The Zodiac Killer appeared to be using Mount Diablo as a reference point as early as November 9th 1969, when he mailed the Bus Bomb letter and supplied us with some crosshairs and five X's on its circumference. Using this diagram it is possible to determine that the Zodiac Killer was identifying Mount Diablo as his initial or center point. Mount Diablo was used for the purpose of land boundaries in the majority of Northern California and Nevada, with the summit used as the "initial point", the north/south meridian and the east/west baseline intersection point. However, because of the vastness of California, surveying required three "initial points" of Mount Diablo, Mount Pierce and the San Bernardino Mountain to form grid lines. The Zodiac Killer knew the prominence of Mount Diablo from an elevation standpoint, but very likely knew some of the history from a navigational perspective  - and why he chose this mountain as his "initial point".

In the Dripping Pen card the Zodiac Killer was claiming the brutal stabbings of Kathie Reyne Snoozy & Debra Gaye Furlong on August 3rd 1969. On November 12th 1969, somebody featured in the San Francisco Chronicle used the San Jose double murder in their analysis of the Bus Bomb letter crosshairs, very likely concluding the "initial point" was Mount Diablo, without actually referring to the mountain by name. When you look at the five X's around the circumference, it's fairly obvious that they all sit on the left side of the crosshairs center (from 180 degrees to 330 degrees). They were positioned at 6, 8, 9, 10 and 11 on a clock face. Therefore, the "initial point" must be to the east of all the confirmed attack sites. When we attempt to line up the uppermost X with the Zodiac Killer's uppermost crime at Lake Berryessa, it becomes quickly apparent that only one position satisfies four of the X's on the circumference, and that one X represents both Lake Herman Road and Blue Rock Springs. If we draw a line through the Lake Herman Road and Blue Rock Springs attack sites, the line passes directly over the summit of Mount Diablo and beyond. By moving the crosshairs "initial point" along this line, we can see that only one position satisfies at least four of the X's.     

The Zodiac Killer only gave us a rough drawing of his crosshairs, so any interpretation must take this into account. The above diagram, centered over Mount Diablo, lines up the five locations the Zodiac Killer was claiming as his murders (Lake Herman Road, Blue Rock Springs, Lake Berryessa, San Francisco and San Jose). The (unaccounted for) red line above, travels directly over the Salesian High School of Daniel Williams, who Zodiac targeted from October 23rd 1969 to November 5th 1969 by prowling his house, poisoning his drink, making malicious phone calls, and threatening to shoot him via the Martinez Police Department. His subtle threats continued in the Dripping Pen card and Bus Bomb letter, explained thoroughly in the article The Quest For Number Eight. This is why he wrote "PS. Be Shure to print the part I marked out on page 3 or I shall do my thing" next to the crosshairs on the Bus Bomb letter. That "thing" was a threatened attack on Salesian High School, depicted by the red line on the map. The orange line shows Magnetic North of 16.5 to 17.0 degrees in 1969. The tilted crosshairs are slightly shy of this mark. But remember, the Zodiac Killer only drew us a rough guide in his correspondence. These Bus Bomb crosshairs were the precursor to the Mount Diablo map on June 26th 1970, when the Zodiac Killer again used the mountain's "initial point" as a directional tool, but this time to locate a proposed bus bomb on the Southern Freeway by Ingleside Police Station, using four radians and five inches. The Mount Diablo Map and Code Solution.     

The Zodiac Killer's 38 character code may be solved by examining three of his other ciphers (two solved and one unsolved), including the day he mailed the first Fairfield letter in December. The Z340 (November 8th 1969), Z38 (December 7th 1969), Z13 (April 20th 1970) and Z148 (probably May 3rd 1971) all have one other date in common - October 22nd 1969.

