The Zodiac Killer: The 'Man Who Enjoyed Killing' That Manipulated Ciphers and Media
1. Indiscriminate Death and the Curse of the “Z340 Cipher”
The motive for the Zodiac’s crimes was neither money nor a personal grudge. He was a quintessential modern psychopath whose goals were “purely to enjoy killing” and “to intoxicate himself with the fact that he was controlling society through terror.”
Every time he committed a murder (or as a warning of an impending one), he relentlessly sent letters to local media outlets, primarily the San Francisco Chronicle. Enclosed in many of these letters were cryptograms composed of bizarre symbols, accompanied by the threat: “If you do not print this cipher on the front page of your paper, I will cruise around all weekend killing lone people in the night.”
The 408-symbol “Z408 cipher” sent among these was decoded almost immediately by amateur cryptanalysts at the time. Its contents—“I like killing people because it is so much fun, it is more fun than killing wild game in the forest”—corroborated his absolute abnormality.
Even more famous is the “Z340 cipher.” This puzzle consistently repelled the challenges of the FBI and hardened cryptologists. A full 51 years after the crimes, in 2020, it was finally deciphered through supercomputer analysis by an international team of programmers. What was revealed was nothing more than an array of his bloated ego offering no clues to a resolution: “I am not afraid of the gas chamber because it will send me to paradice [sic] all the sooner because I now have enough slaves to work for me.”
2. Numerous Remaining Mysteries and a Cowardly True Face
The Zodiac attempted to stage himself as an “untouchable, genius criminal.” However, the reality was by no means flawless. Composite sketches (a heavy-set man wearing thick-rimmed glasses) were created based on the testimonies of surviving victims and witnesses, and he made blunders that brought him incredibly close to being questioned by patrol officers.
As soon as he realized the risk of his own arrest had heightened, he abruptly stopped his actual killings. For years afterward, he exposed his extreme cowardice and vanity by continuously sending letters claiming that even unrelated, cold cases from the past were “my doing.” (This point starkly highlights that his true motive was the “display of dominance.”)
3. Consumption as Media Entertainment
As vividly depicted in director David Fincher’s film Zodiac, this case derailed the lives of the journalists and investigators who pursued him. The “cipher” game he orchestrated blended intellectual curiosity with terror, exerting immense influence on subsequent criminals (such as the BTK Strangler).
The Zodiac is, in essence, the analog-era prototype for the “cyber-terrorism by thrill-seekers and theatrical crimes” occurring in our modern digital society.
*Jack the Ripper: The Anonymous Killer of Victorian London Who Mocked Forensics : The spiritual ancestor of the Zodiac, who constructed the system of “theatrical murder” by inciting the media and sending anonymous letters. *The Golden State Killer: The Total Victory of ‘Forensic Genealogy’ That Broke a 40-Year Silence : Another monster who, like the Zodiac, plunged 1970s California into terror—but one whose true identity was finally unmasked by the latest DNA analysis. *The Glico-Morinaga Case: Japan’s Premier Theatrical Mystery : Investigating a major Japanese unsolved case where criminals similarly manipulated the media and police.