Many Zodiac enthusiasts have pondered from where did the Zodiac Killer acquire his pseudonym, or when he decided upon the name Zodiac. The Bay Area murderer arrived at Lake Herman Road on December 20th 1968, where he callously executed David Faraday and Betty Lou Jensen with six shots to the head and body. Just over seven months later, on July 31st 1969, he mailed three pieces of correspondence to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald, but failed to introduce himself as Zodiac despite having over half a year to formulate a pseudonym. He only introduced himself as the "killer" and "murderer".

Three letters, detailing his crimes and awash with cryptograms, announcing his arrival to the newspapers, seemed like the perfect opportunity to announce those infamous words of "This is the Zodiac speaking" - yet nothing. His next communication was only sent in response to Vallejo Police Chief Jack E. Stiltz, who doubted the letter writer and killer were the same person and "urged the writer yesterday to send more letters with more facts to prove his connection with the crimes". The Bay Area murderer immediately replied on August 4th 1969, stating "This is the Zodiac speaking. In answer to your asking for more details about the good times I have had in Vallejo, I shall be very happy to supply even more material". It can be seen that this letter would never have been sent, had Vallejo Police Chief Jack E. Stiltz not urged the killer to do so. If the letter had not been sent, then our killer would not have presented himself as Zodiac on August 4th 1969. In fact, he may not have adopted the pseudonym at all.

In absence of this letter, the next letter to contain his pseudonym was mailed two days after the Paul Stine murder on October 13th 1969. So, it's entirely plausible that the muderer of five could have begun and ended his attacks in the Bay Area as a nameless killer. The Vallejo News Chronicle published one-third of his 408 Cipher on August 1st 1969, the San Francisco Chronicle did the same on August 2nd 1969, with the San Francisco Examiner waiting until August 3rd 1969 and publishing all three parts, but on a lowly page nine. All three carried the message from Vallejo Police Chief Jack E. Stiltz, yet despite the Examiner publishing their part of the cipher the latest and relegating it further from the front page than the other publications, in defiance of his demands for front page coverage by Friday afternoon, it was the Examiner he chose to introduce his pseudonym to. In other words, they complied the least, but the killer chose to "supply more details" to them rather than a Vallejo publication and to the home city of Vallejo Police Chief Jack E. Stiltz, who he was supposedly addressing.

There is a real possibility that the murderer of three chose the San Francisco Examiner because they were the only publication to give the murderer a pseudonym, which may have ultimately triggered the following communication a day later. The Examiner wrote "The police telephone system was clogged by anxious callers asking if the "cipher killer" had been caught". The murderer seemingly didn't appreciate the pseudonym given to him and a day later, on August 4th 1969, he introduced himself to the Bay Area with "This is the Zodiac speaking". But why this phrase? The Examiner article noted that "the police telephone system was clogged by anxious callers asking if the "cipher killer" had been caught", so what better way to announce yourself as you might do over the telephone. This wasn't an anxious caller, this was the Zodiac speaking.  

Without this San Francisco Examiner article and resultant Debut of Zodiac Letter on August 4th - announcing yourself as the "Zodiac" on October 13th 1969 after the end of a ten month series of murders, certainly wouldn't have had the same impact. Without the publication of "cipher killer", the pseudonym of the Zodiac Killer would in all probability never have existed.

The counter-argument to the above, is the killer had ample time to give himself a pseudonym from December 20th 1968 to July 31st 1969, and only began the trinity of letters with "murderer" and "killer" because he had reserved the pseudonym "Zodiac" for the 18 characters at the foot of the Chronicle cipher. This was the portion he claimed held his "identity". A hidden pseudonym would be negated had he began the correspondence with "This is the Zodiac speaking". With the entirety of his communications beginning with this phrase, does it lend credence to the notion its absence from the introduction to these three letters, is validation to its concealment in the 18 unsolved characters?  If he hadn't preselected his pseudonym in advance of the July 31st 1969 letters, one could revert back to the notion it was the "cipher killer" attribution that triggered his reply on August 4th 1969. For 35 years starting in 1965, the San Francisco Chronicle and Examiner operated under a Joint Operating Agreement whereby the Chronicle published a morning paper and the Examiner published in the afternoon. The Examiner published the Sunday paper's news sections and glossy magazine, and the Chronicle contributed the features. Circulation was approximately 100,000 on weekdays and 500,000 on Sundays. By 1995, discussion was already brewing in print media about the possible shuttering of the Examiner due to low circulation and an extremely disadvantageous revenue sharing agreement for the Chronicle. Wikipedia. The Bay Area murderer's reply on August 4th, including his pseudonym for the first time, would therefore have been formulated in the mind of the killer from the moment he read the Sunday Examiner publication to his creation of the letter. The Zodiac Killer being born on August 3rd 1969, or early Monday morning on the fourth.
   

However, if he had decided upon his pseudonym in advance of the July 31st 1969 letters and had consciously withheld his pseudonym from his introduction so as to place it within the 18 unsolved characters - then having failed to do so - would be counterintuitive. One could argue that his use of the words "killer" and "murderer" were chosen for purpose, thereby lending credence to a viable solution with respect to the 18 unsolved characters. 

The 18 unsolved characters (if they contain any meaning whatsoever) clearly operate under a different technique of decryption to the other 390 characters. So if the Zodiac Killer didn't happen upon his pseudonym on August 3rd or 4th, then we have the very real possibility that the identity of "Zodiac" does reside in these final 18 characters, to which he alluded to in his address to Vallejo Police Chief Jack E. Stiltz on August 4th 1969. The Zodiac Killer stated "when they do crack it, they will have me".

The Zodiac Killer committed the senseless slayings of David Faraday and Betty Lou Jensen on December 20th 1968. Six and a half months later he would follow this up with a second attempted double murder at Blue Rock Springs Park on July 4th 1969, in which sadly, Darlene Ferrin would succumb to her devastating injuries. Approximately one month later, the Zodiac Killer mailed three letters to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald announcing that he was responsible for the three murders and attempted murder, while challenging authorities to decode a 408 character cipher. The Zodiac Killer threatened the newspapers, stating "If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend".  Imagine his horror when the two main newspapers failed to bow to his threats, with the San Francisco Chronicle placing the story on page 4 of the August 2nd 1969 edition, and the San Francisco Examiner demoting him to a lowly page 9 on August 3rd 1969. The problem was further compounded, with Vallejo Police Chief Jack E. Stiltz even questioning the validity of the author and "urged the writer to send more letters, with more facts to prove his connections to the crimes."

The Zodiac Killer in his haste to prove he was the killer responsible for three people, immediately sent a letter to the San Francisco Examiner on August 4th 1969 - and despite the Examiner printing his letter the same day, in which he declared "This is the Zodiac Speaking" and that he "was not happy to see that he did not get front page coverage", imagine his utter disbelief when he discovered that the San Francisco Examiner had again relegated his letter supplying more details of the crimes to page 4. It equally wouldn't have escaped his attention, that on the front page of the same paper it featured the double knife slaying of two young girls from San Jose. Deborah Furlong (14) and Kathy Snoozy (15) had been brutally stabbed while picnicking on a grassy knoll on August 3rd 1969. The Zodiac Killer had now murdered three people, nearly killed Michael Mageau and sent four communications (including three cryptograms), yet he was still unable to command front page coverage. But now he knew exactly what was required - and it was staring him squarely in the face on page one. August 4th 1969 was not only the day he announced his pseudonym to the world, but the day he realized that a brutal stabbing was required to secure himself front page coverage. This was the day the fate of Bryan Hartnell and Cecelia Shepard would be sealed, almost two months in the making.   

