When the Zodiac Killer sat down to put the finishing touches to his October 27th 1970 Halloween card, what inspired him to draw an eye mask on the second skeleton and use the prominent word "BOO" on the card inner? Maybe the Zodiac Killer was influenced by something he recently read or watched on the television (or both). The day before the card was postmarked (October 26th 1970), the San Francisco Examiner featured the "Bay Area's Most Complete Television Logs".. At 8:00 pm on the NBC network waa the extremely popular Rowan and Martin's Laugh-In, an American sketch comedy television program that ran for 140 episodes from January 22, 1968, to March 12, 1973, hosted by comedians Dan Rowan and Dick Martin. The Halloween edition of the show was aptly titled "The Halloween "Boo-In" hour, featuring special guests Orson Welles, Vincent Price and Rod Serling. It can be seen on the Internet Movie Database here. The hosts began the show by covering their eyes with eye masks as they addressed the audience. The show was heavily advertised statewide, many of which contained extensive coverage of the guests, storylines and sketches.

This isn't the most compelling or interesting observation regarding the Zodiac Killer case, but the "Boo-In" Halloween edition of the show did appear in a newspaper familiar to the Zodiac Killer, in an area he most likely lived, the evening before the Halloween card was postmarked. 

The Zodiologists website took a deep dive into the three Cheri Jo Bates letters mailed on April 30th 1967 and wrote "It can be reasonably assumed that the signature has a particular meaning beyond of just being a letter. If we should pick just one of the available options, we would say that the signature is a combination of the letter Z and the number 3. If it would be only the letter Z, there would be no need to write its top in flying-bird shape. The line at the bottom of the letter is straight. We also could not find a symbol that would resemble the signature. Therefore, we consider Z-3 as most plausible". 

​In the Confession letter, mailed on November 29th 1966, the author stated that Cheri Jo Bates was "not the first and she will not be the last", suggesting that the typist was claiming more than one victim. This conforms to the notion of a signature with an attached victim count, also displayed by the Zodiac Killer alongside his crosshairs in the numerous letters and cards he mailed. However, there is one communication that may have used a similar signature to that used in two of the Bates letters.

The Halloween card, mailed by the Zodiac Killer on October 27th 1970, gave us a victim count of "14" on the skeleton's hand, and fashioned the number fourteen as "4-TEEN", using the number "4" to express the word "four". The Zodiac Killer may have used the same tactic with the symbol on the envelope and card inner, using 4 dots to indicate that the "F" stood for "fourteen" rather then "fifteen". If the symbol on the Halloween card inner and outer denoted a victim count for a third time, we have the possibility of a joined "Z" and "F" denoting the fourteen victims claimed by the killer - extremely similar to the joined "Z" and "3" suggested by the Zodiologists website. If this hypothesis is true, it could indicate a common thread from Riverside to the Bay Area through the correspondence of a killer. It must also be noted that the Halloween card was the only confirmed communication to use the letter "Z" to denote the "Zodiac" pseudonym - and it used the letter "Z" twice - just like the two Bates letters (if you believe the premise). The Zodiac Killer also used the word "BY" in prominent positions four times within the Halloween card, mirroring the "BY" which headed both Confession letters. The use of a Halloween card to convey these similarities is pertinent to the fact that the body of Cheri Jo Bates was discovered on Halloween morning  

The Zodiac's Little List letter (July 26th 1970), believed by some to be the previous communication to the Halloween card, began his little list by misspelling "victim" to "victom", and wrote. "Some I shall tie over ant hills and watch them scream + twich and sqwirm". The Confession letter author began his little list by using the misspelling "victom", before typing "She squirmed and shook as I chocked her, and her lips twiched. She let out a scream once". The author of the Confession letter had a smaller list, but included "the beautiful blond that babysits near the little store" and "the shapely blue eyed brunett that said no when I asked her for a date". The Zodiac Killer could have fashioned the Little List letter and Halloween card to make journalists and/or law enforcement draw the conclusion he was responsible for the murder of Cheri Jo Bates in Riverside on October 30th 1966. This ultimately became the case, when Paul Avery presented the link in the San Francisco Chronicle on November 16th 1970, much to the dismay of law enforcement. 

The information regarding the Confession letters was readily available to the Zodiac Killer, when the Inside Detective magazine published a comprehensive article about Cheri Jo Bates in January 1969. However, the signature on two of the Bates' letters had not been published in the newspapers or magazines prior to October 27th 1970, making the possibility of two "Z's" and a victim count, deployed in Riverside and the Bay Area, through three communications and one killer, a viable proposition. If Riverside really was the Zodiac Killer, had he reset his victim total when switching from "Z" to the "Zodiac" pseudonym, beginning anew some 450 miles north? 

If we want to discover the motivation and design of a Zodiac communication, we usually have to look no further than one or two newspaper articles precedent to the correspondence in question. Can the preceding newspaper article in the San Francisco Chronicle on October 12th 1970 tell us anything about the Halloween card mailed on October 27th 1970, including an answer to the strange symbolism depicted on the envelope address side and card inner.

The newspaper article was entitled "Gilbert and Sullivan Clue to Zodiac". Therefore, it shouldn't be any surprise that the Zodiac Killer chose a greeting card that opened with the wording "From your secret pal. I feel it in your bones, You ache to know my name, And so I'll clue you in". This was the only communication thus far that contained white text, which the Zodiac Killer adopted by adding 4-TEEN, BOO and the symbolism at the foot of the card, rather than using pasted newspaper clippings. The Zodiac Killer was very likely claiming 14 victims when he wrote this total on the skeleton's hand on the front of the card, followed by a head count of 4-TEEN above the second skeleton on the card inner, and concluding with the symbolism at foot of the card. 

The Zodiac Killer likely combined his victim count of 4-TEEN with the claimed murders of four teenagers by October 27th 1970. Having claimed the August 3rd 1969 San Jose murders of Kathie Reyne Snoozy (15) and Debra Gaye Furlong (14) in his Dripping Pen card by the addiition of "Aug" within a monthly chronological victim count, the Zodiac Killer was effectively telling us that he was incorporating 4 teenagers in his Halloween card victim count of fourteen - David Faraday, Betty Lou Jensen, Kathie Snoozy and Debra Furlong. The October 12th 1970 newspaper article stated "And he is now claiming 13 persons. Homicide detectives who've been hunting Zodiac for nearly two years frankly admit he is as much an enigma now as he was on Dec. 20, 1968, when he chalked up his first two victims. On Dec. 20, 1968, he gunned down teen-agers David Faraday and Betty Lou Jensen". The Halloween card entry of a hyphenated 4-TEEN, not only incorporated his first two victims within his total, but "chalked them up" in blackboard style writing. The Zodiac Killer had written "14" on the hand of the first skeleton, "4-TEEN" over the skull of the second skeleton, so it could be argued that the symbolism at the foot of the card containing what appeared to be a joined "F", was likely "fourteen" as well  The symbolism could represent "Zodiac Fourteen" or "Zodiac Victims Fourteen" (with the four dots representing the four teenagers, just as he had incorporated them by separating "4" and "TEEN" earlier). His victim totals all neatly chalked up within the Halloween card.

The vast majority of the newspaper article was dedicated to the two act comic opera, The Mikado, and the search for individuals who may have played Ko-Ko in recent years, Many Zodiac researchers have considered whether the Zodiac Killer was of British origin, had British parents, or was influenced by British theatrical plays, based upon the language he adopted in his communications. It is extremely likely that the Zodiac Killer chose to write PEEK-A-BOO around the knothole of a tree because he knew the alternative British term for this saying.

