In the previous article I covered William Frederick Friedman and the "CSP 888" cipher machine, a highly secure, electromechanical rotor-based cipher machine used for top-level communications during World War II. Friedman was instrumental in leading the Army's cryptologic services during the 1920s and 1930s, which set the stage for the development of secure machines like the CSP 888. There is much reason to connect Edgar Allan Poe to the design of the Zodiac Killer's Z340 and Z13 through his cryptographic works, such as Poe's July 1841 essay "A Few Words on Secret Writing", which William Friedman mentioned in his 1937 bulletin entitled “Edgar Allen Poe, Cryptographer”.

​In Poe's essay, the alphabet was split A through M and N through Z, which was seemingly adopted by the Zodiac Killer on April 20th 1970, beginning and ending his ciphertext characters with the letters A and M, in an array of characters totalling thirteen (half an alphabet). To then find the three circled 8's present in the cipher and possibly mimicking the cipher machine "CSP 888", was extremely interesting (whether deliberate or accidental). Especially when you consider that William Friedman and Edgar Allan Poe are bound together by the words in “Edgar Allen Poe, Cryptographer” (1937), written by Friedman, whose career in the field of cryptology was originally inspired by Edgar Allan Poe. Was the Zodiac Killer influenced by the cryptographic work of William Friedman, and drew upon his knowledge of this individual when he was challenged by Donald C. B. Marsh of the American Cryptogram Association, who asked the Zodiac Killer to mail a cipher which truly included his name?  A challenge published in the San Francisco Examiner on October 22nd 1969, just 17 days before the Zodiac Killer mailed his infamous 340 cipher on November 8th 1969, which may also have been influenced by the works of William Friedman.

The 340 cipher was finally cracked in December 2020 by David Oranchak, Sam Blake and Jarl Van Eycke, who discovered that the cipher was a combination of substitution and transposition (using frequency analysis). The Riverbank Publications is a series of pamphlets written by the people who worked for millionaire George Fabyan in the multi-discipline research facility he built in the early 20th century near Chicago. They were published by Fabyan, often without author credit. The publications on cryptanalysis, mostly written by William Friedman, with contributions from Elizebeth Smith Friedman and others, are considered seminal in the field. In particular, Publication 22 introduced the Index of Coincidence, a powerful statistical tool for cryptanalysis. 

​William Friedman's work on transposition ciphers at Riverbank Laboratories (circa 1916–1920) established foundational, mathematical techniques for solving complex reordering ciphers. Notably, Riverbank Publication No. 19, Formulae for the Solution of Geometrical Transposition Ciphers, provided analytical methods to solve transposition, which he compared to reassembling jigsaw puzzle pieces. It's quite ironical that the title of Friedman's work was called Riverbank Publication No. 19, Formulae for the Solution of Geometrical Transposition Ciphers, when a period 19 shift was required to break the Zodiac Killer's 340 transposition cipher. This was a fraction of the work issued by William Friedman. But was he the inspiration for the Zodiac Killer, who employed this type of cipher on November 8th 1969? 

​Unfortunately, there is one final intriguing aspect to this story - and sadly it's very final. Just six days before the 340 cipher was mailed on November 8th 1969, William Frederick Friedman died of a heart attack at the age of 78. He passed away on November 2nd 1969, about a week before the Zodiac Killer's transposition cipher arrived at the San Francisco Chronicle. He was buried with full military honors at Arlington Cemetery on November 5th 1969. 

The Zodiac Killer was riding high in October 1970, currently sitting on four unbroken ciphers he had mailed on November 8th 1969, December 7th 1969, April 20th 1970 and June 26th 1970. On October 6th 1970 the Zodiac Killer would mail the 13-Hole "Punch Card" with thirteen holes punched through the fabric of the card, while simultaneously declaring himself "crackproof". His use of the words "crack" or "cracked" were usually chosen when referring to his ciphers, so one could conclude that the thirteen punch holes in the card, having been mailed 5 1/2 months after his 13-Symbol cipher on April 20th 1970, which contained the words "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is....", could be related.

​Creating thirteen punch holes in the card (previously used in coding machines), in combination with the word "crackproof", may suggest a link between the two communications mailed on April 20th 1970 and October 6th 1970. Especially when you consider no cipher was included in the card mailed in October. It has previously been shown that the 13 punch holes were positioned in a 10:3 configuration, with the 3 punch holes placed directly below where they sat in the 13-Symbol cipher on April 20th 1970 (see below). If these two communications were linked together, we need to examine the Zodiac Killer's decision to use punch holes, his choice of the word "crackproof", and his selection of the three circled 8's in his 13-Symbol cipher, to see if we can connect all three to one encipherment technique or coding machine.  

The Zodiac Killer was "about 40" years of age in 1969 according to the three sets of eyewitnesses at Presidio Heights, so he would have been around 16 (or possibly slightly older) at the time World War II ended. If he had an interest in cryptography, he would almost certainly have known about Alan Turing, a British mathematician who led the crucial World War II effort at Bletchley Park, England to crack the German Enigma machine, an electromechanical rotor device used for secure military communications. This cipher machine is arguably the most famous cipher machine in the world, but it was far from unbreakable. 

It was clear to US cryptographers well before World War II that the single-stepping mechanical motion of rotor machines (e.g. the Hebern machine) could be exploited by attackers. In the case of the famous Enigma machine, these attacks were supposed to be upset by moving the rotors to random locations at the start of each new message. This, however, proved not to be secure enough, and German Enigma messages were frequently broken by cryptanalysis during World War II. William Friedman, director of the US Army's Signals Intelligence Service, devised a system to correct for this attack by truly randomizing the motion of the rotors. His modification consisted of a paper tape reader from a teletype machine attached to a small device with metal "feelers" positioned to pass electricity through the holes. When a letter was pressed on the keyboard the signal would be sent through the rotors as it was in the Enigma, producing an encrypted version. In addition, the current would also flow through the paper tape attachment, and any holes in the tape at its current location would cause the corresponding rotor to turn, and then advance the paper tape one position. In other words, the punch holes were a key ingredient to the encipherment process. link.

SIGABA (also known as the ECM Mark II) was primarily developed by a team of American cryptographers in the mid-1930s, with key contributions from William Friedman. The device was an electromechanical rotor-based cipher machine developed in the late 1930s in the United States as a joint effort of the US Army and US Navy  At the time it was considered a superior cipher machine, intended to keep high-level communications absolutely secure. It was used throughout WWII and was so reliable that it was used well into the 1950s, after which it was replaced by newer machines like AFSAM-7 (KL-7). As far as we know, SIGABA was never broken by Axis powers. In other words it was the primary encryption technique used in World War II by America - and to the best of our knowledge - remained "crackproof" throughout its service.

This gives us the "punch holes" in paper and the "crackproof" elements, but where do we find the "888" present in the 13-Symbol cipher, that was possibly highlighted in the 13-Hole "Punch Card"? The U.S. Army called the cipher machine SIGABA or Converter M-134. The U.S. Navy called the machine the CSP-888 (Cryptographic Security Publication) and CSP-889. The machine has three banks of 5 rotors each. The main bank (at the rear) holds 5 rotors with 26 contacts each. These are the main cipher rotors. They work in a similar way as the rotors of the con­temporary German Enigma machine.

