Although most have taken the account of the hijacking as a single man act, authorities began to consider that there might have been an accomplice that assisted Cooper. Alongside this, Cooper expressed extensive familiarity with the parachutes, although his actual competence level is up for debate. It’s widely believed that Cooper initially demanded two pairs of parachutes within his ransom note. Officials chalked this demand up in an attempt to make authorities believe that Cooper intended to take a hostage along with him. Authorities initially gambled on the concept of sabotaging one of the parachutes as a result, but fell away from the idea as they didn’t “wish to sentence an innocent to death.”

In the haste to acquire the ransom however, authorities accidentally provided Cooper with a nonfunctional dummy-chute normally used for training purposes. And as it was, Cooper ended up taking those chutes that involved the dummy-chute in the end. Alongside this, the pair of chutes that included the dummy-chute was technically inferior and older than the other, genuine pair of chutes. Although it looks as if Cooper made a genuine mistake, the dummy-chute could’ve been used by him as a means to secure the bag of money. This is actually what Cooper planned to do with the first pair of chutes, of which included a fully functional reserve chute, leading authorities to believe he intended to attempt the same method with the dummy-chute.

Although the pair of parachutes Dan decided to carry out his escape with were technically inferior and older than the other pair of chutes, there is an actual motive behind this as the first chute was actually a civilian-luxury chute, while the inferior chute that was actually chosen was a military chute. This decision ultimately suggests that Cooper most likely has had past experience as a paratrooper, or other position within the military. Alongside this, Cooper also mentioned the McChord Air Force Base while the flight maintained a holding pattern, which was only 20 minutes from the Seattle-Tacoma Airport. Although these assumptions mainly suggest that Cooper had a military background, others actually point towards a potential background with the CIA. During the time of the hijacking, the country would’ve been towards the end of the Vietnam War, in which the CIA used a Boeing 727 to covertly airdrop supplies and troops. Flight 205, was registered as a commercial Boeing 727.