[1] The Z340 (November 8th 1969) was a response to the October 22nd 1969 Jim Dunbar Show, stating that the person who phoned into the show was effectively an imposter or phony, encoding a contemporary message and using wording similar to the headlines in the San Francisco Chronicle on October 24th 1969. The 340 message read, in part "That wasn't me on the TV Show", mimicking the headlines of "That Wasn't Zodiac, Say 3 Who Know" and "It Wasn't Zodiac, Say 3 Who Know". He also responded to the Jim Dunbar Show and the October 23rd 1969 Chronicle article, entitled "A TV Runaround With Zodiac Calls", in which "Belli told Sam he'd attempt to get a promise from District Attorney John J. Ferdon that Zodiac would be spared the gas chamber if convicted of murder". The Zodiac Killer responded in code that he was "not afraid of the gas chamber".​ 

​[2] The Z148 code (probably mailed May 3rd 1971) was again contemporary in nature, and a response to the police arrest and interview of Karl Francis Werner on April 29th 1971. Three newspaper articles ran with the headlines "San Jose Student Held in Slaying of Three Girls", "San Jose Student Held in Slaying of 3 Girls" and "Youth Arraigned in Knife Slayings of Three Girls". The Zodiac Killer encoded these headlines in his 148 character cipher by promising to "skin three kids and make a suit from the skin" if his latest letter was not published. He also encoded the statement "stop listening to phonys" in the Z148, referring to both Karl Francis Werner (who was being interviewed for the Snoozy & Furlong murders on August 3rd 1969, to which the Zodiac Killer had already claimed as his victims) and Eric Weill (who phoned into the Jim Dunbar Show at least twice, claiming to be Zodiac}. The second phone call was reported in San Francisco Chronicle on February 6th 1970, entitled "Talk Show's 'Zodiac' Caller a Phony", with Inspector David Toschi pitching in: "Homicide detectives later listened to a tape recording of the conversation and concluded that Sam was a phony. It most certainly was not Zodiac, said Inspector David Toschi".  The headlines of the October 24th 1969 and February 6th 1970 Chronicle articles both placed within the encoded text of the Z340 and Z148.

[3] The Zodiac Killer mailed the Z13 on April 20th 1970, very likely a response to the October 22nd 1969 article in the San Francisco Examiner, entitled "Cipher Expert Dares Zodiac to Tell Name". It read "Dr Marsh told the Examiner today: The killer wouldn't dare, as he claimed in letters to the newspapers, to reveal his name in the cipher to established cryptogram experts. He knows, to quote Edgar Allen Poe, that any cipher created by man can be solved by man. Zodiac has not told the truth in his cipher messages to the Examiner, the Chronicle and the Vallejo Times-Herald. Zodiac has not done this, because to tell the complete truth in relation to his name-in cipher code-would lead to his capture. I invite Zodiac to send The American Cryptogram Association a cipher code, which will truly and honestly include his name". The Zodiac responded on April 20th 1970 by stating "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is___ " The letters N, A, M and E could be found in the ciphertext of the code.

[4] The Z38 mailed on December 7th 1969 began with "This is the Zodiac speaking. I just need help", mimicking the caller (Eric Weill) to the Jim Dunbar Show on October 22nd 1969. It is clear that this cry for help was a disingenuous attempt at ridicule from a killer who either listened to the Jim Dunbar Show on October 22nd 1969, or read the subsequent newspaper articles. On October 22nd 1969, the Los Angeles Times reported that "Belli was put on the line, and the voice said "I want help". On October 23rd 1969, the Desert Sun newspaper claimed that Melvin Belli told the caller “All of San Francisco wants to help you. The hand is out, you can feel the hands out.” On the same day of December 7th 1969, we have a man mailing a letter to the San Francisco Chronicle mocking the call to the Jim Dunbar Show by stating "I just need help", followed a few hours later by a call to an Oklahoma radio station by a man doing an awfully good impression of the man who rang the Jim Dunbar Show on October 22nd 1969. This impressionist caller could possibly be the Zodiac Killer mocking the Jim Dunbar Show, just as he had done in the letter earlier that day.

​Therefore, we have the Z340 (November 8th 1969), Z38 (December 7th 1969), Z13 (April 20th 1970) and Z148 (probably May 3rd 1971), all relevant to the date of October 22nd 1969. Bearing in mind the Z38 carried the same four and five characters from the beginning and the end of the 340 cipher, along with the observations above, we could expect the Z38 message to be somehow related to these other ciphers. The message may very well lie in the newspaper inches from October 22nd 1969 to December 7th 1969 - and may be related to the Jim Dunbar TV Show yet again. 

On December 18th 2021, the Zodiac Speaking podcast will be releasing an interview with Jo Anne Goettsche, former roommate of Donna Lass at 4122 Balboa Street in San Francisco. It is approximately 55 minutes running time.

