D.B. Cooper has eluded FBI agents for almost 40 years. But now new evidence has brought life back to what was a cold case file. A woman has come forward with information and she is claiming to be his niece.

Marla Cooper's story has prompted FBI agents to re-open their files on the cold case that's eluded them for four decades.

Among the evidence that Marla has provided the FBI is a guitar strap and a Christmas photo of her uncle, Lynn Doyle Cooper, with the same strap. The FBI is checking her story and this new evidence against case files and evidence according to ABC News.

In case you are not familiar with the D.B. Cooper story, On November 24th, 1971, a man calling himself Dan Cooper hijacked a Northwest Orient Airlines flying from Portland to Seattle.

D.B. Cooper demanded that the plane land, and a ransom of $200,000 in small bills be brought to him. Once he had the money, he ordered the plane's pilot set a course and fly to Mexico. But mid-flight, D.B. Cooper lowered the back ramp of the plane and jumped out over the Pacific Northwest and was never heard from again.

ABC News has the exclusive story: