Evaded justice? Artists sketches of America's most elusive fugitive DB Cooper who hijacked a jet and extorted $200,000 from the FBI before escaping by parachute in 1971. Agents believe he may have died a decade ago
For decades he has remained one of America's most elusive fugitives.
In 1971 D.B. Cooper commandeered a plane claiming he had dynamite, eliciting a $200,000 ransom, before parachuting out of the plane and disappearing forever.
But, on the 40th anniversary of the notorious skyjacking, new physical evidence the FBI believe could help them close in on the suspect, has emerged.
The new lead is a titanium particle from the clip-on tie Cooper left when he jumped from the Seattle bound-plane in skies above Washington, NBC affiliate KING 5 News reported.
An elite group of scientists have been examining evidence from the infamous case for the last three years.
Tom Kaye the lead scientist in the private team said: 'One of the most notable particles that we’ve found, that had us the most excited, was titanium metal.
The titanium was found by team members studying Cooper’s tie with an electron microscope.
Titanium is now integral in numerous household items from golf clubs to cookware, but was very rare in at the time.
Aircraft manufacturer Boeing was one of the first manufacturers to use titanium in a civilian aircraft.
Plot: A hijacked Northwest Airlines jetliner 727 sits on a runway for refuelling at Tacoma International Airport on November 25 1971
But the company canceled its Super Sonic Transport project shortly before the hijacking.
Kaye told the station: 'In 1971 there was a big upheaval in the titanium industry with the cancelling of the SST project, which happened to be at Boeing, and that laid a lot of people off in the industry. So Cooper could have been part of the fallout.
Kaye said that the titanium is pure, not processed like the sort used in the manufacture of planes
So the team believe he was probably not a Boeing worker but employed at a titanium production plant.
Alternatively he may have worked at a chemical plants where titanium was mixed with aluminum.
Kaye said aluminum particles were also found.
'Because he wore a tie, we think he was an engineer or manager who went out on the shop floor regularly.
The new leads could be instrumental, Kaye believes.
Coming up with a profile that narrows him down to hundreds of people instead of millions we think is pretty significant,' he said.
The FBI reopened the case in 2008. And earlier this year the agency believed it finally had the mysterious fugitive in its sights, when a woman claimed her uncle was the missing fugitive.
There have been more than 1,000 suspects over the past four decades.
The mysterious hijacking has intrigued federal agents and amateur sleuths.
A man calling himself Dan Cooper boarded the Northwest flight after buying a $20 one-way ticket to Seattle.
After getting on the plane wearing sunglasses, he ordered whisky and lit a cigarette before passing a flight attendant a note that read: 'I HAVE A BOMB IN MY BRIEFCASE.
I WILL USE IT IF NECESSARY. I WANT YOU TO SIT NEXT TO ME. YOU ARE BING HIJACKED.
Cooper told the captain that in return for $200,000 and four parachutes, he would allow 36 people to leave the plane when it landed in Seattle.
The FBI agreed to the swap and the plane took off again under Cooper's orders to fly towards Mexico at an altitude of under 10,000 feet.
Clues: Three packets of ransom money, totalling $5,800, were found on the Columbia river in February 1980
Somewhere over the lower Cascade mountains in southwestern Washington, Cooper stepped out of the plane with a parachute strapped to his back.
Several people have claimed to be Cooper over the years but were dismissed on the basis of physical descriptions, parachuting experience and, later, by DNA evidence recovered in 2001 from the cheap tie the skyjacker left on the plane.
Items recovered from the skyjack include $5,800 of the stolen money, in tattered $20 bills and Cooper's tie
Many believe that Cooper was Richard McCoy, a Vietnam War veteran, experienced parachutist and BYU political science student who staged a similar hijacking several months later.
But the FBI has said that McCoy - who was killed in a shoot-out with law enforcement officers after a prison break in 1974 - simply didn't fit the description of Cooper provided by two flight attendants.
In 1980, a boy walking near the Columbia River found $5,800 of the stolen money, in tattered $20 bills.