Fifty-one years after he sent it to the San Francisco Chronicle, the Zodiac Killer’s infamous 340 cipher — so called because of the 340 characters it contains — was cracked this month by a three-man team of code-breakers, SFGate reports.
Zodiac, whose true identity remains unknown, is known to have killed five people and injured two others, but he claimed to have killed 37 people in letters he sent to newspapers in northern California, where his deadly spree took place.
Several of Zodiac’s dozens of letters were cryptograms, including the card he sent to the Chronicle on November 8, 1969, which was unsolved until December 5.
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American computer programmer David Oranchak, Belgian programmer Jarl Van Eycke, and Australian mathematician Sam Blake solved the puzzle, beginning with Blake’s 650,000 simulations just to determine the direction the characters should be read. On December 3, phrases appeared — “trying to catch me” was one, “the gas chamber” was another — but it wasn’t until Oranchak and Van Eycke realized Zodiac had made a slight error in constructing his complex cipher that they were able to completely decipher his message:
I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME
THAT WASNT ME ON THE TV SHOW
WHICH BRINGS UP A POINT ABOUT ME
I AM NOT AFRAID OF THE GAS CHAMBER
BECAUSE IT WILL SEND ME TO PARADICE ALL THE SOONER
BECAUSE I NOW HAVE ENOUGH SLAVES TO WORK FOR ME
WHERE EVERYONE ELSE HAS NOTHING WHEN THEY REACH PARADICE
SO THEY ARE AFRAID OF DEATH
I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE IS
LIFE WILL BE AN EASY ONE IN PARADICE DEATH

The FBI confirmed that “a cipher attributed to the Zodiac Killer was recently solved by private citizens” but had no further comment about the message.
#Breaking – Our statement regarding the #Zodiac cipher: pic.twitter.com/cJCtlDEbMw
— FBI SanFrancisco (@FBISanFrancisco) December 11, 2020
While nothing in the message provides any clues to Zodiac’s identity, its second line confirms something investigators already suspect — that a man who called into local TV talk show The Jim Dunbar Show a few weeks earlier wasn’t him.
Zodiac also regularly misspelled the word “paradise” in his communications while correctly spelling more complex words. He also spoke of “slaves” in “paradise” on several occasions, including at one point saying the will “torture all 13 of my slaves that I have waiting for me in Paradice.”
The seven victims definitively attributed to Zodiac are:
- David Arthur Faraday, 17, and Betty Lou Jensen, who were shot and killed on December 20, 1968, in Benicia
- Michael Renault Mageau, 19, and Darlene Elizabeth Ferrin, who were shot in Vallejo on July 4, 1969. Mageau survived the attack
- Bryan Calvin Hartnell, 20, and Cecelia Ann Shepherd, 22, who were stabbed on September 27, 1969, at Lake Berryessa. Hartnell survived eight stab wound to the back, while Shepard died from her injuries two days later
- Paul Lee Stine, 29, who was shot and killed on October 11, 1969, in Presidio Heights in San Francisco. Stine was a cab driver.
Survivors Mageau and Hartnell both said the voice of the man who called in to the Dunbar show was not the same man who attacked them.
Numerous other disappearances and deaths are thought to possibly be the work of Zodiac — including some from as early as 1963. The taunting letters continued into the 1970s, with the last one known to be from the killer sent to the Chronicle on January 29, 1974. The letter praised the movie “The Exorcist” as “the best saterical comidy that I have ever seen” and included a final score taunting the San Francisco Police Department: “Me = 37, SFPD = 0.”
Several letters have been received since that time, but their veracity is under debate.
After DNA helped investigators confirm the identity of the Golden State Killer, investigators said they hoped to use similar technology to find Zodiac’s identity, as CrimeOnline previously reported.
One further cipher remains unsolved, and the codebreakers who cracked the 340 say it’s unlikely to be deciphered. In one letter, Zodiac wrote “My name is” followed by 13 symbols. They say it’s just too short to find the patterns that are needed to decode it.
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[Featured image: FILE photo of SFPD wanted bulletin and letters from Zodiac. (AP Photo/Eric Risberg, File)]