The 13-Symbol cipher on April 20th 1970, many believe was a response to the challenge by Donald C. B. Marsh, who told the San Francisco Examiner on October 22nd 1969: "The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in the cipher to established cryptogram experts. He knows, to quote Edgar Allan Poe, that any cipher created by man can be solved by man. Zodiac has not told the truth in his cipher messages to the Examiner, the Chronicle and the Vallejo Times-Herald. Zodiac has not done this, because to tell the complete truth in relation to his name, in cipher code, would lead to his capture. I invite Zodiac to send The American Cryptogram Association a cipher code, however complicated, which will truly and honestly include his name". 

By invoking the name of Edgar Allan Poe, it was probably hoped that the Zodiac Killer would use one of the cryptographic techniques described (or used) by Poe in his famous works, such as "A Few Words on Secret Writing", which contained all the ingredients used in the decryption of the 340 cipher and the design of the 13-character code, including the scytale method of decryption, the splitting of the alphabet, A throgh M and N through Z, and the cipher wheel, which uncovers a potential message in the Z13 code. The SIGABA cipher machine has room for three rows (or banks), of five cipher wheels each.

​In total, we have 13 punch holes and 13 ciphertext characters, a famous "crackproof" cipher machine and the same declaration by the Zodiac Killer on October 6th 1970, the 10:3 configuration on the "Punch Card" possibly highlighting the position of "888" as the key in the April 20th 1970 letter, the CSP-888 cipher machine used by the U.S. Navy in World War II, the cipher wheel explained by Edgar Allan Poe in July 1841 in A Few Words on Secret Writing, prompted by cryptographer Donald C. B. Marsh in a newspaper article on October 22nd 1969, and the signature of "ME⊕" revealed in the Z13 by using three right shifts of 8, which was also present in the Exorcist letter on January 29th 1974. The other possibility, is we have nothing. 

`` Edgar Allan Poe (1809–1849) popularized cryptography in the 1840s through stories like "The Gold-Bug," prompting a young William Friedman (1891–1969) to pursue the field. While Friedman became a legendary U.S. Army codebreaker who valued Poe’s role as a catalyst, he famously critiqued Poe’s actual cryptanalytic skills as amateurish in his 1936 analysis, "Edgar Allan Poe, Cryptographer". Could we therefore have a crossover between the cipher machine CSP-888 and the essay of Edgar Allan Poe, A Few Words on Secret Writing, manifesting itself on April 20th 1970? A Few Words on Secret Writing is mentioned by William Friedman on page 146 of his analysis (see below).  

​​William F. Friedman on Edgar Allan Poe
THE FRIEDMAN LECTURES ON CRYPTOLOGY

On September 25th 1990, the Zodiac Killer mailed the Celebrity Cypher to the Vallejo Times-Herald, very likely responding to the Sally Jessy Raphael TV Show featuring Robert Graysmith and Pam Huckaby, which aired a few weeks earlier. This postcard, written largely in code, suggested an introductory message, a name and a return address  But before the name (or more likely a pseudonym) of 13 characters (5 and 8) we have three coded words of 2, 4 and 2 characters, very reminiscent of the April 20th 1970 "My name is" letter.

​It is with little doubt that this was the intention of the sender. This meant that the ciphertext character "M" was represented by itself, and the fourth word in the message sequence of seven words, was likely two letters in length (one hidden beneath the stamp). If this had been designed as only one word (either "I" or "A") then the next word in the sequence becomes problematic. Bearing in mind who appeared on the Sally Jessy Raphael Show, it would be reasonable to conclude that the sender was addressing Pam Huckaby by coding the words "To Pam from me, my name is" or "To you from me, my name is". Once the letter M's were placed into the cryptogram below, the introductory message becomes very limited. 

Just after the television show, the Vallejo Times-Herald released a comprehensive newspaper article about Pam Huckaby, mentioning that she had received cryptograms and zodiac signs at her home in Antoch, entitled "Zodiac victim's sister says killer is after her". So it's not surprising that a few weeks later the Vallejo Times-Herald received a cryptographic correspondence from the killer, that may have included her name.

In my recent articles I have presented a case that the Zodiac Killer jokingly gave his name as "ME ⊕" ("ME" followed by the Zodiac crosshairs) in his April 20th 1970 letter. And here in 1990, we possibly have a message of "To Pam from me, my name is" or "To you from me, my name is". The Zodiac Killer could have been jokingly referring to himself as "me" yet again, followed by "my name is", to remind us what was present in the code on April 20th 1970.

​A few months later, somebody masquerading as the "Scorpion" mailed several cryprograms to John Walsh, host of the TV show "America;s Most Wanted", one of which was headlined by "Hi, Remember me". Therefore, we have two sets of cryptographic mailings in response to two TV shows in 1990 and 1991 (just like the Zodiac Killer did when he responded to the Jim Dunbar TV show in 1969), and mailed the 340 cryptogram to the San Francisco Chronicle. Three TV shows and three cryptograms, headlined by "I hope you are having lots of fun trying to catch me", "To Pam from me, my name is" or "To you from me, my name is" (maybe). and "Hi, Remember me".

EXTRA READING:  Four and Half Years of Me and The Identity in the Halloween Card 

​Many Zodiac researchers have contemplated whether the Z13 code mailed on April 20th 1970 contains a name or meaningful message, but extensive analysis of this cipher appears to show that neither are hidden beneath the ciphertext supplied by Zodiac. The first thing we notice when looking at the 13-character code is its symmetry. We have three alphabetical characters at the beginning and end. We have three circled 8's at positions 5, 7, and 9. And we have two non-alphabetical symbols four positions in from either side.

​This code can contain a valid name or message as shown by cryptographer David Oranchak. However, if the Zodiac Killer provided a genuine message or name of 13 plaintext characters, which creates the ciphertext scenario of three 8's, two A's, two M's and two N's, it must be considered highly unusual that when these ciphertext characters are placed alongside the alphabet (A through M) and we count the alphabetical difference between the two rows (as shown below), it produces yet further symmetry. Positions 1 to 4 and 9 to 13 gives us "03110" twice. The middle five positions gives us "05050". Therefore, we have a symmetrical ciphertext offering by Zodiac on April 20th 1970, that generates further symmetry in number form when placed alongside the alphabet.

​Using an identical technique in the 340 cipher, we took the pseudonym ZODIAC and placed it above the "near Zodiac" in the form of ZO∆AIK on the 20th row, and counted the alphabetical difference between the two rows. This generated the numbers 000888 that formed the basis of the three 8's in the symmetrical Z13 code, which produced further symmetry when placed alongside the alphabet. This was a 13-character code almost certainly inspired by the October 22nd 1969 newspaper article by Will Stevens, in which Dr. D. C. B. Marsh challenged Zodiac to give us his name in cipher form. An article in which Dr. Marsh invoked the name of Edgar Allan Poe, probably hoping that Zodiac would research and use cipher techniques outlined by Poe. The essay by Poe entitled "A Few Words on Secret Writing" contains all the ingredients used in the decryption of the 340 cipher and the design of the 13-character code, including the scytale method of decryption, the splitting of the alphabet, A throgh M and N through Z, and the cipher wheel, which finds the potential message in the Z13 code.
​
See    Cracking the Crackproof.   Same Methodology Between Z340 and Z13.   Effectively a 353 Character Cipher.
​

For the Z13 code to contain a random and/or spontaneous message, we would have to believe that all of the above scenarios were created by sheer happenstance. The only reasonable way the Zodiac Killer could have formulated these interlocking occurrences between the 340 cipher, 13-character code and Edgar Allan Poe, is if his message on April 20th 1970 was anything but random. It had to be a decipherment of simplicity, in which the majority of his ciphertext characters were chosen for the sole purpose of manufacturing this web of symmetry, not to create a plaintext message (or name) of 13 characters. 

