In June 1995, the New York Times and The Washington Post both received copies of a 56-page, typewritten document called “Industrial Society and Its Future.” The single-spaced 35,000-word treatise began, “The Industrial Revolution and its consequences have been a disaster for the human race.” From there it embarked on a sprawling condemnation of a technological society that intentionally created an unfree and alienated populace. It ends with a call for revolution, to be carried out by pushing the current system to its breaking point while propagating an anti-technology mindset.
The author was the then-elusive figure known in the media as the “Unabomber,” based on the FBI moniker given him; since 1978, he had targeted universities and airlines with bombs delivered by mail. By 1995, he had killed three people and maimed another 23. Authorities had few leads; their most prominent clue was a police sketch made in 1987, thanks to a Salt Lake City eyewitness who noticed a man loitering outside her local computer store. The now-famous sketch showed a white male wearing aviator glasses and a hooded sweatshirt.
The manuscript arrived with a threat. The Times or the Post had to publish the essay in its entirety, or there would be more killings. After several months of deliberation and consultation with the FBI and the Department of Justice, both newspapers decided to publish it as “The Unabomber Manifesto.” It was a difficult and significant decision, one of the few times an American newspaper bowed to the publication demands of a criminal—almost thirty years before, a trio of San Francisco newspapers published the ciphers sent by the Zodiac Killer, which were promised to reveal his identity.
In the Zodiac case, the newspapers decided that if printing the ciphers could prevent more killings, they would do so. Facing the Unabomber’s threat, the Post and Times made a similar calculation. Donald Graham, the Post‘s publisher, told the paper, “We are printing it for public safety reasons, not journalistic reasons.” Publishing the work, many argued, might help a reader identify its author.
The manifesto appeared as an eight-page insert and soon gained even wider distribution. One of the people who read it was David Kaczynski. He’d already begun to harbor suspicions about his estranged brother, Ted, a Harvard-educated former mathematics professor, who’d retreated from modern life in the early 1970s to an off-the-grid cabin in Montana. Reading the manifesto, David Kaczynski recognized the long-running debate he’d had with his brother about the roles of art and science in society; the manifesto used the phrase “cool-headed logician,” which David had often heard his brother use.
After reading the manifesto, David Kaczynski hired a private detective to investigate his brother. He passed the results on to the FBI, which led agents to Ted Kaczynski’s Montana cabin in April 1996. Inside, authorities found carefully labeled cans of chemicals, a sweatshirt similar to the one seen by the Salt Lake City witness who provided the famous description, and a trove of writing—some 20,000 pages.
“We are printing it for public safety reasons, not journalistic reasons.”
With Kaczynski arrested, his court-appointed attorneys sought to have all the evidence from the cabin thrown out, arguing that the search warrant was invalid. In addition to David Kaczynski’s description of his brother and other circumstantial evidence, the affidavit supporting the search warrant claimed to have found similarities between “Industrial Society and Its Future” and Ted Kaczynski’s known writing. The defense team wanted to challenge that analysis, arguing that anyone with an axe to grind against modern society could have written it.
In response, the federal prosecutor asked Don Foster, a professor of English literature at Vassar College, to examine the Unabomber Manifesto, compare it to Kaczynski’s known writing, and offer his opinion on the question of authorship.
The authorities came to Foster in part because he’d already received popular attention for identifying political commentator Joe Klein as the author of Primary Colors, an anonymous 1992 novel fictionalizing Bill Clinton’s first presidential campaign. Using an electronically searchable copy of the novel, he’d compared text from the novel with Klein’s Newsweek columns, looking for repeated words, parallel syntax use, and unique phrases. As it turned out, the author of Primary Colors favored words like “lugubrious,” “puckish,” and even the phrase “tarmac-hopping,” all of which were used repeatedly and uniquely by Klein.
