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Sergeant John Lynch of the Vallejo Police Department received a typewritten card from a "concerned citizen" on August 10th 1969 stating "Dear Sergeant Lynch. I hope the enclosed "key" will prove to be beneficial to you in connection with the cipher letter writer. Working puzzles criptograms and word puzzles is one of my pleasures. Please forgive the absence of my signature or name as I do not wish to have my name in the papers and it could be mentiond by a slip of the tongue. With best wishes. concerned citizen". It also contained a working key to the 408 cipher, which was mailed by the Zodiac Killer in his three "code letters" to the Vallejo Times-Herald, San Francisco Chronicle and San Francisco Examiner on July 31st 1969. On October 7th 1969, another concerned citizen, this time describing himself as a "good citizen", mailed another cryptic message to Sergeant John Lynch, stating "On occasion, while thinking of the code letters, the pencil wrote:Go to 56 Beach Street. I get the name Jerry, perhaps he knows people or his name is XXXXXXX". The author by mentioning "code letters" is clearly referring to the trinity of communications mailed on July 31st 1969, to which the August 10th 1969 communication provided a key. Despite both the "concerned citizen" and "good citizen" communications being extremely brief in nature, both utilized the word "name" twice. The author of these two communications can be argued to be the Zodiac Killer, who also mailed the April 20th 1970 letter, teasing us with "my name is". Crucially, the "concerned citizen" card and code key had not been released into the public domain by the arrival of the "good citizen" letter.  

Recently I have been examining the murder of Robert Michael Salem, who was found stabbed in his 745 Stevenson Street, San Francisco apartment on April 19th 1970. The April 20th 1970 Zodiac Killer letter was received at the San Francisco Chronicle the same day the Robert Salem murder was reported in their newspaper. The letter read "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is", belatedly followed by "I hope you have fun trying to fiygure out who I killed". The Zodiac Killer chose three Christian symbols in his enclosed 13 character code, that mirrored the Christian symbolism written in blood on the apartment wall of Robert Salem. Above the Japanese tatami mat where Robert Salem's body lay, was the drawing of an Egyptian ankh or "crucified man", along with the wording "Satan Saves" and "Zodiac". The murder of Robert Salem and the April 20th 1970 letter so reeked of Christian symbolism, that it was hard to ignore that the two weren't connected, and led me to believe that the wording "Satan Saves" had some biblical meaning with respect to Robert Salem and his homosexual lifestyle. Whether the drawing of the Egyptian ankh or "crucified man" on the wall of Robert Salem were interchangeable in the mind of the killer is unknown, but the San Francisco Chronicle on April 20th 1970 made no mention of the Egyptian ankh - making the appearance of the Christian anchor in Zodiac's 13-Symbol cipher intriguing. Anchor and ankh have the same phonetic root - and when the Zodiac Killer's crude anchor in the code is superimposed over the ankh drawing on Robert Salem's wall - a full and complete Christian anchor is revealed.   .

The ankh (key of life) was commonly held in the hands of ancient Egyptian deities, or being given by them to the pharaoh, to represent their power to sustain life and to revive human souls in the afterlife. The ankh was one of the most common decorative motifs in ancient Egypt and was also used decoratively by neighbouring cultures. Coptic Christians adapted it into the crux ansata, a shape with a circular rather than oval loop (as seen in the image above), and used it as a variant of the Christian cross. The message of "Satan Saves" rather than "Jesus Saves", along with a crucifix style cross, gives the strong impression of a murder with religious connotations, bearing in mind the anti-gay and intolerant Christian attitudes that permeated society in 1970 (and to a lesser extent today). Robert Salem was a gay man, who may have unfortunately attracted somebody with the belief he was a sinner or non-believer - and hence the sarcastic message of "Satan Saves" and the "key of life" being drawn on his stomach. Clearly, the person who drew the symbol and writing, was portraying a message to the viewer (whether a belief sincerely held or not).

