Wordprints or Forensic Linguistics

How do you catch a twisted genius who aspires to warn our technological age of the possible problems of technology for humanity—who builds untraceable bombs and delivers them to random targets, who leaves false clues to throw off authorities, who lives like a recluse in the mountains of Montana and tells no one of his secret crimes?

How do you show critics of the Book of Mormon that the Book of Mormon is really scripture and a translation of an ancient text and not the product of Joseph Smith Jr., any of his colleagues, or taken from fiction books of his time? 

One answer of many is Wordprints or Forensic Linguistics.

In 1982, Wayne A. Larsen and Alvin C. Rencher, Brigham Young University professors of statistics, presented the first comprehensive statistical wordprint study of the Book of Mormon. Using computerized text and powerful statistical techniques, they were able to establish that the different sections of the Book of Mormon were authored by different people and that none was authored by Joseph Smith, Sidney Rigdon, Oliver Cowdery, or any other 19th-century candidates put forth by Book of Mormon critics.

Following their work, applied physicist John L. Hilton and five of his fellow scientists in the Bay Area of California (three of them non-members of the Latter-day Saint church) repeated that study using a wholly different and more conservative form of wordprinting analysis. Again, different authors were detected other than those put forward by critics, and none corresponded to the 19th-century candidates. Later, in retirement as an adjunct professor of statistics at BYU, Hilton used his techniques to identify anonymous writings of the 17th-century philosopher Thomas Hobbes to show which of Francis Bacon’s works were authored chiefly by Bacon’s staff of secretaries. 

The techniques developed by Larsen, Wrencher, Hilton, Reynolds, and others used to identify authors of articles became important in the arrest of the Unabomber when, in collaboration with the FBI, the same wordprint techniques were used to identify possible authors of the Unabomber’s Manifesto.

In 1979, an FBI-led task force that included the ATF and U.S. Postal Inspection Service was formed to investigate the “UNABOM” case, code-named for the UNiversity and Airline BOMbing targets involved. The task force would grow to more than 150 full-time investigators, analysts, and others. In search of clues, the team made every possible forensic examination of recovered bomb components and studied the lives of victims in minute detail. These efforts proved of little use in identifying the bomber, who took pains to leave no forensic evidence, building his bombs essentially from “scrap” materials available almost anywhere. And the victims, investigators later learned, were chosen randomly from library research.

Many who have heard of the Unabomber and seen the famous composite sketch of his hooded face still remain unaware of the central role that language played in the elusive Unabomber’s eventual capture.

Strange to think that a handful of mere words, short of a blatant confession, could end up pointing the finger at unknown perpetrators of a crime. But, like DNA, words and the ways we use language can potentially reveal features of ourselves, our intentions, and our actions, left in our writing without our being aware of it.

Stranger to think that because of wordprint analysis on the Book of Mormon a serious criminal was apprehended.

It’s thanks to the quirky use of idioms, oddly-placed punctuation, vocal tics, and certain other idiolectal, dialectal and stylistic markers, that anonymous speakers and authors have often been identified. Linguistic evidence or wordprints left behind in wire taps, ransom notes, texts, tweets, and emails, has sometimes led to major breakthroughs and even the resolution of many famous cases.

One phrase in the Unabomber’s Manifesto “You can’t eat your cake and have it, too,” instead of the usual form, which is “You can’t have your cake and eat it, too.” alerted those looking for the Unabomber. This form of the phrase, discovered by FBI investigator James Fitzgerald said, “is actually a traditionally middle English way of using the term. He technically had it right. It was one of the big clues that allowed investigators to make the rest of the comparison and submit a report to the judge who signed off on a search warrant.”

Theodore Kaczynski

The big break in the case came in 1995. The Unabomber sent a 35,000 word manifesto “Industrial Society and Its Future” claiming to explain his motives and views of the ills of modern society. After much debate about the wisdom of “giving in to terrorists,” FBI Director Louis Freeh and Attorney General Janet Reno approved the task force’s recommendation to publish the essay in hopes that a reader could identify the author. After the manifesto appeared in The Washington Post and The New York Times, thousands of people suggested possible suspects but it was Kaczynski’s sister-in-law (who he’d never met), Linda Patrik, who put two and two together and convinced her husband David Kaczynski to review the published manifesto. He immediately recognized unique phrases, idioms, and oddly familiar ideas that were often used by his brother, such as the unusual term “cool-headed logicians.” David described his troubled brother Ted, who had grown up in Chicago, taught at the University of California at Berkeley (where two of the bombs had been placed), then lived for a time in Salt Lake City before settling permanently into the primitive 10’ x 14’ cabin that the brothers had constructed near Lincoln, Montana. This was the crucial start of the FBI’s interest in Ted Kaczynski, but certainly not the end.

The common sense linguistic intuition that led David Kaczynski to identify his brother as the Unabomber through the written word was the spark, but needed to be reinforced by more rigorous methods. The linguistic analysis used to identify writers of the Book of Mormon was done by one of the FBI profilers working on the case, James Fitzgerald.

Fitzgerald used a simple computational method looking at word frequencies, spelling variants and the like to build up a linguistic profile in an attempt to compare and match up the authors. For example, similarities included both authors using “analyse” for “analyze,” “licence” for “license,” “wilfully” instead of “willfully,” “instalment” instead of “installment,” etc.

David Kaczynski provided letters and documents written by his brother and the detailed linguistic analysis or wordprints 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. 

Cabin of Theodore Kaczynski, the Unabomber, in the woods of Montana, where he was arrested on April 3, 1996.

On April 3, 1996, investigators arrested Kaczynski and combed his cabin. There, they found a wealth of bomb components; 40,000 handwritten journal pages that included bomb-making experiments and descriptions of Unabomber crimes; and one live bomb, ready for mailing.

Kaczynski’s reign of terror was over. His new home, following his guilty plea in January 1998: an isolated cell in a “Supermax” prison in Colorado. 

The link between Ted Kaczynski and the Unabomber could very well have been missed based on the expert opinion available, without help from David Kaczynski’s knowledge of his brother’s speech patterns and linguistic analysis learned from those searching the Book of Mormon. Law enforcement’s lack of experience with forensic linguistics meant that many of the academic experts called in to consult had no training in linguistics.

For more information on the Book of Mormon and wordprints here are a couple of links:



John Hilton – Wordprints