Forever the narcissist, the Zodiac Killer couldn't believe his luck when he happened upon three young girls on the shores of Lake Berrryessa by Smittle Creek. I am sure for a brief moment he could see the headlines flash in front of his eyes: "3 Girls Stabbed, Sunbathing Murders, Footprint Clue". However, the Zodiac Killer for whatever reason, decided against the attack, returned to his vehicle and drove away. Fortunately, the three young women from Pacific Union College would escape the wrath of the Zodiac Killer - but he was not done yet. Approximately two hours later and eight tenths of a mile south, the Zodiac Killer would reappear and set his sights on the 1956 White Karmann Ghia of Bryan Hartnell and Cecelia Shepard, before traversing the 510 yard hillside descent to the area of the picnicking couple. Driven by an insatiable desire to secure front page coverage, he proceeded to callously stab the young couple sixteen times before finally returning up the hillside and out of sight. The thoughts of the San Jose murders of Deborah Furlong and Kathy Snoozy - and the headline news they generated - were probably in the forefront of his mind when he approached the Volkswagen Karmann Ghia and pulled the black marker pen from his pocket. He proceeded to write on the car door of Bryan Hartnell's vehicle, to leave you in no doubt that he was mimicking the murders of the two young girls from San Jose. He wrote "Vallejo 12-20-68, 7-4-69, Sept 27-69 - 6:30 by knife". If you ever wondered why he wrote the time 6:30 on the car door, even though he rang in the crime just seventy minutes later, then the newspaper article below may give you a clue. This is the article from the San Francisco Examiner on August 4th 1969 - the very reason why the Zodiac Killer arrived at Lake Berryessa on September 27th 1969 in the first place.  

This annotation of 6:30 on the car door of Bryan Hartnell's vehicle was supposed to mark the time that the young couple at Lake Berryessa failed to return home also.

We know the Zodiac Killer was an avid reader of the newspapers, often replying to law enforcement officers such as Vallejo Police Chief Jack E. Stiltz and Captain Martin Lee, as well as arbitrary content from the newspaper articles themselves. Therefore, would it be any great surprise if he found his pseudonym in the newspapers as well. Covered very briefly on Zodiac Killer Mystery forum and Tom Voigt's old message board, this finding deserved another showing. The Zodiac Killer and the influence of astrology has been widely covered throughout the years, but below we have a column that featured daily over several decades in many newspapers, including the Vallejo Times-Herald throughout the relevant time period of the Lake Herman Road and Blue Rock Springs attacks. The Star Gazer astrology column was created by Clay R. Pollan and ran in over 400 newspapers. He was a newspaper editor and publisher for many years, and founded the Inter-American Features Syndicate in the mid 1940s which distributed Star Gazer and Scram-lets puzzles.

The columns began with "To develop the message for (day), read words corresponding to numbers of your Zodiac birth sign". We mention the Zodiac Killer crosshairs being found in conjunction with the word "Zodiac" on a watch, but here we have a column that would have featured in the Vallejo Times-Herald in 1969, that contained a hidden message within the Zodiac horoscope - and on July 31st 1969, the Zodiac Killer mailed a hidden message in three portions of code, one of which was sent to the Vallejo Times-Herald, and one which was mailed to the San Francisco Chronicle, in which he wrote "In this cipher is my idenity". Is it conceivable that the inspiration for his pseudonym was derived from this Zodiac horoscope, which further inspired him to begin his letter writing campaign with a concealed message?  

Twenty-one years later, could the Zodiac Killer have returned and used the very same technique, when he mailed the Celebrity Cypher. Luis Campos, born in Santiago, Dominican Republic is an inventor, poet and cryptographer who created puzzles and ciphers for the United Features Syndicate of New York, beginning in 1983. He would create six celebrity ciphers a week, featuring famous quotes from well-known people, past and present. The reader had to identify the person and quote from the encoded text. The characters in the cryptograms were deliberately spaced into separate words, as shown below.  

On September 25th 1990, somebody mailed the Celebrity Cypher to the Vallejo Times-Herald, approximately three months before the 1990 'Eureka' card - often associated with the Zodiac Killer. Bearing in mind the 408 cipher mailed to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald on July 31st 1969, many have pondered whether this postcard was mailed by the Bay Area murderer.

We may now have two sets of Zodiac communications inspired by the hidden messages of Clay R. Pollan and Luis Campos, with the Vallejo Times-Herald the common denominator in both instances. We know the Zodiac Killer derived inspiration from the newspapers, but did this inspiration extend to mimicking the art of hidden messaging? This concept could have extended even further, when the Zodiac Killer designed his infamous unsolved 340 cipher, that may have been taken straight from the Dick Tracy comic and breakfast cereals of children - again receiving widespread publicity in the newspapers. See the Dick Tracy 340 Cipher article. 

The Zodiac Killer mailed us three parts of one cipher on July 31st 1969, to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald. In his communication to the Chronicle he stated "In this cipher is my idenity". Bearing in mind this is the only portion of cipher with unsolved characters, it could be argued that any identity the Zodiac was offering would be found at the signing off phase in this cipher. It didn't really matter, because only four days later he gave us his identity in the form of "This is the Zodiac Speaking". The Zodiac Killer clearly made a mistake when taking his draught message into his 408 cipher, accidentally omitting the word "people" from the final offering. If we therefore conclude his original identity to be left was actually six characters shorter, it would have reduced the 18 unsolved characters to 12. Using the first-person singular pronoun of "I", his identity at the base of the 408 cipher would read "I am the Zodiac", to become "I am the Zodiac Killer" upon realization of his mistake. The Bay Area murderer literally gave us the exact wording to his unsolved 18 characters through his introductions in the Examiner and Herald letters (both communications began with "I am the killer"). Once we knew the pseudonym or identity as Zodiac on August 4th 1969, the conversion to "I am the Zodiac Killer" was the next logical step. This would become a habit for the Zodiac Killer, who would ultimately give us the exact wording to solve his remaining three ciphers. Not only would he give us the solutions to the codes, but his practice of using 'filler' with no apparent correlation to the solution would continue.  

The Zodiac Killer was no master criminal in the style of Moriarty, but he was nobody's fool either. To make the false assumption he didn't understand ciphers or codes when creating his remaining three offerings to the San Francisco Chronicle, would be a misguided one. Even somebody with limited knowledge of coding, knows that giving us a 32 character code with 29 unique characters within its framework, is practically unsolvable without a key. You can literally fill in the blanks as you choose. Therefore, the only realistic solution to the two smaller codes can come in two forms: [1] The Zodiac Killer can give us a key to decrypt the code, or [2] He can simply give us the answer. The Zodiac Killer may well have chosen option two, and given us the entire solution to all his three unsolved codes in subsequent communications. In fact, the possibilty exists that he supplied us with all the answers in three consecutive communications from July 26th 1970 to October 27th 1970 - in the Little List Letter (07/26/70), 13 Hole Postcard (10/05/70) and Halloween Card (10/27/70). The Zodiac Killer was likely giving us all the solutions before slipping back into anonymity. The newspaper article on November 16th 1970 by Paul Avery, linking Zodiac to the Riverside murder of Cheri Jo Bates on October 30th 1966, likely drew one final breath from the Zodiac Killer through 1971, before his race was run.    

The "key" phrases for the four codes are *in this cipher is my identity", "the Mt. Diablo code concerns radians and inches",  "Fk, I'm crackproof" and "sorry no cipher". The 408 cipher we have examined, so we will now tackle the 32 symbol code.

The Little List Letter mailed on July 26th 1970, one month after the Mount Diablo code (06/26/70), told us the code "concerns radians and # inches along the radians". It was as simple as adding in two figures to complete the code (hence the hashtag symbol denoting a number). The Zodiac gave us the exact wording for the solution, detailed here in a previous article. As stated above, the 32 symbol code with 29 unique characters couldn't be solved without a key or the answer. The Mount Diablo map and crosshairs were the framework, onto which we "coupled" the code for the location of the bomb. The answer was likely "4 radians and 5 inches along the radian", thereby giving us the solution word for word. An alternative to this solution (where only the hashtag is replaced by the number 5), is "P.S. The Mt. Diablo code concerns Radians and 5 inches along the radians". The Zodiac didn't necessarily have to incorporate the number 4 because we already knew the radian value from the bold, black circle provided on the Little List Letter crosshairs.