The most unusual and notable features inflicted to the body of Robert Salem, were the crucifix style design "drawn" on his stomach and the removal of his left ear. Both of these featured heavily in the crucifixion of Jesus. Simon Peter, a disciple of Jesus, attempted to "save" and protect Jesus from arrest by severing the ear of Malchus, who was a servant of the Jewish High Priest Caiaphas. According to the gospels, Calaphas organized a plot to kill Jesus. The arrest of Jesus was a pivotal event in Christianity recorded in the canonical gospels. It occurred shortly after the Last Supper (during which Jesus gave his final sermon), and immediately after the kiss of Judas, which is traditionally said to have been an act of betrayal since Judas made a deal with the chief priests to arrest Jesus. This event ultimately led, in the Gospel accounts, to the crucifixion of Jesus. Although the right ear of Malchus was severed, as opposed to the left ear of Robert Salem, this was the most viable connection I could find that links the two unusual features discovered by investigators on the body of Robert Salem.​

The immediate murder with a Zodiac connection after the "latent homosexual" suggestion was floated in the San Francisco Chronicle, where the Bay Area murderer's pseudonym was found at the crime scene, was the murder of gay man, Robert Salem on April 15th 1970 in San Francisco. The Zodiac Killer's 13-Symbol cipher is arguably contemporary in nature, with his April 20th 1970 letter being mailed the same day this murder was published in the newspapers. Homosexuality and acceptance has been a continuing struggle for gay activists to this day, but the 1960s and 1970s were arguably more difficult times, with newspaper coverage on this topic less than acceptable. Many religious people were unwilling to accept individual rights, claiming that homosexuality was the mark of the beast, and was an abomination in the eyes of God. The writing in blood on Robert Salem's apartment wall stating "Satan Saves" must have had some meaning to the killer - so was it in any way connected to the sexual preferences of Robert Salem? I couldn't help thinking that the "Satan Saves" element written in blood on the apartment wall had a more important role to play, not only in the fact Robert Salem was homosexual, but in the damage inflicted to his body and the removal of his left ear. So I looked for a bible verse that may have been known to the killer. 

​I also had to be mindful that the bible verse was relevant to perceived "sins of the flesh". In other words, the murderer of Robert Salem had an issue with homosexuality, believing it to be satanic, and wanted to deliver him unto Satan to be saved (see image above). Hence the wording "Satan Saves". 1 Corinthians 5:5 featured Paul, who had commanded the Christians in Corinth to remove from among them a man who was sleeping with his father's wife, a form of sexual immorality that even their own pagan culture condemned. The killer of Robert Salem may have considered his lifestyle the devil's work and a form of sexual immorality, that resulted in "destruction of the flesh" as witnessed by investigators at the crime scene. I also took the "Satan" element from the apartment wall and combined it with the "destruction of the flesh", to create a relevant solution to the 13-Symbol cipher of "Skin A Satanist". Not only did the Zodiac Killer encipher the word "skin" twice in the 148 character cipher in 1971, but it was relevant to the Robert Salem crime scene in April 1970.

Robert Michael Salem was found murdered in his 745 Stevenson Street San Francisco apartment on April 19th 1970, accompanied by the drawing of a religious crux ansata (crucified man) and the words "Satan Saves" scrawled in blood on the wall. This somewhat mirrored the religious characters in the 13 character code mailed by the Zodiac Killer the following day (April 20th 1970), when he posed the question "I hope you have fun trying to fiygure out who I killed". Investigators found no forced entry at Robert Salem's apartment, and little appeared to have been taken from the property, other than possibly some money from an open wallet on a shelf. The crime scene appeared to scream of far more than a simple robbery. This opens up the possibility that Robert Salem was murdered by somebody known to him, or somebody that befriended him with common interests. Robert Salem was a lamp designer, whose products had been exhibited in Japan, England and Russia. His apartment certainly showed an Oriental influence, with a Japanese hurricane lamp hanging from the ceiling, tree trunks prominent in the apartment in the style of Japanese tea houses, and he was discovered murdered wearing Oriental lounging clothes on top of a Japanese tatami mat.