​Interviewed by Mike Morford, she talks frankly about her recollections of Donna Lass and the relevant time period before and after September 6th 1970, having traveled to South Lake Tahoe the day of her disappearance to spend a couple of days sightseeing with Donna. Unfortunately, that meeting never transpired, and Donna Lass was never seen again. We will also discuss a private investigator's report, provided to the family of Donna Lass by the investigator they hired. The season finishing podcast should be an interesting listen of about 90-120 minutes. So don't forget to tune in on December 18th.           

To indent writing is to begin text with a blank space between it and the margin

Take a look at the the four consecutive known letters from April 24th 1978, May 2nd 1978, May 6th 1986 and October 28th 1987, shown below. Now imagine these are from different authors hoaxing Zodiac letters. All four managed to use "indented writing" on the opening introduction of "This is the Zodiac speaking", which was never used prior to 1978 in any of the four published introductions in the San Francisco Chronicle (or in any Zodiac communications). This means that despite having the "This is the Zodiac speaking" introduction available for them to mimic, all four (or multiple) authors failed to keep the introduction in line with the text beneath it (signifying a consistent change in pattern). Subsequent to the introduction, all four authors also began with the personal pronouns of "I" and "You". In three of these the text begins with "I". All of these three examples fail to use correct punctuation between "speaking" and "I". Ideally, these two words should be separated with a comma or full stop (period), but in every instance the author fails to do so, just like the authenticated Melvin Belli letter from December 20th 1969, an image of which was not available to the author of the 1978 letter (if they were a hoaxer). This should prove beyond any reasonable doubt we are dealing with one author who penned the December 20th 1969, April 24th 1978, May 6th 1986 and October 28th 1987 letters. It should also prove it was the Zodiac Killer who wrote at least four of the letters, one of which we know has a full DNA profile. If the 1978 envelope has DNA beneath the stamp and/or envelope seal, why not the others? The 1978, 1986 and 1987 letters are almost certainly genuine Zodiac communications, so why were law enforcement attempting to secure Zodiac DNA from two of the July 31st 1969 envelopes nearly four years ago, when they already have it? Sadly, this is another avenue that will be ignored.     
​​Relevant article: Still Driving Around in 1987 [PT2].

Thanks to Druzer for his great work on this topic of indented writing.    

In the San Francisco Examiner on August 3rd 1978, four experts, Keith Woodward (head of Los Angeles documents department), John Shimoda (Postal Service crime laboratory), Robert Prouty (Chief documents section/Bureau of Criminal Identification and Investigation) and Terry Pasco (also Criminal Identification and Investigation), all deemed the 1978 letter a fake. Keith Woodward described the 1978 letter "a carefully drawn copy of the true Zodiac printing". He concluded it "was a poor attempt by an unknown writer". John Shimoda declared it "an attempt to duplicate Zodiac letters and is not authentic". Robert Prouty and Terry Pasco said basically the same thing, while Robert Graysmith disingenuously turned on this letter when he realized the DNA extracted from it didn't match the profile of Arthur Leigh Allen, claiming a light table may have been employed to hoax the letter. He then boldly trumpeted the above arguments of handwriting analysis - a subjective analysis - that has forever divided document examiners in the case of JonBenet Ramsey and the three-page ransom note supposedly authored by a "foreign faction".

Handwriting analysis cannot be used to exclusively and definitively argue for the authenticity, or otherwise, of a Zodiac communication. However, it can be used as a supporting argument where other evidence exists. This still hasn't stopped vociferous sections of the Zodiac community buying into the notion of an authenticated list of Zodiac communications based solely upon the narrative they have been sold from day one. 