The only constraints the Zodiac Killer faced when constructing the Z13 code, was beginning it with the ciphertext character A and ending it with the ciphertext character M, to allude to Poe. It was then a simple task of adding the three circled 8's, along with the ciphertext character E and the crosshairs, in such a position that a right shift of eight from each circled 8 (across and around the code) created the message of "ME ⊕". A message that was further explored in Four and Half Years of Me and The Identity in the Halloween Card. ​The A, M and three circled 8's all produced a numerical shift of zero when placed alongside the alphabet, allowing the Zodiac Killer to add the "E" and "⊕" (to complete the message) and manufacture the remainder of the code with symmetry in mind.

EXTRA READING: THE DEMON INSIDE OF ME 

One puzzling aspect of the Zodiac Killer's 340 cipher is his decision to separate the encipherment into three parts of 9, 9 and 2 rows, rather than simply dividing the cipher into two parts. The third section of two rows didn't follow the same technique as the other two parts. Therefore, one could conclude that it was important for the Zodiac Killer to separate the cipher into two equal parts of 9 rows, leaving the final 2 rows for an entirely different purpose, such as his signature on the 20th row. If we assert that the "near Zodiac" signature (ZO∆AIK) on the final row was a deliberate choice and not accidental, it may follow that this misspelling of "Zodiac" was purposely designed as a key.    

When we place the correct spelling of "ZODIAC" above the "near Zodiac" of ZO∆AIK, and count the alphabetical difference, the Z to Z requires a 0 shift, the O to O requires a 0 shift, and the D to ∆ requires a 0 shift, giving us three zero's. But when we look at "IAC" to "AIK", we require three shifts of 8, giving us three eight's (which when combined, gives us the three circled 8's seen in the Z13 code). Therefore, we have a 340 cipher split downwards into three parts of 9, 9 and 2 rows, with a "near Zodiac" signature on the 20th line that easily gives us three circled 8's.

​If we apply the same technique across the Z13 code, and cycle around the ciphertext to the 9th, 18th and 20th positions (9, 9 and 2), it again completes the 888 signature (shown below)..The 20th position of the Z340 and Z13 puzzles both highlight the 888 signature of Zodiac. When we apply the three shifts of 8 found by comparing ZODIAC to ZO∆AIK into the Z13 code, we get "ME ⊕" ("ME" followed by the Zodiac crosshairs)​. Two of the signatures used by Zodiac to identify himself in his letters. This has been pointed out previously by the use of "Me" as his signature within the Exorcist letter on January 29th 1974.  

In David Oranchak's excellent YouTube video entitled Let's Crack Zodiac, the 340 Cipher is Solved, he stated "The message doesn't really say a whole lot, it's more of the same attention seeking junk of Zodiac. We were disappointed that he didn't put any personally identifying information in the message, but we didn't expect him to. Maybe his name really is in the thirteen character cipher sent almost six months after the 340. Unfortunately there is not much hope of confirming any solutions for such a short cipher without getting lucky and discovering new evidence". 

I believe the personally identifying information in the 340 cipher is the "near Zodiac" on the 20th line, that gave us the three circled 8's present in the Z13 ciphertext, which produced "ME" and the "crosshairs" by employing a simple right shift of eight. The Zodiac psuedonym has been shown to be inextricably linked to the three 8's. thereby giving us "Zodiac", "Me" and the "crosshairs" in the Z13 code. The Z13 code is believed by many Zodiac researchers to be too short to solve, but by combining it with the 340 cipher it effectively becomes a 353 character cipher, where traveling 9, 9, and 2 downwards and across in both Z340 cipher and Z13 code, ultimately finds the key of 888. Which we can then apply using three right shifts of eight to reveal two further identities of "ME" and "⊕".


FURTHER READING: SAME METHODOLOGY BETWEEN Z340 AND Z13
                                     FOUR AND A HALF YEARS OF "ME"

The Zodiac Killer, having witnessed the young girl in the film being possessed by a "thing" inside of her, as he had claimed several years earlier by writing "help me" to Melvin Belli three times, must have been influenced by the writing on Regan's torso in one particular gruesome scene, when the words "help me" appeared on the young girl's skin, as her inner soul pleaded to be free from the force that had invaded her body.

​And you wonder why the Zodiac Killer, who mentioned The Exorcist movie in this letter, changed his signature to "Me" at the foot of the communication. He obviously altered his signature for a reason. The immediate correspondence after the Melvin Belli letter, stating "help me" three times, was mailed on April 20th 1970 and has been shown to contain the signature of "Me" by employing a simple right shift of eight. 

​But after mocking the 1973 movie by writing "I saw + think "The Exorcist" was the best saterical comidy", the Zodiac Killer completely switched to the Japanese themed theatre production of The Mikado by adding a verse from Tit-Willow (and the Japanese style symbolism). Why would the Zodiac Killer introduce this apparent dichotomy into his communication? In one scene from The Exorcist movie, Father Damien "Demis" Karras, one of the main protagonists in the 1973 film, enters the language laboratory with his tape recordings of Regan's "demonic voice" for analysis. Above the door is the word TASUKETE written on a poster. This is a Japanese word meaning "Help Me" or "Save Me". This poster foreshadows the "Help me" message that appears on Regan's body in the next scene of the film.

​The Zodiac Killer added this verse from Tit-Willow by introducing it with "yours truley", The signature of "yours truly" simply means "me". The next line of the Tit-Willow verse, which the Zodiac Killer didn't write on the Exorcist letter, contained the phrase "My name is". An introduction that gave us the 13 character code on April 20th 1970, which has been shown to contain the signature of "Me", just like the Exorcist letter, which featured The Exorcist movie and "help me" on the girl's torso, that mimicked the Melvin Belli letter on December 20th 1969.

In The Exorcist (1973), the phrase "me" relates to the demonic entity possessing young, Regan MacNeil, who claims to be the devil ("I am the devil himself!") and often uses "me" in threats, demands, and insults, particularly toward her mother, Chris MacNeil, and the priests during the harrowing exorcism rituals, revealing the entity's powerful, blasphemous identity. It's a core part of the possession, highlighting the internal struggle and the demon's contempt for humanity. 

• Identity: The demon (using Regan's voice) asserts its divine status, saying, "I am the devil himself!".
• Blasphemy: It uses "me" in conjunction with obscene acts, like masturbating with a crucifix, shocking the mother and priests.
• Manipulation: It taunts the priests with "Lick me, lick me!" and other vile commands, using "me" to exert control.
• Physical Manifestation: The word "ME" also famously appears scratched onto Regan's stomach, a terrifying visual cue of the demon's presence and power. 

Essentially, "me" in The Exorcist isn't just a pronoun; it's the voice of pure evil, a declaration of self from the demonic entity fighting for control of Regan's soul. ​

In a recent article entitled Four and a Half Years of Me I came to the conclusion that the 13-character cipher was likely done in haste, and the Zodiac Killer jokingly provided his name as "ME ⊕" ("ME" followed by the Zodiac crosshairs), which I showed to be also present in the 408 cipher, Halloween card, Exorcist letter, and maybe was hinted at in the Eureka card. To achieve the "ME ⊕" identity, all we had to do was apply a "period 8" right shift to each circled 8 and cycle around the cipher, exactly the same methodology that was used in the 340 cipher five months earlier, where a "period 19" right shift was needed to decode his message.  .  