Three months after this crime, the Zodiac Killer mailed the Little List letter on July 26th 1970, paraphrasing two acts from The Mikado, a Gilbert & Sullivan comic opera set in Japan. The first act he paraphrased was entitled A More Humane Mikado, followed by As Some Day It May Happen, in which victims or society offenders must be found, and who would never be missed. His introduction in the communication detailed how he would torture his victims in paradise, stating in one part: "Others I shall skin them alive + let them run around screaming". In the middle of 1971, the Zodiac Killer would again mention the skinning of victims, when he encrypted the following in his 148 character cipher: "If this is not on the front page in a week I will skin 3 little kids and make a suit from the skin", and wrote in accompaniment to the cipher "Next time I will send a patch of human skin". This is why I found the phrase "Skin A Satanist" very interesting, when from a cryptology standpoint, it satisfied the 13 character code on April 20th 1970, arriving the same day the Robert Salem story broke in the San Francisco Chronicle detailing the "Satan Saves" on the apartment wall. Robert Salem was effectively skinned, when his left ear was severed and taken from the crime scene. On January 29th 1974, the Zodiac Killer would again recite a section from The Mikado, using a verse from Tit-Willow. Not only did he paraphrase the Japanese based opera, but he added some Oriental characters at the foot of the letter. One line in this act reminded me of the introduction in the April 20th 1970 (My Name Is letter). It read "Now I feel just as sure as I'm sure that my name Isn't Willow, titwillow, titwillow", 

Robert Salem was a flamboyant character with an interest in the arts, having been the lighting designer for the historic Haslett Warehouse at 680 Beach Street, San Francisco in 1969. Other than the mention of Washington and Maple streets on October 13th 1969, the only other street the Zodiac Killer ever imentioned in his communications (if authentic} was when he mailed a letter to Sergeant John Lynch on October 7th 1969, when he wrote ''Go to 56 Beach Street. I get the name Jerry, perhaps he knows people or his name is XXXXXXX''. So, was the Zodiac Killer in the apartment of Robert Salem in April 1970?​​​

​​Cragle, an excellent Zodiac researcher who contributes to both forums, sent Michael Morford some invaluable information that he knew I would like (and Mike subsequently added some extra findings). It was fantastic news. A letter was possibly mailed by the Zodiac Killer on October 7th 1969, containing the wording ''Go to 56 Beach Street. I get the name Jerry, perhaps he knows people or his name is XXXXXXX'' (and mentioned code letters). This letter can now be inextricably linked to the Concerned Citizen card postmarked August 10th 1969, which gave us a key to the 408 cipher, mailed by the Zodiac Killer within three "code letters" on July 31st 1969. The 56 Beach Street address never existed in 1969, only on street planning maps. Cragle found a Carl John Welz (married to Jerry Hatcher) who were working at 680 Beach Street, San Francisco and living at 2529 Union Street, San Francisco in 1969, He had a Batchelor and Master of Arts, taught in many public and  private schools and was well known in Christian science circles, with a mentioned periodical from him in 1967 (see below).

If this was the "Jerry" a possible Zodiac Killer was referring to, then this is an enormous find, Carl John Welz (and wife) would most likely have been working at 680 Beach Street at the same time as Robert Michael Salem, who was murdered by somebody claiming to be the Zodiac Killer on April 15th 1970. Throughout 1969, Robert Salem worked as the lighting designer for the historic Haslett Warehouse at 680 Beach Street. Carl John Welz wrote an anti gay article entitled Homosexuality Can Be Healed, so the fact that murdered Robert Salem was a homosexual, with the wording "Satan Saves" and a "crucified man" drawn in blood on his apartment wall, with the pseudonym Zodiac present also, makes this is a significant find. We can now connect the August 10th and October 7th 1969 communications, link the name "Jerry" to the Haslett Warehouse at 680 Beach Street, and to murder victim Robert Salem, who also worked there - and finally - combine the religious overtones from the above article to the apartment wall, and to the Zodiac Killer's 13-Symbol cipher.. 