​"Peekaboo (also spelled peek-a-boo) is a form of play played with an infant. To play, one player hides their face, pops back into the view of the other, and says Peekaboo!, sometimes followed by I see you!  There are many variations: for example, where trees are involved, "Hiding behind that tree!" is sometimes added. Another variation involves saying "Where's the baby?" while the face is covered and "There's the baby!" when uncovering the face". Wikipedia. A British term for "peek-a-boo" is "peep-bo" - which just happens to be one of the characters from The Mikado.

​The Zodiac Killer chose the introduction on the Halloween card outer in response to the newspaper article entitled "Gilbert and Sullivan Clue to Zodiac", because it stated "And so I'll clue you in". He then responded to this introduction by inserting "peek-a-boo" around the knothole of a tree, with an eye peering from within. A saying which has the alternative of peep-bo - a character from the Gilbert and Sullivan opera. The teaser of "I'll clue you in" and the answer of "peep-bo" both inspired by The Mikado featured in the October 12th 1970 newspaper article. The Zodiac Killer would not give us the Ko-Ko investigators were desperately attempting to track down, only the protector or ward of Ko-Ko.

Although I believe the Cheri Jo Bates murder and accompanying communications have nothing to do with the Zodiac Killer, it would be foolish to unequivocally rule out of any of the commonly mentioned pre-canonical crimes suggested as possibly being the work of the Bay Area killer. So let us once again examine the Halloween card on October 27th 1970, that inspired Phil Sins to contact American journalist, Paul Avery, shortly after its arrival at the San Francisco Chronicle, and point out his thoughts on the relationship between the Halloween card and the murder of Cheri Jo Bates on October 30th 1966. Even though a link between the Zodiac murders and Riverside had been considered the previous year by investigators, this wasn't common knowledge on October 27th 1970. Phil Sins was also unaware that three letters had been mailed to the Riverside Press Enterprise, Riverside Police Department and Joseph Bates on April 30th 1967 by somebody claiming to be the killer of Cheri Jo Bates.

​In 2012, Mike Morford of Zodiac Killer Net interviewed Phil Sins, who stated that despite going to the Riverside Police Department with Paul Avery "where the letters & desktop were discussed or shown", he himself did not get to see them. Therefore, he had no knowledge regarding the contents of the Bates' letters when he drew his original conclusions between the Zodiac and Riverside cases. And neither, have we yet proved, did the Zodiac Killer. This is why the Halloween card and the Zodiac Killer's previous letter, the Little List letter mailed on July 26th 1970, are so curious. If not responsible for any of the Riverside activity, the Zodiac Killer could have been aware of the Cheri Jo Bates case and the Confession letter when he mailed both the Little List letter and Halloween card, because the Inside Detective magazine published on January, 1969 featured both. However, he wouldn't have been aware of the three Bates' letters (had he not been the author).  

Had the Zodiac Killer read the Inside Detective magazine and thought now is the time to plant the seed in investigators minds that he may have been responsible for the Riverside murder? The Confession letter mailed on November 29th 1966 read "She died hard. She squirmed and shook as I chocked her, and her lips twiched. She let out a scream once and I kicked her in the head to shut her up". The Little List letter on July 26th 1970 read "Some I shall tie over ant hills and watch them scream + twich and sqwirm". Did the Zodiac Killer deliberately group this sequence of words together (including the misspelling of twich) to encourage individuals to draw the comparison between both communications and force investigators to strongly consider his involvement in the Riverside murder (and authorship of the Confession letter)? Or were these word comparisons sheer coincidence? Before you draw any conclusions, it is important to consider the Halloween card, which followed three months later.

The whole premise of the Halloween card cover was seemingly chosen on the understanding that when the card was opened it would reveal his name. One notable feature of the card was the prominence of the word "By", followed by the four methods of death. The Zodiac Killer had written "By Fire, By Gun, By Rope and By Knife". The 1966 Confession letter also tempted us with a name, when the author began his typewritten letters with "The Confession", followed by the word "By" and several underscores. The word "By" playing a significant role in both communications. We also have the Halloween theme running through the 1970 card and the Riverside murder of Cheri Jo Bates, whose lifeless body was discovered on Halloween morning. But it's the addition of the "Z" symbol (meant to infer "Zodiac") placed at the foot of the Halloween card that conjures the most interest. The Zodiac Killer had mailed 15 confirmed communications prior to October 27th 1970 (probably in excess of 20), yet he had never once used the letter "Z" to sign off a communication. In fact, no communication subsequent to October 27th 1970, verified or otherwise, ever signed off with the letter "Z".​

​The only time the Zodiac Killer used the letter "Z" as a signature, was in conjunction with Halloween on October 27th 1970. This is what is so interesting about the potential "Z" like signatures accompanying the April 30th 1967 Bates' letters, concerning the murder and discovery of Cheri Jo Bates' body on Halloween morning. Of course, the signatures on the Bates' letters may not have been the letter "Z", and the "Z" signature on the Halloween card may just have been a fortunate coincidence, but these three letters would have been unknown to Phil Sins when he contacted Paul Avery about a Zodiac connection. So, I suppose the discovery of the Bates' letters was an added bonus to Paul Avery when he entered the Riverside Police Department in 1970, and ultimately made the "Z" connection between the cases. Was it extremely fortunate for the Zodiac Killer to tie together Halloween, the prominent wording of "by" and the perceived "Z" signature - in combination with the common phraseology between the Little List letter and Confession letter, just three months previously - or did the Zodiac Killer deliberately place these markers on the Halloween card to plant a seed in the mind of investigators - or was he involved in the murder and/or letter writing in Riverside four years earlier?

The Zodiac Killer may have done exactly the same thing on November 8th 1969 when he claimed seven victims within the Dripping Pen card, forcing investigators to draw the conclusion he was responsible for the murder of Kathie Snoozy and Debra Furlong in San Jose on August 3rd 1969 by the addition of "Aug" in his chronological list of months. As he did on March 22nd 1971, mailing us another cryptic card, this time encouraging investigators to connect him to the Donna Lass disappearance on September 6th 1970 by the addition of "Lake Tahoe areas" and "Sought Victim 12". Once Paul Avery had connected the Riverside and Zodiac murders together, the Zodiac Killer then cemented that notion by giving "credit for stumbling across his Riverside activity". However, not once did he ever categorically claim or prove these murders were his. He only let investigators draw such a conclusion.  

The Zodiac Killer had a long memory when constructing a communication, often citing newspaper headlines and the content within them from many months and years earlier. On Saturday, November 1st 1969 the Vallejo Times-Herald ran an article entitled You Couldn't Tell It Was Halloween, expressing surprise that the Zodiac Killer had not written or made an appearance during the Halloween festivities, writing "He made no threats - in fact, he did not even communicate to police departments in the Bay Area about any plans he may be developing for Halloween. Nevertheless, parents and youngsters alike were on the extremely cautious side". Vallejo Police Chief Jack E. Stiltz warned it could be a very dangerous time for youngsters to be on the streets.

Whether the October 28th 1987 Zodiac letter was just a product of fortuitous language, or whether the Zodiac Killer religiously kept a scrapbook of newspaper articles about himself, is unknown. But this letter stated "Tell the blue pigs if want me I will be out driving around on Halloween in my death machine looking for some kiddies to run over. Cars make nice weapons. The pigs can catch me if They can find me out there. Just like in the movie The car. Tell the kiddies watch before They cross the street on halloween nite". Regardless of this distant future communication, the following Halloween after the November 1st 1969 article was published, the Zodiac Killer mailed the October 27th 1970 Halloween card to Paul Avery, referring to teenagers through the use of the word "TEEN". He also failed to use his pseudonym, and supplied us for the first time with the character "Z" (twice) as his identity, by way of a greeting card suggesting he was going to clue us in on his name, beginning "I feel it in my bones, you ache to know my name, and so I'll clue you in." The answer once the card was opened was "BOO", emblazoned in prominence. The strange symbolism in the card, in accompaniment to the letter "Z", was not only placed within the card, but positioned on the return address side of the envelope. Was this used to indicate his identity, as it may have been on the 408th plaintext character of the July 31st 1969 cryptogram.    