Many have speculated that the Zodiac Killer's opening wording in the April 20th 1970 letter of "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is....", indicated that we needed to solve the 340 cipher to give us a clue to decoding the 13-symbol cipher. I have put forward that the Z13 may have revealed two forms of Zodiac identity in "ME ⊕", by using the three circled ​8's in the cipher. But how can we prove that this was the Zodiac Killer's intention? How can we prove that this was the Zodiac Killer's key? Did the answer lie in the decoding of the 340 cipher?

If the 340 cipher had been solved before April 20th 1970, we would have known that the Zodiac Killer split his cipher into three parts of 9, 9, and 2 rows. These three parts were comprised of row 1 to row 9, followed by row 10 to row 18, and finally the last two rows up to the 20th line. The Zodiac Killer gave us the key to the 340 cipher by splitting it into a 9, 9, 2 configuration. We then had to apply the "period 19" right shift to make the message possible. This configuration of 9, 9, 2 went down the cipher, so let's apply the same methodology to the Z13 by going across the cipher.

If we travel from position 1 to 9, we land on the right circled 8. If we travel from position 10 to 18, we land on the left circled 8. If we travel from position 19 to 20, we land on the middle circled 8. The configuration employed in the 340 cipher gave us the key to its solving. Does the same configuration applied to the Z13 gives us a clue to its solving? It gives us the three 8's. Once the configuration (of three parts) was identified in the 340 cipher, the "period 19" right shift was applied. Once the configuration (of three parts) was identified in the Z13 cipher, the "period 8" right shift was applied to get the message. The "period 19" right shift in the 340 cipher was crucial in finding the message. The "period 8" right shift in the 13-symbol cipher was crucial to finding the message of "ME ⊕". A personal pronoun that is seen twice in the Halloween card, and clearly written as the Zodiac Killer's identity on January 29th 1974 in the Exorcist letter.

The Zodiac Killer may also have highlighted these three circled 8 positions in his 13 punch holes in the October 6th 1970 "Pace" postcard. 

ADDITIONAL READING: FOUR AND A HALF YEARS OF "ME"     

There are only four communications from July 31st 1969 to January 29th 1974 where the Zodiac Killer teased us with his identity or name. The letter to the San Francisco Chronicle on July 31st 1969 promised that "in this cipher is my idenity", but only gave us 18 characters that seemingly have no discernible message. The April 20th 1970 letter with a thirteen character code tempted us with "my name is". The October 27th 1970 "Halloween" card began with the message "I feel it in my bones you ache to know my name. And so I'll clue you in". And finally, the January 29th 1974 "Exorcist" letter substituted part of the "Tit-Willow" verse for a signature, by introducing the verse with "Signed, yours truley". The Zodiac Killer teased us in each instance - yet to this day - no common thread has been found linking all four Zodiac offerings together. However, the following presentation will serve up the same "identity" in all four communications. An identity (if correct)  that would clearly have been chosen as a joke.
​
The first is incredibly tenuous, but it does exist. The deciphered portion of the 408 cipher mailed to the San Francisco Chronicle on July 31st 1969 gave us 18 letters of illegible text, yet within these 18 apparently meaningless letters the Zodiac Killer may have placed his signature, shown inside the yellow rectangle below. This suggestion is wholly unconvincing on its own, but hopefully the remainder of this analysis will maybe change your mind.

The April 20th 1970 "13-Symbol" code letter, I have argued had the key of 888, derived from the murderer's pseudonym in the 340 cipher (see here), which when applied to the Z13 code with a right shift of 8, gave us the signature of "ME ⊕" ("ME" followed by the Zodiac crosshairs). In other words, when cycling 8 positions to the right from each "circled 8", we get the signature of "ME" and his "gunsight" logo.

​If the Halloween card on October 27th 1970 was going to give us the answer of "ME" proposed in the 408 cipher and Z13 code, you would expect to find this word embedded in its design. Not only was the word "ME" curiously obvious in the Halloween card inner, it was present twice. The Zodiac Killer was clearly employing the eye in the knothole of the tree as himself, by surrounding the knothole with the ominous threat of "Peek-a-boo you are doomed".

But there is one striking feature about the writing on the tree. After the phrase "PEEK-A-BOO" the Zodiac Killer positions the word "DOOMED", such that the "ME" lines up with "PEEK-A-BOO" to create "PEEK-A-BOO, ME". It is definitely noticeable that the word "ME" is visibly larger and bolder than the rest of the writing, as if to place emphasis on this pronoun. The skeleton's left arm is also affixed to the Halloween card in such a manner that it separates the word "GAME" to spell "ME". The word "BOO" is written on the card inner at a 45 degree angle so that it too lines up with the word "ME".

The word "BOO" around the knothole and the word "BOO" to the immediate left of the skeleton, are both positioned in alignment with the word "ME". Was the Zodiac Killer giving us the answer of "ME" to "I feel it in my bones you ache to know my name. And so I'll clue you in"? Thereby replicating the answer of "ME" possibly given by the proposed solution to the Z13 code on April 20th 1970. And the signature of "ME" sitting innocuously within the 18 characters of the 408 cipher.

Finally, on January 29th 1974, the Zodiac Killer probably got tired of playing games and outright gave us his signature in plain sight, by writing "Me - 37". In fact, he effectively gave us the signature of "Me" (or "ME") a total of three times in the "Exorcist" letter. The first, as already explained, sat alongside his running victim count. The second was in the words "Signed, yours truley", because while it is often used in formal and semi-formal correspondence, in some specific contexts, it can also be used humorously or self-referentially in conversation to mean "myself". The signature of "yours truly" simply means "me". The third can be shown by using the "Tit-Willow" verse that followed "Signed, yours truley".

When we look at the Exorcist letter mailed on January 29th 1974, the Zodiac Killer appears to add the "Tit-Willow" verse from "The Mikado" for no apparent reason. However, the verse was preceded by "Signed, yours truley;" and may suggest that his identity of "Me" should be found somewhere within the verse. This concept hit a roadblock, until I looked up the following line from the complete song. The Zodiac Killer plagiarised the section below (marked in red) to place into his letter. The next line in the below verse (marked in blue) reads, in part, "Now I feel just as sure as I'm sure that my name Is". which the Zodiac Killer wrote on April 20th 1970 to introduce his Z13 code, that has already been shown to easily create the signature of "ME" and his crosshairs. Therefore, we have the "Exorcist" letter with a signature of "Me -37", the phrase of "yours truley" which means "me", introducing a "Tit-Willow" verse whose next line contains "my name is", that preceded the Zodiac Killer's Z13 code, which by using the three circled 8's as a mathematical tool, easily creates the signature of "ME". A "Tit-Willow" verse, by the way, which is split into three sections of eight lines, just like the 408 cipher. 

​July 31st 1969: "I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife", but "in this cipher is my identity". EBEORIETEMETHHPITI.

August 4th 1969: "By the way, are the police having a good time with the code? If not, tell them to cheer up; when they do crack it, they will have me".

There may have been a change in the Zodiac Killer's approach to encrypting his ciphers/codes after the 408 and 340 cryptograms, in that the Z13 and Z32 were specifically designed with maybe just six characters forming the bedrock of each solution, but with a key of just three characters. The key characters in the April 20th 1970 letter were the three 8's, whereas the key characters in the "Button" letter Z32 code on June 26th 1970 were the three repeating symbols of C, O and the triangle. These three symbols (characters) were seemingly the key to unlocking both codes mailed on April 20th 1970 and June 26th 1970, with the remaining characters beyond the total of six possibly meaningless filler placed around them.

