The 1971 skyjacking by a man using the name Dan Cooper left the world breathless as he ransomed 36 hostages aboard Northwest Orient Flight 305 for $200,000, then parachuted from the plane with the money.
D.B. Cooper disappeared from sight and into history, his true identity unknown.
Sheridan Peterson was chief among the suspects, with investigators pointing to his experience as a smokejumper, his love of skydiving and taking physical risks, and even reportedly “experimenting with homemade bat wings,” according to The Oregonian.
Peterson died Jan. 8, according to Legacy.com, a memorials website. The circumstances of his death are not known. He is survived by his son and daughter.
The California native served in the Marines during World War II and later worked as a technical editor at Boeing, based in Seattle.
A stash of money was found buried along the Columbia River near Portland, Ore., in 1980, but the FBI continued its manhunt. The case remains the only unsolved skyjacking in U.S. history, with many interesting candidates topping the list of suspects.
Pheonix entrepreneur Eric Ullis spent years trying to figure out D.B. Cooper’s identity. In the end, Ullis was “98%” certain that Peterson was the man behind the famous heist.
Peterson flirted with the idea that he was D.B. Cooper on a number of occasions: He most prominently toyed with suspicion in a 2007 issue of Smokejumper, a magazine published by the National Smokejumper Association.
“Actually, the FBI had good reason to suspect me,” Peterson wrote. “Friends and associates agreed that I was without a doubt D.B. Cooper. There were too many circumstances involved for it to be a coincidence.”
“At the time of the heist, I was 44 years old,” Peterson explained. “That was the approximate age Cooper was assumed to have been, and I closely resembled sketches of the hijacker.”
Peterson also admitted that he did himself no favors when photos surfaced from a Boeing news sheet that showed him dressed in the exact same formal attire reportedly worn by D.B. Cooper during the heist. Peterson insisted that he was in Nepal at the time of the skyjacking, but the FBI continued to monitor him as a prime suspect.
Peterson is not the first suspect to have passed away before the FBI could come to any final conclusion about the D.B. Cooper case.
Another suspect, Robert Rackstraw, died in 2019 at the age of 75.
Many amateur sleuths pointed to Rackstraw, but the FBI discounted him due to his age: He would have been 28 at the time, while witnesses said the suspect was 35 to 45 years of age.
Rackstraw once jokingly admitted to being the jumper, and codebreakers claimed that a letter sent by D.B. Cooper indicated Rackstraw was the culprit.
Another researcher claimed in 2018 to have determined that D.B. Cooper was actually William J. Smith, who may have taken the name from his deceased friend Ira Daniel Cooper.
The analyst speculated that Smith and his wife, a woman named Dolores, may have planned the spectacular crime together. Dolores retired at the fairly young age of 54.
Fox News’ Ryan Gaydos, Chris Ciaccia and Louis Casiano contributed to this report.