Two weeks prior to the November 1st 1969 newspaper article, on October 15th 1969, another article ran in the Los Angeles Times entitled Identity In Code? Zodiac Killer-Chilling Portrait Of Madness. The whole premise of the article was analyzing and ruminating on the identity of the Zodiac Killer, stating  "He could be old Mrs. So-and-So's boy, who never says boo and still lives at home. Or that batchelor that keeps to himself and never seems to have any fun". As a response to his name, one year later he would say "BOO" in the Halloween card. The article went on to examine the July 31st 1969 letters and cryptograms, along with the unsolved 18 characters at the foot of the 408 cipher, pondering whether "his name, or some other vital clue was written in the cryptogram". Did he finally give us the vital clue to the identity in the 408 cipher, when he used the character "Z" in the Halloween card for the very first time? See The Missing Line in the 408 Cipher. 

​It could be argued that the Zodiac Killer deliberately introduced himself as the "murderer" and "killer" in his July 31st 1969 letters to withhold his identity for the 408 character cryptogram. Possibly the identity of "Z", to which he would expand upon a few days later, when he introduced his now infamous "This is the Zodiac speaking" phrase. Maybe there were only 17 redundant ciphertext characters at the foot of the 408 cipher? 

Some people have considered that the Zodiac Killer may have worked at the San Francisco Chronicle newspaper offices, with inside information pertaining to the investigation days or weeks before its release to the general public. The Zodiac Killer could have (and probably did) mail in excess of twenty communications before October 27th 1970, but not one single communication expressed the Zodiac pseudonym in the form of the letter "Z". This would change on October 27th 1970, when for the first time the Zodiac Killer used the letter "Z" within his Halloween card mailed to Paul Avery. This departure from the norm came just fifteen days before a San Francisco Chronicle article published by Paul Avery on November 12th 1970, which wrote that "the printing on the 'Bates Had to Die' envelopes seemed to match exactly the desk top poem writing. And perhaps the most meaningful discovery was that two of the three notes had been signed with a "Z".

​The Halloween card was mailed by the Zodiac Killer on October 27th 1970, it was addressed to Paul Avery, it referenced Halloween and it contained the letter "Z". Fifteen days later, Paul Avery is reporting on Cheri Jo Bates being found murdered on Halloween morning, with the Bates' letters signed with a letter "Z". Paul Avery's article was likely triggered by somebody (Phil Sins) noticing similarities between the Halloween card and the murder of Cheri Jo Bates, but what were the chances of somebody recognizing something in the Halloween card in respect to the murder of Cheri Jo Bates, pursuing this angle, and subsequently finding a "Z" like signature that mirrored the Halloween card? (used for the first time by Zodiac). What are the chances of Zodiac marrying Halloween and the pseudonym "Z" together, which mirrored the discovery of a murder victim on Halloween morning, which later had accompanying letters signed with a "Z" style signature? The Halloween card coming just three months after the Zodiac Killer mirrored the Cheri Jo Bates Confession letter of "She squirmed and shook as I choaked her, and her lips twiched. She let out a scream once": when he wrote in the Little List letter on July 26th 1970 "Some I shall tie over ant hills and watch them scream + twich and sqwirm".

In a time span of just three months, the Zodiac Killer had combined scream, twich, squirm, Halloween and a "Z" signature, possibly merging crucial details from the Confession and Bates letters together. Four of these details were already available in the January 1969 edition of the Inside Detective magazine, but the "Z" signature was not. If the signature on two of the Bates' letters was really meant to be the letter "Z", then the fact that the Zodiac Killer broke with tradition and used the pseudonym "Z" within a Halloween card for the first time, could be argued as carrying some significance. 

The Zodiac Killer mailed the Little List letter on July 26th 1970 setting out his search for "society offenders", but this lengthy communication was withheld from publication in the newspapers until October 12th 1970. Despite a comprehensive article in the San Francisco Chronicle on September 26th 1970 featuring the disappearance of Donna Lass from Lake Tahoe on September 6th 1970, the Zodiac Killer never raised his victim total of 13 from July 26th 1970 to October 5th 1970, when the 13-Hole postcard arrived. He never previously needed any prompting to falsely inflate his victim total in previous communications, yet a month after the abduction and likely murder of Donna Lass from the Sahara Tahoe Hotel & Casino, the Zodiac Killer kept his victim total static, suggesting at this juncture he was not claiming the young nurse as victim 14. That is, because he never murdered her. Besides, he would later retrospectively claim he had sought her as victim 12 in the March 22nd 1971 Pines card, while she was still present in San Francisco and working at the Letterman General Hospital by the Presidio.

Donna Lass would have been working as a nurse in the Presidio park in the relevant time period for her to be sought as victim 12. Bearing in mind that the Zodiac Killer was last seen entering the Presidio park after the murder of Paul Stine on October 11th 1969, he knew that by retrospectively claiming he had targetted Donna Lass in San Francisco before her eventual disappearance, it would carry more weight to his suggested involvement in her demise through the Pines card.

It is unlikely that the punched hole in the top right corner of the Pines card can be used to find the burial location of Donna Lass, because the Zodiac Killer has provided no evidence he had any involvement in her murder. The vague and cryptic phrases pasted on the Pines card could just have been designed to identify the name of Donna. When the "Sierra Club" on the postcard is aligned over the Sierra Club of Clair Tappaan Lodge, the punched hole can be aligned over the "Donner" of the Donner Memorial State Park. This notion carries a little more weight when we consider a similar pasted card, dubbed the Monticello card, that arrived at the San Francisco Chronicle on July 13th 1971, again hinting at the identity of a murdered woman, that of Kathy Bilek. This time, the author pasted "Woods", "April" and "near Monticello" as a clue to her name. However, on this occasion, the sender would actually direct us to a burial site.

Buried in the Oak Hill Memorial Park & Cemetery in the Monticello neighborhood of San Jose was the resting place of Kathie Snoozy, claimed as a victim by the Zodiac Killer in the Dripping Pen card on November 8th 1969. She was the namesake of Kathy Bilek, who along with Debra Furlong, were all victims of the real murderer, Karl Francis Werner. The Monticello card followed the exact pattern of the Pines card, in which the Zodiac Killer retrospectively claimed the April 11th 1971 murder of Kathy Bilek in the Villa Montalvo woods of Saratoga, by pasting "shought victim 21" on the card. He never murdered Kathy Bilek and he very likely never murdered Donna Lass. When Karl Francis Werner was credited with two of Zodiac's previously claimed victims, that of Snoozy and Furlong, he doubled down and more, by adding Kathy Bilek retrospectively in a vain attempt to discredit the notion of Werner being responsible for all three. This belated tactic was used to claim Donna Lass as a victim also, with the Zodiac Killer selecting a time period between the 10 victims on April 20th 1970 and 12 victims on June 26th 1970, while Donna Lass was still working at the Letterman General Hospital for a large chunk of this time. He knew this would add credence to his claim of involvement in her disappearance and likely murder, particularly when he noticed the proximity of her profession to the Washington and Cherry intersection in Presidio Heights.

In fact, the Halloween card, Pines card and Monticello card may have all been retrospective communications, with the Halloween card incorporating the murders of Kathie Snoozy and Debra Furlong into its design by the addition of two skeletons and the 4-TEEN on the card inner. The Zodiac Killer was only claiming four teenagers as murder victims by October 27th 1970, that of David Faraday, Betty Lou Jensen, Debra Furlong and Kathie Snoozy. We know that the Zodiac Killer wasn't responsible for the three victims eventually attributed to Karl Francis Werner, despite him valiantly trying to retrospectively claim all three on numerous occasions. Therefore, we should place little credence to his suggestion of involvement in the untimely disappearance of Donna Lass through the Pines card, especially when he had every chance to elevate his victim total on October 5th 1970. This should give you pause for thought when the Zodiac Killer retrospectively inferred his involvement in Riverside on March 13th 1971, four and a half years after the fact.

