On December 7th 1969 the Zodiac Killer mailed a letter and code from Fairfield just hours before he phoned the Oklahoma radio station KTOK, both times imitating the caller to the Jim Dunbar TV show on October 22nd 1969. The person who mailed the letter provided crucial information in the Z38 code that showed intrinsic knowledge regarding the mechanics of the 340 cipher and its use of the knight's move in chess. In other words, the person who mailed the December 7th 1969 letter knew how to solve the 340 cipher. They knew this because they were the Zodiac Killer. The following will show how I arrived at the plausible solution of  "TRYING TIMES. SO I NEED APPOINTMENT TO GET HELP". 

Bearing in mind that the phone call to Oklahoma and the letter mailed on December 7th 1969 to the San Francisco Chronicle, were both continuing the theme of the Jim Dunbar TV show and Melvin Belli fiasco, in which the hoax caller was pleading for help, there is a strong probability that the Z38 code may contain a message along the same lines. If it did, it would almost certainly have been something the Zodiac Killer read in the newspapers on this topic, such as the article in the Los Angeles Times newspaper on October 23rd 1969, the day after the television show.
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In the 340 cipher message, decoded by David Oranchak, Sam Blake and Jarl Van Eycke on December 5th 2020, the Zodiac Killer used the headlines from the San Francisco Chronicle newspaper on October 24th 1969, which was titled over two pages, reading both "That Wasn't Zodiac, Say 3 Who Know" and "It Wasn't Zodiac, Say 3 Who Know". In his 340 message he stated "That Wasn't Me on the TV Show". The numerous references in the newspapers immediately after October 22nd 1969 about the caller saying "I don't want to go to the gas chamber", was replied to by Zodiac, who encoded "I am not afraid of the gas chamber". The Zodiac Killer would emphasize these two points in the first seven lines of the deciphered message.   ​

The news was abound with the failed meeting between the "Zodiac Killer" (Sam) and Melvin Belli at the Vincent de Paul thrift store in Daly City, later that day. The Los Angeles Times newspaper on October 23rd 1969 read "Attorney Melvin Belli in a phone booth at a San Francisco television station talking to caller who said he was the Zodiac Killer. Caller made an appointment but didn't keep it". This was the sort of the thing the Zodiac Killer may have mocked, after writing "I just need help" on December 7th 1969. There were two plus signs (+) together in the Z38 code, so I knew they had to represent the same plaintext letter, and gambled on the word "appointment". This would not only fill up a significant portion of the Z38 code, but would mean that the code ended with the plaintext letter "P". That was likely the last letter of "help", which also featured prominently in the Los Angeles Times newspaper and others. In fact, the title of the article was "I Want Help, Zodiac Caller Tells Attorney on Telephone". After placing "appointment" and "help" in the Z38 code, it allows us to form the word "to" immediately after "appointment" because of the double character (dotted circles). The phrase "appointment to get help" was then easy to work out. 

The first 18 ciphertext characters could then be filled in somewhat, with the dotted circle represented by the plaintext letter "T",  the circle with the single vertical line through it represented by the plaintext letter "I", the plain circle ​represented by the plaintext letter "E", the square represented by the plaintext letter "G", the triangle represented by the plaintext letter "O", and the slanted line​ represented by the plaintext letter "N". We were left with this.

The plaintext letters in blue on the top line looked like it could spell "times", followed by the word "so", thereby satisfying the double "L" ciphertext. So I took a gamble and placed the words into the message like so. 

The rest was pretty simple. After the word "so" I added the personal pronoun of "I", and "need" was the obvious next choice. The final part was filling in the blanks for the starting five plaintext letters ending in "G". Trying times" is a well-known phrase that one might experience, and necessitates the need for an "appointment to get help". This completed the Z38 code. Whether it is the correct solution I can't say for certain, but it satisfies the workings of a substitution cipher and has relevance to the contemporary events the Zodiac Killer was reading in the newspapers at the time, just like the message in the 340 cipher.

In cryptography, unicity distance is the length of an original ciphertext needed to break the cipher by reducing the number of possible spurious keys to zero in a brute force attack. That is, after trying every possible key, there should be just one decipherment that makes sense, i.e. expected amount of ciphertext needed to determine the key completely, assuming the underlying message has redundancy. For a simple substitution cipher, the number of possible keys is 26! = 4.0329 × 1026 = 288.4, the number of ways in which the alphabet can be permuted. Assuming all keys are equally likely, H(k) = log2(26!) = 88.4 bits. For English text D = 3.2, thus U = 88.4/3.2 = 28. So given 28 characters of ciphertext it should be theoretically possible to work out an English plaintext and hence the key. Wikipedia. 

• Simple Monoalphabetic Substitution Cipher: The theoretical unicity distance is about 28 characters. In practice, cryptanalysts typically need around 50 characters to perform reliable frequency analysis and achieve a definite solve.

FURTHER READING: "IRON" AND "DEATH" FEATURED IN TWO CIPHERS   

On October 22nd 1969 Will Stevens published an article in the San Francisco Examiner, in which Professor Donald C. B. Marsh urged the killer to contact him in code, stating "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"

Professor Donald C. B. Marsh, by invoking the name of Edgar Allan Poe, was probably hoping that the Zodiac Killer was going to use techniques mentioned or used by Poe, making any future offering by Zodiac easier to solve. The next two ciphers/codes mailed by the Zodiac Killer can be linked to Poe's 1841 essay "A Few Words on Secret Writing" from the July edition of Graham's magazine. The scytale method of decryption featured by Poe can solve the 340 cipher. The immediate next passage of  A Few Words on Secret Writing further describes cryptographic techniques, showing the splitting of the alphabet into ABCDEFGHIJKLM and NOPQRSTUVWXYZ, creating two portions of thirteen letters. The Zodiac Killer's April 20th 1970 communication was a 13-Symbol cipher beginning with A and ending with M. Edgar Allan Poe then describes a cipher wheel that can be used to give a credible answer to the Z13 code. But of course, it doesn't end there.

Not only did the Zodiac Killer use the encryption techniques described by Edgar Allan Poe, he may have embedded two of Edgar Allan's poems in the mechanics of the 340 cipher. Notable words from these two poems were visible when the cipher key was applied to the 340 cipher (before the period 19 shift was used to acquire the message). The presence of the second Edgar Allan Poe poem in the 340 cipher (after the key was applied) was highlighted by the author of the Z38 code mailed from Fairfield on December 7th 1969, who was undeniably the Zodiac Killer.

But let us deal with the first poem that was plainly visible in the deciphered 340 message, that read: I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME - THAT WASN’T 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.

"To One in Paradise" was written by Edgar Allan Poe. This poem was first published as part of the short story titled "The Visionary" (later retitled as "The Assignation"). The poem was also published under the names "To lanthe in Heaven" and "To One Beloved". The title "To One in Paradise" was used in the February 25th 1843 edition of the Philidelphia Saturday Museum. This poem was written after the death of Poe's wife. He writes that she was his life and he lived for her and now he looks forward to the future where they will be together again in death. link. Now let's look for the second poem by Edgar Allan Poe. When the Zodiac Killer mailed the Z38 code on December 7th 1969, he repeated two notable segments of ciphertext from the 340 cipher. The first four ciphertext characters, and the last five ciphertext characters (shown below). 