The next solutions were given to us in the 13 Hole Postcard - that may ultimately become the most important communication of them all. By combining the "red crucifix" decoder and 13 punch-holes in true "Dick Tracy" style, the Paradice and Slaves formation would be revealed, bisecting the 340 cipher along its mid-section both horizontally and vertically. See the article 'The Dick Tracy 340 Cipher'. The Zodiac Killer would again push us in the right direction by revealing the 340 was "sorry no cipher", by way of a cross formation on the Halloween Card envelope just 22 days later. If that wasn't enough, he wrote Paradice and Slaves in the identical formation it could be found within the 340 cipher. Three clues within the space of three weeks. See the article 'Zodiac Admitted 340 Not a Real Cipher'.

The Zodiac Killer also gave us the phrase "Fk, I'm crackproof" (upside down) on the 13 Hole Postcard. Apart from an expletive, the other viable option here, is the Zodiac Killer exclaiming that he is crackproof, preceded by his initials. The reason for this line of thinking, is the Zodiac Killer's wording before the 13 Symbol Cipher on April 20th 1970. The code is designed symmetrically and looks contrived, with three circled 8's fashioned at its center. The Zodiac Killer couldn't have supplied us with his name with any expectation it would be solved, because the code was simply too short and capable of providing us with thousands of solutions. However, he could provide us a solution to the code by giving us his initials. By doing it this way, he is in a roundabout way, giving us his name and a solution to the code that satisfies the introduction that preceded it: "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is Fk, I'm crackproof".

This solution not only fits into the 13 Symbol Cipher, but reads continuously if imagined in circular fashion. The Zodiac Killer gave us three 8's within a circle (the symbol of infinity, and regeneration and rebirth within Christianity), with the letters K and M positioned ideally in the code to fit "Fk, I'm crackproof" around. There are three elements to this phrase: Fk, I'm, and crackproof. When the entire phrase is slotted around the letters K and M, the number 8 begins each element of the phrase (as shown below). As a side note, "Fk, I'm crackproof" can be spelled using the letters from the 32 Symbol Cipher characters, with only the F and K reversed.      

The Zodiac Killer had effectively given us the exact wording of "I am the Zodiac Killer", "Paradice and Slaves", "Fk I'm crackproof" and "radians and inches along the radian" - all of which can be inserted untouched into all four ciphers and provide us with solutions that don't require a key. The idea of a killer who constantly responded to the newspapers at every turn, somehow resisting the temptation to ever disclose the workings of his codes and ciphers is a difficult story to sell. If we are of the belief that the 32 and 13 character codes are simply too short and too variable to be solved, then without a key the Zodiac Killer likely supplied an alternative. In the case presented above, the "key" and "answer" could be described as exactly the same thing - and It was just a case of transferring the wording from one communication to another in at least three of the examples.

John Rose used Dave Oranchak's webtoy to create features of the Halloween Card in just an 81 character block around the center of the 340 cipher. Some have stated that the variability of the characters in this area of the cipher have allowed the freedom to manufacture such a result. While that may be the case, a larger pattern of Paradice and Slaves is replicated in a 17 X 17 formation along both same midsections, effectively mirroring the John Rose presentation. The fact that both are even achievable in the same cipher, is worthy of mention. The Bay Area braggart must have been itching to throw us a few clues to his unbroken codes and ciphers - so the notion that he didn't give us any before he disappeared into the twilight - is somehow difficult to swallow.   

David Oranchak, owner of the Zodiac Killer Ciphers website, gave a very interesting and informative presentation on the Zodiac ciphers at the Cryptologic History Symposium on October 22nd 2015. If you want to discover some of the features and quirks regarding the composition of the ciphers, this is an extremely good place to start. But there was one particular section that peaked my interest, despite the fact it would probably contradict a number of articles I have featured on this site. Nevertheless, I would like to present the part of the Cryptologic History Symposium here, using the words of David Oranchak. In the video, beginning at 34:37, David states "Here's an interesting coincidence. If you take two standard sized pieces of paper, 8 1/2 inches wide by 11 inches in length and you divide the paper into equal half inch squares, you end up with these sheets that have 17 columns and 22 rows. If you write both ciphers (the 340 and 408) back to back, you end up filling both sheets exactly with no leftover squares. It is an interesting coincidence. Does it mean that Zodiac drafted both of his ciphers together on two sheets of paper? It's an interesting question".

It certainly is an interesting question, bearing in mind the difficulty experienced in solving the 50-year-old 340 cipher and the still unsolved 18 characters at the foot of the 408 cipher. The Zodiac Killer stated in the 408 cipher, preceding the final 18 characters, that "I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife". If the unsolved section of the 408 cipher didn't contain his name or identity, is it possible these 18 characters were supposed to bleed into the message on the 340 cipher. This has to a realistic proposition when we consider the 340 cipher begins with the final three letters of the word cipher. Was this just another coincidence - or did each cryptogram share half of the word cipher, as well as sharing a message? It is a compelling argument that the Zodiac Killer may have intended to leave only 12 unsolved characters at the foot of the first cipher (possibly decoding to "I am the Zodiac"), but the accidental omission of the word people from the message may have resulted in an unwanted extra 6 characters, thereby forcing a change of plan. Could the 18 characters now form part of a 21 character bridge (or more) between cipher one and two? The 408 cipher ending with cip and joining the her of the yet to be released 340 cipher. If the remainder of the 408 cipher and beginning of the 340 cipher was somehow conveying the idea of "sorry no cipher", in similar fashion to the October 27th 1970 'Halloween' card, then the message on the November 8th 1969 greeting card stating "I thought you would need a good laugh before you hear the bad news", may be pertinent to the cipher that accompanied it.           

Sorry no cipher written on the Halloween card once would have sufficed, to inform us that no code was present on the greeting card, yet the Zodiac Killer appeared to fashion it to mimic the Paradice and Slaves configuration on the card, which equally mimicked the possibility shown present in the 340 cipher on the right. This configuration perfectly bisected the 340 cipher (17 by 17) both horizontally and vertically.

By extension, from the Halloween card to the 340 cipher, was the Zodiac Killer telling us that the second cryptogram was "sorry no cipher"? And by extension, was the Zodiac Killer telling us exactly the same thing from the 408 cipher to the 340 cipher, hence the tantalizing her at the beginning of the cryptogram. It could be argued that the placement of her at the beginning and the near-Zodiac towards the end, is a little too convenient. A message of "sorry no cipher" through three sets of communications may be a bit difficult to shake off as coincidental.

If the Zodiac Killer created a rambling message akin to the 408 cipher and randomly allotted his cipher key, then he was extremely unfortunate to have crafted the possibility of the configuration on the right, involving the words paradice and slaves, by in each quadrant, with her at the beginning and Zodaik near the end. This is not what you want to achieve when you are trying to convince the world it's a genuine cipher, because people like me come along. The prospect of finding the same mini-message shared between the 408 and 340 cipher, that was found on the envelope inner of the Halloween card would certainly be "bad news" for some.

I would like to thank David Oranchak for his contribution regarding the Cryptologic History Symposium, and would encourage everybody who is interested in ciphers to click the highlighted link. Below is just one rudimentary example I have drummed together, using a screenshot of the Youtube video, keeping 7 of the 21 characters in their original format.

