Thanksgiving 2011 Marks 40th Anniversary of DB Cooper’s Skyjacking

Forty years ago Thursday, a man known as D.B. Cooper pulled off one of the most daring crimes in U.S. history: He hijacked Northwest Orient flight 305, leaped from the plane wearing a business suit and a parachute, and made off with $200,000 in ransom money.

It was Nov. 24, 1971, the night before Thanksgiving, when the man who has been described as someone in his 40s with dark sunglasses and olive complexion boarded the Northwest flight from Portland to Seattle-Tacoma International Airport.

The man who many have come to know as D.B. Cooper paid $20 for his ticket under the name Dan Cooper. However, reports are that an early wire service report misidentified him as D.B. Cooper and so the name stuck.

After jumping out of the plane that night D.B. Cooper vanished and his true identity is still a mystery.

Thursday marks the 40th anniversary of the skyjacking and FBI agents believe they now have new physical evidence in the cold case.

That piece of evidence comes from the clip-on tie D.B. Cooper left behind on the hijacked plane.

A team of scientists who have been studying the evidence in D.B. Cooper's case for three years, at the FBI's invitation, believe they have a lead with a particle they have found.

One of the most notable particles that we've found, that had us the most excited, was titanium metal, lead scientist Tom Kaye told NBC Affiliate KING 5 News.

Kaye said the titanium was identified through the use of an electron microscope.

Though titanium is now used in things such as golf clubs and cookware, back in 1971 it was extremely rare.

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, Kaye told KING 5 News. So Cooper could have been part of the fallout.

On Dec. 31, 1966, the federal government chose Boeing to build the prototype for the country's first supersonic transport, or SST. Twenty-six airlines ordered 122 of the transports, according to Boeing's and government funding was withdrawn in 1971 before the prototype was finished, according to Boeing's Web site.

The project was canceled.

According to KING 5 News, that project was one of the first civilian planes to use titanium.

Because he wore a tie, we think he was an engineer or manager who went out on the shop floor regularly, Kaye told KING 5 News.

Kaye added that the titanium the team found is pure unlike the processed kind used in aircraft manufacture. Therefore, D.B. Cooper was likely not a Boeing employee.

The team told KING 5 News that they believe D.B. Cooper was probably employed at a titanium production or fabrication facility or a chemical plant, as chemical plants used titanium mixed with aluminum for anti-corrosive properties.

Kaye also told the news station that aluminum particles were also found on D.B Cooper's tie.

Coming up with a profile that narrows him down to hundreds of people instead of millions we think is pretty significant, Kaye said.

Ayn Sandalo Dietrich, a spokesperson for the FBI in Seattle, confirmed with the news team that it received the new evidence. The FBI didn't say anything more.

Back in August, the FBI revived people's interest in the 40-year-old cold case when it announced that it has a promising new lead in the mystery.

The bureau said it was investigating whether a man who died in the Pacific Northwest was D.B Cooper, as they received a tip from a retired law enforcement official that the dead man could have possibly been the mysterious hijacker.

FBI agents have requested the personal effects of the possible suspect so they could find possible fingerprints and DNA.

Moreover, Marla Cooper, a woman who claimed to be the niece of the airplane hijacker, told the media that she is sure that her uncle Lynn Doyle Cooper is the one who pulled off the notorious 1971 hijacking.

Marla Cooper told ABC News that she recalls being 8 years old and hearing her two uncles making suspicious plans while at her grandmother's Oregon home near where D.B. Cooper jumped.

My two uncles, who I only saw at holiday time, were planning something very mischievous, she told ABC News. I was watching them using some very expensive walkie-talkies that they had purchased. They left to supposedly go turkey hunting, and Thanksgiving morning I was waiting for them to return.

The Northwest Orient flight 305 was hijacked a day later and her uncle L.D. Cooper came home and said he was in a car accident.

Marla provided FBI agents with a guitar strap and a Christmas photograph of her uncle pictured with the same strap, which agents tested for DNA evidence.

But DNA failed to match a suspect the FBI believed was D.B. Cooper.

But Special Agent Fred Gutt has cautioned that the recent test doesn't necessarily rule out the dead suspect because there are three different DNA samples on the tie tested and that it's still unclear where the hijacker got it.

There are some questions about the tie itself: Was it a used tie, a borrowed tie? Gutt told the Seattle Times.

According to The Associated Press, a some events are planned for Saturday to mark the anniversary to including a Cooper symposium at a Portland, Ore.