I have recently read Zodiac researcher Mike Rodelli's new book 'The Hunt for Zodiac: The Inconceivable Double Life of a Notorious Serial Killer'. In it he tackles the payphone call from the Springs and Tuolumne intersection to the Vallejo Police Department in the early morning of July 5th 1969. He takes the widely perceived directions given by the killer to identify the location of St John's Mine Road along Columbus Parkway, from which investigators would be led 'one mile east' to the location of the crime scene. The Zodiac Killer chose this location because he was creating radian angles using the payphone as a vertex to St John's Mine Road and the Lake Herman Road murder site.

This theory relies entirely on the transcription of the message given by Zodiac being written and recorded correctly, despite the fact that police dispatcher Nancy Slover and the Zodiac Killer were talking over each other for part of the message. The police report clearly stated "Writer received call from male subject who did not identify himself. Substance of statement was as follows". The 'substance of statement' reference, indicates that this is not necessarily a verbatim transcription of the spoken message, just the overall substance of the call. The above theory also relies on these locations being predetermined to create the necessary radian angles, and supposes that the killer already had 'radians' in his mind one year in advance of his letter proclaiming the use of such a term. The killer has once again been elevated to a master criminal, creating a labyrinth of puzzles from the terrain of northern California. This is the truth - or there is a much simpler and far more mundane answer.
The idea that the Zodiac Killer was just a ruthless killer scouring the Bay Area for victims using 'hit and miss' tactics, isn't half as appealing as the Moriarty style puzzle merchant he has metamorphosed into in recent years.
What is the likelihood that a killer calling the Vallejo Police Department from a payphone near the police station, was directing the police to the crime scene from their location, rather than creating an elaborate puzzle from a predetermined position along Columbus Parkway to manufacture radian angles? This is for you to decide. 

Thomas Horan, author of 'The Great Zodiac Killer Hoax of 1969', admits that the Nancy Slover police report statement of the message is not a verbatim transcription, but goes on to say "Blue Rock Springs is not one mile east of Vallejo Police Department." Despite this, he then uses the transcription to identify a fire station one mile west of the crime scene in his following hypothesis. Both theories rely on the wording and context of the message having been recorded exactly as it was spoken by the killer. The crime scene is neither 'one mile east' of the fire station or St John's Mine Road. A significant portion of the journey would be traveling closer to south than east. At best (as the crow flies), southeast would be the more accurate determination.  

Zodiac researcher Gian Quasar also tackled this problem on his website 'The Quester Files'.  He stated "The Zodiac does not know the name of the park. Nor was he in a state to notice the sign. Feigning ignorance would buy him nothing. Not knowing the name or just pretending he didn’t know the name would not indicate he was a stranger. Under normal circumstances a stranger would have noticed the park sign. When he calls the police, he actually gives them directions. But even in these he is quite wrong. He is really not aware of directions and distances.
Blue Rock Springs was neither 1 mile east of where he called, nor a mile east of the junction of Springs Road and Columbus Parkway. It is north of Springs Road by about 1 mile and 3 miles away from where he had called. Instead of simply saying the name of the park, which would tell all and sundry the location, The Zodiac gives instructions and doesn’t really have a grasp on distance and direction. He didn’t stalk his ground much at all. Nor was he in a state to notice the sign. He could not have been a Vallejoan."

​This statement makes the assumption that Nancy Slover recalled and recorded the spoken message of Zodiac 100% correct, while just assuming that Zodiac was incorrect with his payphone message. It doesn't consider the possibility that Zodiac was 100% correct and Nancy Slover recalled and recorded the message incorrectly. This same bias was not applied to either party at Presidio Heights, regarding the incorrect negro male adult description given to responding personnel. We will show later that the message by Zodiac was in all likelihood correct - and Nancy Slover also got the wording of the message correct, but with one crucial mistake. Reading into the message and claiming Zodiac was feigning ignorance by only mentioning the word 'park' is a stretch, and again the same argument could be applied to "The S.F. Police could have caught me last night if they had searched the park properly". Using the word 'park' is not proof of Zodiac knowing the area or not. 

Here is a newspaper article statement regarding the murder of Cheri Jo Bates in Riverside on October 30th 1966.
A Mexican-American student who noticed Cheri Jo Bates close to opening time, stated "he knew Cheri Jo Bates and had noticed her in the library the night in question. He said he saw the girl "writing something with a ball point pen in her blue spiral school notebook." The boy told us he was outside about 5:30 pm, waiting for the library to open at 6:00 pm, and it was then he saw the girl". This statement is confusing, as it can be read in two different ways - did he see Cheri at 5:30 pm or 6:00 pm. 

Let us consider the three teenagers at the corner of Washington and Cherry Streets, and assume they had a direct hotline to Officer Armond Pelissetti one mile west on Washington Street. They are viewing Zodiac heading up Cherry Street, so they call Officer Pelissetti and state "If you go one mile east, on Cherry Street you will see Zodiac." In the second instance they call Officer Pelissetti and state "If you go one mile east on Cherry Street you will see Zodiac." Both statements are composed of the same words, but mean two different things entirely. The only difference is intonation or the use of a slight pause or break, making the first statement correct, while the other giving the impression of directional unawareness. 

Applied to the Blue Rock Springs call, we go from "If you will go one mile east on Columbus Parkway to the public park, you will find the kids in a brown car" to "If you will go one mile east. On Columbus Parkway to the public park, you will find the kids in a brown car." The wording hasn't changed, but the meaning of the payphone call has changed entirely. The Zodiac Killer is instructing police to head east to Columbus Parkway, from where they will find the stricken couple at the public park. All this is achieved by a simple full stop. Why would he be directing Vallejo police from a point on Columbus Parkway, when he is ringing the police station near to the payphone?  Police traveling from the station along Solano Avenue to Springs Road, would then have to travel 1.34 miles east before reaching Columbus Parkway, on which they would head north towards the crime scene. Do you want this boring answer, or do you want something far more exciting? The choice is yours. 

Paul Avery, a reporter at the San Francisco Chronicle, covered many of the Zodiac stories during his reign of terror and became the focus of the murderer's attention when the Zodiac Killer mailed the Halloween card to the San Francisco Chronicle newspaper on October 27th 1970. The murderer responded to an article published on November 16th 1970 by Paul Avery, linking him to the Riverside murder of Cheri Jo Bates on October 30th 1966. This would be followed nearly three years later, when the Exorcist letter was mailed on January 29th 1974, closely followed by the SLA letter on February 3rd 1974, mailed the day before the Symbionese Liberation Army kidnapping of  Patty Hearst, a media heiress, on February 4th 1974. "Paul Avery covered the Hearst case until the newspaper heiress-turned-bank robber was arrested in September 1975. Avery then holed up on his houseboat at Gate 5 in Sausalito with Boston writer Vin McLellan to write The Voices of Guns, a book on the SLA and the Hearst kidnapping." Wikipedia.