Cragle, an excellent Zodiac researcher who contributes to both forums, sent Michael Morford some invaluable information that he knew I would like (and Mike subsequently added some extra findings). It was fantastic news. A letter was possibly mailed by the Zodiac Killer on October 7th 1969, containing the wording ''Go to 56 Beach Street. I get the name Jerry, perhaps he knows people or his name is XXXXXXX'' (and mentioned code letters). This letter can now be inextricably linked to the Concerned Citizen card postmarked August 10th 1969, which gave us a key to the 408 cipher, mailed by the Zodiac Killer within three "code letters" on July 31st 1969. The 56 Beach Street address never existed in 1969, only on street planning maps. Cragle found a Carl John Welz (married to Jerry Hatcher) who were working at 680 Beach Street, San Francisco and living at 2529 Union Street, San Francisco in 1969, He had a Batchelor and Master of Arts, taught in many public and  private schools and was well known in Christian science circles, with a mentioned periodical from him in 1967 (see below).

If this was the "Jerry" a possible Zodiac Killer was referring to, then this is an enormous find, Carl John Welz (and wife) would most likely have been working at 680 Beach Street at the same time as Robert Michael Salem, who was murdered by somebody claiming to be the Zodiac Killer on April 15th 1970. Throughout 1969, Robert Salem worked as the lighting designer for the historic Haslett Warehouse at 680 Beach Street. Carl John Welz wrote an anti gay article entitled Homosexuality Can Be Healed, so the fact that murdered Robert Salem was a homosexual, with the wording "Satan Saves" and a "crucified man" drawn in blood on his apartment wall, with the pseudonym Zodiac present also, makes this is a significant find. We can now connect the August 10th and October 7th 1969 communications, possibly link the name "Jerry" to the Haslett Warehouse at 680 Beach Street and to murder victim Robert Salem, and finally, combine the religious overtones from the article to the apartment wall. 

LATEST UPDATE, INCLUDING POLICE REPORTS & PHOTOGRAPHS

Thanks to Cragle and Mike.

ASSOCIATED ARTICLES:
ANCHORS AWEIGH
ROBERT SALEM-A ZODIAC MURDER?
A CONTEMPORARY CODE ON APRIL 20TH 1970
THE ZODIAC KILLER-DRIVEN BY DEVIANCY     
A SATANIC MESSAGE IN CODE? 
THE "SKIN MARKINGS" ON ROBERT SALEM 
​DELIVER UNTO SATAN
MURDER THROUGH THEATRE?

On August 10th 1969, somebody mailed a typewritten communication to Vallejo Police Sergeant John Lynch providing the code key to the 408 cipher, that may or may not have been authored by the Zodiac Killer. The communication, ending with "concerned citizen", was withheld from publication. This means that a second communication mailed just two months later, on October 7th 1969, again addressed to Vallejo Police Sergeant John Lynch, with the phraseology "code letters" and ending with "a good citizen", was very likely the same author. This was the cryptic footnote by Sergeant John Lynch regarding the "good citizen" letter.

The writer has a strong feeling of ESP. While having these feelings, the writer writes with a pencil. On occasion, while thinking of the code letters, the pencil wrote: ''Go to 56 Beach Street. I get the name Jerry, perhaps he knows people or his name is XXXXXXX''.  