This may not seem significant, until you consider that when the original 340 cipher was changed using the key, it created the words "IRON" and "DEATH" in these two exact positions (see below). Are we are expected to believe that when the author of the Z38 code selected these four and five sections of ciphertext from the 340 cipher, taken from the beginning and end of the cipher, he chose two legible words created by the 340 key by accident, which he should have had no knowledge of unless he was the Zodiac Killer. No hoaxer should have been aware of this fact and had the foresight to highlight these sections in the Z38 code. The person who created the Z38 code broke up the "Zodiac-like" pseudonym (ZO∆AIK) from the last row of the 340 cipher to create the word "death", something that would not have been expected from a hoaxer. The person who did this knew exactly what they were doing, because they created the 340 cipher.

It must be remembered that Edgar Allan Poe wrote "To One in Paradise" upon the death of his beloved wife, Virginia Eliza Poe. But how can "IRON" and "DEATH" introduce a second Edgar Allan Poe poem into the equation? Edgar Allan Poe wrote "To One in Paradise" about the death of his wife, but this wasn't the only poem written by Poe about the death of Virginia. The inspiration for the second poem, "The Bells", was reported as coming from his friend, Marie Louise Shew, who likened the sound of the Fordham University bell made of "iron", to "death".

​Edgar Allan Poe's poem "The Bells" uses different types of bells (silver, gold, brazen, iron) as powerful metaphors for the stages of human life, from the joy and playfulness of childhood (silver sleigh bells) through the harmony of youth and marriage (golden bells), to the panic and chaos of maturity (brazen bells), culminating in the inescapable melancholy and terror of death (iron bells). Written at the end of his life, the poem's shifting sounds and increasing length mirror the journey from youthful delight to the despair and inevitability of mortality, exploring the passage of time and its emotional toll. Edgar Allan Poe's poem "The Bells" was inspired by the sounds of bells from Fordham University's church while he lived nearby in the Bronx, New York, capturing the changing emotions of life, from youthful joy (silver bells) to despair and death (iron bells), a reflection of his own grief after his wife Virginia's passing.. Inspiration for the poem is often granted to Marie Louise Shew, a woman who had helped care for Poe's wife Virginia as she lay dying. One day, as Shew was visiting Poe at his cottage in Fordham, New York, Poe needed to write a poem but had no inspiration. Shew allegedly heard ringing bells from afar and playfully suggested to start there, possibly even writing the first line of each stanza.

I always wondered why these two prominent English words began and ended the 340 cipher after the key was applied to the original 340 ciphertext, and then highlighted by Zodiac in the Z38 code. The poems "The Bells" and "To One in Paradise" were written about the grief Edgar Allan Poe experienced upon the death of his wife, with "IRON", "DEATH" and "PARADISE" instrumental to both - which just happened to be present at the beginning and end of the Zodiac Killer's 340 cipher after the key was applied (although "one in paradice" was reversed at this point). Throw in the essay A Few Words on Secret Writing by Edgar Allan Poe, containing a technique that can solve Zodiac's 340 cipher (and a further technique that possibly influenced the design and solution of the Z13), and we have a story steeped in history. 

FURTHER READING: THE MECHANICS OF THE Z38 CODE 

Thanks to the brilliance and determination of David Oranchak, Sam Blake and Jarl Van Eycke, the 340 cipher was finally cracked after 51 years on December 5th 2020. However, with the exception of a few people, little has been done to find the inspiration for a killer who created a cipher that required the knight's move in chess to reconfigure the ciphertext and allow the message to be broken using homophonic substitution. The 340 cipher needed a one down, two across system to make the cipher easier to crack, with the Zodiac Killer's errors creating a further roadblock. Ciphers are mathematical, relying on algorithms, modular arithmetic, and complex equations for encryption and decryption, evolving from simple letter shifts to advanced concepts in number theory and abstract algebra for modern digital security. They use mathematical procedures to transform readable text (plaintext) into unreadable text (ciphertext) and back, making them a core part of cryptography, which sits at the intersection of math and computer science.

Radians, chosen by the Zodiac Killer for us to discover the location of his hidden (likely pretend) bomb, are fundamental to mathematics, serving as the standard unit for measuring angles, especially in calculus and physics, because they simplify formulas by relating angles directly to the circle's radius, making calculations for arc length, sectors, and trigonometric functions much cleaner than using degrees. Radians are essentially a unitless count of "radius units", making them a natural fit for mathematical expressions. This was another of Zodiac's puzzles that lay unbroken for 51 years until Zodiac researcher, Druzer, filled in the blanks on December 27th 2020. But what is another form of mathematics that may have inspired the Zodiac Killer to fashion the 340 cipher the way he did? A form of mathematics that Zodiac mentioned in his letters?​  

On July 19th 1978, a deeply controversial communication, that is almost certainly genuine Zodiac material, was mailed to the Los Angeles Times. It read: "I am the ZODIAC and I am in control of all things. I am going to tell you a secret. I like friction tape. I like to have it around in case I need to truss someone up in a hurry....I have my real name on a small metallic tape. You see, while you have it in your possession, I want you to know it belongs to me and you think I may have left it accidentally. I am athletic. It could be swim fins, or a piece of scuba gear. But maybe you play chess with me. I have several cheap sets in closets all over. I have my name on the bottom of the lid with the scotch tape....My tape is waiting for me all over California. Do you know me? I am the ZODIAC and I am in control". This letter probably formed the basis of Robert Graysmith's mentioning of Zodiac's crimes as an "outdoor game of chess".

Chess is deeply mathematical, relying on logic, patterns, probability, and combinatorics, even though it's not about traditional arithmetic; it's a game of finite states and algorithms with a vast solution space, making it a practical application of mathematical thinking. While you don't need advanced math skills to play, the underlying principles of strategic calculation, geometry, and problem-solving connect it directly to mathematics. Coming the day after the opening game in the World Chess Championship between Anatoly Karpov and Viktor Korchnoi on July 18th 1978, this letter told of a person who had "chess sets all over California" and suggested that David Toschi, who had been demoted to pawn detail, play a game of chess with him.

​If the Zodiac Killer really had an avid interest in chess and puzzles, he would very likely have known about the knight's tour challenge, a mathematical problem where you have to move a knight around a chessboard (8 X 8 grid) and visit all 64 squares without landing on a square more than once. The Knight's Tour is very well-known, recognized as a classic, over-thousand-year-old mathematical puzzle and graph theory problem, first appearing in 9th-century Sanskrit texts and later analyzed by Leonhard Euler, becoming famous for its complexity and links to magic squares, popularizing it through chess history and computer science as an illustration of algorithms. 

Ciphers are essentially algorithms (or sets of rules/steps) used for encryption and decryption, transforming readable text (plaintext) into unreadable ciphertext and back again, using keys to control the process. So did the Zodiac Killer use a knowledge of chess and the well-known puzzle of the knight's tour, and create a more complex 340 cipher that required the very same move to begin decoding his message on November 8th 1969? 

