D. B. Cooper Redux: Help Us Solve the Enduring Mystery. Federal Bureau of Investigation, 31. Dezember 2007, abgerufen am 26. März 2011 (englisch): „We originally thought Cooper was an experienced jumper, perhaps even a paratrooper. We concluded after a few years this was simply not true. No experienced parachutist would have jumped in the pitch-black night, in the rain, with a 200-mile-an-hour wind in his face, wearing loafers and a trench coat. It was simply too risky. He also missed that his reserve chute was only for training and had been sewn shut—something a skilled skydiver would have checked.“
D B Cooper Part 7 of 7. (PDF, 3.92 MB) In: FBI Records: The Vault. U.S. government, U.S. Department of Justice, S. 10–12, abgerufen am 18. Februar 2016 (englisch).
D. B. Cooper Freigegebene Dokumente des FBI aus der Zeit bis Mai 1992.
Beispiele: Teil 10 der Dokumentsammlung besteht aus 523 Seiten, Teil 22 aus 359 Seiten.