This case is an outlier as it represents the only unsolved skyjacking in American history. The FBI were good at their jobs, they solved all the other cases, so why did Cooper escape justice? The common reaction has been to say Cooper died in the jump so the FBI had no one to catch. This is current orthodoxy in this case: An unknown individual, a loner with few social connections, boarded the plane, jumped with the money, and impacted somewhere in the Washougal watershed. The FBI may not have found his body, but they know he didn’t escape with the money.
However, there are other explanations for why Cooper was able to avoid the FBI. In fact, Cooper would have been the only skyjacker who had a good opportunity to avoid justice because he was the first to actually jump out of the aircraft.
– The FBI, and others, did not expect Cooper to jump. Up to this point in history, all other hijackings had similar modus operandi: the plane would be hijacked, then flown somewhere, often Cuba. (Humorously, the Cubans would arrest plane hijackers regardless of their Marxist views.) It wasn’t even publicly known if an airliner could be jumped safely. Only a very small group of people at the CIA and Boeing knew the 727 was a safe skydiving platform.
-Cooper also lucked out because no one knew how to estimate the drop zone. Thus, during the most important time of the heist, the 24 hours after the jump, the FBI had no idea where to look, other than a vague search area encompassing almost all of Cowlitz and Clark counties in Washington. Himmelsbach even flew his airplane south of Portland in the days after the hijacking, before testing confirmed the Ariel jump location. Later, based on his hijacking and later testing, investigators could pinpoint a drop zone within a few miles.
-Cooper’s audacity resulted in what can only be described as a very slow reaction from law enforcement. During later hijackings, the FBI created a chain of communication that activated search parties, roadblocks, helicopters and flares to a drop zone very quickly during a hijacking. Richard McCoy could actually see the search operations targeting him before he hit the ground. For Cooper, there was almost no ground operation on the night of the jump, and only a cursory search over the following week.
-Finally, it’s clear that, live or die, Cooper made no large purchases with the ransom money. No mistaks were made prior to or after the hijacking. No one recognized him from the sketches; he was not missed by friends or family. Whoever he was, he had no one close to him who could identify him as the skyjacker. This is a significant indicator of his social status at the time of the hijacking, and any suspect has to match this particular situation.
Basically, Cooper and only Cooper could have gotten away with this crime. He was the first guy to attempt such a heist, which was the primary key to his success, and he made no major errors before/during/after the hijacking to get himself caught.