Once the Zodiac Killer had supplied us with the prompt of "The Mt. Diablo Code concerns Radians & # inches along the radians" on July 26th 1970, the placement of "four radians and five inches" into the Z32 from position 9 to 32, unlocked the answer of "estimate" from position 1 to 8, to identify the complete solution of "Estimate: four radians and five inches". There was a total of six characters at play here, but only three were key characters involved in the solution. The key characters in the Z13 on April 20th 1970 were the three circled 8's, but a total of six characters may also have been at play here. They were the three 8's, and the "M", "E" and "crosshairs". If the proposed solution of "Me⊕" for the Z13 is correct, then both the Z13 and Z32 codes follow the same template.   

It can be seen above in the Z32 that six characters are at play here, but only the three characters at positions 14, 26 and 32 are key to the solution. The characters at 14, 26 and 32 within "four radians and five inches", unlock the characters at positions 1, 2 and 6 to give us the word "estimate" and complete the full solution. In the Z13 below we again have six characters at play, but only three characters at positions 5, 7 and 9 are key to the solution of "Me⊕".    

This drives at the heart of the question, of whether the Zodiac Killer used redundant characters in 54% of the Z13 and 81% of the Z32 to change the methodology he employed in his previous ciphers. If the proposed solution to the Z13 is correct, then there is a good argument to be had that the Zodiac Killer used only six functional characters in both designs, of which, only three were key to each solution. That key being the three circled 8's in the Z13, and the C, O and △ in the Z32.

Recently I have released two articles examining the solution of "Me⊕" in the April 20th 1970 letter mailed by the Zodiac Killer, having been formulated by a combination of Edgar Allan Poe, the 340 cipher and the three 8's in the Z13 code. Further hints towards this solution have possibly been unearthed in the 13-Hole postcard mailed a few months later in October, and Exorcist letter mailed on January 29th 1974 in which the Zodiac Killer changed his signature to "Me" for the first time.

​The April 20th 1970 letter tempted us with an identity stating "My name is", the 13-Hole postcard contained 13 holes punched into the fabric of its design and the phrase "Fk I'm crackproof", the March 13th 1971 "Los Angeles" continued the theme by proclaiming "This is the Zodiac speaking Like I have allways said, I am crack proof", with the Exorcist letter again suggesting an identity might be hidden in its contents by the introduction of "Yours truley", followed by the Tit-Willow verse from "The Mikado". But crucially, the January 29th 1974 letter added the signature of "Me", that can be replicated using the three 8's from the Z13 code by employing a cipher wheel described by Edgar Allan Poe. But there is one communication nestled in between these other mailings, that also tempted us with a name, much like the April 20th 1970 letter. The Halloween card, mailed on October 27th 1970, began with "I feel it in my bones you ache to know my name. And so I'll clue you in".    

If the Halloween card was going to give us the answer of "Me" proposed in the Z13 code, you would expect to find this word embedded in its design. Not only was the word "Me" curiously obvious in the Halloween card inner, it was present twice. The Zodiac Killer was clearly employing the eye in the knothole of the tree as himself, by surrounding the knothole with the ominous threat of "Peek-a-boo you are doomed".

But there is one striking feature about the writing on the tree. After the phrase "PEEK-A-BOO" the Zodiac Killer positions the word "DOOMED", such that the "ME" lines up with "PEEK-A-BOO" to create "PEEK-A-BOO, ME". It is definitely noticeable that the word "ME" is visibly larger and bolder than the rest of the writing, as if to place emphasis on this pronoun. The skeleton's left arm is also affixed to the Halloween card in such a manner that it separates the word "GAME" to spell "ME". The word "BOO" is written on the card inner at a 45 degree angle so that it too lines up with the word "ME".

The word "BOO" around the knothole and the word "BOO" to the immediate left of the skeleton, are both positioned in alignment with the word "ME". Was the Zodiac Killer giving us the answer of "ME" to "I feel it in my bones you ache to know my name. And so I'll clue you in"? Thereby replicating the answer of "ME" possibly given by the proposed solution to the Z13 code on April 20th 1970. And the signature of "Me" he would ultimately deliver on January 29th 1974 to the San Francisco Chronicle.    FURTHER READING:

The April 20th 1970 letter opens with "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is....". One of the takeaways from the mention of his previous cipher while beginning this communication, has been that something about that previous cipher may aid in the solving of the current Z13 code. Many have taken the code key from that now solved 340 cipher and tried to apply it to the Z13 code. While some of those attempts have produced interesting outcomes, they have all required some form of manipulation to generate a desired result, which leaves room for objection. But what if the answer or key lay in the unsolved 340 cipher at the time Zodiac mailed his Z13 code on April 20th 1970. Bearing in mind this latest letter was suggesting that the Z13 code would reveal a "name" or "identity", it is quite possible that his identity in the unsolved 340 cipher held the clue.

In the 340 cipher on the final line he appeared to give us his signature of ZODIAC from characters 333 to 338. However, he replaced the "D" with a blackened triangle, reversed the "I" and "A", and changed the "C" for a "K". Despite this, it's unmistakable presence is there for all to see. What if we took this identity to solve the Z13 code.  

As stated previously, Professor Donald C. B. Marsh invoked the name of Edgar Allan Poe to challenge Zodiac to reveal his name on October 22nd 1969, hoping that the Zodiac Killer would utilize the cryptographic works of Poe to create any forthcoming ciphers. Taking one look at Poe's essay, "A Few Words on Secret Writing" in the July edition of Graham's magazine, you can see the scytale method of decryption that can be used to solve Zodiac's 340 cipher, the cryptographic technique of splitting of the alphabet A through M and N through Z, which Zodiac employed in his design of the Z13 code, and the cipher wheel explained by Poe, which not only decodes the "near Zodiac" on the final line of the 340 cipher to give us the key, but provides us with a resulting key that the Zodiac placed directly into his 13 characters on April 20th 1970, that generates an answer he would later reveal as his signature on January 29th 1974. That signature was "Me". 

The "near Zodiac" in the 340 cipher has simply been manipulated using a cipher wheel. When we compare the correct spelling of ZODIAC to the version supplied on the final line of the 340 cipher, we can see that Z to Z, O to O, and D to triangle generates no difference alphabetically (000). Whereas "IAC" to "AIK" generates a shift of 8 positions for each letter, producing 888. This provides us with 000888, the possible origin of the three circled 8's in the Z13 code. Visit the Caesar cipher wheel here and type in the number 8 (see below). The inner wheel will spin 8 positions clockwise so that the outer wheel "I" is represented by the inner wheel "A" (and vice versa). The outer wheel "K" is represented by inner wheel "C" (and vice versa). This is the bedrock of the switch from "IAC" to "AIK" in the spelling of ZODIAC. If we place the 13 characters from the April 20th 1970 letter within a cipher wheel (shown above), forming an inner and outer ring, and then spin the inner wheel clockwise by 8 positions, the three circled 8's land over "ME" and the "crosshairs". The signature he chose to use in the "Exorcist" letter on January 29th 1974, created by a technique described by Poe in "A Few Words on Secret Writing".    

But how do we know that the three circled 8's are the key to solving the Z13 code? In the April 20th 1970 letter the Zodiac Killer wrote "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is....", followed by 13 characters. The next time the Zodiac used the verb "to crack", is when he told us he was crackproof in the 13-Hole postcard at the beginning of October 1970, five and a half months later. The Zodiac Killer stated "Fk I'm crackproof" and punched 13 holes into the fabric of the postcard. But just like the April 20th 1970 letter featured three circled 8's in a configuration of 13 characters, the postcard in October separated out three punch-holes from the other ten. These three punch-holes were positioned almost directly below the positions the three 8's slotted into the Z13 code (see below). In other words, pull the three 8's downwards from the Z13 code and you get the 10:3 configuration shown in the 13-Hole postcard.  

