This HBO doc may be the umpteenth look at the famous 1971 Hijacking case, but, Director John Dower takes an interesting enough to keep one watching. While the basics of the case are laid out (including interviews with the stewardess and a co-pilot on the flight), Dower is more interested in fleshing out how some of the suspects in the crime have effected their family and friends left behind. Others who have investigated the case on their own are also profiled.
The Documentary focuses on four suspects (all deceased) from the many who have had the finger pointed at them over the decades. While their stories are all different, what unites them is that those who were close to them are all convinced that their husband/uncle/friend/acquaintance is THE D.B. Cooper (one even took a lie detector). None of the investigators seem convinced that there is one correct answer, including one who believes Cooper died because of the rough terrain he would have landed in.
Dower isn't really interested in finding out who did it (or, even in debunking the claims of the interviewees), but more in the psychology of the various witnesses: What makes them keep the story alive? Why do they feel compelled to tell their story? Why do they insist that you believe their version of events? None of these questions is fully fleshed out, and that lack of answers will frustrate many viewers (others will be puzzled why the several other suspects aren't even cited).
THE MYSTERY OF D.B. COOPER isn't the definitive Doc on the subject, but, it's a casually interesting look at how the story has remained in the consciousness for close to four decades.