Professor D.C.B. Marsh, in the October 22nd 1969 San Francisco Examiner newspaper article by Will Stevens, laid down a challenge to the Zodiac Killer to reveal 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 Allen 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". It is highly unlikely the Zodiac Killer would have been suckered into providing a genuine cipher of any length knowing that 'any cipher created by man can be solved by man'. The 13 and 32 symbol ciphers mailed in 1970 proved this very fact - both effectively crackproof without a recognizable key. However, the Zodiac could certainly have sent us a rudimentary message within the 340 cipher utilizing the wording contained within his 408 cipher.

Paradice and slaves is a well-trodden theme in the Zodiac communications, and as I have stated before, the Halloween card mailed on October 27th 1970 (almost the anniversary of the D.C.B. Marsh challenge) actually admitted that the 340 cipher was "sorry no cipher". The Zodiac Killer had never apologized previously for not sending a cipher in his 'cipherless' communications, so why start now. Even if the "sorry no cipher" writing on the envelope inner was to inform us that in about two seconds we had no cipher, then just write "sorry no cipher" once. The fact it was fashioned into a cross formation that mimicked the paradice and slaves configuration on the card inner, seemed designed to suggest that this configuration would be found in a cipher that effectively had no solution. The sheer fact that this configuration can also be found in his 340 cipher, exactly bisecting the cipher vertically and horizontally (17 by 17), one would like to believe is a convincing argument to suggest that the Zodiac Killer was finally admitting the 340 cipher wasn't a cipher at all. Additionally, it did mimic the 408 cipher with its inclusion of the paradice and slaves reference. Although this may be interesting, it understandably isn't enough to convince certain quarters of the Zodiac community who are steadfast in their belief that the 340 cipher contains a cogent but elusive message. Regardless, one couldn't help thinking that this wasn't the only time the Zodiac admitted the 340 cipher was devoid of any meaningful solution. Fortunately, the answer came in the communication prior to the Halloween card.  

If I am correct, and the paradice and slaves (13 letters) configuration was intentional in the design of the 340 cipher, then this is a significant point of interest. Two other notable features stand out in the 340 cipher. Firstly, the corrected sixth line where the Zodiac Killer blacks out a forward K and replaces it with a backward K. Secondly, the distinct possibility that he placed his pseudonym on the final line of the 340 cipher. All these three features are present in the '13 Hole' postcard.

Despite the fact that Zodiac made many spelling errors in his design of the 408 cipher and his communications as a whole, he seemed conscientious enough to correct one character in his 340 cipher, that inevitably would have made no difference in it being deciphered, had it contained a genuine solution. The fact he spoiled an otherwise neat and tidy presentation appeared designed to convince us that it was a genuine cipher. After all, why would Zodiac correct a collection of gibberish, if not to convince us it wasn't. The correction seemed contrived in order to validate the authenticity of the cipher, to which he would allude to in the '13 Hole' postcard.        

Many have speculated on why the Zodiac Killer reversed the bottom section of text on the '13 Hole' postcard. He certainly didn't do this for absolutely no reason, as he didn't create the "sorry no cipher" configuration for no reason either. The Zodiac Killer pasted the lettering "Fk I'm crackproof" on the '13 Hole' postcard in a first attempt at showing us the 340 cipher had no solution. The definition of crack-proof is something that is unable to be cracked, or in the case of a cipher, unable to be decoded. He used this word in his April 20th 1970 letter, sarcastically stating "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you". He knew only too well that it hadn't been cracked, because it couldn't be cracked - and now was telling us it was crackproof by association to himself.

The Fk has been suggested as a shortened expletive or possibly a name - but what if we take it on face value, and the Fk actually means Fk and nothing more. It is like Ronseal and 'does exactly what it says on the tin'. The Zodiac Killer is essentially telling us that the corrected Fk on the 340 cipher was a ruse, because his cipher was crackproof. This is why the text on the '13 Hole' postcard is reversed, exactly the same as the reversed K on the 340 cipher. The K on the 340 cipher is not only reversed, but it is now much smaller than all the other characters on the 340 cipher, which is why the Zodiac Killer pastes "Fk I'm crackproof" rather than "FK I'm crackproof". ​ Crackproof, Fk and the reversal of text on the '13 Hole' postcard, coupled with the cross design of 13 (paradice and slaves), inevitably leads back to the 340 cipher. Either that, or he pasted "Fk I'm crackproof" upside down on the '13 Hole' postcard for no reason whatsoever.

What we effectively have, are two consecutive October 1970 communications stating ​"Fk I'm crackproof" and "sorry no cipher", both furnished with a cross design that mimics the appearance of paradice and slaves on the 340 cipher. It is my contention that the Zodiac Killer responded to the challenge of Professor D.C.B. Marsh, but he simply wasn't going to abide by the rules laid down by the cryptography expert, yet he stayed true to the paradice and slaves message in the 408 cipher, albeit in his own inimitable style. The paradice and slaves design in the 340 cipher (extending 17 rows down) still leaves the tantalizing prospect of three 'vacant' rows comprising of 51 unobstructed characters, that may harbor a second puzzle or message. With the Zodiac pseudonym almost appearing toward the end of the cipher, there may be a twist in the tail yet.       

The Bay Area murderer mailed three communications in total to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald on July 31st 1969, demanding that his ciphers be printed on the front page of the respective newspapers by Friday afternoon (August 1st). This is what he wrote to each newspaper after stating several facts about his crimes.

Vallejo Times-Herald - Here is a cyipher or that is part of one. the other 2 parts have been mailed to the S.F. Examiner + the S.F. Chronicle 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. I will cruse around and pick of all stray people or coupples that are alone then move on to kill some more untill I have killed over a dozen people.

San Francisco Examiner - Here is a cipher or that is part of one. The other 2 parts are being mailed to the Vallejo Times + S.F. Chronicle I want you to print this cipher on the frunt page by Fry afternoon Aug 1-69. If you do not print this cipher, I will go on a kill rampage Fry night. This will last the whole weekend, I will cruse around killing people who are alone at night untill Sun Night or un till I kill a dozen people.

San Francisco Chronicle - Here is part of a cipher the other 2 parts of this cipher are being mailed to the editors of the Vallejo Times and SF Examiner. I want you to print this cipher on the frunt page of your paper. In this cipher is my idenity. If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend. 

In a previous article we examined the present and past tense usage in the three letters, along with the stamps applied to the envelope, to make the case for the Zodiac Killer being a Vallejo resident. The following will be nothing groundbreaking, but examines the phrases and grammar used by the author to paint a picture of the subject when considering his identity. The Zodiac Killer threatened chaos over the weekend if his codes were not published on the front page of the papers. Unfortunately for him, the main two publications refused to bow to his threats. On August 2nd 1969, the San Francisco Chronicle under the title Coded Clue in Murders placed one-third of his cipher on page 4, while the San Francisco Examiner under the banner Vallejo Mass Murder Threat Fails (despite publishing the entire cipher) relegated it to page 9 on August 3rd 1969. This lowly showing in the San Francisco Examiner clearly upset the Zodiac Killer the most, when he hurriedly delivered by hand the August 4th 1969 'Debut of Zodiac' letter to the Examiner, stating "I was not happy to see that I did not get front page coverage". Putting aside the December 16th 1969 'Fairfield' letter (which many dispute), he never wrote to the San Francisco Examiner again.  

In a recent article we discussed the topic of geographic profiling to narrow the search field for an offender's home residence. Equally, the wording used by the Zodiac Killer in his communications may also help pinpoint a location, or at the very least give us an insight into his comfort zone or movements. Target or Victim Backcloth is the model by which a murderer may select his victims. The Zodiac Killer (wherever he lived) would have selected his victims dependent upon availability and location, along with the constraints of time and the day of the week. For a serial killer committing his crimes in Vallejo, his knowledge of the Target Backcloth may govern the types of individual he chooses. This seemed evident in his choice of couples parked up in lonely areas on December 20th and July 4th.