The Exorcist letter has recently courted new attention with the publication of Mike Rodelli's new book 'The Hunt for Zodiac: The Inconceivable Double Life of a Notorious Serial Killer', pouring some doubt on the authenticity of this communication. This letter, once again, appeared another response to a Paul Avery newspaper article, featuring the recently released Exorcist movie - an American horror film released in 1973, directed by William Friedkin and adapted for screenplay by William Peter Blatty, based on his 1971 book. The San Francisco Chronicle article entitled Weird Goings on at the Movies, was published on January 11th 1974 and detailed the audience reaction to what they had just experienced. The opening lines of the article are extremely interesting when we consider the opening lines of the January 29th 1974 Exorcist letter, only 18 days later.     

The article began "If these crowds queuing up three times a night for "The Exorcist" prove anything, it's that a lot of people are willing to go to a lot of trouble to get their wits scared out of them. Since the day after Christmas, some 60,000 persons have endured a harsh winter's elements standing in lines - sometimes for as long as two hours - to see the see the current cinema rage playing at the Northpoint Theater near Fisherman's Wharf. It is an experience that produces reactions ranging from vomiting to fainting, to one apparently jaded patron's demand for his money back because it was about as scary as Snow White". 

The author of the 'Exorcist' letter apparently concurred with this disgruntled patron, beginning the letter with "I saw + think "The Exorcist" was the best satirical comedy that I have ever seen". The author also made sure to place "The Exorcist" in quotation marks, just like the article. If this letter was the Zodiac Killer, he would go on to use quotation marks around words in his following two correspondences - something he had never previously done in his communications from 1969 to 1971. 

It could be argued that the middle section of the Exorcist letter is signed yours truley 'Ko-Ko Lord High Executioner' by means of Tit-Willow from The Mikado's On a tree by a river. The same can be said of the Little List letter on July 26th 1970, which also featured Ko-Ko in A more humane Mikado.

Then we travel to the most interesting part of the Exorcist letter at the bottom of the correspondence, and its comparison to the first letters mailed by the Zodiac Killer on July 31st 1969. The Exorcist letter was mailed to the San Francisco Chronicle, so we will take a look at the July 31st 1969 letter mailed to the same paper. This is what the killer signed off with: "I want you to print this cipher on the front page of your paper. In this cipher is my idenity. If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend." It begins with a demand to print his material in the paper and finishes with the threat "to kill" again if his instructions are not followed.       

The foot of the Exorcist letter begins with a demand to put this note in the paper and finishes with a threat you know he is capable of. We know what the killer was capable of - it is "to kill" - as he threatened at the foot of the July 31st 1969 San Francisco Chronicle letter if his demands to print the cipher were not met. Even the decoded cipher rammed home the message "To kill something gives me the most thrilling experience". Therefore, by logical deduction, the strange characters at the foot of the Exorcist letter should read "To Kill". Thanks to the great work of Zodiac researcher Kevin Robert Brooks, this is exactly what he showed. Even more importantly, the beginning of each word began with an upper case letter, just like "The Exorcist" - forming the words "To Kill" with significant emphasis on the 'K' of "Kill".

This emphasis would be carried forward into the SLA letter, mailed on February 3rd 1974, where he used quotation marks to highlight the word "kill" once more. The murderer now appeared to have slayed his demons, signing off the letter with "a friend" - albeit, a friend you wouldn't invite home for tea and scones with grandma.

His reformation now appeared complete in the May 8th 1974 Citizen letter, remonstrating against the publication of advertisements for the "Badlands" movie starring Martin Sheen and Sissy Spacek, based upon the real life events of spree killers Charles Raymond Starkweather and his girlfriend Caril Ann Fugate.
​
His final consternation would be reserved for Marc H Spinelli in the July 8th 1974 Red Phantom letter, calling for the cancellation of his Count Marco column. The murderer now seemingly devoid of the Zodiac persona after exorcising his demons subsequent to January 29th 1974, along with his inability to spell.

Had the Zodiac Killer returned after an absence of nearly three years, or was the return of the Bay Area murderer a demon that had to be resurrected for the sake of publicity in an ever dwindling case?

Zodiac researcher Mike Rodelli recalled a conversation with Alan Keel, Criminalist at the San Francisco Police Department, San Francisco, California from 1996 to 1999. He stated "In contrast (to earlier communications), Keel analyzes two other letters, one of which is the 1978 forgery, and finds that this letter and one of the 1974 letters are loaded with saliva and cells. He then easily extracts DNA from both of these letters using the more primitive DNA technology of that time and finds that the DNA matches between those two letters, thus proving that one person sent both".

For these two communications to be matched definitively using DNA, "proving that one person sent both", they must have revealed full DNA profiles - because a partial DNA profile in one could not have proved conclusive. The DNA tests conducted by the San Francisco Police Department in the late 1990s. indicated that subsequent to 1974 only the January 29th 1974 'Exorcist' letter had been processed and "cells found". There was no mention of the other 1974 letters being processed. Therefore, one could conclude that the two letters discovered to match one another (according to Keel), were the 1974 'Exorcist' letter and the April 24th 1978 letter - and therefore written by the same individual.

The 1978 letter is listed in the report as "not authentic Zodiac letter". If the San Francisco Police Department concluded the 1978 letter was not an authentic Zodiac letter, then the 'Exorcist' letter would not be either. This brings forth some interesting questions.    

Michael Butterfield wrote an article entitled 'Zodiac DNA:The Magic Bullet' on his 'Zodiac Killer Facts' website, stating
"In the late 1990s, San Francisco police obtained DNA from a suspected Zodiac letter, and the DNA did not match Allen’s DNA".. The San Francisco Police Department surely wouldn't have used the DNA obtained from the April 24th 1978 letter for comparison, as they themselves had deemed it "not authentic Zodiac correspondence" and it had long been considered questionable material. Therefore, they must have obtained this DNA from another letter they "suspected" was a Zodiac letter, to compare to known suspects. But if the 'Exorcist' letter (as Mike Rodelli suspects) and the 1978 letter matched in DNA - were written by the same individual - and so by association were considered "not authentic Zodiac correspondence", then which "suspected Zodiac letter" did the San Francisco Police Department use to compare to Allen's DNA. 

In the San Francisco Police Department report the only letters in which they stated "cells found", other than the 'Exorcist' letter, were the July 24th 1970 'Kathleen Johns' letter and July 26th 1970 'Little List' letter. Every correspondence tested prior to July 24th 1970 were labelled 'Envelope processed for DNA - few cells'. The 'Exorcist' letter came under scrutiny, alongside the 1978 letter, when Inspector David Toschi fell under the microscope in 1978 for forging one or both. So, would it be likely the 'Exorcist' or 1978 letter would be chosen by the San Francisco Police Department in the 1990s as a "suspected Zodiac letter" (and for the reasons given above), and used to rule out Arthur Leigh Allen's DNA? They surely would have turned to more credible sources. But they only had two other letters where "cells were found".