Let us look at the words of John Shimoda, who stated that the 1978 letter was "an attempt to duplicate Zodiac letters and is not authentic". The author of the 1978 letter was that good at duplicating Zodiac letters, they failed to duplicate the opening introduction of "This is the Zodiac speaking", which was always self-contained on a separate line in every confirmed Zodiac communication mailed to the San Francisco Chronicle, San Francisco Examiner and Los Angeles Times prior to 1978. The hoaxer had four examples of this to copy from the San Francisco Chronicle newspaper, when it released images of the ​October 13th 1969, November 8th 1969, April 20th 1970 and March 13th 1971 letters to the public (see images below). The hoaxer failed to copy any of these. Instead, they wrote "This is the Zodiac speaking I" (mimicking the unreleased image of the Melvin Belli letter and its punctuation error). The author of the 1978 letter had the January 29th 1974 Exorcist letter available to them - widely published in the San Francisco Chronicle on January 31st 1974 - yet they failed to misspell "truly" to "truley", clearly evident in the Exorcist letter. The author of the 1978 letter failed to add a customary running total, which would have been the easy option to choose for somebody wanting to convince us they were Zodiac. Instead they placed the word "guess". The author of the 1978 letter failed to keep the "This is the Zodiac speaking" introduction in line with the text beneath it (thanks Druzer). In the 1978 letter they used "indented writing" (to indent is to begin text with a blank space between it and the margin). This absence of indented writing during the introduction phase was present in every published letter up to 1978 (see below). So, you can see that the claim of the 1978 letter author attempting to "duplicate Zodiac letters" from the newspapers, carries no merit whatsoever. This individual wasn't attempting to copy anybody. 

If there is one letter that "suspect chasers" have a vested interest in dismissing out of hand, it's the 1978 letter (because a DNA sample has been obtained from it). If their suspect's DNA is available for comparison to a genuine Zodiac letter tomorrow, then it would only be a matter of days or weeks before their suspect is possibly confined to the compost heap of history, along with many other poor suspects in this case. They cannot take that chance, so play the odds and reject the letter beforehand. It is in the interest of "suspect chasers" to never accept the bloody taxicab fingerprint as originating from Zodiac (if their suspect's fingerprints exist on file), to never accept that Zodiac licked the stamps and envelopes, to never accept the 1978 letter as genuine, and for a minority, that DNA is never found in the Zodiac case. The longer they can promote their suspect, the better.

The Zodiac community have been eager to constantly enquire about the round of DNA testing reported in 2018, but show little interest in submitting the 1978 letter for familial DNA analysis. The reason for this apathy, is that many have looked at the 1978 communication and concluded it wasn't authored by the Zodiac Killer, primarily because they didn't like the handwriting or the tone of the letter. You cannot argue with research like this. For those who believe the 1978 letter is genuine, the search for Zodiac DNA is over. 

The Zodiac Killer is allowed to produce handwriting in subsequent letters the same or similar to previous communications because he is effectively doing no more than mimicking himself. A copycat or hoaxer can mimic the Zodiac Killer using previously published letters and envelopes in the newspapers, but what they cannot do is mimic unreleased communications by the Zodiac Killer. To my knowledge, only two envelopes were released to the newspapers prior to January 29th 1974 that were addressed to San Francisco. The envelope to the Melvin Belli letter was released on December 28th 1969 with the address of "Mr. Melvin M. Belli 1228 Mtgy San Fran Calif". The envelope to the 340 cipher was released on November 16th 1970 with the address of "S.F. Chronicle San Francisco Calif Please Rush to Editor".  The author of the Exorcist letter (if a hoaxer) when addressing their envelope to the San Francisco Chronicle only had these two envelopes to work with, but copied neither. This mimicry would have been expected of a hoaxer.  

Instead, the author of the Exorcist letter chose to mimic part of the address from two envelopes mailed by the Zodiac Killer in April 1970. These two envelopes were addressed San Fran (dot) Chronicle on April 20th and April 28th 1970 and never publicly released via the newspapers prior to January 29th 1974. When you look at the April 28th 1970 envelope in particular, it isn't just the handwriting that is extremely similar, it's the positioning of the detached full-stop, the spacing between each of the three components, the very slight left to right slant, the marginally elevated letter L, the letter I is dotted directly above in every instance, and both the letters R and H are slightly separated. The April 20th and April 28th envelopes were the only two Zodiac communications up to January 29th 1974 that were addressed in this fashion, yet the author of the Exorcist letter (if a hoaxer) would have managed to virtually replicate every facet of this address despite having never laid eyes on them. This clearly shows that the Exorcist letter author was the Zodiac Killer, putting to rest any notion that this letter may have been fraudulent.     

