He has been working independently on the D.B. Cooper mystery since 1982. He joins Ian for an update on his research which shows that four D.B. Cooper letters all surfaced within one week after America&apos;s most celebrated, unsolved air hijacking. All four letters were sent to major newspapers, not to the FBI. The sequence and timing of the letters is very important, as they show the "escape route" of D.B. Cooper. They also show a "connection" to the suspect, Bill Gossett.