FURTHER READING: A PAWN IN A GAME OF DEATH   ​

​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.
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See    Cracking the Crackproof.   Same Methodology Between Z340 and Z13.   Effectively a 353 Character Cipher.
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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"

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"     

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 

The April 20th 1970 letter with the phrase "My name is", along with its accompanying 13 character code, was very likely prompted by Professor 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".

There is good reason to believe that the inspiration for both the Z340 and Z13 codes came from an essay by Edgar Allan Poe called "A Few Words on Secret Writing", Whatever the case, you can solve the 340 cipher using the scytale (or skytale) method of cryptography. Although Dave Oranchak doesn't believe the Zodiac Killer used the scytale method of encryption in the creation of the 340 cipher, this decryption tool does actually decode the message in the 340 cipher. The immediate cipher mailed by the Zodiac Killer after the challenge by Professor Donald C. B. Marsh was the 340 cipher postmarked November 8th 1969, so is it possible the Zodiac Killer used Marsh to create his cipher? If so, the clue to solving the 340 cipher would have been ever present at the American Cryptogram Association.  

Helen Fouché Gaines (October 12, 1888 – April 2, 1940) was a member of the American Cryptogram Association and editor of the book Cryptanalysis (originally Elementary Cryptanalysis) first published in 1939. The book described the principal cryptographic systems of the 19th century and cracking methods including elementary contact analysis (cryptanalysis). The original black and white logo of the American Cryptogram Association appeared on the cover of "Elementary Cryptanalysis: A Study of Ciphers and Their Solution" by Helen Fouché Gaines. The logo featured a scytale cipher. So, did the Zodiac Killer design and mail a cipher that could be solved using the scytale method of decryption, inspired by the American Cryptogram Association logo, from right under the nose of ​Professor Donald C. B. Marsh, the very man who challenged Zodiac seventeen days earlier. Below is the original and modernized version of the logo. The first cipher discussed in Edgar Allan Poe's  "A Few Words on Secret Writing" was the scytale cipher (scytala), present on the American Cryptogram Association logo, with both featuring in the San Francisco Examiner challenge by D. C. B. Marsh on October 22nd 1969.

The address of the American Cryptogram Association was 818 14th Street, Golden, Colorado. Here is a "Union Cipher Disk", with the address numbers of the American Cryptogram Association and the 888 present within the 13-Symbol cipher. A cipher disk is an enciphering and deciphering tool developed in 1470 by the Italian architect and author Leon Battista Alberti. He constructed a device, (eponymously called the Alberti cipher disk) consisting of two concentric circular plates mounted one on top of the other. The larger plate is called the "stationary" and the smaller one the "moveable" since the smaller one could move on top of the "stationary". This type of encryption features in Poe's "A Few Words on Secret Writing". In fact, the first three enciphering techniques described in "A Few Words on Secret Writing" are somewhat connected to the Z13 and Z340. [1] Scytale Cipher [2] Splitting the alphabet A to M, N to Z, into two parts of thirteen characters [3] Cipher wheel/disk. Here is a working cipher wheel using the alphabet. 

MY NAME IS ARTHUR GORDON PYM - TAKEN FROM POE'S ONLY COMPLETE NOVEL
​TO ONE IN PARADISE - A POEM BY EDGAR ALLAN POE (PRESENT IN THE 340 CIPHER)

On October 22nd 1969 Eric Weill hijacked the Zodiac Killer's appearance on the Jim Dunbar TV Show and passed himself off as the infamous Bay Area murderer, effectively claiming responsibility for the canonical Zodiac murders by default. Three and a half months later, on February 5th 1970, Eric Weill would again contact the Jim Dunbar TV Show repeating the ruse. This was readily dismissed by Detective David Toschi, who confidently stated that "it was most certainly not Zodiac", with homicide detectives listening to the tape of the caller's voice and concluding that "Sam" was a phony The San Francisco Chronicle, the following day, ran with the appropriate headline of "Talk Shows 'Zodiac' Caller Called a Phony". It is with little doubt that the Zodiac Killer would have noticed these headlines of a second call.

​Fast forward to May 1971 when the Zodiac Killer mailed the 148 character cipher and letter. This communication arrived just after the arrest and questioning of Karl Francis Werner for the April 11th 1971 murder of Kathy Bilek in Saratoga, and the distant murders of Kathie Reyne Snoozy (15) and Debra Gaye Furlong (14) in San Jose on August 3rd 1969. This clearly irked the Zodiac Killer, who after claiming the murders of Snoozy and Furlong in his Dripping Pen card on November 8th 1969, saw Karl Francis Werner as another individual stealing victims from under his nose, just like Eric Weill on the Jim Dunbar TV Show. Encoded within his 148 character cipher he urged police to "stop listening to phonys", using the description given to Eric Weill by homicide detectives in the San Francisco Chronicle article on February 6th 1970. The Zodiac Killer was likening Karl Francis Werner to Eric Weill and calling them both "phonys".  

The Zodiac Killer was calling out Eric Weill in his 148 character cipher just as he had called him out in the 340 cipher, encrypting the wording "That wasn't me on the TV show". This shows that the author of the 148 character cipher had intrinsic knowledge to the contents of the 340 cipher plaintest, despite this cipher remaining unbroken for another 49 1/2 years. However, this wasn't the only thing that bound the two ciphers together under one author. 

The 148 character cipher and letter stated that he would "skin 3 little kids and make a suit from the skin" if his cipher was not printed on the front page of the newspaper. The July 31st 1969 letters demanded newspapers that they printed the 408 cipher "on the front page of your paper". The Dripping Pen card communication also requested that the 340 cipher be placed on the "frunt page". Every lengthy cipher/communication wanted front page coverage for his cryptic offerings. But crucially, both the 340 cipher/Dripping Pen card and 148 character cipher were bound together through two victims. The Dripping Pen card inflated the known victim count from five to seven, adding "Aug" to the chronological list of months by including the murders of Snoozy and Furlong on August 3rd 1969 in San Jose. The 148 character cipher also included Snoozy and Furlong, along with Kathy Bilek, when he threatened to "skin 3 little kids and make a suit from the skin". The Zodiac Killed claimed he would "skin 3 little kids and make a suit from the skin" and "send a patch of human skin if there is some left over", but neither of these statements mentioned the potential murder of three kids. That is because he was referring to the three previous murder victims of Kathie Snoozy, Debra Furlong and Kathy Bilek.  ​

​Edward Theodore Gein, dubbed "The Butcher of Plainfield", was found guilty in the first degree murder of Bernice Worden (58), who was abducted and later found hung and decapitated in a shed on Gein's property. Although he was only convicted of one murder and found criminally insane, Edward Gein was believed to have killed many more, including Mary Hogan (51), Georgia Weckler (8) and Evelyn Hartley (15). Called the "House of Horrors", his property in Plainfield, Wisconsin revealed the true depravity of an individual who had lost touch with reality, when detectives found a lampshade made from a human face, a waste basket made from human skin, a corset made from a female torso and bowls made from human skulls, to name just a few of the devilish offerings.