His communications to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald exemplified this knowledge of a Target Backcloth perfectly, when he only threatened to kill couples in his address to the Vallejo Times-Herald (or stray people). He knew exactly where to find them, despite the fact it was highly unlikely he would continue to kill in the same area again. The Zodiac Killer never used the word couples in his address to the San Francisco Chronicle and Examiner, suggesting that his knowledge of the Target Backcloth was less comprehensive and more uncertain in this city- and why at San Francisco he would target a lone taxicab driver rather than target the location, as he did at Lake Herman Road and Blue Rock Springs. As Kim Rossmo stated  "The San Francisco murder differs significantly from the Zodiac's other crimes. Up to this point he was hunting in locations that had a good probability of containing his desired victims. Target selection was a function of area, not of an individual. However, it is unlikely the Zodiac was successful in all his searches; serial killers typically engage in extensive hunting activities, and for every attack there are many unsuccessful search attempts. In San Francisco, however, the Zodiac controlled the situation through his selection of victim type. The need for such control could be indicative of the distance the Zodiac had to travel to the crime site. Criminals who travel longer distances to offend are less likely to use uncertain target selection techniques".  

The Zodiac Killer wrote of ​"killing lone people in the night" or "killing people who are alone at night" to the Chronicle and Examiner, which is exactly what he did just over two months later on October 11th 1969, when Paul Stine was brutally gunned down inside his taxicab at Presidio Heights. The target selection began with the individual not the location. He then directed Paul Stine to an area to facilitate his best chance of escape. A Target Backcloth requires knowledge of an area and will govern to some extent the victims chosen, as displayed by some serial killers who target sex workers.   

It was considered that if the Zodiac Killer lived in Vallejo, he likely had a 9-5, Monday to Friday profession, based upon the fact, that when constrained by time he murdered close to home on a Friday, but unconstrained (on his day off), he was able to venture further afield to San Francisco and Lake Berryessa. He admitted as much in all the July 31st 1969 communications.

"I will go on a kill ram-Page Fry. night. I will cruse around all weekend" and "I will cruse around killing people who are alone at night untill Sun Night". The Zodiac Killer may potentially be limited in searching for courting couples on weekdays, but certainly not for lone victims in San Francisco, Vallejo or elsewhere Yet he has specifically tied himself to murder within the parameters of Friday night to Sunday night in these letters, and therefore highly suggestive he is employed on a weekday basis. 

The Brentingham model of geographic profiling details an activity space where an individual lives, works and plays. The Zodiac Killer targeted the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald in his first communications to the newspapers, indicating that Vallejo and San Francisco were his primary sites of travel. He most likely lived and worked in both. The newspapers he chose and the location he lived, part of his mental map, exhibited to its fullest extent when he subconsciously used the present and past tense in his three July 31st 1969 letters 

The Zodiac Killer - A Vallejo Resident [Part 2]​   

The 408 cipher, mailed in three parts to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald on July 31st 1969 had 18 unsolved characters at its foot. However, the Zodiac Killer likely made an error when transferring his original message into the encrypted version, accidentally omitting the word "people" from the section of code mailed to the San Francisco Chronicle: "The best part of it is that when I die I will be reborn in paradice and all the (people) I have killed will become my slaves". Had he transferred the message correctly, the intended version would have had only 12 unsolved characters in which his identity may have resided, such as "I am the Zodiac". After all, he promised us his identity not his name. What are the chances the Zodiac Killer left a similar message at the foot of the 340 cipher?

Professor D.C.B. Marsh, in the October 22nd 1969 San Francisco Examiner newspaper article by Will Stevens, laid down a challenge to the Zodiac Killer to reveal 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 Allen 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". It was speculated that the Zodiac Killer certainly wasn't going to provide another conventional cryptogram to be easily decoded, so instead created the appearance of a cryptogram with hidden "puzzles" contained within it, such as "paradice" and "slaves" running vertically and horizontally across its mid-section. This was later revealed in the 'Halloween' card, where the Zodiac Killer belatedly informed us the 340 code was "sorry no cipher" and placed "paradice" and "slaves" in a cross formation to point us in the right direction.   

The "sorry no cipher" section of the 'Halloween' card has one section running from bottom to top. The '13 Hole' postcard mailed before this offering has "Fk I'm crackproof" flipped upside down. This gave rise to the idea that the 340 cipher needed to flipped vertically, which I was able to do on Dave Oranchak's excellent Webtoy on the Zodiac Killer Ciphers website. 

​When Professor D.C.B. Marsh laid down the challenge to Zodiac, it was initially considered that the message at the foot of the 340 cipher may have teased the American Cryptogram Association with something like "next time I will tell you who the Zodiac is", bearing in mind where the near-pseudonym was placed. Then, five months later he would follow this up with the reveal of his name, which he effectively teased us with by stating "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...."  

This statement is very telling, when we consider that it was patently obvious that his last cipher hadn't been solved - so why did he add this to the opening of the April 20th 1970 communication? The final section of the 340 cipher may explain why he began this correspondence in the way he did. It may be conceivable that the last section of the 340 cipher promised to reveal his name in the next cipher, hence the blatantly obvious introduction in the April 20th 1970 communication, of "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...."  We effectively have to bridge the gap between "I am the Zodiac" (if correct) on the 408 cipher to "My name is" on the April 20th letter. The obvious connector would be the promise of a new cipher or code containing the Zodiac Killer's name. 

It is notable that the 340 cipher begins with "her" (the last three letters of cipher), however, it is impossible to form the word "cipher" in the format offered. The uniform 17 X 20 pattern of the cipher would be broken by adding "cip" to the beginning. For this section to provide us with the word "cipher" within the existing pattern and the promise of a new cipher containing the Zodiac's name, the 340 cipher has to be flipped - possibly as the 'Halloween' card and '13 Hole' postcard had hinted nearly a year later. Other than the 408 cipher mailings, every other Zodiac correspondence began with the introduction of "This is the Zodiac Speaking". The 340 cipher, when flipped, enables this introduction to begin the 340 character message also. ​ 

But what is the likely message encoded at the foot of the cipher? Without having decoded it, I can only make a calculated guess from other Zodiac correspondence. In the August 4th 1969 'Debut of Zodiac' letter, the killer wrote "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".  

In the April 20th 1970 communication, the killer wrote "By the way have you cracked the last cipher I sent you. My name is...." 

Therefore, I will use the literal words of the Zodiac Killer to complete the last 27 characters of the 340 cipher, obviously changing "last" to "next".
​
By flipping the 340 cipher vertically we are able to use the clue of "Zodiac" to generate his usual introduction and then form the bridge between cipher one and cipher three with the promise of his name in cipher two, using the words of the Zodiac Killer himself. Whether this analysis has any semblance of truth is another matter entirely. 

