pipes, and nails.

“He was moaning very softly,” she said at Kaczynski’s sentencing in 1998. “The fingers of his right hand were dangling. I held his left hand. I told him help was coming. I told him I love him.”

As Kaczynski stepped up his bombings and letters to newspapers and scientists in 1995, pundits suspected the Unabomber was jealous of the attention given to Oklahoma City bomber Timothy McVeigh.

The threat to blow up a plane in Los Angeles before the end of July 4th weekend threw air travel and mail delivery into chaos. The Unabomber later claimed it was a “prank”.

The Washington Post printed the Unabomber’s manifesto at the urging of federal authorities after the bomber said he would renounce terrorism if a national publication published his paper.

Patrik had had an uneasy feeling about her brother-in-law even before seeing the manifesto, and eventually persuaded her husband to read a copy in the library. After two months of arguments, they took some of Ted Kaczynski’s letters to Patrik’s childhood friend, Susan Swanson, a private investigator in Chicago.

Swanson, in turn, passed it on to former FBI behaviorist Clint Van Zandt, whose analysts said whoever wrote it likely also wrote the Unabomber’s manifesto.

“It was a nightmare,” said David Kaczynski, who as a child idolized his older brother, in a 2005 speech at Bennington College. “I literally thought, ‘My brother is a serial killer, the most wanted man in America.'”

Swanson reached out to a corporate lawyer friend, Anthony Bisceglie, who contacted the FBI. The investigation and prosecution were overseen by current Attorney General Merrick Garland during a previous tenure at the Justice Department.

David Kaczynski wanted his role to remain confidential, but his identity quickly came to light and Ted Kaczynski vowed never to forgive his younger brother. He ignored his letters, turned his back on him at court hearings, and in a 1999 draft book described David Kaczynski as “Judas Iscariot (who)…does not even have the courage to hang himself.”

Ted Kaczynski was born on May 22, 1942 in Chicago to second-generation Polish Catholics—a sausage maker and a homemaker. He played trombone in the school band, collected coins, and skipped sixth and eleventh grade.

His high school classmates found him odd, especially after he showed a wrestler how to make a mini-bomb that exploded during chemistry class.

Harvard classmates remembered him as a lonely, skinny boy with poor personal hygiene and a room that smelled of spoiled milk, food, and foot powder.

After completing his graduate studies at the University of Michigan at Ann Arbor, he got a job teaching mathematics at the University of California at Berkeley, but found the job difficult and resigned abruptly. In 1971, he bought a three-acre lot about four miles outside of Lincoln and built a cabin there with no heat, water, or electricity.

He learned gardening, hunting, tool making, and sewing, living on a few hundred dollars a year.

In the late 1970s, he left his cabin in Montana to work with his father and brother at a foam rubber products manufacturer outside of Chicago. But when a manager fired him after two dates, he started posting abusive limericks about her and wouldn’t stop.

His brother fired him, and Ted Kaczynski soon returned to the wild to continue his vengeful killing spree.