In 2002, Dr. Cydne Holt performed a new round of tests on some of the early 1969 Zodiac letters. Having failed to find suitable DNA on these letters (as suggested by the "few cells" findings of the 1990s), it has now come to light that the ABC Primetime documentary scoured the outside of the envelopes and stamps for DNA instead, thereby negating any findings as to the identity of the Zodiac Killer.

But why were they searching for Zodiac DNA, to compare to suspects such as Arthur Leigh Allen and Kjell Qvale, when "in the late 1990s, San Francisco police obtained DNA from a suspected Zodiac letter, and the DNA did not match Allen’s DNA". The new round of tests performed in 2002 would now suggest that the DNA they found in the 1990s from a "suspected Zodiac letter" was no longer believed to be from Zodiac. 

In 2018 "Vallejo police Detective Terry Poyser, who has worked the Zodiac case for four years, said his agency has submitted two envelopes that contained letters from the Zodiac Killer for a type of advanced DNA analysis that previously had not been available in the case. The department has three letters and two envelopes from the Zodiac, Poyser said. The envelopes each have a double stamp, which Poyser said was a trademark of the Zodiac. They originally were sent to the San Francisco Chronicle and the San Francisco Examiner, he said. The third letter was sent to the Vallejo Times-Herald, but does not have an envelope with it, he said". Sacramento Bee.

However, these are the July 31st 1969 envelopes and stamps already tested by Dr. Cydne Holt in 2002, which failed to produce any viable results. The hope is that more advanced DNA analysis may turn up something new. But what about the "suspected Zodiac letter" from the 1990s with "cells found". Couldn't this be examined using advanced DNA analysis? This letter has apparently already produced a DNA profile to rule out Allen, so why is it being ignored - or is it?

In a poll of 93 people conducted on this site, 85% believe the 'Exorcist' letter to be genuine Zodiac correspondence, whereas in a poll of 94 people conducted on this site, only 54% believe the 1978 letter to be genuine Zodiac correspondence. If Mike Rodelli's suspicions are true, then both the 'Exorcist' and 1978  letter are "not authentic Zodiac correspondence". If the San Francisco Police Department have long considered these two communications as not credible, then which "suspected Zodiac letter" was used to rule out Arthur Leigh Allen in the 1990s - and can it be used again for advanced DNA analysis?

We have long been led to believe the 'Exorcist' letter was the last confirmed communication by the Zodiac Killer. If the poll on this site were true of the entire Zodiac community, then 85% of people believe the 'Exorcist' letter to be genuine Zodiac correspondence. If the other 1974 letters were not tested or found to contain DNA (as the SFPD report suggests), then it is extremely likely a full DNA profile exists for the 'Exorcist' letter (shown at the top of this article).

For those who believe the January 29th 1974 'Exorcist' letter to be an authentic mailing from the Zodiac Killer with a full DNA profile, you should be asking "why hasn't this been run through GEDmatch".

Here I will tackle the question of the Blue Rock Springs phone call, traced to the Springs Road and Tuolumne Street payphone on the morning of July 5th 1969. The Zodiac Killer stated in the August 4th 1969 'Debut' letter, that "the man who told police that my car was brown was a negro about 40-45 rather shabbly dressed. I was in this phone booth having some fun with the Vallejo cop when he was walking by. When I hung the phone up the damn thing began to ring & that drew his attention to me + my car."
Despite the fact that there was no mention of this individual in the police report, and his supposed description of Zodiac and his vehicle never surfaced in the newspapers, the debate regarding his existence rages on.

This negro male individual became the perfect eyewitness for Zodiac, tying the phone call and brown car into one neat package. The Zodiac Killer attempted to authenticate this individual by giving us his color, age and mode of dress - along with the convenient timing of a phone call which drew attention to him and his brown car. How absolutely unfortunate for the Zodiac Killer to have his vehicle confirmed by this individual as brown, just like the recollection of surviving victim Michael Mageau. This selling job should be viewed with skepticism, when we consider the tracing of the phone call by ring-back.

The Zodiac Killer described in his own words, that once he "hung the phone up" it began to ring. This must have happened almost immediately, because the negro male (according to Zodiac) was "walking by" the phone when it rang, which caused him to notice both Zodiac and his vehicle together. The premise of the following, is that Zodiac is selling us a big fat red herring and he wasn't in his vehicle. He had driven home and had walked back to the payphone to place the call. The introduction of a brown vehicle, designed for purpose, and give the impression that Zodiac could have driven anywhere after the payphone call - and the proof is in the police report, time-stamped at 12:47 am.     

But before we discuss the police report, here are a few commentaries by some Zodiac researchers.
In 'The Cases That Haunt Us' by John Douglas and Mark Olshaker, they stated "It took seven minutes for Pacific Telephone to trace the call to a payphone in front of a service station".

In 'Unsolved in America' by by Harold Schechter, Lee Mellor, Michael Newton, Kim Cresswell, Aaron Elliott, Robert Hoshowsky, they stated "Within an hour, the call had been traced to a payphone outside Joe's Union Station". 

In 'The Hunt for Zodiac: The Inconceivable Double Life of a Notorious Serial Killer' by Zodiac researcher Mike Rodelli, he stated "Several minutes later the call was traced back to a phone booth located at Joe's Union 76 Station in Vallejo". 

The question that has to be asked - is that, if the trace was achieved after several minutes, or even seven minutes, why was Zodiac still at the payphone when the ring-back occurred. He clearly stated "the damn thing began to ring & that drew his attention to me + my car." If this were the case, then are we to conclude that the Zodiac Killer after hanging up the telephone, remained alongside his vehicle by the payphone for several minutes until police traced the call and rang it back. This clearly doesn't stack up. That is why we know he is lying. The whole negro eyewitness story of a man spotting his "brown car" was designed to divert attention away from the truth - that he was on foot and lived nearby.

Even if the call was traced within 30-40 seconds, how could the Zodiac have heard the phone ring. As soon as he had hung up the phone (bearing in mind his claims of a negro eyewitness and brown car), he would have immediately returned to his vehicle and driven away. He would have been out of audible range. If the call was traced fairly quickly, or if the call was traced after several minutes, a killer in a car would have been long gone. But if the killer lived nearby and was on foot, he could easily have heard the phone ring as he was walking away. The distance he can cover is reduced, keeping him within earshot of the payphone for longer.
Below is an example of the distance the Zodiac Killer could have traveled on foot, putting him within audible range of the payphone. He could have traveled further than the examples shown below and still have heard the payphone ring. 

If you believe the Zodiac researchers above, then the only feasible way the Zodiac Killer can hear the payphone ring after several minutes, is if he is walking away from the intersection of Springs and Tuolumne, negating his claim of being in his vehicle. This could have wide reaching implications regarding the home location of our killer as of July 5th 1969. Here is a further angled view of the location.      

