Calling the investigation one of the longest and most exhaustive in the agency’s history, the FBI Seattle field office said it was time to focus on other cases.
The agency said it will preserve evidence from the case at its Washington DC headquarters, but it doesn’t want further tips unless people find parachutes or Cooper’s money.
“The mystery surrounding the hijacking of a Northwest Orient Airlines flight in November 1971 by a still-unknown individual resulted in significant international attention and a decades-long manhunt,” the FBI said.
“Although the FBI appreciated the immense number of tips provided by members of the public, none to date have resulted in a definitive identification of the hijacker.”
On November 24, 1971, the night before Thanksgiving, a man described as being in his mid-40s with dark sunglasses and an olive complexion boarded a flight from Portland, Oregon, to Seattle-Tacoma International Airport.
He bought his $20 ticket under the name “Dan Cooper,” but an early wire-service report misidentified him as “D.B. Cooper,” and the name stuck.
Sitting in the rear of the plane, he handed a note to a flight attendant after takeoff. “Miss, I have a bomb and would like you to sit by me,” it said.
The man demanded $200,000 in cash plus four parachutes. He received them at Sea-Tac, where he released the 36 passengers and two of the flight attendants.
The plane took off again at his direction, heading slowly to Reno, Nevada, at the low height of 10,000 feet. Somewhere, apparently over southwestern Washington, Cooper jumped.
He was never found, but a boy digging on a Columbia River beach in 1980 discovered three bundles of weathered $20 bills — nearly $6,000. It was Cooper’s cash, according to the serial numbers.
Over the years, the FBI and amateur sleuths have examined innumerable theories about Cooper’s identity and fate, from accounts of unexplained wealth to purported discoveries of his parachute to potential matches of the agency’s composite sketch of the suspect.