It had been approximately two months since any Zodiac communication was received, yet the "good citizen" letter referenced ESP and 56 Beach Street. A form of ESP (Extra Sensory Perception) is second sight, whereby a person perceives information in the form of a vision about future events before they happen. Four days after the "good citizen" letter, the Zodiac Killer entered the taxicab of Paul Stine on October 11th 1969. After his murder at the intersection of Washington & Cherry Streets, the Zodiac Killer was believed to have entered Presidio Park just a few minutes later, mocking law enforcement in a letter he mailed two days later, in which he stated "The S.F. Police could have caught me last night if they had searched the park properly instead of holding road races with their motorcicles". The northeast corner of Presidio Park is 296 meters from Beach Street. This means we have a letter mentioning 56 Beach Street just four days before the Zodiac Killer escaped into Presidio Park, the northeast corner of which sits near the western tip of Beach Street. This street runs from Pier 39 to the Palace of Fine Arts,  A contributor to this website informed me that:"56 Beach St is the old block numbering from the original planning maps, which comes out as 1654/1656 on the street numbering. 1654/56 Beach St, San Francisco, CA is a condo home that contains 2,141 sq ft and was built in 1938".  

On April 20th 1970, the San Francisco Chronicle ran an article on the murder of Robert Michael Salem at 745 Stevenson Street in San Francisco. The pseudonym "Zodiac" was written in blood on his apartment wall next to the body. The San Francisco Chronicle noted that "Salem's designs have been exhibited in England, Japan and Russia under State Department cultural exchange programs. Until last year (1969) he had been the lighting designer for restoration of the historic Haslett Warehouse. The address of the Haslett Warehouse is 680 Beach Street at Hyde. This location is less than one mile from 1654/56 Beach Street (see map below). The author of these two "code" communications from "concerned" and "good" citizens may not have been Zodiac, but did they know the identity of the killer?

The Concerned Citizen card was mailed from San Francisco and postmarked August 10th 1969, arriving one day after the article A Murder Code is Broken which featured in the San Francisco Chronicle newspaper. In this article "Vallejo Police Sergeant John Lynch, in charge of the investigation of the murders and of the cipher letter writer, asked The Chronicle to send Harden's code breaking worksheets to him for further checking; which was done". The Concerned Citizen communication (with attached 408 cipher key) was not mailed by Donald Harden, having been sent from either a genuinely helpful citizen or from the Zodiac Killer himself. When deciding which is the case, we can look at the typed message on the card (shown below).

For somebody who pleasures in the solving of cryptograms and word puzzles, while at the same time making basic spelling mistakes and errors in punctuation, seems rather reminiscent of somebody we have become accustomed to. Three months after this correspondence, the Zodiac Killer mailed the infamous 340 cipher, a curious blend of both word puzzle and cryptogram. This cipher had "paradice" and "slaves" criss-crossed on its canvas, with a full message beneath the superficial design. The canvas and cipher both contained the encoded words of "paradice" and "slaves", thereby continuing the theme from the 408 cipher, but on this occasion he seemed eager to add a little more complexity to its design.

The decoding of the 340 cipher revealed that the majority of the message effectively ran diagonally (one down, two across) in a cipher divided up into three parts of 9, 9 and 2 rows. The last two rows were composed of a curious blend of forward and backward words, which is standard fare in the construction of word search puzzles, as is the creation of diagonal wording running across a word search grid. When we couple this with the disguised "paradice" and "slaves" running down and across the center of the 340 cipher canvas, this cryptogram becomes the embodiment of cipher and word puzzle all rolled into one.

If that wasn't enough, the Zodiac Killer would mail two more communications on December 10th 1969 and December 11th 1969 with coherent messages in the form of a pre-printed horoscope, overlayed with cryptic messages pasted predominantly 90 degrees clockwise, running down the page. These two communications were entitled Day-by-day forecast for Cancer and Day-by-day forecast for Leo. The second coming the day after the abduction of Leona LaRell Roberts (16) on December 10th 1969, leading to the possibility that this was a further play on words by the Zodiac Killer, who may have used the phrase "forecast for Leo" to insinuate the future plight of Leona Roberts. He may have had no hand in the abduction of Leona Roberts, but it wasn't unusual for the Zodiac Killer to insinuate his involvement in crimes committed by others. 