What one has to ask themselves, is which was more likely in 1969 - a call traced to the payphone in about 1-5 seconds, or a call traced to the payphone after 30 seconds, or upwards of a minute. The answer may lie in the police report. This may back up the statements of the Zodiac researchers above.

Page 13 of the police report stated "At 12:47 am Mrs JOHNSON PT&T Operator called. The above call was traced to a coin operated telephone at Joe's Union, Tuolumne and Springs Road. The call was traced by Betty Main whose supervisor would not allow her to give a statement at this time."
It states that Mrs Johnson called the police at 12:47 am to report the call had been traced to Joe's Union Gas Station. But what time was the actual call traced using ring-back. 
This was an urgent matter- a killer had just rang in to Vallejo Police Department at 12:40 am via the operator. If they had rang back the payphone immediately, as Zodiac claimed, and traced the call by at least 12.41 am, why on earth, considering the gravity of the matter, would Mrs Johnson wait 6 minutes before calling the police. One would suspect they would have called the police the instant they had traced the call. The fact that they called the police at 12:47 am, would indicate they had just traced the call moments earlier. Had this been approximately 12:46 am and Zodiac heard the payphone ring, we would have to assume he was still at the payphone over 5 minutes after he hung up. Having just committed a heinous crime at nearby Blue Rock Springs, and made a phone call to Vallejo Police Department, situated in close proximity to the payphone, do we really believe that he just sat by the payphone in excess of 5 minutes. 

But after 5 minutes, had he walked away from the payphone, he realistically should have been out of earshot, as he would have been in a vehicle. However, if he lived in a residence within earshot of the payphone, it wouldn't have mattered when the phone rang back. He would always be in audible range. Was this why the Zodiac Killer was so eager to convince police he was in his vehicle alongside the payphone? Had the police interviewed neighbors close to the payphone about anything they heard or saw that night? Was the residence of the Zodiac Killer closer to the payphone than we ever could have imagined, and the 'Debut of Zodiac' letter was the perfect opportunity to paint a completely different picture of the events that morning.

The Debut of Zodiac letter was received by the San Francisco Examiner newspaper on August 4th 1969 and immediately turned it over to the Vallejo Police Department for comparison to previous Zodiac correspondence. The FBI files above constantly referred to the July 31st 1969 trinity of letters and envelopes, but there was a notable absence of the word "envelope" when referring to the August 4th 1969 communication, and more importantly, on the day it was received. The FBI files explicitly state that the correspondence was "undated" and sent "anonymously". In the absence of any dated or postmarked envelope, this strongly indicates that the three-page letter was hand delivered by the killer to the offices of the San Francisco Examiner at Third and Market Streets.

The Zodiac Killer painstakingly detailed his first two crimes in the July 31st letters "stating some facts which only I + the police know", so must have been aghast at the statement of Vallejo Police Chief Jack E Stiltz in the Sunday August 3rd 1969 San Francisco Examiner & Chronicle, wanting more facts to prove the letter writer was the killer. This may explain his eagerness in rushing off his three-page letter to the San Francisco Examiner. He may have considered posting it in a public mailbox, but his apparent desire to back up his claims in the July 31st letters and have it published in the Examiner by Monday afternoon, forced him to opt for the direct route of hand-delivery. 

For 35 years starting in 1965, the San Francisco Chronicle and Examiner operated under a Joint Operating Agreement whereby the Chronicle published a morning paper and the Examiner published in the afternoon. The Examiner published the Sunday paper's news sections and glossy magazine, and the Chronicle contributed the features. Circulation was approximately 100,000 on weekdays and 500,000 on Sundays. Wikipedia.

Below, the Vallejo News Chronicle details the Zodiac Killer's fourth letter to the San Francisco Examiner on Monday August 4th 1969,        

The noticeable absence of the word "envelope" is not the only reason for believing the Debut of Zodiac letter was hand-delivered, when we look at the layout of the 3rd page, where the Zodiac Killer writes "NO ADDRESS". Why on earth would the sender feel the need to write "no address" at the foot of the letter? Probably because there was no envelope containing the address of the San Francisco Examiner.   

The scale on the left is slightly cut off, but the 3rd page measures approximately 10 inches in length.

If the Zodiac Killer had placed all three pages together, placing the 3rd page facing outwards on the top or bottom, then by folding the letters in the middle twice, the face of his communication would measure approximately 2.5 inches in height. The highlighted pink section would be the visible part of his communication, and where the address of the newspaper should have been written. But because he delivered it directly to the San Francisco offices, there was no need for an address - which is exactly what he wrote.

Does the hand-delivery of this letter tell us anything else about the Zodiac Killer, other than his eagerness for publication? The following is speculative and must be regarded as such.

The Zodiac letters have been heavily dissected to discover the likely home residence of the Bay Area murderer, and so we shall attempt to make some observations regarding this communication.


How prepared would the Zodiac Killer be, to travel a long distance just to hand-deliver this letter, rather than mail it?

If the Zodiac Killer lived or worked in San Francisco, then it isn't a problem to deliver it in person, either by making the journey specifically or en route to his workplace. However, if he lived in an outlying area (but didn't work in San Francisco) such as Napa (44 miles), Sacramento (94 miles), Santa Rosa (57 miles), Vallejo (29 miles), Oakland (9 miles), then how likely would it be for a person to travel these distances for no other purpose than the desire to hand-deliver a letter?  Surely, based on the 'least effort principle' of geographical profiling, the further away he lives, the less likely this would be the case   

This may suggest that the killer either lived and worked in San Francisco, or lived in one of these other regions and traveled into San Francisco for his profession. If he lived in Napa, for example, would he travel 44 miles (88 miles round trip) for the sole purpose of dropping off a letter, rather than mail it in Napa or somewhere close by? Unless, he lived in Napa and worked in San Francisco.

If the August 4th 1969 Debut of Zodiac letter was personally delivered by the murderer to the San Francisco Examiner, does it in some small way reveal something about Zodiac Killer and his likely residence, or is "no address" the likely outcome?    

I have just finished reading 'The Hunt for Zodiac: The Inconceivable Double Life of a Notorious Serial Killer' by Zodiac researcher Mike Rodelli. While I don't agree with everything in the book, it is an extremely well researched and informative addition to the Zodiac Killer story, even if you don't arrive at the same conclusions on the murderer's identity. For beginners and seasoned veterans alike, it will not disappoint as a comprehensive introduction to the case, as well as a complimentary addition to any existing knowledge you may already have. While fresh in my mind, I would like to explore one important feature of the book, regarding the topic of DNA, which is currently hanging over the case like a dose of skeptical optimism.. 