Was the Zodiac Killer highlighting the three punch-holes (888) from the total of 13 to show that these were the key to solving the "crackproof" Z13 code on April 20th 1970? In total, we have the three circled 8's generated by a cipher wheel from the "near Zodiac" in the 340 cipher, placed into the Z13 code five months later, which by using a cipher wheel once again, generated the signature of "Me" from the Z13 code, that is present as the signature in the Exorcist letter on January 29th 1974. The Edgar Allan Poe essay "A Few Words on Secret Writing", featuring the cipher wheel, the scytale method of cryptography, and the technique of splitting the alphabet into 13 characters, which are all integral to the solving of the 340 cipher and the possible design of the Z13 code, may very well have been chosen because of the challenge by Marsh on October 22nd 1969. He wanted the Zodiac Killer to send a cipher to The American Cryptogram Association that would honestly include his name. The murderer of five may have given Professor Marsh more than he bargained for.

On January 29th 1974, April 24th 1978 and October 27th 1987, the Zodiac signed himself "Yours truley" or "Yours truly" as an added signature. "Yours Truly" simply means "Me". Both were used in the Exorcist letter on January 29th 1974. "Yours truly" originated as a formal sign-off for a letter, a shorter version of phrases like "I am truly yours". Today, it is mostly used in a conversational or informal context to refer to oneself in a playful, humorous, or self-deprecating manner. I believe that when the Zodiac Killer mailed the April 20th 1970 letter and Z13 code, he gave us the answer of "My name is....Me" as a playful joke. He was taking the piss.

A solution created by converting ciphertext into plaintext from just 13 characters could never be verified, which is probably why he employed a different technique, inspired by the writings of Poe in Graham's Magazine in 1841. Those three circled 8's may have stood out for a reason. 
 
FOLLOW UP ARTICLE: THE SAME IDENTITY IN THE HALLOWEEN CARD 
FURTHER READING: AN IDENTITY DISCLOSED IN TWO LETTERS 

Four months had elapsed between the Melvin Belli letter on December 20th 1969 and the Z13 code on April 20th 1970, so what (if anything} inspired the Zodiac Killer to mail this most recent letter in April? For a long time I believed it was the newspaper coverage of Robert Salem's murder in San Francisco on the same day this letter was postmarked. However, this communication appeared like a response to a challenge laid down by Professor Donald C. B. Marsh, who told the San Francisco Examiner on October 22nd 1969 that "The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in the cipher to established cryptogram experts. He knows, to quote Edgar Allan Poe, that any cipher created by man can be solved by man. Zodiac has not told the truth in his cipher messages to the Examiner, the Chronicle and the Vallejo Times-Herald. Zodiac has not done this, because to tell the complete truth in relation to his name - in cipher code - would lead to his capture. I invite Zodiac to send The American Cryptogram Association a cipher code - however complicated - which will truly and honestly include his name". See article.

The newspaper story was entitled "Cipher Expert Dares Zodiac to Tell Name", so it seemed that this letter stating "My name is" was the Zodiac Killer's response to the challenge six months earlier. But why would the killer of five have waited half a year to deliver his response? Was there something significant about the data of April 20th? The challenge by Marsh and the invocation of Edgar Allan Poe's name, can be seen as a subtle prompt by Marsh to direct Zodiac down the path of encryption using techniques featured by Poe, thereby making any subsequent solve easier. It may have worked.

​George Rex Graham was the founder of Graham's Magazine, who hired Edgar Allan Poe as a critic and editor in February 1841. The magazine was the first to publish "The Murders in the Rue Morgue", "A Descent into the Maelström", "The Island of the Fay, The Mask Of The Red Death - A Fantasy", and others.

​Edgar Allan Poe's publication "A Few Words on Secret Writing" featured in Graham's Magazine in July 1841, showing different cryptographic methods, that began with the scytale method of decryption which can be employed to solve the 340 cipher. This was immediately followed by another cryptographic technique of splitting the alphabet into two lots of 13 characters, A through M, and N through Z, just like the Zodiac appeared to do with the Z13 offering. His code of thirteen characters began with A and ended with M, which when rotated by 8 positions on a circle, would create a signature later used in the Exorcist letter  This technique of using a cipher disk was another encryption method thoroughly covered in "A Few Words on Secret Writing"  Everything in Poe's publication in Graham's Magazine is instrumental to both the Z340 and Z13. But again, why would the Zodiac Killer wait six months to reply to the challenge of Professor Donald C. B. Marsh on April 20th, unless of course, this date was significant to Edgar Allan Poe and Graham's Magazine.  

On April 20th 1841 Graham's Magazine was the first to publish "The Murders in the Rue Morgue", a short story by Edgar Allan Poe, credited with being the first modern detective story. As the first fictional detective, "C. Auguste Dupin is a man in Paris who solves the mystery of the brutal murder of two women. Numerous witnesses heard a suspect, though no one agrees on what language was spoken. At the murder scene, Dupin finds a hair that does not appear to be human".Wikipedia. Bearing in mind that the Zodiac case was turning into an extremely intriguing mystery that confounded the likes of Detectives David Toschi and Bill Armstrong who searched tirelessly for the murderer of five, it's quite possible that the Zodiac Killer found it humorously apt to mail a code on April 20th based on Edgar Allan Poe's featured cryptographic methods in Graham's Magazine, which coincided with the release date of the first modern detective story, "The Murders in the Rue Morgue"..

​Professor Donald C. B. Marsh would offer the Zodiac a cryptic challenge on October 22nd 1969 invoking the name of Poe, with his coded reply possibly coming six months later on the exact day and month that Edgar Allan Poe, a prolific solver of ciphers, released the first modern detective story in Graham's Magazine. During 1970, the newspapers were filled with news of an impending Hollywood blockbuster entitled "Murders in the Rue Morgue" starring Jason Robards, Herbert Lom and Christine Kaufmann, to be released the following year. If the Zodiac Killer needed any reminder in April 1970 to the challenge given by Professor Donald C. B. Marsh, then the news of a movie to be released based on an Edgar Allan Poe short story, may have been the trigger. Not any movie, but "Murders in the Rue Morgue", initially published in short form on April 20th.

In the July edition of Graham's Magazine containing "A Few Words on Secret Writing", somebody mailed in a cryptographic challenge to Poe dated April 21st 1841, the same day and month Zodiac's Z13 cipher should have landed on the desk of the San Francisco Chronicle. The letter in Graham's Magazine introduced itself with the very same dash that followed the "My name is" introduction in the April 20th 1970 letter (see below). However, if the Zodiac Killer's initial trigger was "The Murders in the Rue Morgue", this subsequent date may have been a fortunate by-product. The "Sketches of Conspicuous Living Characters of France" and the mention of different languages (published in April), could be connected to "The Murders in the Rue Morgue", which was set in Paris, France - and in which - several of the witnesses reported hearing two voices at the time of the murder, one male and French, but who disagreed on the language spoken by the other. In other words, Edgar Allan Poe may have been continuing a theme in the April 20th edition of the magazine, to which the person below responded by dating his letter the following day and mailing it sometime later. This would effectively bind the two dates of April 20th and April 21st to the April edition of Graham's Magazine, If the Zodiac Killer had searched for cryptographic material on Edgar Allan Poe in 1969 and/or 1970, he may have found "A Few Words on Secret Writing" in the July edition of Graham's Magazine, which ultimately led him to the April edition and "The Murders in the Rue Morgue". Whether this is a viable route to the date of April 20th 1970 and the mailing of the Z13 code, is still open to question. 
​
The Mystery Writers of America (MWA) is a professional organization of mystery and crime writers, founded in New York City in 1945, which presents the Edgar Award, a small bust of Edgar Allan Poe, to mystery or crime writers every year. The Mystery Writers of America honors Edgar Allan Poe's groundbreaking work, particularly "The Murders in the Rue Morgue" as the foundation of modern detective fiction. The annual Edgar Awards, given by the MWA, are named after Poe in recognition of his role as the genre's inventor.