His mother, Augusta Wilhelmine Gein (who died on December 29th 1945), was a domineering woman with an intense hatred for females, but whose death from a stroke left Edward Gein devastated and alone in the farmhouse. Soon after his mother's death, Gein began to create a "woman suit" so that "he could become his mother and literally crawl into her skin". He would achieve this by exhuming the bodies of recently deceased middle-aged women from local graveyards and using their skin to fashion his grizzly creations. The Zodiac Killer, who must have been aware of the Ed Gein story, clearly ran with this concept and threatened to exhume the bodies of Kathie Snoozy, Debra Furlong and Kathy Bilek, and "make a suit from the skin", just as Ed Gein had sourced graveyards for his skin. It's doubtful that the Zodiac Killer was ever going to follow up on this macabre threat, but he may have come close.

​On July 13th 1971, the Monticello communication was mailed by the Zodiac Killer, insinuating the murder of Kathy Bilek (18), who died in the Villa Montalvo woods on April 11th 1971, by using the burial site of her phonetic namesake Kathie Snoozy (15), who was murdered alongside her friend Debra Furlong (14) in San Jose on August 3rd 1969. The Zodiac Killer included the following message into the correspondence, pasting the newspaper text of "Near Monticello Shought Victims 21 ... In The Woods Dies April". Kathy Bilek was murdered "near Monticello" in the Villa Montalvo "woods" on "April" 11th 1971. Kathie Snoozy was buried at the Oak Hill Memorial Cemetery "near the Villa Montalvo woods" in the "Monticello" neighborhood of San Jose. The Zodiac Killer chose the location of "Monticello" to bind together the murders of Kathy Bilek, Kathy Snoozy and Debra Furlong - the latter two of which he had claimed on November 8th 1969 in the Dripping Pen card.

Just over two years later, on September 18th 1973, somebody removed a tombstone from the Oak Hill Memorial Cemetery in Monticello at First Street & Curtner Avenue, and deposited it at the gated front entrance. The tombstone had the pseudonym "Zodiac" written on it in crayon. There are good reasons to believe the Zodiac Killer committed this unsavoury act, because we know that the Zodiac Killer had a vested interest in the murder of Kathie Snoozy and the location of her burial site. Of all the places in America (or California) this could have occurred, somebody just happened to remove a tombstone from the Oak Hill Memorial Cemetery in Monticello and write "Zodiac" on it, despite the Monticello card never being released into the public domain. The card has been known to researchers in recent times, but was certainly not public knowledge on September 18th 1973. The person who removed the tombstone from the Oak Hill Memorial Cemetery in Monticello must have been the Zodiac Killer. The body of Kathie Snoozy wasn't exhumed in 1973, but the Zodiac Killer may have stood just six feet away from a victim he once claimed.. 

The first part of this presentation is from a previous article.
On October 22nd 1969, the San Francisco Examiner newspaper published an article by Will Stevens, which laid down a challenge from Professor D.C.B. Marsh of the American Cryptogram Association (ACA) to the Zodiac Killer, attempting to coax him into revealing his name.

The newspaper stated "Dr Marsh told the Examiner today: "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".

Professor D.C.B. Marsh was probably hoping the Zodiac Killer would employ a cryptographic technique featured in the works of Edgar Allan Poe, thereby making any future cipher mailed by the Zodiac Killer easier to crack. As it turned out, the Zodiac Killer's 340 cipher mailed on November 8th 1969 could be solved using the scytale method of encryption detailed in Edgar Allan Poe's essay A Few Words on Secret Writing in the very first paragraph. We have Professor D.C.B. Marsh of the American Cryptogram Association creating the trigger, by inserting Edgar Allan Poe into the mind of the Zodiac Killer. The Zodiac Killer then created the 340 cipher that could be deciphered using the scytale method featured in Poe's A Few Words on Secret Writing. Therefore, what are the odds that one of Edgar Allan Poe's poems would partially appear in the solution to the 340 cipher?

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME - THAT WASN’T 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.   

"To One in Paradise" was written by Edgar Allan Poe. This poem was first published as part of the short story titled "The Visionary" (later retitled as "The Assignation"). The poem was also published under the names "To lanthe in Heaven" and "To One Beloved". The title "To One in Paradise" was used in the February 25, 1843 Saturday Musuem. This poem was written after the death of Poe's wife. He writes that she was his life and he lived for her and now he looks forward to the future where they will be together again in death. link.

The Zodiac Killer would eventually mail the April 20th 1970 letter containing a 13 character code, prefixed with "My name is". The 340 cipher could be solved with the scytale method of decryption featured in Poe's essay A Few Words on Secret Writing, so it was extremely noteworthy that the second encryption technique covered in Poe's A Few Words on Secret Writing involved splitting the alphabet A through M, and N through Z. The Zodiac Killer's code on April 20th 1970 began with "A", ended with "M", and was 13 characters in length (half the alphabet). But why did the Zodiac Killer prefix the code with "My name is"? Edgar Allan Poe's only complete novel was entitled "The Narrative of Arthur Gordon Pym of Nantucket". The very first line of this book read  "My name is Arthur Gordon Pym". 

Edward Theodore Gein, dubbed "The Butcher of Plainfield", was found guilty in the first degree murder of Bernice Worden (58), who was abducted and later found hung and decapitated in a shed on Gein's property. Although he was only convicted of one murder and found criminally insane, Edward Gein was believed to have killed many more, including Mary Hogan (51), Georgia Weckler (8) and Evelyn Hartley (15). Called the "House of Horrors", his property in Plainfield, Wisconsin revealed the true depravity of an individual who had lost touch with reality, when detectives found a lampshade made from a human face, a waste basket made from human skin, a corset made from a female torso and bowls made from human skulls, to name just a few of the macabre offerings.

His mother, Augusta Wilhelmine Gein (who died on December 29th 1945), was a domineering woman with an intense hatred for females, but whose death from a stroke left Edward Gein devastated and alone in the farmhouse. Soon after his mother's death, Gein began to create a "woman suit" so that "he could become his mother and literally crawl into her skin". He would achieve this by exhuming the bodies of recently deceased middle-aged women from local graveyards and using their skin to fashion his grizzly creations. 

​A well read Zodiac Killer was seemingly inspired by the continuing fascination of the story of Edward Gein, that featured in many movies, beginning with Psycho (1960), produced and directed by Alfred Hitchcock, and starring Anthony Perkins and Janet Leigh, along with later productions such as The Texas Chainsaw Massacre (1974) and The Silence of the Lambs (1991). The Zodiac Killer mailed a cryptogram and letter in the middle of 1971 (likely early May) claiming the murders of Kathy Bilek (18), Debra Furlong (14) and Kathie Snoozy (15), whose brutal slayings had all been recently attributed to Karl Francis Werner in the newspapers. The Zodiac Killer would make reference to all three girls in his 148 character and letter, asking investigators not to listen to "phonys" such as Werner, and warning them he would "skin three little kids and make a suit from the skin", and "send a patch of human skin if their is some left over". Having claimed the brutal stabbing of Snoozy and Furlong on August 3rd 1969 in San Jose through the "Aug" reference in his November 8th 1969 "Dripping Pen" card, he was now left with the necessity of claiming the stabbing of Kathy Bilek also. She became the focus of his later Monticello card, mailed on July 13th 1971, stating "Near Monticello Shought Victims 21 ...... In The Woods Dies April". ​ Kathy Bilek was stabbed in the Villa Montalvo woods in Saratoga (near Monticello in San Jose) on April 11th 1971.  