People will say this just further proves that the Exorcist letter was penned by Inspector David Toschi, who had inside knowledge of the two April 1970 letters. Why would Inspector David Toschi copy the address so perfectly from an envelope that had never been released into the public domain by January 29th 1974, thereby drawing suspicion towards somebody from within? He was an intelligent seasoned investigator, not an imbecile. The exact same reasoning can be applied to the 1978 letter when comparing the opening line from each communication. A copycat or investigator would apply logic, and mimic the widely publicized "This is the Zodiac speaking" introduction displayed in four San Francisco Chronicle publications (or mimic the 11 out of the 12 communications prior to January 29th 1974 that carried this introduction), not mimic an introduction never released into the public domain such as "This is the Zodiac speaking I" in the Melvin Belli letter. However, the Zodiac Killer is perfectly allowed to be himself.   

According to Alan Keel, Criminalist at the San Francisco Police Department, San Francisco, California from 1996 to 1999, he "revealed that there were two letters in possession of the department that, in contrast to the "true" Zodiac letters, had abundant saliva and DNA-containing oral epithelial cells on them, that DNA was easily extracted from these two letters, and that the DNA extracted from these two letters matched between them. These two letters were considered forgeries, since the "true" Zodiac verifiable letters had not been licked by the sender". According to Zodiac researcher, Mike Rodelli, Alan Keel had "analyzed two 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". 

In Mike Rodelli's latest book In the Shadow of Mount Diablo he makes it obvious that he believes the SLA and Red Phantom letters are communications mailed by the Zodiac Killer. He is also fairly confident that the true Zodiac letters were not licked by the sender. This being the case, then he must accept that the SLA and Red Phantom letters should have no oral epithelial cells on them. The Badlands postcard was pre-stamped, so provided no opportunity for reliable DNA testing. Therefore, the only possible match between the DNA from the 1978 letter and one of the 1974 letters, using Mike Rodelli's thought process, had to be between the 1978 letter and the Exorcist letter. If Alan Keel's claimed statement is correct, then I agree. The problem however, is that the Exorcist letter is almost certainly genuine Zodiac material because of the comparison between its envelope and the unpublished envelopes from April 1970 (which hadn't been published by January 29th 1974). So, if the Exorcist letter is genuine, so is the 1978 letter.        

If the SLA and Red Phantom letters had been tested and had hypothetically produced a full DNA sample, then Mike would probably agree that the DNA on both letters should have matched (and therefore was secreted from Zodiac). In fact, they couldn't have been tested to produce a full DNA sample, because if they had been authored by the same individual, the 1978 letter would have matched at least two 1974 letters, not one (as apparently claimed by Alan Keel). This is apparent in the DNA chart, that doesn't attribute anything to the Red Phantom letter in comments, and doesn't even include the SLA letter at all. If correct, then the statements of Alan Keel implies that both the 1978 and Exorcist letters have a full DNA profile, which can then be stored and entered into CODIS when required, or used in the science of genetic genealogy. Unless this DNA "print out" has been mislaid or thrown away (which would seem inconceivable), then the profile of these communications can be used, much like Joseph James DeAngelo Jr, to search for any genealogical links that may be relevant to a killer operating in the Bay Area of Northern California.  

FOLLOW UP ARTICLES:
THE GENETIC IDENTITY OF THE KILLER      WE MAY ALREADY HAVE ZODIAC DNA

Based on Mike Rodelli's book and everything he has stated over the last few years, we should today have the ability to either incriminate or exclude Kjell Qvale as the Zodiac Killer.once and for all. According to Alan Keel, Criminalist at the San Francisco Police Department, San Francisco, California from 1996 to 1999, he "revealed that there were two letters in possession of the department that, in contrast to the "true" Zodiac letters, had abundant saliva and DNA-containing oral epithelial cells on them, that DNA was easily extracted from these two letters, and that the DNA extracted from these two letters matched between them. These two letters were considered forgeries, since the "true" Zodiac verifiable letters had not been licked by the sender". According to Mike, Alan Keel had "analyzed two 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". The only problem with the statements by Alan Keel is that the 1978 letter is unlikely to be a forgery. 