On August 3rd 1969, cyclists made the grim discovery of the bodies of Kathy Snoozy and Deborah Furlong from San Jose, each stabbed in excess of a hundred times and found beneath an oak tree in Almaden Valley. The Chief of Detectives, Barton Collins spearheaded an investigation that eventually saw the arrest of Karl Francis Werner in the April of 1971.

The Zodiac Killer on August 6th 1969, after viewing the extensive front page coverage of this crime that he believed he deserved, very likely switched to a knife for his brutal attack on Bryan Hartnell and Cecelia Shepard at Lake Berryessa on September 27th 1969. The Zodiac Killer would indirectly refer to Kathy Snoozy and Deborah Furlong through multiple communications spanning two years, most notably the "by knife" attribution on Bryan Hartnell's car door and the Dripping Pen card, when he inflated his victim total to seven by adding the month of "Aug". He may also have done this in the December 16th 1969 Fairfield letter when he drew the Bleeding Knife of Zodiac with seven drops of blood falling from the blade. He wasn't responsible for the murders of Kathy Snoozy and Deborah Furlong on August 3rd 1969, but he wanted us to believe he was. 

This leads us to the Halloween card on October 27th 1970, approximately one year after the Dripping Pen card. The greeting card contained an eye peeking from the knothole of a tree with the circled wording of "peek-a-boo you are doomed". It is this childlike terminology of "peek-a-boo" used by parents when playing with their children, that could reveal an alternative meaning to the Halloween card. There are many variations of "peek-a-boo", such as where trees are involved: "Hiding behind that tree" is sometimes added. Wikipedia. Kathy Snoozy (15) and Deborah Furlong (14) were extremely young victims, with Kathy Snoozy described by investigators as much younger looking than 15 years. The Halloween card depicting a tree with somebody hiding behind it, in accompaniment to the two skeletons adorning the card (one purposefully added}, seemed to mirror the attack on the two young girls by an oak tree. The Halloween card deliberately designed to signify two victims, explaining why the Zodiac Killer went to the extra effort of adding a second skeleton to the card inner, and featuring "by knife" on the rear of the card, just like he did on the car door of Bryan Hartnell at Lake Berryessa.  

The San Francisco Chronicle on August 6th 1969 stated "Dr. Hauser, so shaken by the brutality of the crime he could scarcely find words, said the Snoozy youngster had 150 wounds on her back, 50 on the front and a "storm" of punctures on her neck. Deborah's body had about 100 wounds on her back and upper front and a dozen on her neck. Dr. Hauser said he was "puzzled" by many aspects of the brutal slaying. He said neither girl had been sexually molested; neither had suffered any wounds below her waist, neither gave evidence of having struggled to escape. Only the Snoozy girl, he said, had one small mark on her hand, suggesting she may have tried vainly to deflect the plunging knife". The Zodiac Killer placed a pumpkin over the groin/waist region of the first skeleton, giving rise to the notion that this communication had a malevolent undertone attached to it. But these observations are backed up by the Zodiac Killer's running victim total presented in three forms. He wrote 14 on the first skeleton's hand, he wrote 4-TEEN over the skull of the second skeleton, and may have written "Zodiac Fourteen" at the base of the card inner by combining two features, adding 4 dots to signify "four" once again.

The Zodiac got creative by listing seven victims with the addition of "Aug" on November 8th 1969 and adding seven drops of blood on December 16th 1969 on the Bleeding Knife of Zodiac drawing, so did he get creative in the Halloween card? The Zodiac Killer didn't write 4-TEEN as his victim total for no reason, therefore we have to examine why he did it. The number 4 is self evident, meaning 4 victims. The word TEEN is short for teenager or teenagers. This indicates that the Zodiac Killer has incorporated 4 teenagers into his victim total of fourteen. At this juncture, he was claiming the murders of Betty Lou Jensen (16), David Faraday (17), Darlene Ferrin (22), Cecelia Shepard (22), Kathy Snoozy (15), Deborah Furlong (14), Paul Stine (29), Richard Radetich (25) and Donna Lass (25). That is nine claimed victims of the fourteen he had placed on the Halloween card, but only four were teenagers, hence the wording of 4-TEEN. The two skeletons may sadly have represented Snoozy and Furlong, adding the two teenagers from San Jose to the existing two teenagers from Lake Herman Road in Benicia, that we already knew for certain. 

Halloween is a time when the children venture out into the night, dressed in costumes to play trick or treat in the neighborhood. The Zodiac Killer, on the other hand, may have played the sickest game of all, when he mailed the Halloween card on October 27th 1970, claiming yet again his involvement in two murders he had no hand in.

The following is probably better answered by Dave Oranchak, who recently, alongside Sam Blake and Jarl Van Eycke cracked the Zodiac 340 cipher from November 8th 1969. The correlation between the Halloween card and 340 cipher has long been considered, but is it a comparison that deserves any further attention in light of the encryption techniques used by the Zodiac Killer when designing his 340 cipher? Is the comparison between the two communications justified?

On October 27th 1970, the Zodiac Killer mailed the Halloween card with a configuration of "paradice" and "slaves" in cruciform. In each quadrant of this design we had four methods of death (knife, gun, fire and rope), preceded by the word "By". The "paradice" and "slaves" element can be shown to exist on the canvas of the 340 cipher, bisecting it both horizontally and veritically in a 17 by 17 formation, imitating the cruciform design within the Halloween card. The four "By" words are present in each quadrant of the 340 cipher. The writing on the envelope stamp of "In the beginning God" falls nicely into the beginning line of the 340 cipher, with the word "God" landing squarely over the ciphertext supplied by the Zodiac Killer. The LAV of Paul Averly on the envelope also appears to be underlined. And finally, we have the Zodiac pseudonym visibly present on the final line of the 340 cipher, albeit slightly altered. Almost as though he was signing the canvas of his masterpiece.

Did the Zodiac Killer provide two puzzles on November 8th 1969? A superficial design on the canvas of the 340 cipher akin to a design on the cover of a book, with a hidden message that lay beneath the imagery in the form of a cryptogram.  

If the Zodiac Killer designed his 340 cipher key randomly by just allotting ciphertext characters to plaintext characters, what are the chances that all these above observations would fall out by chance and be highlighted a year later in the Halloween card design? However, if the Zodiac Killer began the 340 encipherment of the canvas first, with "paradice" and "slaves", "by", "God" and the near signature of Zodiac, he would be able to manipulate a superficial design onto the face of the 340 cipher before continuing to encode the rest of the message underneath. The "sorry no cipher" phrase written on the flap of the Halloween card envelope in cruciform, I wrongly concluded was a hint that the 340 cipher was not a genuine cryptogram. But was the "sorry no cipher" on the cover of the Halloween card somehow related to the cover of the 340 cipher?

The desire to unearth hidden meanings in the Zodiac communications is an insatiable one, that often leads to conclusions with no foundation or basis in reality (and the above interpretations may be one such example). Dave Oranchak would be able to shed much more light on the above comparisons made between the Halloween card and 340 cipher from a statistical standpoint, expanding upon the premise of a Zodiac Killer creating two puzzles for the price of one, or destroying the notion once and for all. It would answer the question of whether the Zodiac Killer created a superficial design and signed the canvas of his masterpiece cipher, or whether it is just a picture created in nothing more than the mind.

On October 22nd 1969 in the San Francisco Examiner, Dr. D.C.B. Marsh challenged the Zodiac Killer under the banner of Cipher Expert Dares Zodiac to Tell Name, to reveal something about his identity no matter how complicated. I doubt anybody with a modicum of intelligence seriously contemplated that the Zodiac Killer would supply us with his full name, however, the tactic of encouraging the Bay Area murderer to write more communications and possibly create a second cipher, had the potential to reveal more clues about the killer, while serving the secondary purpose of keeping him writing rather than killing.