​Edward Theodore Gein was determined to raid graveyards and "make a woman suit from the skin", whereas the Zodiac Killer promised to "skin three little kids and make a suit from the skin". Kathy Bilek was buried in the Madronia Cemetery in Saratoga, Debra Furlong in the Oak Wood Cemetery in Santa Cruz, and Kathie Snoozy in the Oak Hill Memorial Park & Cemetery in San Jose.

I have always assumed that the Zodiac Killer was promising to kill three more kids in the future and make a suit from the skin, but based on the possible inspiration of the Edward Gein story, was the Zodiac Killer suggesting the macabre intention of visiting the three graveyards of Snoozy, Furlong and Bilek, and removing their skin to create a suit? Then mail "a patch of human skin if their is some left over". 

This may seem far-fetched, until you discover that Kathie Snoozy was buried in the Oak Hill Memorial Park & Cemetery in San Jose, located in the neighborhood of Monticello, near Saratoga. Hence the wording "Near Monticello Shought Victims 21 ...... In The Woods Dies April" in the Zodiac Killer's message on July 13th 1971. The neighborhood of Monticello is near to the Villa Montalvo woods in Saratoga, where Kathy Bilek was brutally stabbed to death on April 11th 1971. There is no doubt that the Monticello card is referring to the murder of Kathy Bilek, through the gravesite of Kathie Snoozy - and so linking the Zodiac Killer to all three girls. But did the 148 character cipher and letter have a much more sinister connotation to its contents than first thought, inspired by the continuing story of Edward Theodore Gein?   

Kathy Bilek was murdered in the Villa Montalvo woods on April 11th 1971, hence the words "In The Woods Dies April". The Zodiac Killer also gave us a clue to the name of Kathy Bilek by identifying her namesake, Kathy Snoozy, who was buried in the Oak Hill Memorial Park & Cemetery in the Monticello neighborhood of San Jose. The murder of Kathy Bilek in the woods in April was near to the Monticello neighborhood. The three murder victims of Snoozy, Furlong and Bilek were all credited to Karl Francis Werner, who was arrested and questioned about their murders on April 29th 1971. The Zodiac Killer, having previously insinuated himself responsible for the murders of Snoozy & Furlong on November 8th 1969, now felt compelled to also claim the murder of Kathy Bilek in the Monticello card. The fact that Kathy Bilek, "in the woods died April", with "Monticello" containing the burial site of Kathy Snoozy, who were both murdered by Karl Francis Werner (along with Debra Furlong) and claimed by the Zodiac Killer, should not be overlooked when examining the Pines card mailed four months earlier. 

The Monticello card contained pasted newspaper text and never directly named Kathy Bilek as the victim he was claiming, but gave us directions to the burial site of one of his previously claimed victims (Kathy Snoozy). The Pines card used the same template, by again using newspaper cuttings, and failing to mention the name of Donna Lass (but insinuating her as the victim). The newspaper cuttings on the March 22nd 1971 "Pines card" appear to direct us to the deposition or burial site of the Lake Tahoe nurse, just like he did with Kathy Snoozy at Monticello. If the Zodiac Killer was the author of the Pines card, then he retrospectively claimed the lives of Donna Lass, Kathy Snoozy, Debra Furlong and Kathy Bilek months after their murders. He would retrospectively claim the murder of Cheri Jo Bates also. We may now have two pasted postcards, both possibly giving us directions to the remains of a murder victim claimed by the Zodiac Killer.

For many years now I have stated that the Zodiac Killer designed the Monticello card on July 13th 1971, reading "Near Monticello Shought Victims 21 ...... In The Woods Dies April". The card was claiming the murder of Kathy Bilek (18), who was murdered in Saratoga, in the Villa Montalvo woods near the neighborhood of Monticello (in San Jose) on April 11th 1971. Kathy Snoozy (15) was the phonetic namesake of Kathy Bilek, and was buried in the Oak Hill Cemetery at 300 Curtner Avenue in the Monticello neighborhood of San Jose.

The Zodiac Killer chose the location of "Monticello" to bind together the murders of Kathy Bilek, Kathy Snoozy and Debra Furlong, the latter two of which he had claimed on November 8th 1969 in the Dripping Pen card. He added Kathy Bilek to his total when he mailed the 148 character cipher and letter in (likely) May of 1971, and confirmed this on July 13th 1971 with the mailing of the Monticello card. These two communications in 1971 were a response to the arrest of Karl Francis Werner for the murder of all three girls. The burial location of Kathy Snoozy became integral to the Zodiac story on July 13th 1971, but investigators have apparently never made this connection. This is what makes the events of September 18th 1973 so very, very interesting.

On this date, somebody removed a tombstone from the Oak Hill Cemetery at First Street & Curtner Avenue and placed it in front of the cemetery gate. The tombstone had the pseudonym "Zodiac" written on it in crayon. We don't know the identity of the perpetrator who committed this unsavoury act, but we do know that the Zodiac Killer had a vested interest in the murder of Kathy Snoozy and the location of her burial site. I will leave it to you to guess the tombstone removed.   

​The Zodiac Killer's interest in the case of Kathy Snoozy & Debra Furlong likely began on August 6th 1969 (3 days after their murders) when the San Francisco Chronicle released a comprehensive front page article of the knife slayings, with a reference to her burial at the Oak Hill Cemetery in San Jose.

​In his very first communications, the Zodiac Killer wrote three letters to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald on July 31st 1969, and fully expected to receive front page coverage, demanding "I want you to print this cipher on your frunt page by Fry Afternoon Aug 1-69, If you do not do this I will go on a kill ram page Fry night that will last the whole week end". After all, he had now committed the murders of David Faraday, Betty Lou Jensen and Darlene Ferrin, while seriously injuring Michael Mageau.

He again reiterated the importance of publicity when the August 4th 1969 Debut of Zodiac letter arrived at the San Francisco Examiner offices, stating "I was not happy to see that I did not get front page coverage". This trend would continue in the Dripping Pen card on November 8th 1969 when he asked politely "Could you print this new cipher in your frunt page", and when the Los Angeles letter was mailed on March 13th 1971, declaring "The reason I'm writing to the Times is this, They don't bury me on the back pages like some of the others". 

By August 4th 1969 he had killed three, nearly killed another, sent four letters and created a 408 character cipher formed of three parts - but despite this - the two main newspapers in the Bay Area relegated his cipher offerings to page four and page nine in the San Francisco Chronicle and San Francisco Examiner respectively. The Zodiac Killer was probably wondering what more he had to do to achieve the front page coverage his crimes and communications merited. The answer would come sharply into focus, when two days after he announced himself to the world as "Zodiac" - and while he was scouring the newspapers for any progress on his 408 cipher - the San Francisco Chronicle wrote a comprehensive article on the front page of their newspaper featuring the brutal slayings of Kathie Reyne Snoozy (15) and Debra Gaye Furlong (14) in San Jose on August 3rd 1969. The two young teenage girls were brutally stabbed countless times as they picnicked atop an oak grove in Alamedan Valley. 