Mike tackles this problem in extensive detail, particularly with regards to the viability of the DNA tests conducted by Dr. Cydne Holt in the 2002 ABC Primetime documentary, in addition to his discussions with Alan Keel, Criminalist at the San Francisco Police Department, San Francisco, California from 1996 to 1999.

The disputed results of the 2002 'showpiece' are now well documented, however, Mike delves further into the DNA analysis with respect to two later 'Zodiac' letters, namely the 1974 'Exorcist' letter and the subsequent 1978 'I Am Back With You' letter, both mailed after a lengthy silence from the Zodiac Killer - leading some to question their authenticity. 

Mike recalls information of his conversation with Alan Keel: "In contrast (to earlier communications), Keel analyzes two other letters, one of which is the 1978 forgery, and finds that this letter and one of the 1974 letters are loaded with saliva and cells. He then easily extracts DNA from both of these letters using the more primitive DNA technology of that time and finds that the DNA matches between those two letters, thus proving that one person sent both." 

This is a stunning revelation (if correct) when we consider the findings of the San Francisco Police Department laboratory in the 1990s, in which there was a notable absence of saliva/DNA present on the envelopes prior to the 1974 'Exorcist' letter. Would a killer who seemingly didn't lick any of his envelopes or stamps throughout the majority of his letter-writing campaign, now suddenly break that habit in the 1974 and 1978 communications? The SFPD report, shown here, references the April 24th 1978 letter, claiming that the "DNA SAMPLE OBTAINED - NOT AUTHENTIC ZODIAC LETTER".   

This lack of saliva or DNA on the earlier letters may have become more evident, as Dr..Cydne Holt struggled to generate any tangible results from the sealed sections of stamps and envelopes using more advanced forensic DNA testing in 2002, compared to the earlier and more primitive testing undertaken in the 1990s. This apparent dichotomy brings into stark reality the essence of Mike Rodelli's argument.     

The bold statement of "DNA  sample obtained- not authentic Zodiac letter" opens up the proverbial can of worms. On first reading, it gives the impression that they have something to compare it to. How would they know the DNA sample obtained from the 1978 letter was not from Zodiac, if they didn't have Zodiac's DNA? If they had Zodiac's DNA in the 1990s, this wasn't the impression given by the search for Zodiac DNA in the 2002 ABC Primetime documentary.

"DNA  sample obtained- not authentic Zodiac letter" could imply they know the sex of the DNA present on the 1978 letter, and therefore by extension, not the Zodiac Killer (as suggested on many forums). But, it could imply they know the identity of the individual who contributed the DNA to the 1978 letter, and having identified that individual, know they were not the Zodiac Killer. This lack of clarity has led Zodiac researchers to question the transparency of the San Francisco Police Department.     

We know that a partial DNA profile from a letter can exclude suspects, but not definitively identify an individual. Therefore, the apparent (but unconfirmed) revelation of Alan Keel that "DNA matches between" one of the 1974 letters (possibly the 'Exorcist' letter) and 1978 'I Am Back With You' letter, would suggest that full DNA profiles have been obtained for both letters.
​If only a partial DNA profile had been obtained from the 1978 letter (much like the exclusion of suspects) it can only be excluded as matching a profile from the 'Exorcist' letter (if this had a full DNA profile), but not definitively matched to it.
As such, the statement of "DNA matches between those two letters, thus proving that one person sent both", would be indicative of a full DNA profile obtained from both the 1974 and 1978 letters in the 1990s.. 

For those who believe the 'Exorcist' letter to be genuine Zodiac correspondence, then this could imply that a full DNA profile may exist for this letter (or one of the 'lesser' 1974 letters), and consequently the profile of the Zodiac Killer. However, the search for Zodiac's DNA in 2002 negates this premise - unless the San Francisco Police Department knew all along that both the 'Exorcist'/74 letter and 1978 letter were not mailed by the Zodiac Killer. In fact, the Exorcist and April 24th 1978 letters were the only two communications mentioned with regards to the controversy surrounding Inspector David Toschi, who led the investigation for many years. He came under suspicion for forging the 1978 letter, after the San Francisco Chronicle columnist and author, Armistead Maupin, discovered that David Toschi had mailed fictitious fan mail to a series he had written, with the inclusion of the detective.  ​

​Armistead Maupin had first met David Toschi in 1976 while he was writing the 'Tales of the City' series. Wanting to energize the series with a murder mystery element, he contacted San Francisco Chronicle reporter Bob Popp, who then introduced him to David Toschi. The police inspector would make a debut appearance in 'Tales of the City' on September 10th that year, with a character based on his attributes. Further episodes would follow under his real name, as a friend and confidant to Armistead Maupin's fictitious Detective Inspector Henry Tandy. 

Here is an excerpt from the San Francisco Chronicle, published on July 14th 1978 "Police officials are investigating the possibility that Inspector David Toschi forged a Zodiac letter in The Chronicle in 1974 as well as a similar letter the newspaper received earlier this year. Toschi - who said he was interrogated officially last Friday about both letters - has denied writing any letters in the guise of Zodiac, the killer of six who eluded capture by Toschi for nearly nine years before the detective was transferred out of the homicide detail last week. Deputy Clement DeAmicis, who had recommended the transfer to Chief Charles Gain, confirmed yesterday the probe was being extended".  

The fact that Inspector David Toschi was questioned regarding these two communications, only heightens the mystery surrounding Alan Keel's statement of "the DNA matches between those two letters, thus proving that one person sent both" and the San Francisco Police Department's report concerning the 1978 letter, in which it noted that a "DNA  sample was obtained, but indicated it was not an authentic Zodiac letter".

We don't know for certain that Alan Keel is referring to the 'Exorcist' letter when he stated "one of which is the 1978 forgery, and finds that this letter and one of the 1974 letters are loaded with saliva and cells".  However, since the 'Exorcist' letter for the large part has been widely regarded as the last confirmed correspondence mailed by the Zodiac Killer, as opposed to the other 1974 communications,  it would be the logical correspondence to test for Zodiac Killer DNA  when searching for the Bay Area murderer. Testing the other much more questionable 1974 mailings would not make as much sense - which is probably why the San Francisco Police Department report is blank or omitted next to these communications. 

The 'go to' mailing, when testing for Zodiac DNA from the 1974 letters, would undoubtedly be the 'Exorcist' letter rather than its dubious companions. So, if this was the case and the statement of Alan Keel were true, then the 'Exorcist' mailing would not be an authentic Zodiac correspondence - and as a result - would quite possibly shrink the Zodiac reign by nearly three years.  

Rex Bolt, author and avid Zodiac researcher, has made an excellent video on Youtube about his thoughts on the October 11th 1969 murder of Paul Stine, detailing with the use of a comprehensive slideshow the possible escape route of the Zodiac Killer.
It is a fantastic analysis of the area of Presidio Heights, with respect to the options Zodiac faced that night as he walked away from the intersection of Washington and Cherry. Of course, it was around 10:00 pm at night when the Zodiac Killer departed the crime scene, and the route ahead of him was far more claustrophobic.      

