It is without much doubt that the Zodiac Killer had an ability to garnish his letters using references from newspapers, days, weeks, months, and sometimes years previous. Absent of stocking up on piles of newspapers in his home, one of the easiest options for the Zodiac Killer was to work in, or regularly frequent the library and harvest the current publications, or access microfiche to unearth historic material. This was exemplified by his encoded phrase in the 408 cipher, in which he used the quote of Merian C. Cooper upon release of The Most Dangerous Game (1932). Cooper was quoted as saying "man is the most dangerous animal of all" in only a handful of newspaper publications. Currently I have only found this quote from the movie's assocate producer three times - and all were in 1932 - thirty-seven years prior to the trinity of letters on July 31st 1969. This sort of effort from a killer demonstrates a conscientiousness unrivalled in the savage and stark reality of cold-blooded murder. It appears that the Zodiac Killer went to great lengths when composing his letters to the press.