The two pasted communications in December (with Hidden and FLT a component of both) must have taken some forethought, so the idea that these two communications have no meaning whatsoever, doesn't quite sit right. These messages may need decoding just like the 340 cryptogram, albeit in a slightly different way. The choice of two horoscopes, when we consider the contemporary speculation behind the Zodiac Killer's choice of pseudonym, may have some significance. These two communications were straddled by both Fairfield letters, the first of which (December 7th 1969) contained sections of ciphertext that married up with the beginning and end of the 340 cipher. The months of July, November and December certainly seemed one big cryptic puzzle for the Zodiac Killer, but was it "one of his pleasures" in August. 

Without beating around the bush, we can now say with certainty that the 'Concerned Citizen' card, postmarked August 10th 1969, was not mailed by Donald Harden. The typist responsible for the 3" x 5" card had clearly read several of the recent newspaper articles before he fashioned this correspondence, including the August 4th 1969 edition of the Vallejo Times-Herald, the San Francisco Chronicle article on August 9th 1969 entitled 'A Murder Code is Broken' and the Vallejo Times-Herald on August 9th 1969, stating "Lynch talked to Harden and said, "I'm convinced he has it solved". He said he would talk to him again today. Meanwhile Lynch has Harden's worksheets and is studying and comparing them with the three-part cryptogram and the translation."  

The August 9th 1969 San Francisco Chronicle article stated "Vallejo Police Sergeant John Lynch, in charge of the investigation of the murders and of the cipher letter writer, asked The Chronicle to send Harden's code breaking worksheets to him for further checking; which was done." The author of the 'Concerned Citizen' card had used the same clumsy wording present in this article, when he addressed Sergeant John Lynch at the Vallejo Police Department. The 'Concerned Citizen' card stated "Dear Sergeant Lynch. I hope the enclosed "key" will prove to be beneficial to you in connection with the cipher letter writer.  Working puzzles criptograms and word puzzles is one of my pleasures. Please forgive the absence of my signature or name as I do not wish to have my name in the papers and it could be mentiond by a slip of the tongue. With best wishes. concerned citizen". 

The idea that the 'Concerned Citizen' would just happen to accidentally use this uncomfortable array of wording, such as "cipher letter writer", and didn't read the San Francisco Chronicle article one day before his August 10th 1969 card, would beggar belief. Additionally, why would Donald Harden mail the cipher key to Sergeant John Lynch, when the article clearly stated that Sergeant Lynch already had Harden's worksheets "and is studying and comparing them with the three-part cryptogram and the translation?"  We also have the 'Concerned Citizen' asking that his "signature or name" not appear in the newspapers. Why would Donald Harden request that his name not appear in the newspapers, when it had already been plastered all over them - and the "Concerned Citizen" card author had most certainly read them, on account of his word salad "cipher letter writer"?                           

The other reason we certainly know that the author of the 'Concerned Citizen' card was not Donald Harden, is because "he went to the University of Florida, Gainesville in 1956 for his master degree in education. During his time in University of Florida, Don gained experience by deciphering codes. Harden eventually graduated from the university. Harden began to teach at Howard High School in Orlando, Florida. Don eventually left Howard High School and went to teach at Aurora Central High School in Denver, Colorado in 1960. In 1960, Harden left Aurora Central High School and moved to Salinas, California. He began teaching history and economics at North Salinas High School in 1960". Fandom.com. 

So, would an educated school teacher, good at deciphering codes, be unable to spell the word "cryptogram"? The 'Concerned Citizen' was clever enough to mail in a cipher key to the Zodiac Killer's 408 cipher, but was incapable of spelling the word "cryptogram", failed to put an "e" in mentioned and failed to put a comma after the first "puzzles". And achieved all this in just 69 words. The author of the card was great with "word puzzles" but couldn't spell. This person was clearly pulling our leg - that much is apparent. One person that liked to play 'cat and mouse' games with the newspapers and police was the Zodiac Killer, who I have little doubt was the author of the 'Concerned Citizen' card on August 10th 1969. The cipher key worksheet he mailed to Sergeant Lynch contained mistakes, and was likely one of his draft copies. The Zodiac Killer certainly followed his stories in the newspapers, which is where he likely found his temporary pseudonym of the "concerned citizen" for one day only.   