It is clear that the Zodiac Killer knew he gave us insufficient clues to reasonably solve the Z32 cipher on June 26th 1970, so a month later, on July 26th 1970, he gave us some additional clues such as "P.S. The Mt. Diablo code concerns Radians + # inches along the radians". This provided us with the following answer. So where are the supplemental clues to the Z13 cipher mailed on April 20th 1970? There are hundreds (probably thousands) of possible unverifiable answers to the Z13 using substitution methods, which the Zodiac must have known to be the case. Therefore, one could conclude that this wasn't the method he chose to use. We had to find a later communication that contained the solution to the Z13 that can be simply demonstrated. The identity in this later communication may also be preceded by "My name is". The following is nothing new, but I just wanted to present the findings in a different format.

When we look at the Exorcist letter mailed on January 29th 1974, the Zodiac Killer appears to add the "Tit-Willow" verse from "The Mikado" for no apparent reason. However, the verse was preceded by "Signed, yours truley;" This may suggest that his identity is within the verse. This concept gained little traction until I looked up the following line in the complete song. The Zodiac Killer plagiarised the section below (in red) to place into his letter. The next line in the below verse (in blue) reads in part "Now I feel just as sure as I'm sure that my name Is". In other words, the Zodiac Killer introduced his Tit-Willow verse with "Signed, yours truley:", followed by the next line which contained the phrase "my name is", and ended with his identity of "Me". The complete sequence reading 
"Signed, yours truley: My name is Me". 

When we use the circled 8's in the Z13 to cycle around the cipher by a right shift of eight, we get an identity of "Me" (see below), just like the signature on the Exorcist letter. ​The Exorcist letter, in order, read "Signed, yours truley: My name is Me". The April 20th letter (with a right shift of 8) would now read "My name is Me". The common phrase "My name is Me" can now be shown as a Zodiac identity through two letters, both of which teased us with his name. But is there anything to indicate that the Zodiac Killer employed a "shift-type" cipher on April 20th 1970? Edgar Allan Poe may have the answer.

MUST READ FOLLOW UP ABOUT THE EDGAR ALLEN POE CONNECTION TO THIS ARTICLE 
​ALSO: CRACKING THE CRACKPROOF AND AN IDENTITY IN THE HALLOWEEN CARD

The Zodiac Killer often reacted to newspaper articles within his communications, such as the quotation of Merian C. Cooper that appeared in a handful of newspapers in 1932, when the associate producer of "The Most Dangerous Game" (1932) responded to the release of his latest film while being interviewed and stated "man is the most dangerous animal of all", which Zodiac incorporated into his 408 cipher on July 31st 1969. This quotation had never appeared in any newspaper from 1690 to 1969, other than a few 1932 publications.

If the Zodiac Killer was responsible for the Confession letters sent on November 29th 1966, he may have taken the phrase "it was about time for her to die" from a newspaper in 1888 (the year of Jack the Ripper), and designed the letters around the Whitechapel murderer. We also know that the Zodiac Killer referenced three acts of "The Mikado" (1885) in his communications, and certainly wasn't afraid to delve into the archives and utilize material from yesteryear. Additionally, he appeared to have derived inspiration from Edgar Allan Poe (1809-1849) in the design of his 340 cipher and the wording contained within it.

Recently I made the suggestion of "My name is me" as the answer to the 13-Symbol cipher mailed on April 20th 1970, but couldn't help wondering if the Zodiac Killer plagiarized this quotation as well. So I typed this phrase into a newspaper search engine and got what I was looking for in a piece of literary work by Charlotte Wilson, centered on the word "name". It appeared in several newspapers in 1906, including the Chicago Daily News. If the Zodiac Killer was scanning microfiche to grab quotes such as "man is the most dangerous animal of all" (1932) and "it was about time for her to die" (1888) to incorporate into his letters, was it possible he took "My name is me" from Charlotte Wilson in 1906?

It may seem unlikely until we consider the design of the April 20th 1970 letter which was mailed to the San Francisco Chronicle and featured the bombing of police officers, along with the possible solution of "My name is me", and the three 8's in the 13-Symbol code. If we throw in Vallejo (and Mare Island) where the Zodiac Killer may have lived, then Charlotte Wilson and the Haymarket massacre is central to them all. If the Zodiac Killer had scoured the newspaper archives or was historically familiar with Vallejo, he would have come across this information (as I did with just a cursory search). The numbers 888 (possibly within a clock face) was pivotal to the writings of Charlotte Wilson in 1888.

Charlotte Mary Wilson was an English Fabian and anarchist who co-founded Freedom newspaper in 1886 with Peter Kropotkin, and edited, published, and largely financed it during its first decade. She remained editor of Freedom until 1895. The current headquarters of Freedom Press is 84b Whitechapel High Street in London (127 Ossulston Street in 1898). Charlotte Mary Wilson was a prolific writer, as can be seen here in a comprehensive list of articles. She advocated heavily for the working man and union rights. 

The Haymarket affair, also known as the Haymarket massacre, the Haymarket riot, the Haymarket Square riot, or the Haymarket Incident, was the aftermath of a bombing that took place at a labor demonstration on May 4, 1886 at Haymarket Square in Chicago, Illinois. The rally began peacefully in support of workers striking for an eight-hour work day; it was held the day after a May 3 rally at a McCormick Harvesting Machine Company plant on the West Side of Chicago, during which two demonstrators had been killed and many demonstrators and police had been injured. At the Haymarket Square rally on May 4, an unknown person threw a dynamite bomb at the police as they acted to disperse the meeting, and the bomb blast and ensuing retaliatory gunfire by the police caused the deaths of seven police officers and at least four civilians; dozens of others were wounded.

Charlotte Wilson wrote extensive articles about the Haymarket massacre, that included "The Chicago Anniversary" (1888), "The Chicago Martyrs" (1889), and "In Memory of Chicago" (1889) to name but a few. She wrote "The eight Anarchist Socialists picked out by the Chicago police as victims of the rage and terror inspired in the propertied classes by the growing energy of the labor movement, had absolutely nothing to do with the throwing of the bomb at the Haymarket meeting in May, 1886. The prosecution utterly failed to connect these eight men with the fatal bomb in any sense which did not equally apply to the 20,000 revolutionary Socialists of the Chicago Central Labor Union, or indeed to any active revolutionary propagandist in the world. They were simply selected as the most energetic and earnest advocates of opinions obnoxious to the ruling classes, opinions gaining ground so fast as to threaten the very existence of property and wage-slavery. These opinions were, (1) Socialism, i.e., common property of the workers in the instruments of labor; (2) Anarchism, i.e., the destruction of all arbitrary authority and the substitution of cooperation by free consent and decision by unanimity; (3) that these great social changes can only be brought about by the direct action of the workers; (4) that if the monopolists of property and upholders of authority resist the demands of the people by armed force, the people are right in defending themselves by armed force, and for this contingency they must be prepared".