It is no coincidence that the Zodiac Killer only wrote "in this cipher is my idenity" in the letter he mailed to the San Francisco Chronicle on July 31st 1969, because this one-third of the cipher contained the 18 unsolved characters at its foot. This was also the only letter of the three to begin with "This is the murderer". The other two communications to the San Francisco Examiner and Vallejo Times-Herald began with "I am the killer". This shift in introduction may be completely accidental, may be subconscious or may be completely deliberate on account of the "identity" he is to place at the foot of the cipher. The author of these three communications had deliberately separated them into three parts, and therefore when he was preparing the San Francisco Chronicle letter, one would like to think he was considering the opening line when placing his identity at the end of the cipher. If he was ever going to disclose his identity (but not his name), then logically it would be an extension of "I am the killer" to "I am the Zodiac Killer", and therefore satisfy the quota of 18 unsolved characters required by the cipher. I have inserted "I am the Zodiac Killer" at the end of the opening lines of the San Francisco Chronicle and San Francisco Examiner to show how the revelation of his identity in the Chronicle better suits the introduction of "This is the murderer". 
San Francisco Chronicle: "Dear Editor, This is the murderer of the 2 teenagers last Christmass at Lake Herman + the girl on the 4th of July near the golf course in Vallejo. I am the Zodiac Killer" 
San Francisco Examiner: Dear Editor, I am the killer of the 2 teen-agers last Christmass at Lake Herman and the Girl last 4th of July. I am the Zodiac Killer"     

The Zodiac Killer may have accidentally dropped the word "people" from the San Francisco Chronicle cipher (shown in red above) when he transitioned from one cipher to another, unwittingly missing out this word from his original draft to final version, and thereby forcing him to switch from the intended 12 characters he meant to leave, to a revised 18 characters.To rectify his mistake he simply changed "I am the Zodiac" to "I am the Zodiac Killer". The confirmed murderer of five never used the term "Zodiac Killer" in any of his subsequent communications, opting for "This is the Zodiac speaking", but may have had his hand forced on this occasion. It would have been relatively easy to just rewrite the San Francisco Chronicle cipher, but this was an easy solution. One can see how the Zodiac Killer chose his words in the October 13th 1969 letter, opening up with "This is the Zodiac speaking. I am the murderer of the taxi driver over by Washington St + Maple St last night". He uses the words "I am" because he has already introduced himself as the Zodiac. In the July 31st 1969 San Francisco Chronicle letter he uses the words "This is the murderer" because he has thus far failed to introduce himself, which he reserves for the final line of the cipher, stating "I am the Zodiac (Killer)". It is effectively a reversal of the Paul Stine letter. 
Paul Stine letter: "This is the Zodiac speaking. I am the murderer of the taxi driver".  
San Francisco Chronicle: "This is the murderer of the 2 teenagers. I am the Zodiac Killer"    

The murderer would very quickly introduce himself in the August 4th 1969 'Debut of Zodiac' letter: "This is the Zodiac speaking. In answer to your asking for more details about the good times I have had in Vallejo, I shall be very happy to supply even more material. 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". He was introducing himself as "Zodiac", so when the police did eventually crack the code, in effect, they would have "had Zodiac". 

An anonymous caller in San Francisco declared that whoever devised the code "would have to have a vast knowledge in three fields - surveying, nautical science and marksmanship". How the caller could derive that the triple murderer had a vast knowledge of marksmanship from these attacks is hard to justify, not to mention nautical science and surveying. Was the Zodiac Killer ringing the police and blowing his own trumpet? The murderer did ultimately commit his murders with varied weaponry and did eventually introduce a map and radians into his communications.   

If we are looking for an identity or pseudonym in the 18 unsolved characters of the 408 cipher, then it must include appropriate word usage in order to increase the originally intended 12 characters up to 18 characters. So if the original message was "I am the Zodiac" or "Zodiac Killer", then the author had to supplement it with an extra 6 characters to replace the word "people". The simplest avenue available was to add "Killer" or "I am the", in order to generate these 6 characters. These were all used consecutively in two of the three communications mailed on July 31st 1969, when the Zodiac Killer wrote "I am the killer of the 2 teenagers last Christmass at Lake Herman + the girl last 4th of July" to the San Francisco Examiner and Vallejo Times-Herald.  

The Zodiac Killer had seemingly failed to fully convince Vallejo Police Chief Jack E Stiltz, who was less than satisfied that the letter writer and killer were one and the same, urging the author of the July 31st 1969 letters to send in more details of the crimes. The Zodiac Killer immediately dispatched the 'Debut of Zodiac' letter on August 4th 1969 with the introduction of "This is the Zodiac speaking". Although the Zodiac Killer could add more details of the crimes in this new letter to prove he was the killer, It is conceivable he revealed his pseudonym after only four days to inextricably link himself to the first three letters. The only way he could achieve this beyond any doubt, was to reveal a significant word in the unsolved cipher. Then the police would know for certain when the code was broken, that the author of the August 4th 1969 letter was not only the killer, but the designer of the cryptogram. So he introduced his pseudonym "Zodiac" earlier than he had originally intended and immediately rushed it off to the San Francisco Examiner newspaper on August 4th 1969, before the cryptogram was solved.

​Remember, if Vallejo Police Chief Jack E. Stiltz had not urged the author of the July 31st 1969 letters to send in more details to prove the letter writer was the killer, the 'Debut of Zodiac' letter would likely never have been written and sent to the Examiner. The "Zodiac" would still have been the "killer" by the time of the Paul Stine murder. He revealed his pseudonym to link himself to the San Francisco Chronicle's 18 characters, but unfortunately for him, he clearly underestimated the difficulty of the encryption. The release of his identity or pseudonym "Zodiac" so quickly, may lend credence to its presence in the remainder of the 408 cipher, and by extension, the 18 unsolved characters harboring a genuine and coherent message. 

​"This is the Zodiac speaking. 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".

THE 18 UNSOLVED CHARACTERS [PT1]
THE 18 UNSOLVED CHARACTERS [PT2]
​THE 18 UNSOLVED CHARACTERS [PT3]

Many attempts have been made to conclusively link the Riverside murder of Cheri Jo Bates on October 30th 1966, along with the accompanying communications, to the Zodiac Killer. The three 'Bates' letters, on April 30th 1967, ended the Riverside chapter, with the three July 31st 1969 letters to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald, beginning the Zodiac chapter. But is the hidden identity contained within the 408 cipher (if it exists) somehow connected to the hidden author of the November 29th 1966 'Confession' letter? It is paramount to make a distinction between name and identity when attempting to formulate any cohesive link between the Confession letter and 408 cipher, because the Zodiac Killer claimed he wouldn't give us his name in the decoded 408 cipher, but did claim it would reveal his identity.

​When we take a close look at the decoded 408 cipher, it can be argued that he made a fundamental error when he encoded his original message, accidentally omitting the word "people" in the ciphertext. This is explained in 'The 18 Unsolved Characters [Pt3]'  This effectively created a shortfall of 6 characters in his 408 cipher, which had he not done, would only have left 12 unsolved characters at the end of the message. In view of the Bay Area murderer identifying himself as "Zodiac" just four days later, it was considered that his impatience may have compelled him to reveal his identity earlier than he would have liked, and "Zodiac" was integral to his identity in the 12 characters at the end of the 408 cipher. The hidden identity, therefore, the "Zodiac Killer". 

Had the 408 cipher read "the best part of it, is that when I die I will be reborn in paradice and all the people I have killed will become my slaves", and the last 12 characters contained his identity, then by extension, we should be looking backwards to Riverside for the previous time he used a form of cryptic or hidden message. The only letter that contained such an instance, was the November 29th 1966 letter beginning "The Confession by - - - - - - - - - - - -".  This contained 12 underscores of, presumably, the hidden name or identity of the killer. For those believing a connection from Riverside to the Bay Area, the potential murderer of Cheri Jo Bates may have cloaked his identity behind 12 underscores in the Riverside 'Confession' letter and 12 characters in his communication with the San Francisco Chronicle on July 31st 1969.  The 'Bates' letters correlated via a trinity of letters, whereby the 'Confession' letter correlated through the identity of twelve.

This analysis fundamentally fails to successfully bridge the divide from Riverside to the Bay Area, as many arguments have before - and the connection between the murder of Cheri Jo Bates and associated communications, to the Zodiac Killer, will remain a hot button topic for many years to come no doubt - but the search goes on.