Here is a newspaper cutting from the August 4th 1969 Vallejo Times-Herald, stating "Police received a few anxious telephone calls from concerned citizens Sunday, but no leads to the identity of the cipher writer who claims he killed two teenagers on Lake Herman Road and a young woman at Blue Rock Springs. The callers wanted to know if police had caught the man who confessed the slayings in letters to Gibson Publications and two San Francisco newspapers. His three cryptograms, sent with the letters and supposedly giving clues to his identity, still were in the hands of a Navy Cryptographer who at last report had not solved them".  

Was this newspaper article the origin of the "concerned citizen" offering his help to Sergeant John Lynch on August 10th 1969? If the Zodiac Killer created the 'Concerned Citizen' card, was he also concerned enough to have phoned the Vallejo Police Department on August 3rd 1969, asking the police if they had unearthed the identity of the triple murderer? I certainly wouldn't put it past him. 

It is clear, that whoever mailed the 'Concerned Citizen' card had read the August 9th 1969 San Francisco Chronicle article 'A Murder Code is Broken', by using the phrase cipher letter writer. They therefore knew the 'Murder Code was Broken', and the cipher key therefore unnecessary. But the Zodiac Killer didn't play by the rules.   

As explained in the previous article, there appears little doubt that the author of the "concerned citizen" card had read the August 9th 1969 San Francisco Chronicle article entitled 'A Murder Code is Broken'. The article clearly stated that Donald Harden's worksheets had been forwarded from the Chronicle to the Vallejo Police Department (which would obviously contain the cipher key and method of decryption). It stated "Vallejo Police Sergeant John Lynch, in charge of the investigation of the murders and of the cipher letter writer, asked The Chronicle to send Harden's code breaking worksheets to him for further checking; which was done." The wording "cipher letter writer" is an unusual combination of words, that apparently didn't go unnoticed by the "concerned citizen" author, who used the same sequence in his opening gambit: "I hope the enclosed "key" will prove to be beneficial to you in connection with the cipher letter writer." This should be proof enough that the "concerned citizen" had read the Chronicle article, knew the code had been broken, and knew Donald Harden's worksheets had already been sent to the Vallejo Police Department and Sergeant John Lynch. Therefore, do you have to question the integrity of the "concerned citizen" regarding the motivation behind his August 10th 1969 mailing?    

​The Vallejo Times-Herald also broke the story on August 9th 1969, stating "Lynch talked to Harden and said, "I'm convinced he has it solved". He said he would talk to him again today. Meanwhile Lynch has Harden's worksheets and is studying and comparing them with the three-part cryptogram and the translation." 

So, having presumably read all this, was the "concerned citizen" just a helpful member of the public attempting to corroborate the Harden's solution, or did the Zodiac Killer, knowing his cipher had been broken quickly, begin playing a game of 'cat and mouse'. The author of the "concerned citizen" card didn't want to give the Vallejo Police Department his name for fear it would be published in the newspapers, just like Zodiac stated in the 408 - but did the anonymous card reveal his identity? 

The "concerned citizen" card only contained 69 words, so why did the sender bother to type the message rather than write a handwritten message or simply capitalize the text. When he wrote the cipher key he capitalized the alphabetical letters to mirror the 408, so what purpose was behind him choosing not to do this in his message?

The sender would certainly not have given away his identity by using upper case lettering in the message (as he had already done it in the key), nevertheless, he chose to type it anyway. If the author was the Zodiac Killer, did he believe, that by using capitals in his message rather than handwriting it may have been construed as suspicious, so opted to use a typewriter for a more professional approach and give the card a level of credibility. Opting to write the message in his normal handwriting would obviously have given the game away. He also may have thought it easier to type the message rather than make the effort to disguise his handwriting. The cipher key was obviously written rather than typed because of the unusual characters present within the 408 cipher not being available on a standard typewriter. 

