The case has remained a mystery since Nov. 24, 1971, when a man hijacked a Boeing 727, obtained $200,000 in ransom money and then parachuted to safety. Despite an extensive manhunt and decades-long FBI investigation, the identity of the hijacker has never been determined. The case has spawned countless theories.
In 2007, the FBI opened the case to the public, sharing files and evidence. A scientific team analyzed particles from the clip-on tie Cooper left behind. A powerful electron microscope found cerium, strontium sulfide and pure titanium on the tie, according to KING-TV.
Tom Kaye, lead researcher for a group called “Citizen Sleuths,” said the elements discovered on the tie were rarely used in 1971. However, they were being used in the aerospace industry in the 1960s and 1970s, when Boeing was developing a supersonic transport plane. Kaye and his colleagues theorize that Cooper may have been a Boeing employee or contractor.
“The tie went with him into these manufacturing environments, for sure, so he was not one of the people running these (manufacturing machines). He was either an engineer or a manager in one of the plants,” Kaye told KING-TV.
Kaye and his colleagues are appealing for help from the public on what the materials may have been used for. They’re hoping “old-timers” from the aerospace industry in the Pacific Northwest could be particularly useful.
Find more information about Citizen Sleuths and their investigation at their website.