On October 25th 1969, law enforcement and the newspapers headlined with Cops No Closer on Zodiac Identity, probably attempting to guide the Zodiac Killer into producing his second cipher, writing in conciliatory tone "Homicide detectives in San Francisco, Vallejo and Napa said they are no closer to catching the cryptic killer than they were ten months ago - unless some clue to his identity is among the hundreds of leads still in the process of being checked out".

The next paragraph may have been the inspiration for the next Zodiac communication on November 8th 1969. The Chronicle article continued "Zodiac struck last on October 11 when he gunned down cab-driver Paul Stine on Washington Street in Presidio Heights. He revealed himself the killer in a letter sent to the Chronicle three days later. Since then he has remained silent". In the Dripping Pen card the Zodiac apologized by way of chosen image and wording, stating "Sorry I haven't written, but I just washed my pen". It was hypothesized that the second cipher was inspired by the language adopted in the newspapers, and the Dripping Pen card was specifically chosen in response to "Since then he has remained silent". If so, then there is a real possibility that the 340 cipher was created subsequent to October 25th 1969. 

On October 26th 1969 in the San Francisco Sunday Examiner and Chronicle they dedicated an entire section entitled Hymn to Murder, reminding the reader about the Zodiac Killer's 408 cipher, in part stating "Finally, a school teacher in Salinas broke the code by looking for the words "kill" and "killing". When deciphered, the messages proved to be a hymn to murder by an obviously disturbed person. There was, unfortunately, no clue to his identity in the cyphers".  Again, another newspaper article mentioning identity and ciphers, but this time describing them as a Hymn to Murder. Was it remotely possible that the Zodiac Killer responded to these strategic newspaper messages, bringing about the arrival of his second Hymn to Murder?

The next San Francisco Chronicle newspaper article on November 8th 1969 described the attempted poisoning of Daniel Williams, a Salesian High School teacher, on November 2nd 1969, that culminated a series of menacing phone calls by somebody claiming to be the Zodiac Killer, which began on October 23rd 1969. The language adopted in the Dripping Pen card and Bus Bomb letter strongly suggested that the Zodiac Killer may have been referring to his ongoing pursuit of Daniel Williams. In fact, the Dripping Pen card and accompanying cipher appeared a response to all of the newspaper articles beginning on October 22nd 1969 (including the attack on Daniel Williams), with the card being carefully chosen in response to Paul Avery, who stated that Zodiac had remained silent since his October 13th 1969 letter.

It is certainly possible that the 340 cipher could have been designed to relay a relatively simple superficial message, while still harboring an underlying cryptic message. A picture with a cryptographic solution under the canvas, if you will.

If the Zodiac Killer just allotted ciphertext characters to plaintext characters randomly, then how likely would it be to find the possibility of "paradice" and "slaves" bisecting the mid-section of the cipher both horizontally and vertically (17 by 17), as depicted in the Halloween card on October 27th 1970? How likely would it be for the alphabetical letters B and Y forming "BY" to fall together in each quadrant of the cipher, mimicking the Halloween card? How likely would it be for the cipher to begin with HER, forming the last three alphabetical letters of "cipher"? How likely is it that the near "Zodiac" on the final line would drop out through a randomly designed cipher? Then we have the "sorry no cipher" on the envelope inner of the Halloween card mimicking the formation of "paradice" and "slaves" in both communications.

And finally, we have the Genesis of the Hymn to Murder, found on the envelope of the Halloween card and possibly the 340 cipher. The stamp, commemorating the Apollo 8 launch on December 21st 1968, contains the words "In the beginning God", spoken by Bill Anders from the text of Genesis. This slots nicely onto the first line of the 340 cipher with the ciphertext of "GOD" positioned in acceptance at the very end. Even the half-darkened "O" looks eerily similar to the picture of the earth from the moon on the Halloween card stamp. Did "In the beginning God" introduce the Zodiac Killer's second Hymn to Murder?

On October 12th 1970, Paul Avery of the San Francisco Chronicle wrote an article concerning the Zodiac Killer's latest two communications, notably the July 26th 1970 "Mikado" letter and the October 5th 1970 "13 Hole" postcard. The Zodiac Killer may have used much of this newspaper article to choose and fashion the October 27th 1970 Halloween card, including a continuance of The Mikado theme. The Zodiac Killer wasn't averse to plagiarising reading material for his communications, with the Halloween card fashioned not only from the Tim Holt comic book, but possibly crafted using the Paul Avery article as his inspiration.

The October 12th 1970 newspaper article was entitled Gilbert and Sullivan Clue to Zodiac, thereby giving the Bay Area murderer about two weeks to find the appropriate reply in the form of a Halloween card beginning "I feel it in my bones you ache to know my name. And so I'll clue you in". The newspaper article detailed "Sheriff's detective sergeant Kenneth Narlow who had fruitlessly followed up another 900 tips as to Zodiac's identity since Sept 27, 1969". So finding a Halloween card teasing us again with his name and offering to clue us in, appeared like the ideal card in response.

In the first column of the article, Paul Avery wrote "Homicide detectives who've been hunting Zodiac for nearly two years frankly admit he is much an enigma now as he was on Dec. 20, 1968, when he chalked up his first two victims". Those two victims were teenagers David Faraday and Betty Lou Jensen. The Zodiac Killer decided to chalk his victims on the Halloween card in white marker pen above the head of the inner skeleton and beneath its feet, in the form of 4-TEEN and what could be Zodiac Victims Fourteen or Zodiac Fourteen.

The author of the card could have written 14 (similar to the outer skeleton hand) or fourteen, but intentionally separated it to 4-TEEN. David Faraday and Betty Lou Jensen were two of Zodiac's confirmed victims, but he had also claimed Deborah Furlong and Kathy Snoozy by the addition of "Aug" in the Dripping Pen card on November 8th 1969, who were both teenagers. The Zodiac Killer had claimed 4-TEENS as victims, hence why he altered fourteen to 4-TEEN, to incorporate them into his running victim total. The addition of four dots (little marks) around ZVF or ZF possibly created for a similar reason. It can be noted that Paul Avery also referred to David Faraday and Betty Lou Jensen in the article as teenagers, but he hyphenated the word into teen-agers, just like Zodiac did with his running teenager total of 4-TEEN.

The majority of the newspaper article focused on the July 26th 1970 "Mikado" letter and the search for potential Ko-Ko's, The Lord High Executioner featured prominantly in the July 26th 1970 (Little List) letter. The Mikado Act One Part 5a  As some day it may happen was performed by Ko-Ko of the town of Titipu. This led investigators to consider the possibility of a Zodiac Killer who played Ko-Ko in his student days. But where was The Mikado and Ko-Ko in the Halloween card? Perhaps the investigators could have searched the knothole in the tree.

The original card came with one eye peeking from the knothole in the tree, in which the Zodiac Killer circled the words "Peek-a-Boo you are doomed". But notice how "Peek-a-Boo" and "you are doomed" are deliberately separated.

The Mikado is a two-part comic opera by Gilbert and Sullivan, which opened to the paying public on March 14th 1885 and was hugely successful, running for 672 performances at the Savoy Theatre in London. However, this wasn't the only version of the opera from that time period, In 1888, Ed J. Smith wrote a stage parody of The Mikado called The Capitalist; or, The City of Fort Worth to encourage capital investment in Fort Worth, Texas. In this version, Peek-A-Boo is listed as one of the three sisters and wards of Kokonut (The Lord High Executionist).