 This is all very speculative, however, with very little to indicate one way or another as to the identity of the "concerned citizen", feeding on scraps may be the only avenue. Was the sender of the August 10th correspondence simply being a helpful citizen wanting to corroborate the Harden's solution, or Zodiac attempting to regain a semblance of lost pride by surreptitiously offering a lending hand to the Vallejo Police Department, declaring "I do not wish to have my name in the papers".

This may have been the Zodiac Killer's idea of a joke after having previously stated "I want you to print this cipher on the front page of your paper. In this cipher is my idenity." This contradiction certainly wouldn't have been lost on a killer who craved attention at every turn. A killer who was prepared to confuse with "name" and "identity" in his first communications with the newspapers would not be averse to creating similar parallels with "signature" or "name" in the "concerned citizen" card, just ten days later. 

THE CONCERNED CITIZEN CARD [PT1]    THE CONCERNED CITIZEN CARD [PT3]

Having not covered this topic previously, I thought I would add the Concerned Citizen card to this site, mailed from San Francisco and postmarked August 10th 1969, one day after the article A Murder Code is Broken featured in the San Francisco Chronicle newspaper. In this article "Vallejo Police Sergeant John Lynch, in charge of the investigation of the murders and of the cipher letter writer, asked The Chronicle to send Harden's code breaking worksheets to him for further checking; which was done" (see foot of article for newspaper cutting).     

Many have asked the identity of the "concerned citizen."  Was it Donald Harden, the Zodiac Killer, or a third party who broke the code independently? The latter having not been aware of the code being broken as published in the newspaper. The San Francisco Chronicle according to the August 9th 1969 newspaper article had "already done" sending Sergeant John Lynch the worksheets, so why would Donald Harden be mailing the cipher key through the mail when clearly he was already in contact with police. Therefore, this option can be summarily dismissed as the least likely option. 

The Bay Area murderer, as of August 4th 1969, had already given us his pseudonym with the dramatic introduction of "This is the Zodiac Speaking", so why would he now be acting coy in giving us the cipher key under the guise of a "concerned citizen". This tactic may have surfaced during the 1974 communications, but to implement it so early, just after threatening to "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", seemed an immediate backpedal. From "ruthless killer" to "concerned citizen" in a matter of days. On the other hand, this may have been the start of his game with both the newspapers and law enforcement alike. 

The card reads:
Dear Sergeant Lynch.
   I hope the enclosed "key" will prove to be beneficial to you in connection with the cipher letter writer.
  Working puzzles criptograms and word puzzles is one of my pleasures. Please forgive the absence of my signature or name as I do not wish to have my name in the papers and it could be mentiond by a slip of the tongue.
      With best wishes.
                                     concerned citizen.

​Although it has been stated on many forums that the author of the "concerned citizen" card may have mailed it, unaware of the code being broken and published in the San Francisco Chronicle on August 9th 1969, this seems highly unlikely.

The author used the wording "cipher letter writer", exactly as published in the newspaper. This, from a grammatical standpoint, is highly likely to have been copied from the newspaper, thereby indicating that the person who mailed in the cipher key already knew it had been broken. This could indicate it was Zodiac after all.

Zodiac researcher and cryptographer, David Oranchak, has comprehensively covered all aspects of the Zodiac ciphers on his excellent ZodiacKillerCiphers website, including two offerings on the topic covered in this article. The first is a Detailed Analysis of the 408 Solution  and the second is entitled Who is the Concerned Citizen. The latter will show you the code key mailed by the "concerned citizen" for handwriting comparison purposes. 
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THE CONCERNED CITIZEN CARD [PT2]    THE CONCERNED CITIZEN CARD [PT3]

Vallejo Times-Herald - Cryptogram Deciphered by Teacher August 9th 1969