"I like killing people because it is so much fun it is more fun than killing wild game in the forrest because man is the most dangeroue anamal of all."

"The best part of it is thae when I die I will be reborn in paradice and the I have killed will become my slaves(.)"

"I will not give you my name because you will try to slol down or atop my collecting of slaves for my afterlife."

Zodiac Killer, California, San Francisco Bay Area, 1960s

This was an unsolved case of a serial murderer who enjoyed tantalizing police with hints and taunts, leaving cryptograms to be interpreted that he claimed would lead to his identity if solved. He would send these ominously sinister messages to the San Francisco Chronicle and other newspapers. For  fifty years his manipulation of cryptographic messages remained a mystery to the most industrious of minds working to decipher them. Until finally this week someone did, three men who designed software with algorithms fed into computers.

One might think that to figure out these cryptic messages and design them in a way that would make them even more opaque through manipulating their sequence, the author might be an academic of some twisted talent who had become a bizarre psychopath terrifying the public by repeated murders. It isn't entirely beyond reason that some academics have poor vocabularies and even poorer spelling traits. Unless that too represented an off-setting ploy to ensure that his identity remained well hidden. 

Including the cerebrally challenging and wholly improbable message setting out the implausible reasons why anyone would kill a series of people. Equating human murders with an animal hunt and concluding that people are dangerous animals, when he himself was the obvious prototype of that most dangerous animal, not those he murdered. And he focused on murdering young people, boys and girls in heir teens approaching adulthood secluding themselves in dark lovers' lanes, easy hunting for that malevolent mind.

The true agenda, the reason for his demented hunt and game-bagging may never be known. He might have been among those malcontents in society who now call themselves 'incels', involuntary celibates, men who complain that women overlook their sterling traits as desirable sex partners. 

 

The teens and police worked with a sketch artist to create the famed composite sketch of Z seen here.

Three different newspapers received three sections of the most famous of the cryptograms, Z-408, with the demand that each newspaper publish the section of the ciphertext on its front page, promising that the solution would reveal his identity. A married couple from Salinas California worked on the puzzle and decoded Z-408 which after all contained no identifying information whatever. But it did contain his peevish rationale as a dead master of dead slaves. What made the decoding of Z-408 troublesome for the couple, Donald and Bettye Harden, was the atrocious spelling.

The Zodiac killer went on committing his gun and knife murders, then finally sent to the Chronicle Z-340 named to represent the 340 unique zodiac symbols  it represented. That cryptograph was split into three grids, the order of the symbols altered, beginning at the top left of each grid moving one character down and two across, then back to the top when the edge of the grid was reached. Transposed in such a manner the cryptograph remained unsolved for fifty years. But American David Oranchak, Australian Sam Blake and Jarl van Eycke of Belgium were intrigued.

They felt that letter frequencies in the encrypted message meant there was likely natural language available beneath, leading the three researchers to write code covering hundreds of thousands of possible transposition schemes. Then they scanned Z-340 in the hope a solution would present itself. Strings of text appeared including "TRYING TO CATCH ME" and "THE GAS CHAMBER". The code was partially broken, then with reverse-engineering a transposition error Zodiac had committed halfway through the process they cracked the remainder.

A video uploaded by David Oranchak graphically explains how Z-340 was cracked -- found at zodiackillerciphers.com. It was with the inestimable assistance of computing power allied with cerebral reasoning power that the code was finally deciphered. The FBI placed its trust in the accuracy of the result on statistical grounds along with the deciphered text. Within the text is the sentence, "That wasn't me on the TV show", referring to trial lawyer Melvin Belli taking phone calls on a morning talk show when a caller shouted at Belli and was thought to have been the Zodiac Killer.

So what exactly has been accomplished by the deciphering of the Z-340 cryptogram that has elicited so much attention? Not much, it would seem other than to affirm earlier messages of the time when the atrocities took place. It brings authorities no closer to discovering the identity of the serial killer and what might possibly have driven  him, much less whether he is still alive. But it does demonstrate compellingly the power of computers harnessed to creative human minds looking to solve mysteries, gruesome or otherwise.

For the next half-decade, Zodiac continued to sporadically send letters to newspapers around California. Each one boasted of more victims, but none of those have ever been confirmed. Chronicle Archives