The Mikado original featured Peep-Bo: A ward of Ko-Ko and sister of Yum-Yum and Pitti-Sing. Peep-Bo is the British version of Peek-a-Boo. Peekaboo (also spelled peek-a-boo) is a form of play primarily played with an infant. To play, one player hides their face, pops back into the view of the other, and says Peekaboo!, sometimes followed by I see you! There are many variations: for example, where trees are involved, "Hiding behind that tree!" is sometimes added.

Peep-Bo can also be reversed to Bo-Peep, believed to originate from the 16th century practice of concealment, before reappearing to startle or surprise. See here. Little Bo Peep is a popular English nursery rhyme The earliest record of this rhyme is in a manuscript of around 1805, which contains only the first verse. There are references to a children's game called "Bo-Peep", from the 16th century, including one in Shakespeare's King Lear (Act I Scene iv), but little evidence that the rhyme existed. The additional verses are first recorded in the earliest printed version in a version of Gammer Gurton's Garland or The Nursery Parnassus in 1810.

The phrase "to play bo peep" was in use from the 14th century to refer to the punishment of being stood in a pillory. For example, in 1364, an ale-wife, Alice Causton, was convicted of giving short measure, for which crime she had to "play bo pepe thorowe a pillery". Andrew Boorde uses the same phrase in 1542, "And evyll bakers, the which doth nat make good breade of whete, but wyl myngle other corne with whete, or do nat order and seson hit, gyving good wegght, I would they myghte play bo pepe throwe a pyllery". Taken from Wikipedia. The skeleton on the card inner also appeared to be hanging in the form of punishment, as if placed in a pillory. I suppose the "punishment must fit the crime".

Bearing in mind the newspaper article of Paul Avery, was the Halloween card drawing on the search for Ko-Ko's by its design of inserting Peek-a-Boo around the knothole of the trunk, with the eye "hiding behind that tree"? Was the chalked-up victim count of 4-TEEN above the pilloried skeleton denoting the running total of fourteen, including four teen-agers? The newspaper article of Gilbert and Sullivan Clue to Zodiac may have spawned the choice of Halloween card with the introduction of "I feel it in my bones you ache to know my name. And so I'll clue you in". But did it inspire anything else?

Professor D.C.B. Marsh told the San Francisco Examiner on October 22nd 1969: "The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in the cipher to established cryptogram experts. He knows, to quote Edgar 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". According to Edgar Allen Poe, any cipher created by man can be solved by man. Which is why Zodiac created the apologetic "sorry no cipher".

The video has a minor error - the "rope" in the bottom right quadrant should look like the image on the left. Click to enlarge.

The following will be extremely speculatory and should not to be taken too seriously, but I wanted to examine the prompt by Professor D.C.B. Marsh who told the Examiner on October 22nd 1969: "The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in the cipher to established cryptogram experts. He knows, to quote Edgar 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".

When recently promoting the notion of a killer providing us with all the solutions to his ciphers in Three Months After the Mount Diablo Code, it was considered that the Zodiac Killer did respond to Dr. Marsh, but he certainly wasn't going to be as forthcoming as to provide us with his full name as Dr. Marsh had honestly requested. Hence the idea that he did give us his name, albeit in the abridged version of his initials which he supplied to us in the October 5th 1970 '13 Hole' Postcard. When this was slotted into the April 20th 1970 '13 Symbol' Cipher it read like so: "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is Fk, I'm crackproof". The Zodiac Killer had in effect answered the request of Dr. Marsh, although in a rather devious manner. However, Dr. Marsh issued this challenge on October 22nd 1969 and the 340 Cipher came before the 13 Symbol Cipher.     

One of the most prominent features in the 340 Cipher is the sixth line where he corrects a forward facing K to a backwards facing K, similar in nature to the way he reversed the "Fk, I'm crackproof" phrase on the 13 Hole Postcard. The proximity of F and K can be noted in these two outstanding features - and possibly the Zodiac thought it mildly amusing to provide his name to Dr. Marsh in the extremely "complicated" manner of reversing his name or initials. Everybody was searching for a stunningly complicated solution to the 340 character cipher as Dr. Marsh had requested, so the Zodiac Killer gave us the complete opposite.

The connection between the 13 Hole Postcard and 13 Symbol Cipher was not only bound in the "Fk, I'm crackproof" solution, but the two phrases he used in each communication didn't go unnoticed either. The Zodiac Killer inextricably tied the two correspondences together using similar phraseology, such as "What is the price tag now" and "how much money you have on my head now". On January 29th 1970, the Yellow Cab Company put up a thousand dollar reward for any information leading to the arrest of the Zodiac Killer. In addition, the Teamsters Union which represents the Yellow Cab Company were reported in the San Francisco Chronicle to be considering offering a further reward on February 8th 1970 in the case of Paul Stine and Charles Jarman (another taxicab murder victim). This news was likely what prompted the Zodiac Killer to open this communication with the words "I am mildly cerous as to how much money you have on my head now".  Or could there be another more subtle clue in these phrases with regard to his name?

Where on the April 20th 1970 letter and throughout much of his communications to date (including the 340 Cipher) could money or a price tag be found on a head? The 13 Symbol Cipher letter carried a dated 1966 Franklin D. Roosevelt stamp, where indeed "money" or a "price tag" could be found 'on' the head of Franklin D. Roosevelt. Was this a subtle hint to his first name of "Franklin" or "Frank". This would satisfy the F part of "Fk, I'm crackproof" - but as stated earlier,  very speculative to say the least.

Another communication where he promised us his name was the October 27th 1970 'Halloween' Card, in which he gave us an odd-looking symbol and placed it on the left side of the envelope and the Halloween Card inner, followed by the letter Z. The correct way to address an envelope is to write the sender's name and address in the top left corner of the envelope, shown here on a Youtube video, and the recipient address (in this case Paul Avery) in the center of the envelope. Therefore, this strange symbol could equate to the sender's name. Since we are looking for the initials of the Zodiac Killer (which may be reversed for a third time), it is extremely promising that we have an F looking character on the right side yet again. I don't like too much manipulation and the use of mathematics anymore, but on this occasion I will choose the path of least resistance and take the 7 and 4 dots to equal 11 (K being the 11th letter of the alphabet) - and therefore give us a joined K and F for his name on the return section of the envelope. Unfortunately, manipulation such as this always leads to the possibility of multiple solutions, so we have to be guarded to any conclusions we make. Finally, I would like to take a look at the sister card to the Halloween Card mailed in the December of 1990. It too promised us his name.       

The greeting card was again from our Secret Pal just like the Halloween Card twenty years earlier - it began with the message "FROM YOUR SECRET PAL CAN'T GUESS WHO I AM YET? WELL, LOOK INSIDE AND YOU'LL FIND OUT". Then promised to keep us guessing on the card inner.

All the Zodiac Killer added to the card inner was a Xerox copy of some "keys". It really couldn't be any simpler. The card outer stated "From your secret pal, can't guess who I am yet? Well, look inside and you'll find out" followed by "keys". This may very well be the final really complicated answer to the challenge laid down by Dr. Marsh all those years earlier. The surname of Keys, Keyes or Keays would satisfy the K of FK, from the phrase "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 mocking response to Professor D.C.B. Marsh, who requested that the Zodiac Killer "send The American Cryptogram Association a cipher code - however complicated - which will truly and honestly include his name" was probably befitting of the Zodiac Killer. The answer may have been simpler than we could ever of imagined. Return to sender: Franklin Keys (or alternate options above).

Of course, I am not claiming this to be the answer regarding the identity of the Zodiac Killer, but it would be rather appropriate for the Zodiac Killer to have begun his letter writing campaign with Franklin on the stamps of his July 31st 1969 trinity of communications, and ended with his surname of Keys in 1990 - and thumb a finger to all the cipher experts trying vainly to crack his extremely complicated ciphers, when the answer was literally staring us in the face all along. 

