Nancy Guthrie ransom notes release follows Unabomber ‘precedent' that cracked case, expert says

A veteran retired investigator following the Nancy Guthrie case said the release of two purported ransom notes echoes the investigative strategy that helped identify the Unabomber, as authorities hope the messages will generate new tips six months after her suspected kidnapping in Tucson, Arizona.

"Law enforcement rarely makes the deliberate call to release an offender's own words to the public," said Lisa Miller, a retired investigator from the Colorado Attorney General's Office.

While she's not connected to the Guthrie investigation, she's been following it closely for the past six months.

NANCY GUTHRIE RANSOM DEMANDS RELEASED BY PIMA COUNTY SHERIFF'S DEPARTMENT IN BID TO IDENTIFY SENDER

"The last major precedent: 1995, the Unabomber manifesto…published on the FBI’s recommendation, betting someone would recognize the writing," she noted in an X post over the weekend. "It worked."

GOT A TIP?

David Kaczynski and his wife, Linda Patrik, recognized Ted Kaczynski's writing style and alerted authorities. Ted Kaczynski was arrested in 1996 and pleaded guilty two years later to avoid the death penalty. He spent most of his time behind bars at the ADX Florence Supermax prison in Colorado.

According to FBI records, Kaczynski sent a 35,000-word manifesto outlining his motives "and views of the ills of modern society."

NANCY GUTHRIE CASE COULD HINGE ON MYSTERY TIPSTER WHO EMAILED TMZ

Then-FBI Director Louis Freeh and then-U.S. Attorney General Janet Reno signed off on a plan to publish the document. After it ran in national news, the task force investigating that case received thousands of tips — including a note from David Kaczynski, who included other writing samples that linguistic analysts used to compare against the manifesto.

NANCY GUTHRIE SHERIFF SAYS INVESTIGATORS MAY HAVE MORE VIDEO EVIDENCE AS THEY REVIEW THOUSANDS OF CLIPS

On Friday, the Pima County Sheriff's Department released two notes that have been deemed potentially credible in the abduction of the 84-year-old mother of "Today" co-host Savannah Guthrie.

Authorities said the two notes share a "unique linguistic style" and are believed to have been sent by the same person.

FOLLOW THE FOX TRUE CRIME TEAM ON X

"There are a number of pieces of information in these notes that just might jar someone to say, 'You know, I've heard that,' or the wording, the style of the writing," Pima County Sheriff Chris Nanos said in a video posted to X Saturday. "We hope that by releasing the actual note, we'll get some response from the community."

SIGN UP TO GET THE LATEST TRUE CRIME NEWS

They are much shorter than the Unabomber's lengthy essay and less useful for linguistics analysis, Miller said, but they still contain clues and consistent phrasing that could stand out to someone who knows the writer.

The clearest habit appears to be the sender's tendency to write a statement and then immediately follow it with a comma-spliced reinforcing statement, she said.

For example, she gave the following lines:

LISTEN TO THE NEW 'CRIME & JUSTICE WITH DONNA ROTUNNO' PODCAST

"You will not be able to contact me from here on out, there will be no negotiation."

"We never intended to hurt her, that was not our intention."

Miller said she doesn't believe the notes were written by artificial intelligence. The notes include "uneven grammar and syntax," emotionally charged repetitions and awkward phrasing, she said.

Authorities are looking for help identifying the masked intruder who appeared on Guthrie's Nest doorbell camera on the night of her abduction as well as the sender of the notes.

Anyone with information in the case is asked to dial 1-800-CALL-FBI or, to remain anonymous, call 520-88-CRIME.

The sum of all rewards in the case is over $1.2 million. The money remained unclaimed as of Friday, a day before the six-month mark since Guthrie's kidnapping.