Rex, from the perspective of a native of San Francisco,  takes you on a journey from Mason and Geary, bordering Union Square  (where Paul Stine picked up Zodiac) through to the crime scene and beyond.
​
With photographs showing the layout of Presidio park, Rex comes to the conclusion that Zodiac most likely headed east from Julius Khan playground to the dense wooded area by Presidio Boulevard.
The Zodiac Killer, now waiting for an opportune moment, had just a few hundred feet to escape the Presidio to his waiting vehicle.

The killer would now reach his vehicle, parked somewhere close to Broadway and the Lyon Street Steps. A relatively remote area for residential San Francisco and an ideal location to escape to Highway 101 and the Golden Gate Bridge in a matter of minutes. 
You are now out of San Francisco and away.

There appears an impasse regarding the Zodiac case, as to whether any DNA is likely to be found behind the stamps or envelope seals mailed by the Zodiac Killer. A new round of testing on the Zodiac letters was initiated in late 2017, and widely reported upon in May 2018, bringing fresh hope to the 49-year-old case and its army of sleuths. In 2002, Cydne Holt performed DNA testing on the envelopes and stamps in an ABC Primetime investigation of renewed hope, when a partial DNA profile was discovered on a confirmed Zodiac letter. This hope has subsequently been dashed, after being claimed the DNA sample was lifted from the exterior surface of the letter, and thereby rendering it practically useless.

However, all is not lost. During the analysis of the letters a small section of hair shaft was discovered beneath the stamp of the October 13th 1969 'Paul Stine' letter, in which the Zodiac Killer confessed to the murder of the taxicab driver. He would also  send a small piece of the victim's bloody shirt within the communication. If there is one correspondence in the Zodiac case, that without doubt came from the killer, this is it. This small fragment of hair may yet solve the Zodiac case, or at the very least rule out the many suspects suggested as the Bay Area murderer. 

The three teenagers who witnessed the Zodiac Killer by the taxicab, described him as "a white male, 25-30 years old, 5'8" to 5'9", stocky build, reddish-brown hair worn in a crew cut, heavy rimmed glasses and dark clothing."

In the ABC Primetime documentary Dr Cydne Holt "discovers a reddish-brown hair stuck behind a stamp peeled from this letter". Since the Zodiac Killer can be inextricably linked to this correspondence, then he could very well be the donor of this hair. The hair didn't have any recognizable root structure, so nuclear DNA retrieval wasn't possible. The second option was mitochondrial DNA analysis, but no progress has been reported with regards to this, or if it is even possible on such a small sample size.

However, there is something that may soon break this case wide open. A relatively new forensic tool that will hopefully prove the identity of the Zodiac Killer once and for all.
​If it doesn't identify the Zodiac Killer, then it could certainly rule out an individual as the donor of the hair on the October 13th 1969 stamp. This may not be the killer's hair, but in the absence of usable nuclear DNA on the letters, it is our best opportunity at present to incriminate or eliminate suspects by harboring this new forensic tool. 

Researchers at Lawrence Livermore National Laboratory in California have harnessed the power of "ectracting genetic information from proteins found in hair that is remarkably reliable."
​ 
"Proteins are more stable than DNA and are also more abundant in hair. Mutations in DNA get translated to proteins and sometimes they can even change the protein structure by swapping out one amino acid for another. “We’re looking for those changes in protein structure and by doing that we can infer what was in the original DNA,” says Deon Anex, a chemist at Livermore and co-author of the paper. In other words, even when DNA is absent or is degraded by light, heat or other environmental factors, benign variations in the proteins found in hair can be used to identify individuals.
​
Anex and his team analyzed hair from 76 men and women, who were mostly of European descent, as well as six sets of skeletal remains from the 1700s and 1800s. They found 185 distinct patterns of amino acids, called markers, that allowed them to trace the individuals’ genetic identities. They also compared their protein identification method to known DNA samples from the individuals' blood and were able to correctly identify the person who shed the hair 98.3 percent of the time. The chance of getting a false positive from the protein analysis was just 1.98 percent." link.  

'Scientists from Lawrence Livermore National Laboratory and a Utah startup company have developed the groundbreaking technique, providing a second science-based, statistically validated way to identify people and link individuals to evidence in addition to DNA profiling.

The new protein identification technique will offer another tool to law enforcement authorities for crime scene investigations and archaeologists, as the method has been able to detect protein in human hair more than 250 years old.
​Once the method is optimized, the researchers believe they could use protein markers from a small number of human hairs, possibly as little as one, to distinguish an individual among the world’s population.
​
The researchers believe that the number of individual protein markers that can be used to differentiate people could go as high as 1,000. Protein markers also can be found in other tissue types, such as shed skin cells, bones and teeth, and the scientists have started studying how people can be identified using the latter two tissues.
Using their current sample sizes, the researchers are able to find enough markers to provide a unique pattern for an individual that would distinguish that person among a population of one million.' link.

​With the small sample size required, these protein markers in the fragment of hair on the October 13th 1969 stamp may one day identify the Zodiac Killer. At the very least, it should certainly diminish the ever widening suspect pool. 

This forensic tool may also shed light on the murder of Cheri Jo Bates in Riverside on October 30th 1966. Hair from a blood clot was found at the base of Cheri Jo Bates' right thumb.  

The following is a brief explanation of the crime scene photographs regarding the murder of Paul Stine in Presidio Heights on October 11th 1969. It is designed to address the correct sequence of events that night for anyone new to the case.

The Robbins children observed the murderer wipe down the taxicab that night, as detailed in the police report: "The suspect appeared to be searching the victim's pockets. (Witnesses never heard a gun shot). The suspect then appeared to be wiping (fingerprints) on the interior of the cab, leaning over the victim to the driver's compartment. The suspect then exited the cab by the passenger side front door, also wiping with a white rag, possibly a handkerchief. The suspect then walked around the cab to the driver's side and proceeded to wipe the exterior of the left door area."
This being the case, it would be very unusual for a killer to be wiping away fingerprints from the taxicab, had he used guards on his fingertips as claimed in the 'Bus Bomb' letter mailed on November 9th 1969: "As of yet I have left no fingerprints behind me contrary to what the police say in my killings I wear transparent fingertip guards. All it is is 2 coats of airplane cement coated on my fingertips -- quite unnoticible + very efective."

In a follow up statement the Robbins children went into more detail: "They both watched and observed in silence as Zodiac pushed the driver to an upright position behind the steering wheel, exited the car and walked around the rear of the car and opened the driver's door. Stine had fallen over onto the seat and Zodiac pulled him back up into the seated position and had some difficulty keeping him upright. Once upright, he was seen to have a rag, or something like a handkerchief and began to wipe down the door area and leaning over the driver, part of the dashboard. When he was finished, Zodiac calmly walked to Cherry St. and walked north."

