The 408 Cipher contained the phrase "the most dangerous animal," believed to be referring to a short story 'The Most Dangerous Game' by Richard Connell first published on January 19th 1924, which chronicled a man called General Zaroff. He lived on Ship-Trap Island where he indulged in capturing shipwrecked sailors, before equipping them with hunting clothes, a knife and food before releasing them with a three hour head-start, then he would hunt them down and kill them. If however they survived for three days he would allow them their freedom.
Zaroff had become bored with just hunting wild animals, as he eluded, it posed no challenge, with the 408 cipher stating ' I like killing people because it is so much fun it is more fun than killing wild game in the forest'. It is thought the Zodiac may have drew his inspiration from this short story, particularly in view of his next correspondence, the 'Debut of Zodiac' letter on August 4th 1969, where he revealed he shot his victims with a pencil flashlight attached to his firearm, to better sight his victims. It wouldn't go unnoticed either, that both General Zaroff and Zodiac began with the same letter.
The Most Dangerous Game has been adapted for screenplay, in particular the 1932 version starring Joel McCrea and Leslie Banks. Another was the 1945 production 'The Game of Death' produced by Herman Schlom and Sid Rogell, directed by Robert Wise and starring John Loder and Audrey Long.
The actual cipher itself, shown below, was split into three sections of 136 characters each and mailed to three newspapers on July 31st 1969. The newspapers were the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald, all of which decided to publish. The codes were accompanied by details of the Lake Herman Road murders and Blue Rock Springs attack, that were specific to the killer and unknown to the public. The three letters also came with a warning "If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend."
However some of law enforcement were still skeptical that the letter writer and murderer were one and the same, including Chief Jack E Stiltz, who in two newspaper articles on August 2nd and 3rd asked the author of these letters to provide more details. The Zodiac Killer duly obliged, when on August 4th 1969 the 'Debut of Zodiac' letter arrived at the San Francisco Examiner declaring "This is the Zodiac Speaking." View letter here.
Vallejo Times Herald letter
San Francisco Examiner letter
San Francisco Chronicle letter
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 to kill something gives me the most thrilling experience it is even better than getting your rocks off with a girl the best part of it is that when I die I will be reborn in paradice and all the (people) I have killed will become my slaves I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife.
18 symbols at the foot of the cipher remain undeciphered.
Some people believe these symbols may reveal his name by way of an alternate code to the rest of the cipher. But this remains open to debate.