In the last three articles it was proposed that the author of the 408 cipher may have left his identity within the final 18 characters. He specifically told us that he would not give us his name, but assured us his identity was concealed within the cipher - reasoned to be something like "I am the Zodiac Killer." The theme of his identity and name were integral to the final third of the cipher and letter mailed to the San Francisco Chronicle on July 31st 1969, and may very well have manifested through both his second and third ciphers as well. The third cipher began with "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...."- therefore, the final line of the second cipher (340 cipher) may be the 'narrative bridge' between the first and third cryptic offerings. 

The first cipher achieved everything the Zodiac Killer had wished for. He had fashioned using threats and newspaper rivalry maximum exposure for his handiwork, which was very quickly published by the Vallejo Times-Herald, San Francisco Examiner and San Francisco Chronicle. The failure of Zodiac to give us his name did not satiate the desire of some in the quest for the real identity of the killer, and was championed by Dr D.C.B. Marsh, president of the American Cryptogram Association, who on October 22nd 1969 in an article published by the San Francisco Examiner, stated "The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in a cipher to established cryptogram experts. "Zodiac" had not done this, Marsh suggested, 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."

​This article was not to go unnoticed by the killer, who, two and a half weeks later mailed his infamous 340 cipher, unsolved to this day according to official sources. This cipher was to become the all-important bridge between cipher one and three. If he gave us his identity (the Zodiac Killer) in the unsolved 18 characters of cipher one, and stated "my name is" in cipher three (supposedly giving us his name), then by logical extension, cipher two should have been the promise of a name, and the conduit between the two.

If we can provide a compelling reason to show that the near-Zodiac on the final line of the 340 cipher was actually intended to be deciphered to 'Zodiac', then we are left with the final two characters of the cipher to decode, thereby bridging the gap between cipher two and three. 
Using the most powerful supercomputers in the world and the talent of some of the brightest minds in cryptography, the 340 cipher has failed to buckle. So, it's time to use the character of the Zodiac against himself, and his willingness to respond to the newspapers.

If the Zodiac Killer is responding to Dr D.C.B. Marsh, then he clearly isn't prepared to give us his name immediately in the November 8th 1969 '340 cipher', as the opening line in his April 20th 1970 communication would testify to. It would be over five months later that he stated "my name is".  Therefore, the final two characters of the 340 cipher are the conclusion to an open-ended promise of something more to come, in similar fashion to "my name is."  The Zodiac Killer certainly wasn't going to miss the opportunity to keep Dr D.C.B. Marsh and the public waiting just a little bit longer. 
​
The final line or sequence of the 340 cipher probably read "The next cipher will reveal who the Zodiac is" or "I will soon reveal who the Zodiac is" - or something along these lines. This 'promise' can be seen in his opening gambit of the April 20th 1970 communication: "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...." ​
The statement of "by the way have you cracked the last cipher I sent you" is superfluous, as he knows only too well the 340 cipher has not been cracked, yet, it also lacks his usual abrasive sarcasm. However, it is followed by "my name is", and therefore could be construed as the conclusion to his promise from the final line of his 340 cipher and to Dr D.C.B. Marsh, and the allegorical  bridge between the two ciphers.

But how do we know that the near-Zodiac on the final line of the 340 cipher was to be decoded to 'Zodiac'?  Because he fashioned a bridge between cipher two and three using his pseudonym. Placing the real spelling of Zodiac under the '340 cipher' version of Zodiac, and counting the alphabetical difference numerically between the columns (see here), we achieve the numbers 000888. When combined, the three circled 8's found on the '13 Symbol' cipher.
​
These six characters of the 340 cipher were effectively carried forward numerically and placed front and center of the '13 Symbol' cipher design. You will also notice that the two characters either side of three 8's (shown on the right), are both visible either side of the near-Zodiac on the 340 cipher. A total of eight characters and three circled 8's the common link or bridge between cipher two and three - in which the name of Zodiac played a pivotal part in the formation of the 'My Name is Cipher'. The story is now complete. 

The Zodiac Killer stated on July 31st 1969 "I will not give you my name, but in this cipher is my identity." He promised in the 340 cipher, in a response to Dr D.C.B. Marsh, that he would soon reveal his name. Then, five and a half months later, on April 20th 1970 he stated "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you. My name is...." 

Do ciphers two and three really contain a full and coherent message, not dissimilar to the 408 cipher solution, or had the Zodiac Killer taken Dr D.C.B. Marsh's advice "to send The American Cryptogram Association a cipher code - however complicated", and taken it a step too far?

This is the final installment covering the 18 unsolved characters at the foot of the 408 cipher. Part one. Part two.
Nobody knows for sure the exact process in which the Zodiac Killer crafted the three ciphers mailed to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald, but one possibility is that the author wrote the message first and then transferred it to the chosen grid formation, with the intention of leaving a number of spaces to insert his identity at the end of the cipher - a signature of sorts. The killer actually stated this: "I want you to print this cipher on the front page of your paper. In this cipher is my idenity."

We now know his identity as the 'Zodiac Killer', so one may expect to see 12 unsolved characters remaining at the foot of the cipher. He could have signed off the cipher with the wording 'Zodiac Killer' or 'I am the Zodiac', but either way, he would have had to leave himself 12 available spaces to complete the entire grid of 24 rows and 17 columns. The reason for believing he intended to leave 12 characters for his identity, rather than 18, is that he transferred the message from draft to grid incorrectly, actually omitting one important word - people.
​
The author had just switched from cipher 2 to cipher 3 (see below), which may have instigated the error.
​
In the trinity of letters to the newspapers, the Zodiac Killer described the inevitable consequences of not printing his ciphers. 
To the Vallejo Times-Herald, he wrote "I will cruse around and pick of all stray people or coupples that are alone then move on to kill some more untill I have killed over a dozen people."
To the San Francisco Examiner, he wrote "If you do not print this cipher, I will go on a kill rampage Fry night. This will last the whole weekend, I will cruse around killing people who are alone at night untill Sun Night or untill I kill a dozen people." 
To the San Francisco Chronicle, he wrote "I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend."  

With regards to his threats, he used the word "people" no less than six times, so it was probably unfortunate that this was the word he mistakenly dropped from his grid when transferring the message to it.
The murderer wrote in the cipher "the best part of it, is that when I die I will be reborn in paradice and all the I have killed will become my slaves." It is highly likely that he accidentally reproduced his message incorrectly and failed to include the word "people" in the resultant cipher. The cipher should have read "the best part of it, is that when I die I will be reborn in paradice and all the people I have killed will become my slaves."

Since "killing", "kill" and "people" were routinely written 'hand in glove' in all the three newspaper communications, then it is no great leap of faith that the two words should have been bound together in the cipher as well. 
In the San Francisco Chronicle portion of the cipher below, I have added "people" into the grid, thereby shifting the cipher across six spaces. The resulting cipher now contains 396 characters of legible text, leaving only 12 unsolved characters at its foot. The 12 characters we discussed earlier, in which the author had reserved for his identity or pseudonym. Signing off with the 'Zodiac Killer' or 'I am the Zodiac'.

However, the Zodiac Killer had made an error, accidentally omitting the word "people", and consequently had to improvise by using a combination of 'Zodiac Killer' and 'I am the Zodiac' to enable full use of all 408 spaces on the 24 X 17 grid. He may have settled for 'I am the Zodiac Killer', thereby satisfying the 18 spaces he had inadvertently left himself.

The idea of a 396 letter message (including "people" within it) would have negated the possibility of creating 30 rows by 13 columns totaling 390 characters - which is why he didn't do it. Therefore, he opted for 17 by 24, creating the grid we have been accustomed to. 

What methodology he employed to encrypt these final 18 letters is another matter entirely.    

The blue square shows the end of the word "the". One can see that by moving the letter 'E' across two places to accommodate "those", the remainder of the cipher would be equally shifted. If we added "people" after "the", then the remainder of the cipher would be shifted six places across. The result of this would be removing the final 2 or 6 characters from the 408 cipher.

