Modern Mysteries

FBI publishes new 686-page dossier on the DB Cooper mystery

By T.K. Randall
January 26, 2026 ·  13 comments

Image Credit: Federal Bureau of Investigation One of the most notorious unsolved crimes in American history, the hijacking - which occurred on November 24th, 1971 - began when a man, who identified himself as Dan Cooper, boarded Northwest Orient Airlines Flight 305 to travel from Portland to Seattle.

During the trip, Cooper called over one of the flight attendants and asked them to write out a note declaring that he had a bomb in his briefcase and that the plane was being hijacked.

When the aircraft stopped at Tacoma International Airport, he allowed the passengers to leave in exchange for four parachutes and the sum of $200,000 in cash.

After the plane had taken off again, Cooper strapped the bag of money to himself, put on one of the parachutes and jumped out somewhere between Seattle and Reno. No trace of him was ever found.

Now, more than 50 years after the incident, the FBI has published a large dossier of newly declassified material pertaining to the case.Consisting of 686 pages, the new release doesn't really do much to solve the mystery itself, but it does offer some fascinating new insights, in the form of memos and notes, into the hunt for the culprit.

Among the new revelations revealed by the dossier is the fact that Cooper had taken apart one of the sets of parachutes that had been brought on-board, meaning that he may have only asked for more than one to give the impression that he had intended to take a hostage.

The files also reveal that he had seemingly been well up to speed on specific details of the flight, possessing knowledge of the plane beyond even the crew.

Could this mean that he had some connection to the aviation industry ?

The dossier also reveals that the FBI had been looking into a whopping 325 suspects.

You can check out the dossier for yourself on the FBI's website - here.

Source: Popular Mechanics | Comments (13)

Tags: DB Cooper