But Foster’s methods weren’t without controversy. Critics pointed out that others had already suspected Klein. That’s why his Newsweek columns had been included among the limited number of suspect texts Foster used for comparison. For months afterward, Klein refused to admit he was the author; Foster, it seemed to critics, waffled a bit in the face of Klein’s denial, offering that maybe the columnist wasn’t the only author. Nevertheless, Klein eventually confessed.
So Foster agreed to perform a similar comparison between the manifesto and Kaczynski’s known writing. One overlap he noticed was the phrase “sphere of freedom.” A previous expert had told the FBI the phrase was too common to suppose evidence of authorship. But using LexisNexis, Foster showed that of the 229 results listed by the search engine, 193 instances were quotations. Of the remaining 36 results, nine were dated after the publication of the manifesto. That suggested “sphere of freedom” wasn’t a common phrase at all—it tied Kaczynski to the manifesto.
Similarly, in 1971, Kaczynski had submitted an essay to the Saturday Review in response to three articles about technology and government surveillance. The essay was never published, but Foster examined it. He found repeated words, recurring phrases, and shared diction between it and the manifesto. So clear were the similarities, Foster concluded in his affidavit, “Astonishingly, only 15 words in [the essay] fail to reappear in [the manifesto].” And of those 15 words, two were “Saturday” and “Review”—the name of the magazine itself.
“There are no computer programs that can identify authorship.”
Citing these and other similarities, Foster declared to the court that Kaczynski’s known writing shared “authorial voice, tone, and ideology” with the Unabomber Manifesto, and “share[d] nearly identical diction, phrasing, and syntax.” That led him to offer three possible conclusions: that the Unabomber “directly plagiarized Kaczynski’s essay,” unpublished and more than four decades old; the manifesto and the Saturday Review essay “were written by the same individual … though by someone else” and not by Kaczynski; or Kaczynski authored both documents and was therefore the Unabomber.
Ultimately, the judge ruled the search warrant valid, and the contents of Kaczynski’s cabin were used as evidence in the trial against him. He was found guilty and is now serving eight life sentences without the possibility of parole.
Reached by email recently, Donald Foster says, “Ted Kaczynski is ancient history for me—but I’m happy to help” by describing his analysis. As hard as it may be to believe 20 years later, he didn’t use any specialized programs, no machine learning or carefully calibrated algorithms. There was just the built-in text search, the then-nascent World Wide Web, the LexisNexis database, and some academic search tools; his affidavit from the time is locked in a WordPerfect document. “But,” as he says, “there are no computer programs that can identify authorship.” He had to make his own arguments, based on his own careful observations. In the case of Kaczynski, he says, “As per another musty proverb: It didn’t take a rocket scientist.”
That doesn’t mean his technique was infallible. In the years following the Unabomber case, he retracted a claim to have found a “lost” Shakespeare poem—the claim that had first brought his textual analysis to greater attention. Critics continued to dispute his comparisons of his work to DNA testing. Still, he was brought in as a consultant in the JonBenét Ramsey case and asked to analyze the ransom note; his conclusions were controversial, as he seemed to shift blame from one Ramsey parent to the other, and he was dismissed by authorities.
He also helped the FBI during the investigation of the 2001 anthrax attacks, writing an article for Vanity Fair which focused on Steven Hatfill, long a “person of interest” in the case. Hatfill sued Condé Nast Publications, Vassar College, and the Reader’s Digest Association (which had published an excerpt of the story), for defamation—one of several suits Hatfill filed, arguing he’d been wrongly targeted by law enforcement and the media. Condé Nast settled its suit out of court for an undisclosed sum.
Since then, Foster has returned to his original academic passion for Elizabethean literature. There’s an irony there, as Foster notes in his book, Author Unknown: Tales of a Literary Detective: Ted Kaczynski considered literature among the “bullshit subjects” he wouldn’t bother targeting in his manifesto. He was much more concerned with scientists, engineers, and industrialists. But when it came time to argue that Kaczynski was, in fact, the author of his most famous work, it wasn’t a scientist or an engineer trying to make the case. It was a professor of literature.
Illustration by J. Longo