When the Zodiac Killer left the crime scene Paul Stine's body must have slumped back across the passenger seat, because when Officer Armond Pelissetti arrived shortly thereafter, he stated "When I went over to the cab I could see Mr Paul Stine, who was slumped over the front seat with his head into the well on the passenger side in the front." 
There was extensive blood pooling in the footwell (shown in photograph 1 below).  

This photograph can be estimated at approximately 10:11 pm.

​When the ambulance crew arrived shortly before 10.10 pm, they pulled Paul Stine from the passenger footwell into the position shown on the left. They pronounced him dead at 10:10 pm.
 
It can be seen that there is a complete absence of blood on the tarmac below Paul Stine's head. This indicates that once they pulled him into this position to check for signs of life (causing the splashing of blood from his hands - shown by the white arrow), the photograph must have been taken almost immediately after they vacated the passenger side door. Otherwise there would have been blood present on the roadside beneath Paul Stine's head, as was evident in photograph 2 below.

This indicated that once the medical personnel had arrived at the taxicab and pulled Paul Stine into the position shown, their evaluation must have been brief. It was immediately determined that Paul Stine showed no signs of life and certainly negated any need to circle the taxicab depositing bloody fingerprints on the dividing panel by the driver side door. 

In photograph 2 on the right, it can be seen the devastating impact of the murder, as the blood on the roadside continues to accumulate. This is the reason why photograph 1 must have been taken almost immediately after the ambulance crew retreated.

One unusual feature is the door position. Did the ambulance crew pull Paul Stine into this position without fully opening the door? Were they mindful of preserving the crime scene by their own volition, or under instruction?  Their priority was clearly the welfare of Paul Stine and determining signs of life - but if they had opened the passenger door fully, then it must have either fell back to the position shown on the right or been manually placed back in this position.   

The reasoning for this is shown in photograph 3. 

The door in the photograph on the left is now fully open. This is the position one would have expected the door to be located when the medical personnel were attending to Paul Stine, thereby giving them ample room to pull Paul Stine from the footwell and examine for signs of life. But the door only allowed for restricted access in photographs 1 and 2.

When the medical personnel extricated Paul Stine from the taxicab, a street guide was dragged out onto the roadside. This indicated that it was probably located under the body of Paul Stine on the passenger seat of the vehicle. This sheds doubt on the premise of a front seat passenger, although it cannot rule it out entirely.  

The photograph on the right shows the passenger door in the same position as photograph 3.

The relationship between the inner door handle (in brown on photograph 4) and the blood on the roadside can be seen as markedly different from photograph 2 (and therefore photograph 1).

The similar wider door positions in photograph 3 and photograph 4, indicate that the door was pulled open to acquire better pictures of the inside of the taxicab, before they eventually removed the body of Paul Stine.

This brief timeline takes us from the moment the Zodiac Killer left the front passenger seat of the taxicab, to the time the street guide was photographed on the roadside.

The poignant reminder of a journey that has now lasted 49 years - but a murder that should never be forgotten.

Officer Armond Pelissetti arrived at the Washington and Cherry crime scene, spoke to the teenagers, took a description of the suspect and ushered the children across the street to their residence. He then checked on Paul Stine from the passenger side of the vehicle, who he was "99.9% certain was dead," informed "everybody else" of the updated description over the radio, asked his partner Frank Peda to secure the crime scene and then headed off in the last known direction of the suspect. After his unsuccessful search, he returned to the crime scene just before "P.E.H. ambulance #82 responded, steward Dousette, victim was examined and pronounced dead at 10:10 pm."

The main priority of responding personnel, including police officers and medical crew, was to head to the business end of the taxicab to check Paul Stine for signs of life. This would have taken place from the front right passenger door. Once the ambulance personnel had determined life extinct, the crime scene was photographed and then Paul Stine was extricated from the taxicab. There was absolutely no need for medical personnel (who one would like to think were wearing gloves), to then round the taxicab and deposit bloody prints on the dividing panel of the driver and rear left passenger door. Once Paul Stine had been pronounced dead, it is now a murder crime scene and therefore would have been managed as such. 

Question marks have arisen over the bloody fingerprints, as to whether they were deposited by the Zodiac Killer. There was no reason for medical personnel to touch the dividing panel of the driver side door, and why would any police officer trained in securing a crime scene, rummage around the taxicab or Paul Stine without gloves, then commence to daub their fingerprints around the rest of the taxicab. Even if this hypothesis was believable, then the limited personnel who were present at the taxicab could be latterly screened and eliminated as the donor.

One of the reasons (but not the only reason) why these bloody fingerprints have been challenged, is the determination of individuals aligned with a particular suspect to place doubt on their origin. If their suspect has been ruled out of the investigation using these fingerprints, it is imperative that they cast doubt on the validity of such evidence by inferring medical personnel or police officers may have deposited the fingerprints. Was it a fingerprint already on the surface that was developed by blood, or from a bloody finger? This has also been touted as an explanation to negate the argument it was donated directly from the killer. However, this also requires attending personnel to cover themselves in blood, then round the taxicab and splash blood over an existing fingerprint. One would like to believe these people were trained in their profession to some extent, yet people who have immersed themselves in the belief their suspect is the Zodiac Killer would like you to believe otherwise. 

Many latent fingerprints were retrieved from the taxicab, the payphones, the Volkswagen Karmann Ghia and the Zodiac Killer communications. These have also been questioned as originating from the killer, as supposedly no fingerprint has been matched between crime scenes or letters, despite suspects having been ruled out on the basis of such fingerprints.

On October 16th 1969, the Napa Register published an article entitled 'Zodiac Killer Link Affirmed' in which Undersheriff Tom Johnson was included:"Napa, Vallejo and San Francisco law enforcement officers are certain that the person who stabbed to death a college girl at Lake Berryessa last month and shot to death three youths in Vallejo during the past 10 months is the same man who shot and killed a cab driver in San Francisco last Saturday night. 
By a preliminary match of fingerprints and handwriting, Undersheriff Tom Johnson said that it appears this is the same murderer. However, he pointed out that specialists have not completed, as yet, extensive examinations to verify that identity. "I'm fairly certain it's the same man," he added." 

On October 17th 1969, the Lodi Sentinel stated "Johnson said preliminary analysis of partial fingerprints obtained from crime scenes in Napa County, Vallejo and San Francisco indicated they came from the same man. But he said the prints were not complete enough for an identification of the killer." 

Fingerprints from a crime scene tend to be partial rather than a full rolled fingerprint as would be taken from an individual at the police station. They will then be entered into AFIS (Automated Fingerprint Identification System) and unlike the fiction of crime shows where one suspect pops up, there may be an array of possible matches. The number of distinguishing points on the fingerprint required to enable a match varies from country to country, and from individual to individual (12 to 20 is a good guide).
The more complete the fingerprint (with identifiable features) the less corresponding matches in the database should be achieved. If the fingerprint has less markers, the suspect pool will be magnified. In 1969 the police didn't have the benefit of an automated fingerprint recognition system, so everything was done by hand in a long and arduous process.