​The Zodiac Killer, having created terror in Benicia and Vallejo - and having sent four communications to date - noticed that the Snoozy & Furlong murders received front page coverage, while he received inner-page status. Is it really any surprise that the Zodiac Killer reappeared on the shores of Lake Berryessa on September 27th 1969, armed with a large knife and wearing an ominous executioner's costume. 

​Dr. John E. Hauser, Santa Clara county's chief medical examiner and coroner, stated of the Snoozy & Furlong murders "I've never seen a case with this many stab wounds. You know, I've been in this profession a long time and sometimes I think I'm rather callous, but when I saw these girls, believe me it was terrifying. The Nazi sex mutilations during World War II were nothing compared to what was done to these young girls". 

The Zodiac Killer knew he had to perform an attack that would shock, so it's not difficult to understand why he ramped up the terror in the manner he did, knowing that a close-quarter attack should secure him the front page coverage he felt he warranted. After the attack on Bryan Hartnell and Cecelia Shepard, the Zodiac Killer traveled back up the hill and wrote "Vallejo 12-20-68, 7-4-69, Sept 27-69 - 6:30. by knife" on the car door of the young couples' vehicle. The addition of "by knife" was effectively saying to law enforcement "I've now killed with a knife, do I now get front page coverage like the San Jose murders". The plan worked perfectly, because the Lake Berryessa attack had the added advantage of him being linked to the murders of Kathie Snoozy and Debra Furlong. Something he would capitalize on in the Dripping Pen card on November 8th 1969, when he upped his victim count to seven and added the month of August to his chronological list of murder months.  
 
​There is also the possibility he threatened the family members of Debra Furlong on December 19th 1969 (see newspaper cutting above), when a phone call was received by police dispatcher, Shirley Searey, of the San Jose Highway Patrol, claiming to be the Zodiac Killer and stating "I am going to kill five of you officers and a family of five between now and Monday". The remaining five Furlong family members were Glen Furlong and his wife, along with Glen, 16; Floyd, 12, and Pamela, 11. All the information required to create this phone call and know the burial site location of Kathy Snoozy was available in the August 6th 1969 San Francisco Chronicle newspaper article.  

On October 27th 1970, the Zodiac Killer would mail the Halloween card, upping his victim count to fourteen, but chose to write 4-TEEN as an alternative, to include the only four teenagers he was claiming thus far. Those four were David Faraday (17), Betty Lou Jensen (16), Kathie Snoozy (15) and Debra Furlong (14). Seven months later (probably early May, 1971), the Zodiac Killer mailed the 148 character cipher and letter in response to the recent arrest and interrogation of Karl Francis Werner (18) for the murders of Kathie Snoozy and Debra Furlong, as well as the recent murder of Kathy Bilek (18) in Saratoga on April 11th 1971. The headlines stated San Jose Student Held in Slaying of Three Girls, San Jose Student Held in Slaying of 3 Girls and Youth Arraigned in Knife Slayings of Three Girls.  Paul Avery of the San Francisco Chronicle wrote "He (Werner) was immediately advised of his rights concerning any statements he may make and legal representation to which he is entitled, the detectives said. Werner was then taken to the scenes of the crimes. Late yesterday he was undergoing questioning. The detectives would not reveal what statements, if any, he had made concerning the killings of the three girls".

​The Zodiac Killer, having invested nearly two years linking himself to the Snoozy & Furlong murders, could now abandon his connection to the two young teenagers, or continue the facade, and now claim all three murders, which included Kathy Bilek. It was either all three, or none at all. His choice became apparent when the 148 character cipher included in his 1971 letter was deciphered. It read "T(h)is (is) the Zodiac Speacking. Why can't you stop me. I can't stop killing. Stop listening t(o) phonys. If this is not on the front page in a week I will skin 3 little kids and make a suit from the skin". The Zodiac Killer was urging investigators not to listen to Karl Francis Werner, referring to him as a "phony". 

​The 408 cipher mailed on July 31st 1969 could be considered an introductory cipher by the Zodiac Killer, laying out his plans to collect more slaves for his afterlife and warning police of more murder to come. The 340 cipher, solved by eminent cryptographers David Oranchak, Sam Blake and Jarl Van Eycke in December 2020 was contemporary in nature, effectively calling out Eric Weill who telephoned into the Jim Dunbar TV Show on October 22nd 1969, that initiated the response of Zodiac just over two weeks later, who stated "That wasn't me on the TV show". The 32-Symbol cipher was also contemporary in nature, threatening to detonate a bomb in San Francisco & Vicinity soon after the Zodiac Killer had referenced the Park Police Station bombing (on April 20th 1970) which killed San Francisco police officer Brian McDonnell. The Zodiac Killer also called out Karl Francis Werner shortly after his arrest and interrogation for the murders of Snoozy & Furlong on April 29th 1971, again encoding a contemporary message stating "stop listening to phonys". This message (plural in nature) was not only labelling Karl Francis Werner as an imposter, but included Eric Weill from the Jim Dunbar Show - and so bound the 340 and 148 character ciphers under the banner of one author.

The Zodiac Killer wrote "stop listening to phonys" in 1971. The phonys mentioned by Zodiac were Eric Weill and Karl Francis Werner. Both the 340 cipher and 148 cipher used the headlines (and text) from two newspapers. The 340 cipher effectively rejected the phony caller to the Jim Dunbar TV Show. The 148 cipher rejected the phony, Karl Francis Werner, who was being credited with the murders of Snoozy & Furlong, to which Zodiac had claimed for himself on November 8th 1969, by the addition of "Aug" on the Dripping Pen card.  

The Z148 code (probably mailed May 3rd 1971) was again contemporary in nature, being a response to the police arrest and interview of Karl Francis Werner on April 29th 1971. Three newspaper articles ran with the headlines "San Jose Student Held in Slaying of Three Girls", "San Jose Student Held in Slaying of 3 Girls" and "Youth Arraigned in Knife Slayings of Three Girls". The Zodiac Killer utilized these headlines in his 148 character cipher by promising to "skin three kids and make a suit from the skin" if his latest letter was not published.​

​Victims of serial killers ​make up a very small percentage of the total number of murder victims each year. Communications written by such killers (and accompanying hoaxers) are even less. So imagine the percentage of serial killers and their accompanying hoaxers that mail communications to authorities with cryptograms and codes included within the correspondence. Now imagine two cryptograms contained within two letters unreleased into the public domain, both of which have many crossover features, that both use the ciphertext character "7" to represent the plaintext character "A" in the code, with both claiming to be from the Zodiac Killer, and both using the "sun cross" in their respective codes. These two letters were mailed from Fairfield, California (1971) and Albany, New York (1973). Now imagine mailing a 148 character cryptogram in 1971 using the root word "phony" that was previously used to describe the Jim Dunbar TV Show hoaxer Eric Weill in the headlines of a newspaper article on February 6th 1970, who was the focus of the 340 cipher solve in 2020 when the Zodiac Killer wrote "That wasn't me on the TV show" and effectively proclaimed the caller a hoaxer. A 340 cipher message that wasn't known to anybody else but the Zodiac Killer in 1971. 

