D. B. Cooper - Unidentified man, who hijacked a Boeing 727 in 1971. Parachuted into the night with $200,000 ransom from the plane. Never been found or conclusively identified.
Reading that wiki summary it would seem likely that “Cooper” never made it out of the woods.
Speculation on my part regarding his lack of preparedness for the jump (no boots, poorly clothed, no steerable canopy) and the weather conditions (wet, cold, night) at the time could have resulted in possibly moderate to serious injury on landing in a remote area. Dragging himself to a water source, along with some/all money where he possibly died. Animals disperse the corpse, spring rains expanded the water source and carried money to where it was found.
Then the corpse would have been located. A human body falling from a height doesn't drill into the ground. Also, the parachute would have been detected.
Well he asked for 3 parachutes if I remember correctly. This gave him the opportunity to take a hostage with him and no way to guarantee who got which parachute. So it is unlikely that it was tampered with.
Now did he use it correctly who knows it still could have not opened.
This documentary series on Netflix is well worth the watch. Yes, it covers the details of the incident, but it also does meta-coverage on the people who are on the continuing hunt for answers. You get the DB Cooper story, and you get the DB Cooper legend, and you get those placed into a societal context.