This strikes to the heart of whether the Zodiac Killer originally intended to leave a predetermined identity at the foot of the cipher. He ended up with 18 characters, which to this day remain unsolved. If he had intended to place "those" or "people" in the cipher, but transferred his message incorrectly, then the idea that 18 characters were purposely left to reveal his identity fails to materialize. His new identity would drop to 12 or 16 characters. The 4 consecutive character drop down, from the 8th to 24th line, would also not occur. 

In the last article I suggested that the final 18 characters could read "I am the Zodiac Killer", based on his wording in the trinity of July 31st 1969 communications. With the addition of "people" his intended message could have been relegated to the signature "Zodiac Killer" or "I am the Zodiac" ​ With the addition of "those", an altogether different message would likely have been created. His original intention may have been to create a 12 or 16 character message, but was forced to improvise into a longer version, created by the error on line 17. However, this would negate the premise of the previous article to some extent.
 
To presuppose an original 18 characters being left over for the designated purpose of his identity, would make the assumption that his original message read "The best part of it is that when I die I will be reborn in paradice and all the I have killed will become my slaves," and he transferred it to the cipher correctly.

The idea of a random filler to flesh out a cipher doesn't sit well, when we consider how easy it is to just slightly redesign the message to use all the 408 available spaces. This suggests the 18 unsolved characters do have meaning, and do contain the identity or pseudonym of the Zodiac Killer. This makes more sense than a real name, bearing in mind the author has already decided against this option on lines 18 and 19.

If the Zodiac Killer's original message was 392 or 396 letters in length, he could have created a completely different grid formation with reduced leftovers or none at all, such as 6 rows of 22 characters = 132, mailed to each of three newspapers. This would give us a total of 396. However, he chose to opt for 17 characters in each row, thereby leaving more unused characters. For this reason, there appears a purpose behind the notion of a killer leaving us his identity.
​
Since he hadn't revealed his pseudonym at this juncture, can we assume that part of the 18 unsolved characters held the words "Zodiac Killer." The precursor of "I am the"- the beginning of the 18 characters, just like the introduction written on the San Francisco Examiner and Vallejo Times-Herald newspapers.   

THE 18 UNSOLVED CHARACTERS [PT1]  
THE 18 UNSOLVED CHARACTERS [PT3]

In a previous article it was considered that the Zodiac Killer's identity was born on August 3rd 1969, but on this occasion I shall take an altogether different approach, and consider the possibility that the Bay Area murderer had already decided upon the pseudonym Zodiac when he mailed the trinity of letters and ciphers to the Vallejo Times-Herald, San Francisco Examiner and San Francisco Chronicle on July 31st 1969.
The San Francisco Chronicle letter (part 3) reads as follows "Here is part of a cipher the other 2 parts of this cipher are being mailed to the editors of the Vallejo Times and SF Examiner. I want you to print this cipher on the front page of your paper. In this cipher is my idenity. If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend." The final 18 characters of the San Francisco Chronicle code remain undeciphered. However, the clues to breaking the remaining portion of the cipher may reside within the letters themselves. 
The 408 cipher message read "I like killing people because it is so much fun it is more fun than killing wild game in the forrest because man is the most dangerous animal of all to kill something gives me the most thrilling experence it is even better than getting your rocks off with a girl the best part of it is that when I die I will be reborn in paradice and all the (people) I have killed will become my slaves I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife. ebeorietemethhpiti."  The unbroken characters are shown in red.     

The murderer chose his words carefully, stating "in this cipher is my identity" rather than his name. This became evident when the vast majority of the 408 cipher was cracked a matter of days later, and the killer revealed "I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife." This still left open the possibility that his identity or pseudonym was contained in the 408 cipher. The San Francisco Chronicle letter was the only one of the trinity that contained "in this cipher is my identity," so logically, one could conclude that the 18 undeciphered characters at its foot, was the location of the murderer's identity.
If the killer had already decided upon his pseudonym when he wrote the three July 31st 1969 letters, then his decision to begin all three letters with "This is the murderer" and "I am the killer" (twice) was deliberately engineered to withhold the pseudonym Zodiac from the letters. The reason being - it was concealed in the final 18 characters of the 408 cipher.
It could be argued, that if he was to reveal his identity or pseudonym in the 408 cipher, then logically he would sign off the cryptogram with it. This was also apparent in the 340 cipher, with the near-Zodiac tantalizingly placed on the final line. 
If the Zodiac Killer had revealed his pseudonym straight away, then one of the letters would have opened with "This is the Zodiac" rather than "This is the murderer" (exactly like the August 4th 1969 letter). The other two letters would have opened with "I am the Zodiac Killer" rather than "I am the killer". But the murderer and author of the letters wanted to hide his pseudonym for now, and conceal it in the final 18 characters of the 408 cipher.    

We can now complete the 408 message:
"I like killing people because it is so much fun it is more fun than killing wild game in the forrest because man is the most dangerous animal of all to kill something gives me the most thrilling experence it is even better than getting your rocks off with a girl the best part of it is that when I die I will be reborn in paradice and all the (people) I have killed will become my slaves. I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife. I am the Zodiac Killer."​
This is an attempt at reasoning a solution from within the letters themselves, and not a claim of a definitive solution 

THE 18 UNSOLVED CHARACTERS [PT2]
THE 18 UNSOLVED CHARACTERS [PT3]

It seemed rather fortunate that the 'Halloween' card mailed on October 27th 1970, if designed totally independently to the 340 cipher, that Paradice and Slaves could be found perfectly bisecting the 340 cipher, 17 by 17 characters. Not to mention the word "By" being found in all four quadrants. This is discussed in more detail in the article 'The Illusion of the 340 Cipher.'  
The 'Halloween' card was almost certainly highlighting the Lake Berryessa attack on Bryan Hartnell and Cecelia Shepard, tied up with rope (plastic clothesline) and brutally stabbed sixteen times by the Zodiac Killer. The phrase "peek-a-boo you are doomed" referencing the children's game peekaboo, where 'hiding behind that tree' is sometimes added. This would also be the second time "by knife" would be used - linking the 'Halloween' card to the Volkswagen Karmann Ghia of Bryan Hartnell.
Since these two 'methods of death' (rope and knife) were instrumental to the attack on the young couple, we will focus on Paradice, Slaves, By Knife and By Rope. 
On the 'Halloween' card it is apparent that "By" is written vertically for "knife" rather than horizontally, as displayed by the other 'methods of death'. Could this be a sinister inference to a knife being driven downwards and the predominant focus of this card?   

If we color in the five characters underneath the 'Y' in the bottom left quadrant of the cipher, as is portrayed on the 'Halloween' card, it can be seen that the 'right facing V' would represent the 'E' of knife.
If we  color in the four characters underneath the 'B' in the bottom right quadrant of the cipher, as is portrayed on the 'Halloween' card, it can be seen that the 'right facing V' would represent the 'E' of rope.
To complete the word Paradice and Slaves a 'left facing V' had to be found in the last section of both words for parity. In this instance a 'left facing V' represented the letter 'E'.
When the Zodiac Killer introduced his 408 cipher in the July 31st letters, he stated "Here is part of a cipher" or "Here is a cyipher." When challenged to design another cipher by D.C.B. Marsh in the San Francisco Examiner on October 22nd 1969, the 340 cipher arrived just over two weeks later. The article was entitled 'Cipher Expert Dares Zodiac to Tell Name'. Bearing in mind that the 340 cipher began with "Her," could it have started with "Here is a cipher" or "Here's a cipher" (to marry with the 'P' of Paradice) in direct response to cryptographic expert D.C.B. Marsh.
There are 10 'left or right facing' V's in the entire 340 cipher. If the latter hypothesis was correct, then at least 50% of these would be represented by the letter E, in respect of Here, Paradice, Slaves, Rope and Knife.