The FBI says it has a "credible lead" in one of its most infamous cases: the 40-year investigation into "D B Cooper", an unidentified man who parachuted out of the back of an aeroplane over Washington state, in what is still the nation's only unsolved hijacking.
A spokeswoman for the Bureau said they are testing fingerprints and DNA evidence of someone with a "strong" possible connection to the man responsible for the crime. She described the "significant" new lead as the "most promising" development since the case was opened in 1971.
The elusive hijacker, who called himself Dan Cooper whey buying his ticket, struck on the day before Thanksgiving, on a Northwest Orient flight from Portland, Oregon, to Seattle, Washington. After ordering a whisky, and smoking several cigarettes, he passed note to a stewardess which claimed that he was carrying a bomb.
Cooper, who was wearing sunglasses, a suit and tie, said he would release 36 fellow passengers provided $200,000 and four parachutes were waiting for him in Seattle. Having secured the items, he then instructed the captain to take off again, and fly towards Mexico.
Somewhere over south-western Washington state, he opened the plane's rear exit door, and disappeared into the night sky, carrying two of the parachutes and all of the cash. Bad weather meant that it was days until police could send out proper search parties, and the hijacker was never seen or heard from again.
At least 17 books have been published advancing competing theories about Cooper's identity, and the incident has also inspired a film, starring Robert Duvall. Known only by a photofit, he is seen in many circles as a Robin Hood figure, who managed to outwit both the US government and a major corporation. The nonchalant manner in which he carried out the crime also draws many admirers.
Several potential suspects have made deathbed confessions that they carried out the crime, but each has subsequently been discredited. The only concrete evidence investigators have to go on consists of DNA from eight of his cigarette ends, partial fingerprints from a magazine Cooper read, and a tie he left behind before exiting the plane.
No one even knows for sure if he survived the parachute jump. Temperatures outside were below zero and there was a heavy rainstorm. A portion of the ransom money was found some distance from the drop zone, in a sandbar on the north bank of the Columbia River, west of Vancouver.
News that the FBI is working on a fresh lead comes after a newspaper reporter interviewed its spokeswoman, Ayn Dietrich, while researching a feature pegged to the publication of a new book on the case, called Skyjack, the Hunt for D B Cooper.
"You're the first to know this, but we do actually have a new suspect we're looking at. And it comes from a credible lead who came to our attention recently via a law enforcement colleague," she told the reporter, from The Daily Telegraph. "The credible lead is somebody whose possible connection to the hijacker is strong, and the suspect is not a name that's come up before.
"It would be a significant lead. And this is looking like our most promising one to date," she added. However her comments suggested that the suspect may now be dead. "The majority of subjects we look into now are already deceased based on the timing of this."