Of the three lengthy cryptograms crafted by the Zodiac Killer, the 408 cipher mailed on July 31st 1969 was his introductory message to the public, proclaiming his intention to collect slaves for the afterlife. The cryptogram was a simple homophonic substitution cipher, cracked in a matter of days by schoolteacher Donald Gene Harden and Bettye June Harden (née Tischer) of Salinas, California. The Zodiac Killer's next character laden cryptogram appeared reactionary, in that the design of the 340 cipher on November 8th 1969 was much more complex, despite the fact it contained a contemporary message regarding the "phony" (Eric Weill), who rang into the Jim Dunbar TV Show on October 22nd 1969 and February 5th 1970 pretending to be the infamous Zodiac Killer. Although the design of the cipher was arguably more difficult, it is clear that the Zodiac Killer underestimated its complexity and failings, resulting in the contemporary message contained within it being diminished and compromised by the passage of time. 

​When the Zodiac Killer created his third lengthy cryptogram (in possibly May, 1971), containing yet another contemporary message about "phony" Eric Weill (and claimed additional "phony" Karl Francis Werner), the Zodiac Killer, this time, made sure his message would not be lost to the hands of time by manufacturing a cryptogram much simpler than the 408 cipher, by allotting just one ciphertext character to each plaintext letter. The only three times he deviated from this technique in the cryptogram was with the bold letter "G" that concluded the word "LISTENING" on the third row, and the letter "T" in "THE" and "FRONT" on the first and fifth row. The Zodiac Killer likely incorporated two deliberate errors on the first row when he used two misspellings within his "This is the Zodiac speaking" introduction. These deliberate misspellings, by adding and subtracting a plaintext letter, very likely created to add minor complexity, and prevent an immediate decoding of his cipher.  

Having used the letter "Z" in plaintext for the first time in three cryptograms, it seemed that the Zodiac Killer couldn't resist using the "sun cross" character (similar to his crosshairs) to represent the initial of his pseudonym. This becomes apparent when he uses this individual character to sign off his accompanying letter, rather than the traditional crosshairs or letter "Z".

Victims of serial killers ​make up a very small percentage of the total number of murder victims each year. Communications written by such killers (and accompanying hoaxers) are even less. So imagine the percentage of serial killers and their accompanying hoaxers that mail communications to authorities with cryptograms and codes included within the correspondence. Now imagine two cryptograms contained within two letters unreleased into the public domain, both of which have many crossover features, that both use the ciphertext character "7" to represent the plaintext character "A" in the code, with both claiming to be from the Zodiac Killer, and both using the "sun cross" in their respective codes. These two letters were mailed from Fairfield, California (1971) and Albany, New York (1973). Now imagine mailing a 148 character cryptogram in 1971 using the root word "phony" that was previously used to describe the Jim Dunbar TV Show hoaxer Eric Weill in the headlines of a newspaper article on February 6th 1970, who was the focus of the 340 cipher solve in 2020, when the Zodiac Killer wrote "That wasn't me on the TV show" and effectively proclaimed the caller a hoaxer. A 340 cipher message that wasn't known to anybody else but the Zodiac Killer in 1971. Regardless, we must not let facts get in the way of the long told Zodiac narrative. 

David Oranchak has just released another excellent Youtube video on his Let's Crack Zodiac series, examining the numeric codes of Theodore Kaczynski, the Unabomber, who killed three and injured twenty-three in a seventeen year reign of terror between 1978 and 1995. David Oranchak has delivered the often complex and difficult topic of cryptography to the masses by attempting to simplify this topic through his visual presentations, orchestrated in such a way, it elevates the understanding of the many who once found the art of cryptography perplexing and impenetrable. One of the key members of the team that finally broke the Zodiac Killer's 340 cipher after fifty-one years, alongside Sam Blake and Jarl Van Eycke,

David Oranchak has sought to demystify the specialized skills of codebreaking through eighteen well produced videos. Although some uncharitable individuals claim the hard work in breaking the 340 cipher was achieved predominantly through the use of computers, this overlooks the fact that we have had these powerful computers for many years with no resolution until 2020, the requirement to develop new systems such as "zkdecrypto", and the human input required to recognize the Zodiac Killer's language as it emerges from the noise. These three gentlemen achieved what every other person failed to surmount in over fifty years - and for this - they deserve all the accolades they have been rightly bestowed. 

The 340 message, claimed by many to be another rambling and meaningless collection of Zodiac tropes, has in fact, opened the window to many other Zodiac Killer communications such as the first Fairfield letter mailed on December 7th 1969 and the third Fairfield letter mailed on or around May 2nd 1971, both containing cryptograms known as the Z38 and Z148 respectively (the latter having been solved). Both of these communications were related to the 340 cipher through coding and messaging, despite the 340 cipher solution being decades away from being solved. The Z38 appeared to know the wording in the 340 cipher before the code was broken, and the text in the accompanying letter seemed to pre-empt the wording in the Melvin Belli letter mailed on December 20th 1969, just thirteen days later. The Fairfield letter on December 7th 1969 also pre-empted the phone call to an Oklahoma radio station later that day, in which the author of the letter and phone caller both mocked the caller to the Jim Dunbar Show and Melvin Belli on October 22nd 1969. The phone caller to Oklahoma, mimicking the person who rang into the Jim Dunbar Show, also stated he left California because "it got too hot for me", just like phone caller to the Palo Alto Times newspaper, who stated he had left San Francisco because "because I'm too hot there", less than a day before the Jim Dunbar TV Show. If that isn't enough evidence that the Zodiac Killer was the responsible, we have the solved message in the Z148 calling out both Karl Francis Werner and Eric Weill (the Jim Dunbar caller) as phonys, just like the message in the 340 cipher calling out Eric Well by stating "That wasn't me on the TV show". The Jim Dunbar TV show, in which a second phone call was received on February 5th 1970, from somebody that the San Francisco Chronicle and homicide detectives described as a phony. 

To ascertain whether a communication is authentic or unproven, we must get away from consistently using the reasoning of "handwriting and tone" as a throwaway line to examine Zodiac communications in a matter of minutes. The interconnectivity of Zodiac communications must be examined through the picture created by the Zodiac Killer throughout many years and multiple correspondences and phone calls, just like the story of the San Jose murders which spanned the time period of August 3rd 1969 to July 13th 1971, when the Zodiac Killer mailed the Monticello card to the San Francisco Chronicle.

The interconnectivity between the Monticello card and the Z148 character cipher (and Pines card), the interconnectivity between the Z148 cipher and Albany letter code mailed in 1973, and the interconnectivity between the second Fairfield letter mailed on December 16th 1969 to the phone call delivered to the San Jose Highway Patrol on December 19th 1969, are just a fraction of the strands in the spider web that link these occurrences together. Just staring at a letter for a handful of minutes and declaring it a hoax, is inadequate, when we consider that the Zodiac Killer was traveling on a journey of murder and domestic terrorism spanning many years. To view the whole picture, please open the links provided in this article.