THE 340 CIPHER WAS CRACKED ON DECEMBER 3RD 2020 BY DAVE ORANCHAK, SAM BLAKE AND JARL VAN EYCKE, SO THIS EARLIER ARTICLE SHOULD BE VIEWED IN RESPECT TO RECENT DEVELOPMENTS.

The following article will coalesce several pieces of work from 2019 into one cogent story regarding a handful of communications mailed by the Zodiac Killer in 1970. For some, the following will be repetitive, for which I apologize. It will hopefully make the case that the Zodiac Killer was winding down his operations and ultimately revealing the answers to his Z340, Z32 and Z13 ciphers and codes, to which he knew were practically unsolvable without such a prompt. The Zodiac Killer was a narcissistic braggart, who boasted of his exploits and threatened all and sundry with the possibility of more murders and mayhem if his demands were not met, including the claim he had killed far more than could be accounted for. If we applied the same model to his ciphers and codes, we would have expected him to be unable to resist giving us the answers - or at the very least - some clues to break open his puzzles. The notion of a killer keeping deathly silent on the solutions to his codes for up to 50 years, runs contrary to everything we know about the Bay Area murderer during his brief but deadly reign. That is why I don't believe he did.

The story begins with the final thing he wrote on the July 26th 1970 Little List Letter, and finishes just two communications later with the October 27th 1970 Halloween Card. All the answers to his codes were contained in just three short months. The end of the Little List Letter read "PS. The Mt. Diablo Code concerns Radians and # inches along the radians". The Z32 was the easiest code to crack because the Zodiac Killer just gave us the answer above - the code concerned "Radians and inches along the radians". Why make it any more complicated than it has to be? A code of 29 unique symbols within a total of 32 characters is simply not solvable without a key - and there is insufficient wording on the 13 Hole Postcard, Halloween Card or Los Angeles Letter written in plain English to formulate any such key. The Z32 is even worse than giving us the English alphabet of 26 letters, replacing M with A, W with B and H with C and saying "now solve it". There is no transposition key present in the remaining three communications from October 5th 1970 to March 13th 1971, so if the Zodiac Killer was to be consistent in his inability to resist revealing his deeds, then the only realistic alternative is he gave us all the answers instead.

You need look no further than the Paul Stine police report to notice that the hashtag symbol is used to represent the word "number". The Zodiac Killer, by use of an arrow pointer underneath the hashtag, was telling us to replace the hashtag with a number value. The Mount Diablo map scale was 6.4 miles to the inch, so it is probably unsurprising that the "Mt Diablo code would concern inches". In this instance, I have placed the number 5 into place, giving us the answer of "5 inches along the radians". The reason for 5 inches is self explanatory, because 4 or 6 inches from Mount Diablo to San Francisco would fall into the sea on the east and west side. The San Francisco element will be covered shortly. The Zodiac Killer also gave us a second set of crosshairs (shown below).

This was the first time the Zodiac Killer had ever placed an accentuated zero within his crosshairs alongside the acronym SFPD. This had to be the second clue to the location of the bomb. The hashtag and arrow signified the value of inches required, so this had to signify the radian value. By some massive stroke of luck (almost beyond belief), the bold, black accentuated circle fell over 246 degrees on a compass rose - which is 4 radians and magnetic north (17 degrees in 1970). Therefore, the target of his bomb must have been 4 radians and magnetic north, and 5 inches along the radians. 

All Zodiac's bomb threats were focused towards the San Francisco Chronicle and San Francisco Police Department, so placing this bomb location alongside the acronym SFPD should tell us that the threat was most likely focused toward a police station. By another massive stroke of luck, when we travel 4 radians and 5 inches from Mount Diablo, the target area for the bomb lies right by Ingleside Police Station. Allowing for a degree of flexibility of about 2%, by the Zodiac Killer rounding off his radians and inches, along with the black circle diameter, no other San Francisco police station comes close. However, we need to find a location where a school bus would be traveling from north to south (with the sun to the east), that has an embankment on the right side (as displayed on the April 20th 1970 bomb diagram), with easy and covert access to that embankment, and within a few hundred feet from Ingleside Police Station. The Zodiac Killer certainly wouldn't have wanted to attract attention by parking on the road itself, but by accessing the incline from a secondary location - likely at the top of the embankment - he could achieve this task in relative anonymity. Fortunately for us, that location sits approximately 230 feet from Ingleside Police Station. The perfect location for the Zodiac Killer to target a school bus and thumb his nose at the San Francisco Police Department, with covert access to the top of the embankment via the car park of San Francisco City College.             

Then came the 13 Hole Postcard punched in the style of a 'Dick Tracy' code with a "red crucifix decoder". What are the chances that if we arranged the 13 holes into the shape of a cross and place it over the midsection of the 340 cipher both horizontally and vertically, it would reveal the wording "paradice" and "slaves"? Then, what are the chances that the Zodiac Killer would write "paradice" and "slaves" in his next communication in a cross formation on the card, accompanied by "sorry no cipher" in a cross formation on the inside of the Halloween Card envelope? - totaling three cross formations - but supposedly, all created for absolutely no reason whatsoever in just two communications. Isn't it more believable they were created for purpose. The Zodiac Killer could easily have written "sorry no cipher" just the once, but deliberately fashioned it this way to tell us that the 340 character cipher was not a cipher after all. It was simply a design of "paradice" and "slaves" as exhibited by the Halloween Card. Throw in a few bigrams, pivots and 'corrected sixth line', and hopefully it will look convincing. 

All these clues from the back end of the Little List Letter to the Halloween Card giving us the literal answer to both the Z340 and Z32 in "paradice" and "slaves", and "Estimate: Four Radians and Five Inches". The 32 character code wasn't the complete solution, because the Zodiac Killer explicitly stated "the map coupled with the code will tell you where the bomb is set", which included magnetic north of 17 degrees in 1970. The code contained "four radians and five inches", to be coupled with the map which incorporated the magnetic north, giving us a total of 246.2 degrees.​ See The Blast Estimate of Zodiac and The Blast Estimate of Zodiac (Part Two) and The Blast Estimate of Zodiac (Part Three). Could either the 13 Hole Postcard or Halloween Card give us the answer to the Z13 as well? Again, totally unsolvable because of its limited number of characters, the Zodiac Killer could either keep quiet for up to fifty years or give us the answer.

From a previous article: On January 29th 1970, the Yellow Cab Company put up a thousand dollar reward for any information leading to the arrest of the Zodiac Killer. In addition, the Teamsters Union which represents the Yellow Cab Company were reported in the San Francisco Chronicle to be considering offering a further reward on February 8th 1970 in the case of Paul Stine and Charles Jarman (another taxicab murder victim). The April 20th 1970 letter gave us the code and was immediately followed by "I am mildly cerous as to how much money you have on my head now". The October 5th 1970 postcard gave us the possible solution of "Fk, I'm crackproof" and was immediately followed by "What is the price tag now". These are the only two communications in which the Zodiac Killer asked the police the price of his capture. These two communications not only had a code and an answer that fitted the code, but both were followed by the exact same question. When the Zodiac Killer was designing his 13 Hole Postcard, it is very likely he had at his disposal a copy of his original April 20th 1970 letter, or the San Francisco Chronicle newspaper cutting below, to which he was now supplying the answer. This may have been the trigger that influenced him to repeat the phrase "how much money you have on my head now" into the very similar "What is the price tag now". The Zodiac Killer, in essence, had inadvertently bound both communications together through phraseology, as well as code and solution.   

The Zodiac Killer introduction would now give us his name (albeit his initials) in absence of his full name. It would also read fluently as a sentence, as follows: "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is Fk, I'm crackproof". Nobody realistically believed he was going to supply his full name, but this way he satisfies the promise in a restricted format. Two communications mailed nearly six months apart, with a solution that satisfies the code, as well as a satisfactory introduction to the code - and both followed by the same question.    