Undersheriff Tom Johnson stated "the prints were not complete enough for an identification of the killer."
This indicates that there were not enough distinguishing points on the fingerprints to definitively identify an individual. But this is not the same as the ability to rule out suspects based on the partial fingerprints they had collected. A full DNA profile can be matched definitively to a single individual, but a partial DNA profile cannot. However, it can be used to eliminate suspects.
A partial fingerprint can be approached in a similar manner - it may "not be complete enough for an identification of the killer", but it can be used to rule out suspects, particularly if fingerprints from different crime scenes "came from the same man."  

In the diagram above, I have sectioned off the right edge of a fingerprint with five distinguishing points. This is just an example and not to be taken literally.
​This portion of fingerprint would unlikely be "complete enough for an identification of the killer", but if this section of fingerprint was discovered through several crime scenes and/or letters, then it would greatly bolster the case that one individual was responsible for the Zodiac crimes.

​If a suspect such as Arthur Leigh Allen or Ted Kaczynski (who have fingerprints on file) were then compared to this section of fingerprint, and there was no correlation between the two, then the chances of their involvement in the crimes rapidly fades away. A clear partial fingerprint (which still contains extensive detail) can be examined locally and compared to named suspects in the case. 

The bloody fingerprints from the dividing panel of the taxicab are almost certainly those of our killer. The only person that can be definitively placed there, is the Zodiac Killer. The three teenagers described a killer attempting to haul the taxicab driver into an upright position behind the steering wheel from this location. The Zodiac Killer may have applied some caution when wiping down the door handles of the vehicle, but he may have overlooked the fingerprints from his right hand, when bracing himself against the taxicab door panel while lifting Paul Stine with his left. 
Robbins kids statement: "They both watched and observed in silence as Zodiac pushed the driver to an upright position behind the steering wheel, exited the car and walked around the rear of the car and opened the driver's door. Stine had fallen over onto the seat and Zodiac pulled him back up into the seated position and had some difficulty keeping him upright. Once upright, he was seen to have a rag, or something like a handkerchief and began to wipe down the door area and leaning over the driver, part of the dashboard. When he was finished, Zodiac calmly walked to Cherry St. and walked north."

Tim Reiterman published an article entitled 'Zodiac: 4 years later. What happened to the killer who kept the city in terror?' 
In the article Dave Toschi laid out his thoughts on the Zodiac case, with one notable section: "Although he took care to wipe his fingerprints and boasted that he took other precautions, Zodiac made mistakes. Toschi said "police have enough fingerprints from the Stine murder scene and from a Napa County telephone booth, where Zodiac once called police- to make a positive identification if he is captured or surrenders."'

Captain Martin Lee at the San Francisco Hall of Justice, during a  KPIX News report from November 12th 1969 stated "We assume one day we are going to catch this man, and we are, and certain evidence must be kept from the public, as he cannot be tried in the press. The precise evidence I am speaking of, I cannot even describe to you, but I can say this much - that there is considerable evidence of many different kinds."

Fingerprints being one.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Zodiac- Mysteries at the Museum just aired on the Travel Channel on October 3rd 2018. The first 38 minutes is a routine retelling of the Zodiac case, leaving only the remaining 2 1/2 minutes of any note.
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​The narrator states "The actual Zodiac evidence was collected in a state laboratory in May 2018, who then sent it to a genealogical laboratory in Florida. Analysts then looked for similarities between the Zodiac profile and family members who have already submitted DNA to a public database. If they find a match, genealogists will then create a family tree that could eventually lead them to the Zodiac Killer."

If these statements were true (which hasn't been verified by an official source), then it implies that a viable DNA sample has been sourced from the Zodiac Killer stamps and/or envelope seals, and submitted to GEDmatch for entry into the genealogical database.

​In May 2018, the Sacramento Bee stated "Investigators searching for the Zodiac Killer have submitted evidence to a private DNA lab in the hopes of obtaining a genetic profile of one of California's most elusive criminals — then tracking him down using the same kind of family-tree tracing recently used in the East Area Rapist case. Vallejo police Detective Terry Poyser, who has worked the Zodiac case for four years, said his agency has submitted two envelopes that contained letters from the Zodiac Killer for a type of advanced DNA analysis that previously had not been available in the case. Poyser declined to identify the lab, but said it would attempt to obtain a full DNA profile from saliva on the envelope flap and stamps. He said he expected to have results back from the lab as soon as in the next few weeks, and almost certainly by summer."

If this advanced DNA analysis was successful on the two July 31st 1969 envelopes, and created a Zodiac DNA profile of sufficient information to be submitted to a genealogy database, then it would be sent to GEDmatch in Florida in hope of a familial match. The 'Mysteries at the Museum' episode seems to suggest this has already been done, and would indicate that a viable sample of DNA has been recovered from the Zodiac letters after 49 years.

There have been many question marks over the validity of the tests conducted by Cydne Holt, General Manager and Chief Scientific Officer at Verogen, in 2002. Claims the DNA was sampled from the outside of the letters is unproven, but if true, it would certainly negate any findings, including the elimination of any suspects previously ruled out using such evidence. If a sufficient DNA profile in 2018 has been successfully generated, then the elimination, or otherwise, of suspects touted in the Zodiac case can begin again in earnest (assuming the DNA retrieved is that of our killer). Only a partial profile is required for the latter. 

"California law enforcement investigating the Golden State Killer case uploaded the DNA profile of the suspected serial rapist/killer from an intact rape kit in Ventura County to GEDmatch. It identified 10 to 20 distant relatives of the Golden State Killer, and a team of five investigators working with genealogist Barbara Rae-Vente used this to construct a large family tree, which led them to identify retired police officer Joseph James DeAngelo as a suspect.  Investigators acquired samples of his DNA from items he discarded outside his home, one of which definitively matched that of the killer. The process took about four months, from when the first matches appeared on GEDmatch, to when DeAngelo was arrested in April 2018." Wikipedia.

"As of early this year, more than 12 million people had undergone such tests, mostly from 23andMe and Ancestry DNA, and the number is growing by about one million each month. That’s reaching the point where nearly everyone in the US will have a close relative, cousin, or second cousin who has given a DNA sample. Users of GEDMatch are warned that they have no guarantee of privacy and that their data could be used for purposes other than genealogy." Technology Review.

In cooperation with American law enforcement organizations, Parabon NanoLabs, based in Reston, Virginia started uploading DNA evidence from crime scenes to GEDmatch in an attempt to identify perpetrators. Parabon said they found matches in 20 cases as of 2018.

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

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

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

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

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

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

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

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

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

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