I am fairly confident that the Z38 code mailed on December 7th 1969 is somehow related to the 340 and 148 character ciphers through its messaging. Both the Z340 and Z148 ciphers referenced Eric Weill (the caller to the Jim Dunbar Show), by stating "That wasn't me on the TV show" and "stop listening to phonys" - and the Z38 code was mailed on the same day that somebody rang the Oklahoma radio station mimicking Eric Weill. My contention is that all three were the Zodiac Killer.

​I am not confident I can crack the Zodiac Killer's Z38 cipher because, despite having some limited knowledge of cryptography, this pales into insignificance when compared to individuals such as David Oranchak, Sam Blake and Jarl Van Eycke, who ultimately broke the Zodiac Killer's masterpiece cipher. The recognition of the phrase "gas chamber" in the cryptogram was pivotal in understanding that the Zodiac Killer referenced recent newspaper articles (or the Jim Dunbar TV show) which detailed this very subject pertaining to Zodiac's capture. If we run with this concept, it may help to unearth the message in the Z38 code, which may (or may not) hold vital information of a contemporary nature and unlock the fifth of eight known enciphered messages. I have a strong belief that David Oranchak could make some valuable observations and inroads into the Z38 cipher if he chooses to tackle yet another Zodiac mystery, and thereby, attempt to close another chapter in this intriguing story.

As shown numerous times before, we can usually find the inspiration for Zodiac communications by looking at the most recent newspaper articles published in the Bay Area or Los Angeles. The November 21st 1969 letter to the San Jose Police Department was possibly directed at the recently widowed Diane Kennedy Pike, whose husband James Albert Pike had met an unfortunate death in Israel in September (information provided by Cragle). The letter caused enough alarm to institute 24-hour surveillance on the young woman and her residence. Information regarding this letter is sparse, but the language adopted in this communication is taken directly from the last San Francisco Chronicle newspaper article on November 13th 1969 entitled Zodiac 'Legally Sane', featuring the Zodiac Killer's 340 cipher and investigators attempts to snag the murderer of five.    

The newspaper snippet on the left reads "Through physical clues Zodiac has clumsily left behind at crime scenes and bits and pieces of information about himself he has inadvertently revealed in letters sent to The Chronicle, police feel sure there will be no doubt they have the right man in custody when an arrest is made". Eight days after this newspaper article was released, and thirteen days after he had claimed seven victims (the canonical five and the two San Jose murders of Snoozy & Furlong), the Zodiac Killer wrote to the San Jose Police Department and responded to "there will be no doubt they have the right man in custody when an arrest is made", by writing "There's no doubt I will do my Thing". The Zodiac Killer was clearly confident that no arrest was forthcoming, and his reign of terror would continue by doing his "Thing". His chronological list of victims by using months of the year would continue, when he wrote November=8 in his latest letter. He also added a short six character code of ~+62+~.  

His next letter, postmarked December 7th 1969 from Fairfield, was shown to be authentic by pre-empting the pleading nature of the Melvin Belli letter and his use of another code of 38 characters. This code contained similar characters to the 340 cipher, unlike the following 13-Symbol and 32-Symbol ciphers. It opened the door to the possibility that the 38 character code was somehow related to the 340 cipher and maybe contained a clue to its construction. Druzer, an avid and diligent Zodiac researcher, mailed me the 38 character code deciphered with the 340 cipher key. The result is mostly garbled, but he drew my attention to the final line of both codes ending in "death". The Zodiac Killer only took a 4+ horizontal combination of characters from the 340 cipher to the 38 character code on two occasions. Those were HER> and AIKꞮ+, which spelled the standalone words of IRON and DEATH before the diagonal shift was applied to the 340 cipher to reveal the message. Despite the last two rows of the 340 cipher being a mixture of forward and backward reading words, the word "death" sits at the end of both the 340 and 38 character ciphers, indicating that this word likely concludes the message in each instance. 

Other horizontal words do exist in this format, however, the Zodiac Killer gave us 4 and 5 characters which bound the 340 and 38 character ciphers together, and both formed English words. The Zodiac Killer began and ended his 38 character code with two prominent sections from the start and end of the 340 cipher, both of which contained visible words before any shift was applied (the final word remaining static). This may be another observation, which confirms to the doubters the December 7th 1969 letter as an authentic Zodiac communication. Unless of course, the 38 code hoaxer identified two passages of 4 and 5 characters from the undeciphered 340 cipher, that just happened to accidentally find two English words after the 340 key was applied. This hoaxer would also have to guess that by separating the prominent ZO∆AIKꞮ+ characters on the bottom line of the 340 cipher, into AIKꞮ+ on the bottom line of the 38 character code, he would be reducing these characters to create something meaningful. He apparently did. By separating these characters into the five visible at the end of the 38 character code, he created the word "death", just like the solved 340 cipher. Druzer pointed out the same thing, stating "The most curious/compelling feats are that the author isolated actual words, most notably death, and that he refrained from copying Zodaik, which would certainly be expected of a hoaxer". In other words, he dismantled the ZO∆AIK element, while leaving Ɪ+ in place, to form "death" as the final word on the 38 character code. This appears to show knowledge of the hidden message in the 340 cipher. 

The above image from the San Francisco Chronicle on November 13th 1969 shows the correlation on three rows of the 38 character code to the 340 cipher. We have 4, 5 and 5 characters from three rows of the 38 character code, organized in the correct order to three rows on the 340 cipher. The crucial 10th row of the 340 cipher which begins the second section of the 3-part cipher (9, 9 and 2), contains the four symbols of ~+62+~ in the correct order (and FB which numerically equals 62). Both the November 21st 1969 and December 7th 1969 letters were unreleased to the public, so it would be difficult to envisage how two different authors would choose to supply two relatively short codes that mimicked important features of the 340 cipher independent of one another. The three rows of the Z38 highlighted in blue rectangles above, all either begin or end a row on the 340 cipher - as does the six character code of the November 21st 1969 letter. Was the 38 character code on December 7th 1969 a clue to the construction of the 340 cipher or somehow related to the message ultimately found within it? If so, then the short code of ~+62+~ in the November 21st 1969 letter could be somehow related to the 340 cipher also. The December 16th 1969 letter, also mailed from Fairfield, contained another short code of five characters. This completed a quartet of puzzles from the Zodiac Killer in just over a month.

​The Zodiac Killer was likely reading this newspaper article on November 13th 1969 when he used the wording "There's no doubt I will do my Thing", so it's perfectly feasible that the presence of his 340 cipher prominently displayed within this article, may have been the inspiration to provide further codes based upon its construction. The newspaper article concluded with "Amateur cryptographers by the hundreds were at work trying to decode the cryptogram from Zodiac published in yesterday's Chronicle. It was an amateur - a Salinas teacher - who cracked Zodiac's cipher message in August to which he said the people he killed would serve him as his slaves in paradise. One cryptographer, who has studied the latest message, says it definitely contains word patterns hidden in the 340 symbols. "There is a definite message" he said. "Testing shows it is not just gibberish. Once that is determined then it's just a matter of patience before it pieces itself together". Did the Zodiac Killer take note of this section and provide "bits and pieces" in his next two codes to help in its decryption?