When Jim Fitzgerald urged the FBI in 1995 to convince both the New York Times and Washington Post to publish a 35,000-word, anti-technology manifesto by a mad man threatening to blow up a plane, he was worried his idea wouldn’t work.

The goal was to capture the unabomber, an American terrorist behind 16 mail bombs that killed three people and injured 23 within an 18-year period.

“We all had our concerns,” the former FBI profiler told Fox News. “We realized this could also open the doors for a lot of different people. Every newspaper and every TV news network could be contacted by [terrorists], wanting to get their document of some sort out there to spread the word of what they were doing. And I was very conscious of that.”

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FBI Special Agent in Charge Jim Freeman confirms to reporters the authenticity of the most-recent communication from the notorious Unabomber, seen in a composite photo at left, during a press conference in San Francisco, June 28. The Unabomber has threatened to bomb an airliner leaving Los Angeles in the next six days - RTXFWC0

Despite his hesitations, Fitzgerald knew he was on to something.

“I was one of the first people who had really dug into the manifesto and said ‘Boy, there is so much distinctive language in here; I can’t believe someone from somewhere wouldn’t recognize this guy.'”

The plan worked. The unabomber’s article, titled “Industrial Society and Its Future,” was published in September 1995 and by February 1996, the mystery writer was identified as Ted Kaczynski, a recluse living without electricity or running water on a mountain shack in Lincoln, Montana. In April that year he was arrested and the now-75-year-old is currently serving four life terms in person.

The real-life crime drama is now a scripted series for Discovery titled “Manhunt: Unabomber” where curious viewers learn how Kaczynski, who once had a promising career in academics, became a murderer.

“The unabomber was a very dangerous person because no one ever knew who his next target was going to be or where it would occur,” recalled Fitzgerald. “His bombings seemed random at first and he only earned his nickname because his first bombings were in fact universities or airlines."

Before the killings, Kaczynski was recognized as a genius from Chicago who attended Harvard at age 16 and earned his Ph.D by his mid-twenties. His first position was that of a math professor at California’s Berkeley University.

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Ted Kaczynski poses in his booking mugshot from April 1996. The FBI is asking for DNA samples from "Unabomber" Ted Kaczynski in connection with unsolved 1982 murders involving Tylenol capsules laced with potassium cyanide, FBI officials said on May 19, 2011. Kaczynski, 68, became one of America's most notorious criminals by killing three people and wounding 29 with homemade bombs sent by post from 1978 to 1995. REUTERS/Handout/Files (UNITED STATES - Tags: CRIME LAW HEADSHOT) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS - RTR2MMRH (Reuters)

“He was a confused person growing up, mentally, sexually, philosophically,” said Fitzgerald. “And he didn’t like people… he basically didn’t like himself.”

In 1969, Kaczynski chose to leave behind society for a hermit’s life on a Montana mountaintop. With money he earned from teaching, Kaczynski and his brother David built a cabin together where he would happily reside in for six years.

In 1978, he moved back to Illinois and work alongside his brother in a foam rubber factory. There, he developed a brief relationship with a woman, which quickly soured. It was that same year when his first bombing occurred at Northwestern University.

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Wanda Kaczynski (R), mother of convicted Unabomber Ted Kaczynski, wipes tears from her eyes as Ted Kaczynski's brother David talks to the press outside the U.S. Courthouse in the Fred E. Moss Federal Building January 22. Ted Kaczynski pleaded guilty in court today to all charges filed against him. KACZYNSKI - RTRAPCT

David would ultimately come forward with the unabomber’s identity.

“It had to be one of the most difficult decisions anyone would have had to make in life,” said Fitzgerald. “Even if you’re not that close to [your loved one], his blood runs through your veins, too. And you have to make a decision on whether to just leave him alone and let him do what he does, which is killing people, or come forward and try to save lives. I have no doubt, and I know for a fact, that this was very difficult for David. He kept trying to talk himself out of it.”

Yet, it was Kaczynski’s willingness to publish his lengthy manifesto that proved to be his downfall.

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Workers prepare to right the cabin home of Unabomber suspect Theodore Kaczynki on December 5 after it was unloaded from a truck at the former Mather Air Force Base in Rancho Cordova, California. The 10 x 12-foot cabin was moved by truck from Montana by the defense to exhibit to jurors during the upcoming trial. UNABOMBER - RTR9DCZ

“The first thing I realized was this guy was writing essentially mistake-free, which very few of us ever do without an editor,” explained Fitzgerald. “This guy amazed in sentence structure, his usage of language — everything about it was perfect… He would have a few typos that he would ex out, but anyone using a 1930s mechanical typewriter is going to have a few typos.

"But he also had three pages of corrections after the cover page of his manifesto. I mean, who bothers doing that? These are notes on whether a period should be inside a quotation mark or not, whether a comma should be placed here or there… Nothing of any substance or value that would change the meaning of what he’s writing.”

Fitzgerald also revealed Kaczynski used archaic terminology rarely used in the '90s. And there was one strange sentence that couldn’t be ignored.

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James Fitzgerald and Sam Worthington arrive at Discovery's Manhunt: UNABOMBER reception at the Television Critics Association Summer Press Tour at The Beverly Hilton on Wednesday, July 26, 2017 in Beverly Hills, Calif. Worthington plays Fitzgerald in the Discovery scripted series (Colin Young-Wolff/AP Images for Discovery Communications) (AP Images for Discovery Communic)

“The big one was in paragraph 185… he ended it with the phrase, ‘Well, you can’t eat your cake and have it, too.’ I thought, ‘Wait, he has that backwards. It should be you can’t have your cake and eat it, too. That’s how everybody says it.’ But guess what? He technically had it right. The rest of us had it wrong. Going back to 15th century early modern English.

"A treasure trove of evidence [was found] within the writings of the unabomber, and then when they were matched up with the writings of Ted Kaczynski, we came up with 600 virtually identical sentences and that helped us close the case.”

Kaczynski’s capture wasn’t just gratifying for Fitzgerald.

“Quite frankly, if you’re going to strictly put it in the category of manhunt or wanted person, probably with the exception of Osama Bin Laden… it may still be to this day that the unabomber manhunt was the most expensive one in law enforcement, criminal justice history,” he said.

"Manhunt: Unabomber" airs Tuesdays at 10 p.m. on Discovery.