The three 8's (representing Jesus Christ in gematria), along with the number 8 which symbolizes a new beginning, actually begins each element of the phrase Fk I'm crackproof. In addition, when we begin the phrase on the first 8, it fits perfectly around the existing K and M already present in the code and thereby creating a cyclical format, where the code ends and begins with the same letter. The Little List Letter provided the solution to the Button Letter and Mount Diablo code that preceded it. His next communication, the 13 Hole Postcard, provided the solution to the 13 Symbol Cipher before that, and finally the Halloween Card provided the solution to the 340 cipher. Three chronological solves to the three previous ciphers - and the only thing we had to add was the number "5", for which he inserted the hashtag and arrow. Why look for convoluted and excessively complicated solutions to these ciphers, when the Zodiac Killer gave us all the answers literally word for word.

This isn't a case of dragging wording from the entire Zodiac collection of cards and letters, but using just the two crosshairs of the Little List Letter, followed by the 13 Hole Postcard and Halloween Card. The bold, black circle and "PS. The Mt. Diablo Code concerns Radians and # inches along the radians" to answer the Z32. The 13 holes, red cross, "paradice" and "slaves", and "sorry no cipher" to answer the Z340. And finally, "Fk, I'm crackproof" to give us a shorthanded version of his name, while still retaining his anonymity. The alternative is that the codes are genuine, the designs on the 13 Hole Postcard and Halloween Card are devoid of any purposeful meaning, and the big-headed, braggart called Zodiac, kept his lips 'butoned' for however many years afterwards. 

This has been covered before, but I just wanted to expand in a little more detail without pinpointing a particular location.

How embarassing is the notion of a 50-year-old unsolved cipher, that we were given the answer to in just thirty one days? - and an answer that came straight from the horse's mouth. The 32 Symbol Cipher solution was served to us on a silver platter in the July 26th 1970 Little List Letter using the Zodiac crosshairs and six words. 

When the Button Letter was mailed on June 26th 1970, the Zodiac Killer gave us a map of San Francisco and Vicinity with his crosshairs centered over Mount Diablo, stating "the map coupled with this code will tell you where the bomb is set." If we were to find a perceived bomb, it is fairly obvious we have to travel a certain angle and distance from the top of Mount Diablo to find the location. Therefore, the 32 symbol code, if it served any purpose whatsoever, had to contain a measurement in the form of degrees and distance. The map scale was 6.4 miles to the inch - so that will be the distance the Zodiac Killer has to employ from Mount Diablo to make any sense. The degrees he used was radians, because he told us so in the July 26th 1970 Little List Letter. The Zodiac stated "P.S. The Mt. Diablo code concerns Radians + # inches along the radians". He is actually telling us that the 32 symbol code contains radians and inches in the solution.

"P.S. The Mt. Diablo code concerns (is about ) (has to do with) Radians + # inches along the radians". Any cipher expert such as David Oranchak, or quite frankly, any Joe Bloggs such as myself, will tell you that a 32 symbol code with only three repeating characters is unsolvable without a key. The Zodiac Killer was certainly no muppet - and clearly knew this when he concocted this jumble of random characters. But he gave us a large chunk of the key a mere 31 days later in the form of an arrow and a hashtag, writing "Radians and # inches along the radians" on a separate line to distinguish the very fact. We just had to key in the number. The symbol # is most commonly known as the number sign, The symbol is described as the "number" character in an 1853 treatise on bookkeeping, and its double meaning is described in a bookkeeping text from 1880. The instruction manual of the Blickensderfer model 5 typewriter (c. 1896) appears to refer to the symbol as the "number mark". Some early-20th-century U.S. sources refer to it as the "number sign", although this could also refer to the numero sign. A 1917 manual distinguishes between two uses of the sign: "number (written before a figure)"; and "pounds (written after a figure)". Mainstream use in the United States is as follows: when it prefixes a number, it is read as "number", as in "a #2 pencil" (indicating "a number-two pencil"). The one exception is with the # key on a phone, which is always referred to as the "pound key" or "pound". Thus instructions to dial an extension such as #77 are always read as "pound seven seven". Wikipedia.

All of Zodiac's bomb threats were mailed to the San Francisco Chronicle newspaper - even detailing the murder of San Francisco police officer Brian McDonnell on February 16th 1970, who suffered devastating and sadly fatal injuries when a bomb packed with fence staples exploded on an outside ledge of Park Police Station in the Upper Haight neighborhood of San Francisco. The Zodiac constantly signed off his communications with the barbed acronym SFPD = 0 and threatened "there is more glory in killing a cop than a cid because a cop can shoot back". If that wasn't enough, the Phillips 66 Road Map was labelled San Francisco and Vicinity.  Based on a map scale of 6.4 miles to the inch, only 5 inches would land in San Francisco (4 and 6 inches would fall into the sea, other than Treasure Island). Fortunately, the Zodiac Killer gave us the angle from Mount Diablo, courtesy of his bold, black circle on the Little List crosshairs. It fell 4 radians (and magnetic north) clockwise from his arrowed pointer, around the clock face he provided. Radians are usually measured counter-clockwise, but the Zodiac Killer placed the bold circle exactly 4 radians "set to Mag.N" clockwise.

The answer was now extremely simple. All we had to do was insert a number in place of the hashtag, shown by the big flashing arrow pointing us in the right direction. The hashtag conveniently preceded "inches", so it's here we will slot in the number 5 - and bingo - we have our answer to the inches component of "Radians + 5 inches along the radians" or "Radians and 5 inches along the radians". The full answer of "four radians and five inches", coupled with the magnetic north value of 17 degrees would be our guide.  As with all the best puzzles, the answer is usually hidden in plain sight. Druzer, an avid Zodiac researcher, came up with a solution to the 32 character code which I believe is correct, when he suggested Estimate: four radians and five inches. This solution not only satisfies the 32 characters, but correlates three plaintext letters to the only three repeating ciphertext characters in the code, thereby providing a perfectly valid key. See The Blast Estimate of Zodiac, The Blast Estimate of Zodiac (Part Two). and The Blast Estimate of Zodiac (Part Three). The map scale is 6.4 miles to the inch. This gives us a distance of 6.4 multiplied by 5 (inches). Therefore, the bomb was to be set at 4 radians and magnetic north, and 32 miles from the peak of Mount Diablo. The only San Francisco Police Department that comes anywhere close is Ingleside Police Station. This San Francisco Police Department sits at 30.96 miles from the peak of Mount Diablo (4.84 inches). It also sits at 251 degrees from the peak of Mount Diablo (4.08 radians).

The Zodiac Killer gave us a rough guide of 4 radians and magnetic north, and 5 inches (hence the word "estimate"). If he had given us the exact measurement, it would have been 4.08 radians and 4.84 inches, He was clearly giving us an approximate measurement. Since Ingleside Police Station was the only San Francisco Police Department anywhere close to these measurements, it's fairly obvious this was his target. The Zodiac Killer's distance in miles was 96.8% accurate. His angular accuracy in degrees was 98.0%. The Zodiac Killer was very unlikely to have selected a specific target that fell on an exact whole number of radians and inches.   

In the Little List communication it is apparent that Zodiac Killer gave us two prominent crosshairs: [1] with the accentuated black circle with SFPD=0 alongside, and [2] the extra large crosshairs with "P.S. The Mt. Diablo code concerns Radians + # inches along the radians" scrawled across it. Attaching these important additions was clearly done for purpose, thereby informing us of the radian value required, and the correlation between the crosshairs on the Phillips 66 Map and the measurements of radians and inches. With 29 unique characters in a 32 character code, any correlation between the characters and alphabetical solution was always going to be minimal, therefore it is encumbent upon us to look to other reasons for its design. The Blast Estimate of Zodiac (Part Three).