New evidence uncovered by scientists examining D.B. Cooper's necktie has led to a shocking new twist in the recently closed, unsolved case.

A team of vigilante scientists, the self-titled Citizen Sleuths, devote their time to exclusively researching the mysterious hijacking, in which Cooper parachuted from a plane with $200,000 and was never seen again.

After examining the JC Penney tie left behind by Cooper, the Sleuths discovered a number of rare elements on its surface, which indicate that Cooper may have worked as an engineer for Boeing before the historic hijacking.

Cooper left his tie on the plane before parachuting out the back of the aircraft

After examining the JC Penney tie left behind by Cooper, the Sleuths discovered a number of rare elements on its surface

Using an electron microscope, the scientists were able to pull more than 100,000 particles from the tie, which contained traces of 'rare earth elements'.

'They're used in very narrow fields, for very specific things,' said Tom Kaye, associate researcher for the group told King 5 News.

Such elements included Cerium, Strontium Sulfide, and pure titanium. They were used at the time of Cooper's hijacking by Boeing in the production of their Super Sonic Transport Plane.

Such elements included Cerium, Strontium Sulfide, and pure titanium. They were used at the time of Cooper's hijacking by Boeing in the production of their supersonic Transport Plane

Boeing was cultivating high-tech equipment, like radar screens, in the 1960s and 1970s which utilized the elements found on Cooper's discarded tie.

'The tie went with him into these manufacturing environments, for sure, so he was not one of the people running these (manufacturing machines),' Kaye said.

'He was either an engineer or a manager in one of the plants.'

It has been 45 years since DB Cooper hijacked a plane and then parachuted into the woods somewhere around the border of Oregon and Washington with $200,000, which would be worth more than $1 million today

Kaye and his team are appealing for members of the public with experience in aerospace engineering during that time period to help them investigate further.

It has been 45 years since DB Cooper hijacked a plane and then parachuted into the woods somewhere around the border of Oregon and Washington with $200,000, which would be worth more than $1 million today.

The FBI announced in July of 2016 that they would no longer be investigating the case, as they had exhausted all leads.

However, they finished their official statement on a hopeful note: 'Although the FBI will no longer actively investigate this case, should specific physical evidence emerge - related specifically to the parachutes or the money taken by the hijacker - individuals with those materials are asked to contact their local FBI field office.'

The facts of the case are that on November 24, 1971, a man identifying himself as Dan Cooper bought a ticket at Portland International Airport in Oregon and boarded a Northwest Orient Airlines Flight 305 to Seattle, Washington.

Cooper was later described by passengers and the crew as being in his mid-forties and just under 6 feet tall, wearing a dark suit and black necktie with loafers and a raincoat.

Once the plane took off, he ordered a bourbon and lit a cigarette before casually handing flight attendant Florence Schaffner a note.

On November 24, 1971, a man identifying himself as Dan Cooper bought a ticket at Portland International Airport in Oregon and boarded a Northwest Orient Airlines Flight 305 to Seattle, Washington

Schaffner later told the FBI that she did not look at the note until Cooper whispered to her: 'Miss, you'd better look at that note. I have a bomb.'

He then told her his demands.

Cooper asked for $200,000, four parachutes and a fuel truck to be waiting on the runway when the flight landed in Seattle.

Schaffner conveyed his demands to the cockpit and the plane then circled the area for two hours so police and the FBI could gather Cooper's money and parachutes.

Authorities later found this parachute bag believed to be the one Cooper deployed

The FBI previously recovered partial DNA evidence from items including one parachute

When the plane landed, an employee of Northwest brought Cooper 10,000 unmarked 20-dollar bills and four parachutes in a knapsack, at which point the 36 passengers and Schaffner were allowed off the plane.

While that aircraft was refueling Cooper told the crew that they were to fly to Reno at an altitude of no more than 10,000 feet and a the slowest possible speed that would still keep the plane airborne.

The plane took off again at 7:40pm, two hours after landing, and Cooper ordered the members of the crew who were still on board to gather in the cockpit with the door close.

A helicopter takes off from search headquarters to scour the area hijacker Dan Cooper might have parachuted into two days before, on Oct. 28, 1976 in Woodland, Washington

Three planes followed behind, but a little over 20 minutes after the plane left Seattle a red light alerted the crew that the back hatch had been opened on the plane and Cooper was gone.

