On Thanksgiving Eve 1971, a man calling himself Dan Cooper skyjacked a Northwest Orient flight travelling from Portland to Seattle.
Upon landing in Seattle, Cooper ransomed the passengers for $200,000 and four parachutes. He then directed the jet to take-off and head to Mexico City by way of Reno for a fuel stop.
Approximately 36 minutes after departing Seattle, somewhere just north of Portland, Cooper parachuted out of the back of the jet never to be seen or heard from again.
We believe we've solved the case.
1) He is one of only three people known to have had their DNA compared with the partial DNA profile extracted from Cooper’s tie—this among a field of approximately 1500 suspects. The other two are Duane Weber and Lynn Doyle Cooper.
2) He is the only one of the three DNA-compared suspects that the FBI has not publicly stated didn't match the partial Cooper DNA profile.
3) He was formerly employed by Boeing as a technical editor with access to the commercial and aerospace divisions as well as the Super Sonic Transport (SST) project.
4) He was an expert skydiver with smoke jumping experience and described as a maverick and fearless in skydiving circles.
5) He was living in Nepal during the skyjacking, not employed at the time (2 ½ years), and provided an alibi that has since been disproved.
6) He opened a confidential numbered bank account in 1971.
7) DB Cooper’s tie clip was sold as a set that also included a tie tack, cuff links and money clip. Sheridan owned a pair of the cuff links that were included in these sets.
8) In a 2003 interview with the FBI, Sheridan described the "dummy reserve" (missing parachute) in terms only the skyjacker could have known.
9) He has refused to directly deny being DB Cooper when asked by the FBI.
10) He resembled the physical description given by witnesses.
11) He first came to the attention of the FBI and became a suspect a week after the Thanksgiving Eve hijacking that occurred on Wednesday, November 24, 1971.