The HBO documentary The Mystery of D.B. Cooper examined the case of Richard Floyd McCoy; a Mormon Sunday school teacher and National Guard member suspected by many of being the man who executed the most infamous act of air piracy in American history. McCoy is notable as the only one of the four suspects discussed in the documentary confirmed to have been involved in a crime similar to the skyjacking perpetrated by the man known as D.B. Cooper, yet there are many details regarding Mc Coy and his life that the documentary ignored, particularly in regard to his military record.

The Mystery of D.B. Cooper interviewed three figures regarding the theory that McCoy was D.B. Cooper. One was Ben Anjewierden, a retired Special Forces officer, who was McCoy's roommate in the National Guard and the man who tipped authorities off regarding McCoy's involvement in a skyjacking in Denver, Colorado, five months after the D.B. Cooper robbery. The second was Nick O'Hara, a retired FBI agent, who shot and killed McCoy after his second escape from prison in June 1972. The third was Bernie Rhodes, a retired federal probation officer, who co-wrote the 1991 book D.B. Cooper: The Real McCoy regarding the theory that McCoy was D.B. Cooper.

Related: Mystery of D.B. Cooper: Every Suspect of the Unsolved Skyjacking Explained

While the FBI ultimately dismissed McCoy's heist as a copycat crime inspired by D.B. Cooper, many believe that there are too many similarities between the two robberies to be explained away simply by McCoy being an apt pupil who had studied the Cooper case and plotted his own successful skyjacking. The fact that McCoy had the specialized training many believe D.B. Cooper must have had is largely ignored by The Mystery of D.B. Cooper. The documentary also fails to discuss the physical evidence of the case in regards to McCoy or the full ramifications of McCoy being confirmed to be in Las Vegas around the time of D.B. Cooper's robbery.

McCoy's Military Career and Training

Mystery of DB Cooper Richard Floyd McCoy Army Uniform Photo

The Mystery of D.B. Cooper only skims the surface of Richard Floyd McCoy's military career. Ben Anjewierden discussed his time serving alongside McCoy in the Utah National Guard, noting that he was in Special Forces and that McCoy was in the US Army Corps of Engineers, but McCoy would often fly with the Special Forces officers and was "a fun one to fly with." Anjewierden also recalled that McCoy was a group leader in Vietnam before returning to the United States and joining the National Guard and that he had earned "quite a few medals."

This is something of an understatement on the part of Anjewierden. Richard Floyd McCoy was a Green Beret who served two terms in the US Army and only agreed to reenlist for the second term if he could be guaranteed of going to Vietnam. Over the course of his two terms, McCoy was awarded the Purple Heart (which is presented to those wounded or killed in the line of duty), an Army Commendation Medal for sustained acts of heroism, and a Distinguished Flying Cross.

While McCoy's service is laudable, it also adds a tragic element to his story that such a great man should turn to crime. Nevertheless, McCoy's military service is a subject of interest to D.B. Cooper theorists because of his areas of expertise and training. When McCoy first enlisted, he served as a pilot and demolitions expert. Many believe that D.B. Cooper had experience as a pilot and working with explosives. It should also be noted that while there is no evidence of McCoy receiving paratrooper training during his time in the Army, he did become an avid skydiver upon his return to the United States.

Related: Who Is D.B. Cooper: Is The Skyjacker Alive or Dead? All Updates

The Las Vegas Connection and The FBI's Curious Denial

Mystery of DB Cooper Las Vegas in 1971

One aspect of the case explored by The Mystery of D.B. Cooper which lends credence to the idea that Richard Floyd McCoy was D.B. Cooper is the fact that McCoy can be confirmed to have been within a day's drive of where it is believed D.B. Cooper landed after his Thanksgiving Eve skyjacking. Bernie Rhodes discussed how they had gas station receipts and telephone records confirming that McCoy was in Las Vegas, Nevada, on Thanksgiving Day 1971. While this is circumstantial evidence, it does offer an explanation for what happened to the money after D.B. Cooper's escape. It is Rhodes' belief that McCoy laundered what little money he'd recovered at a casino, after losing most of his $200,000 ransom in freefall while making his escape.

However, one thing The Mystery of D.B. Cooper failed to mention is that the FBI in recent years have dismissed McCoy as a suspect precisely because of his claims that he had been having Thanksgiving dinner with his family in Utah on the day after D.B. Cooper's famous heist.  The FBI have also claimed, in the years after McCoy's death, that he was too competent to have been D.B. Cooper. While the FBI originally operated under the assumption that D.B. Cooper was a skilled tactician and an experienced paratrooper, they ultimately concluded that there is no way any experienced skydiver, no matter how daring, would try to jump under the conditions that D.B. Cooper made his escape.  The possibilities that McCoy's family had been lying to cover for his presence in Las Vegas or that he might have learned from the mistakes made during the first heist (such as failing to secure the money better) before committing his robbery in Denver have been handily ignored.

The Physical Evidence of the D.B. Cooper Case

DNA Testing Hospital Medical Medicine

One fact that the FBI kept closely guarded for many years was that they believed that D.B. Cooper had abandoned his black tie and tiepin before making his escape and that they had recovered the tie and tiepin from the plane after it landed in Reno. DNA samples were taken from the tie and tested by the FBI in recent years against samples taken from various D.B. Cooper suspects and their families. These tests have been used to eliminate suspects such as Duane Weber and LD Cooper, who were also profiled in The Mystery of D.B. Cooper along with Richard Floyd McCoy. However, The Mystery of D.B. Cooper does not discuss any of the physical evidence of the case, focusing instead upon the anecdotes of those who believe a friend or family member was D.B. Cooper.

The tie is a noteworthy clue in Richard Floyd McCoy's case because the tie-pin has been identified as one commonly worn by male students at Brigham Young University. McCoy had attended BYU for a time before dropping out and enlisting. He later re-enrolled as a student and was studying law at BYU at the time of his arrest in 1972. Another important fact The Mystery of D.B. Cooper did not report was McCoy remains one of the few prominent D.B. Cooper suspects not to be officially eliminated by DNA evidence. It should be noted, however, that is due to the McCoy family's refusal to cooperate with the authorities and offer their own DNA or any items owned by McCoy up for testing. McCoy's widow has refrained from speaking about her husband publicly, beyond filing a lawsuit against Bernie Rhodes and his co-author regarding allegations in their book regarding her involvement in her husband's crimes.

More: Mystery of DB Cooper: What The HBO Film Leaves Out So Much About LD Cooper