As a young 6-year-old, he decided that he wanted to become an explorer after reading stories from the book "Explorations and Adventures in Equitorial Africa". Cooper would eventually realise those ambitions. He was also a big game hunter, so when the script for the upcoming movie "The Most Dangerous Game" was presented to him, it obviously appealed greatly to his penchant for adventure, detailing a psychotic big game hunter who deliberately strands a luxury yacht on a remote island, where he plans to hunt its passengers for sport. This movie title has been touted as the inspiration for the Zodiac Killer's wording in the 408 cipher, but it seems that the quote given by Merian C. Cooper to a reporter of "man is the most dangerous animal of all", was the likely origin for the Zodiac Killer's choice of words in his lengthy cryptogram. Something that he could only reasonably have found by trawling through microfiche reels in the library. Currently, I have only found this exact quote in three newspapers, all from America in 1932.
But did the conception of "King Kong" and his love of big game hunting play any part in his quotation of "man is the most dangerous animal of all"? There is a strong likelihood that the Zodiac Killer took this phrase from Merian C. Cooper, but did Cooper develop this phrase from somebody else before him? Somebody who was also an adventurer and big game hunter, who came face to face with a gorilla in Africa. An adventurer who would almost certainly have been known to Merian C, Cooper.
To cover the story of Frederick "Fritz" Joubert Duquesne (born 1877) would take forever, so here is a condensed version of this infamous character, described as a soldier, big game hunter, journalist and spy, who fought with the Boers in the Second Boer War and as a secret agent for Germany during both World Wars, and became known as the man who killed Lord Kitchener, a British Army officer and colonial administrator. Duquesne was an advisor to US President Theodore Roosevelt on big-game hunting, as a publicist in the movie business, as a journalist, as a fictional Australian war hero and as head of the New Food Society in New York. As a youth, Duquesne became a hunter like his father. His hunting skills proved useful not only in the African landscape, but also later in life, when he would publish articles about and give lectures on big-game hunting. Below is a newspaper cutting from 1912 describing one of Roosevelt's hunts in Africa, with the sub-headline "The First Hunt for Buffalo, the Most Dangerous Game in Africa". In numerous statewide articles in America throughout the years, Frederick Duquesne was featured in countless stories, including full page spreads on big-game hunting. One of which we'll get to soon.
Both Merian C. Cooper and Fredeick Duquesne worked for RKO Pictures, with Cooper joining RKO Pictures in 1931, just before the release of "The Most Dangerous Game" (1932) and "King Kong" (1933). With their common lifelong interest in adventure and big-game hunting, and both employed by RKO Pictures during a similar time period, it is not difficult to see how Merian C. Cooper came upon the words "man is the most dangerous animal of all". In one of Frederick Duquesne's many ventures into Africa, he spoke of a "Blood Curdling Gorilla Hunt" in 1909 that was covered extensively in US newspapers, stating that "The most dangerous animal of all to capture is the gorilla".
The filming for "The Most Dangerous Game" and "King Kong" by RKO Pictures overlapped in 1932, so it can be strongly argued that Merian C. Cooper took the quote of "The most dangerous animal of all to capture is the gorilla" from Duquesne, and during the filming of "King Kong" he repackaged it to read "man is the most dangerous animal of all" to fit the narrative of "The Most Dangerous Game", which replaced hunting animals with the hunting of humans. So the phraseology of the Zodiac Killer in his 408 cipher on July 31st 1969 may have its roots as far back as 1909 in the words of Frederick "Fritz" Joubert Duquesne. The Zodiac Killer's wording of "I like killing people because it is so much fun, it is more fun than killing wild game in the forest because man is the most dangerous animal of all", now makes a lot more sense. His claim of using a pencil flashlight on his gun on August 4th 1969 so he could hunt victims, is in keeping with his trinity of letters to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald.
If this was the murderer's vehicle he would have known this. Therefore, the claims of the August 4th 1969 letter writer stating that he used a pencil flashlight for extra illumination is extremely noteworthy. Extra illumination would not have been required in the turnout when you have the use of headlights from your vehicle, along with the illumination from within each vehicle. Also, extra illumination would certainly not have been required if the murderer had kept the couple penned inside their vehicle. The only person that would have required additional illumination (either carried or gun-mounted) would have been somebody venturing into the fields surrounding the turnout. Such as the driver of the white Chevrolet Impala, who apparently never came forward. There is a distinct possibility that this Chevrolet owner wrote the "Debut of Zodiac" letter, because this person had a viable reason to carry additional illumination as he distanced himself from his vehicle that night. Not once, but twice, on a freezing dark night in Benicia. Possibly an individual, who on July 31st 1969, would promote the idea of hunting humans in the wilderness because it was more fun than killing wild game in the forest.