Once the plane landed in Reno the FBI dusted for fingerprints and collected the parachute and tie that Cooper left behind.

They then began to speak with all those who had seen the man to get an idea of what he looked like.

Both Schaffner and flight attendant Tina Mucklow, who had stayed on the plane when it took off from Seattle again with Cooper, had nothing but nice things to say about the criminal.

'He seemed rather nice. He was never cruel or nasty. He was thoughtful and calm all the time,' said Mucklow.

It was almost nine years before there was a break in the case, which came in February 1980 when eight-year-old Brian Abrams found some of the money that had been given to Cooper.

Eight-year-old Brian Abrams found some of the money that had been given to Cooper in 1980

While on vacation with his family in Washington the young boy discovered three bundles of cash while searching for firewood to build a campfire.

It was unclear how the money got there, and since that time the other 9,710 other bills and parachutes have never been found.

A number of conspiracy theories of the potential identity of the mysterious 'DB Cooper' have cropped up over the last four decades.

D.B. COOPER: THE CONSPIRACIES According to Richardson, the true identity of DB Cooper may be Richard Lepsy, who went missing from Grayling, Michigan Ross Richardson, a Michigan author, put forward a theory linking the mystery of DB Cooper to an obscure missing person case involving a married father of four who vanished two years before the skyjacking and was never heard from again. According to Richardson, the true identity of DB Cooper may be Richard Lepsy, who went missing from Grayling, Michigan, in October 1969, leaving behind his wife and four children. The night news of the hijacking broke, Lisa Lepsy, Richard's daughter, recalled that when DB Cooper's composite sketch was shown on TV, everyone in her family looked at each other and exclaimed, 'That's dad!' 'We were stunned because the resemblance was unbelievable, and my brothers and I were all sure that was our dad,' she told WZZM. There were other similarities between Cooper and Lepsy. Richardson noted that the black tie that was left behind by the hijacker was the same black tie that was part of Lepsy's uniform at the store in Grayling. He also said, citing the FBI, that the suspect was wearing loafers during the hijacking; Lepsy's favorite pair of shoes were loafers. Richard Lepsy, however, is only the latest in a long list of names that have been floated over the years in connection to the DB Cooper mystery. Richard Lepsy, however, is only the latest in a long list of names that have been floated over the years in connection to the DB Cooper mystery A filmmaker and his team of 40 experts sued the FBI in September of 2016 in an attempt to prove that a loose cannon ex-army helicopter pilot is in fact legendary hijacker DB Cooper. Thomas Colbert believes 'Cooper' is actually Robert Henry Rackstraw, a 72-year-old Vietnam vet living in San Diego. If he wins, Colbert his team of 40 sleuths - who include former FBI agents, criminologists, journalists and attorneys - may finally have what they need to prove their suspicions are correct. The most far-fetched theory to the series' finale was that Draper would become DB Cooper Television junkies were quick to spew conspiracy theories about the ending of the beloved show Mad Men, which finished its final season in 2015. Many viewers were racked by how the series could end, which features a dashing adman named Don Draper who reinvented himself as a new man after the Korean War. The most far-fetched theory to the series' end was that Draper would become DB Cooper, hijacking the infamous plane and jetting off into a dark night never to be seen again. In response to the theories, the show's creater Matthew Weiner said point-blank to CNN that the Cooper conspiracy was not feasible. Advertisement

In 2011, an Oregon woman claimed her uncle was the elusive plane bandit, saying she had been told by the FBI that her evidence is enough for them to close the file on the case.

In 2011, an Oregon woman, Marla Cooper, claimed her uncle was the elusive plane bandit

Burdened by guilt over her knowledge surrounding the case, Marla Cooper claimed she had a 40-year-old family secret protecting her uncle, a man named Lynn Doyle Cooper.

Marla Cooper said she was eight years old when her uncle, whom she called LD Cooper, came to her home, badly injured, for Thanksgiving in 1971 - the day after the infamous incident. He claimed his injuries were the result of a car crash.

Later, she said, her parents came to believe that L.D. Cooper was the hijacker. Mrs Cooper never saw her uncle again after that day and was told he died in 1999.

It was the FBI's most promising lead for the mystery of who was behind the hijacking.