Rudolph Schnaubelt, the fierce visaged anarchist who was suspected of throwing the Haymarket bomb in Chicago and for whose apprehension the police machinery of the world has been in motion since, died in 1896. The end of his long flight; and years of hiding ended in a little town in southern California. Consumption - also known as tuberculosis - finally found him out. Schnaubelt was one of the first men arrested with Lines, Spies and Schwab after the great riot in Chicago. For ten hours the police kept him in the sweat box, but his nerves stood the test and they let him go. He took immediate advantage of this and disappeared into the night. In fact, there were reports he was seen in Vallejo, California in 1895, including newspaper articles that ran in the San Francisco Chronicle. 

Eight anarchists were charged with the Haymarket bombing on police. They were convicted of conspiracy in the internationally publicized legal proceedings. The evidence put forward in the court trial was that one of the defendants may have built the bomb but none of those on trial had thrown it, and only two of the eight were at the Haymarket at the time. Seven were sentenced to death and one to a term of 15 years in prison. This anarchist bombing was the culmination of workers striking for an 8 hour working day, which grabbed the attention of Charlotte Wilson, who authored and editorialized many articles about it.  

The Haymarket affair is closely associated with the number 888, which symbolized the movement for an 8-hour workday. This number was used to represent the ideal of three 8-hour shifts: one for work, one for rest, and one for personal time ("Three Eights"rule). The affair itself involved a labor protest in Chicago on May 4th 1886, where a bomb was detonated, leading to violence and casualties. The intertwined numbers 888 had previously been placed on many union buildings around Australia. This "Eight Hour March", which began on 21 April 1856, continued each year until 1951 in Melbourne, when the conservative Victorian Trades Hall Council decided to forgo the tradition for the Moomba festival on the Labour Day weekend. In capital cities and towns across Australia, Eight Hour day marches became a regular social event each year, with early marches often restricted to those workers who had won an eight-hour day. The phrase "888" represents the concept of dividing a 24-hour day into three equal eight-hour blocks: eight hours for work, eight hours for recreation, and eight hours for rest. This concept, popularized by Robert Owen in the early 19th century, is often associated with the eight-hour workday movement, which aimed to establish a more balanced and healthy work-life balance. Below is the 888 campaign in Denmark in 1912.

In essence we have Charlotte Wilson, an anarchist, who wrote extensively on the demonstration and bombing of police in Chicago in 1886, in which the numbers 888 were an integral part of the 8-hour workers rally in Haymarket Square, from where, one of the suspected bombers would disappear from and eventually be sighted in Vallejo, California. Rudolph Schnaubelt's brother, Edward (also an anarchist), worked at the United States Naval Shipyard at Mare Island. When the numbers 888, formed into a clock face in the 13-Symbol cipher, are given a right shift of eight positions, they complete the phrase of "My name is me", used by Charlotte Wilson in the above newspaper snippet from 1906 entitled "An Ancient Problem". A signature that would be later used by the Zodiac Killer in the Exorcist letter mailed on January 29th 1974, featuring "The Mikado" (1885). The 13-Symbol cipher letter mailed on April 20th 1970 carries all of these ingredients The police, the bombing, the numbers 888, and possibly the phrase "My name is me". The common denominator being Charlotte Wilson. Or is it just one of a series of coincidences that plague the Zodiac Killer case?     

*The 8-hour workday campaign refers to the historic movement to reduce the standard working day to eight hours. The movement gained momentum in Australia, particularly with the stonemasons' strike in Melbourne on April 21, 1856, which is considered a key event in the fight for an 8-hour day. This strike, along with other worker protests, led to the eventual implementation of the eight-hour day in Australia and other parts of the world. April 21st was possibly the day the Zodiac Killer believed his cipher and letter would be published. 

The following is nothing new, but I am going to run an old story in reverse. Ever since July 31st 1969 the Zodiac Killer had been taunting us with his name or identity through various letters, cards and ciphers, yet only gave us three "signatures" up to January 29th 1974. The SLA letter, Badlands card and Red Phantom letter will not be included in this analysis because they were not authored by the Zodiac Killer.

​The Bay Area murderer gave us three ways to identify himself as the author, by using "Zodiac" and his "crosshairs" in numerous communications, and "Me" (only once) in his Exorcist letter on January 29th 1974. The question being, why did he use "Me" in 1974 when he could have just written "Zodiac" or added his "crosshairs"? The Zodiac Killer usually had purpose beneath his assumed madness.

​The answer probably lay in the verse he added after writing "Signed, Yours Truley" in the Exorcist letter, which carried the 8-letter phrase "My name is" in the extended version of the "Tit-Willow" verse. Only one communication carried all three signatures of the Bay Area murderer if you apply the following logic.

​The April 20th 1970 letter not only began with "This is the Zodiac speaking", carried the 8-letter phrase of "My name is", and had three 8's in the code, but also produced "Me" and the "crosshairs" by simply circling through the code 8 positions from each circled 8. This would give us "Zodiac", "Me" and his "crosshairs" in one communication. A communication with a 13-character code that is practically unsolvable by using standard homophonic substitution methods. This form of cryptography is able to produce thousands of possible answers, so why would the Zodiac Killer use a methodology that provides no resolution to his puzzle?

​He gave us the answer to his Z32 code by writing  "P.S. The Mt. Diablo code concerns Radians + # inches along the radians" one month later, on July 26th 1970. Both "radians" and "inches" could be found in the Z32 solution, so why not "Me" in the Z13 solution. The Zodiac Killer, in mocking fashion, may have been giving us the answer to the Z13 code in the most simplistic of terms. A signature he would corroborate on January 29th 1974 when he unusually added "Me" to his letter. This is the only Z13 solution ever presented as a "signature" that was replicated in a later Zodiac Killer communication. The April 20th 1970 and January 29th 1974 letters would now carry both "My name is" and "Me" in each instance.

We also have to consider why the Zodiac Killer added three circled 8's to his code when he could have just added three triangles, three squares, or indeed, three circles without the 8's? The answer may lie in the dual purpose of both characters. In essence, we have to circle through 8 positions of the code to arrive at the answer. What are the chances that when we apply this methodology to the Z13 code, we produce a signature that is present in a letter nearly 4 years later, that also harbors the phrase "My name is".

If we know that replacing ciphertext characters with plaintext characters can never produce a verifiable answer without later validation, then the Zodiac Killer almost certainly knew it.

​The technique of rotating an outer circle of characters around an inner circle of fixed characters by a desired number of positions was ably covered by Edgar Allan Poe in "A Few Words on Secret Writing".. He wrote about this immediately after detailing another technique of splitting the alphabet into two lots of 13 characters, A through M, and N through Z. Odd therefore, that the Zodiac Killer would create a code of 13 characters beginning with A and ending with M, which when rotated by 8 positions on a circle, would create a signature later used in the Exorcist letter. Both of these techniques coming after Edgar Allan Poe described the scytale method of decryption in "A Few Words on Secret Writing", that can be used to solve the Zodiac Killer's 340 cipher. A cipher that Zodiac referred to when opening his April 20th 1970 letter, stating "By the way have you cracked the last cipher I sent you?".

We have two techniques described in "A Few Words on Secret Writing" that when combined and rotated through eight positions, gives us a signature used in the Exorcist letter. However, it may just be one of those massive coincidences.  
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FURTHER READING: DEATH IN PARADISE