On October 29th 2021, Mike Rodelli stated on the Zodiac Killer message board "The fact remains that in 2007 Keel told me, as he had told Lafferty before me, that there is a 1974 forgery based on DNA and the ONLY 1974 letter that had been tested for the presence of cells during Keel's tenure (as demonstrated by the DNA chart that I believe Keel made in about 2000) was the Exorcist letter. This is not rocket science.  Even if it is not the Exorcist letter that Keel was talking about, it IS a candidate as being a forgery whose DNA matches the 1978 letter based on the information in the chart". Mike Rodelli is correct. The only communication from 1974 that can conceivably match the DNA from the 1978 letter is the Exorcist letter. Mike also stated on the Zodiac Killer Net forum "This is where the rubber truly meets the road in this discussion and where we can see that it is unlikely that anyone but Zodiac wrote the SLA letter. When you look at the hand printing on the SLA letter in a vacuum, it certainly does not jump off the page to me that it was penned by Zodiac. But when you take a close look at the envelope, that is a different story". Mike then shows comparisons between the SLA envelope and the Stine envelope, 340 envelope, Bus Bomb envelope and Kathleen Johns envelope, arguing "It's hard to look at these envelopes and not see the similarities. And note that the November 8, 1969 envelope contained a piece of Stine's shirt, thus proving its authorship as being from Zodiac".       

Therefore, if Mike Rodelli is being fair-minded and believes the SLA handwriting is consistent with these other communications, then he should have no argument conceding that the handwriting and construction of the Exorcist envelope handwriting is consistent with the envelopes from April 20th 1970 and April 28th 1970, which he believes are Zodiac communications. Mike should therefore come to the same conclusion, that since the two April 1970 envelopes were the Zodiac Killer, then so is the Exorcist letter. The April 1970 communications were the only two confirmed Zodiac envelopes to carry the address of San Fran (dot) Chronicle prior to January 29th 1974. The envelopes were also never released into the public domain, meaning the Exorcist letter author could not have mimicked them.       

Mike should now agree that having established the Exorcist letter as genuine Zodiac material - and using the findings of Alan Keel and Mike's correct argument that the 1978 DNA should conceivably match the Exorcist letter DNA (being the only ones tested in the DNA chart) - we have to conclude that the 1978 letter is genuine as well. Mike went on to say on the Zodiac Killer message board "Keel further allowed, although not in this email but in a conversation I had with him at about the same time, that there was so little saliva on the Zodiac letters that it would not be unfair to say that they had been sealed with tap water and the stamps applied with tap water. So if you're wondering why after 20 years we still don't have a verified sample of Zodiac's DNA it's because the only DNA he may have left on these letters is from when he applied the stamps to the envelopes. If he wet the stamps with water but didn't wear gloves then as he applied the stamps to the envelopes the glue could have pulled a few odd cells off of the tips of his fingers thus leaving essentially touch DNA on the stamps. That is why if they do have Zodiac's DNA today it is because of this minute number of cells that they have had to find using the most Advanced Techniques available".

The argument being that the "true Zodiac letters" had few cells, whereas the fraudulent Zodiac letters had "had abundant saliva and DNA-containing oral epithelial cells". However, we have now established that the Exorcist letter is genuine, just like the two April 1970 communications. Yet these two envelopes have few cells found in the DNA chart, whereas the Exorcist letter has abundant cells, despite one author throughout. This disproves the contention of Alan Keel that the 1978 letter is a forgery, that matches one of the 1974 communications. All it proves is that the Zodiac Killer authored the 1978 letter and one of the 1974 communications. These findings also disprove the notion that the Zodiac Killer didn't lick his envelopes and/or stamps. The only way to argue the findings presented above, is to claim that there is unfounded similarity between the Exorcist envelope handwriting and the two April 1970 envelopes, while simultaneously claiming there is a similarity between the SLA envelope and the Stine envelope, 340 envelope, Bus Bomb envelope and Kathleen Johns envelope, But this would be an argument in bad faith.

The DNA chart stating that a "DNA sample was obtained" from the 1978 letter appears to back up Mike Rodelli's statement of this letter producing enough DNA to create a profile, based on the findings of Alan Keel. This being the case, if the profile of the 1978 letter matches the profile of the Exorcist letter, then we have a full DNA profile of the Zodiac Killer. Forensic genetic genealogy can now be used to discover the ancestry of the killer and ultimately identify him, in similar fashion to that used in the case of the Golden State Killer, resulting in Joseph James DeAngelo,Jr. pleading guilty to thirteen counts of murder on June 29th 2020 

FOLLOW UP ARTICLE: WE MAY ALREADY HAVE ZODIAC DNA   

This is a continuation from the article The Day the Zodiac Killer Rang Oklahoma. The original article will be replicated here under Part One, immediately followed by some fresh information under Part Two (with the help of Zodiac Killer Net forum).

Part One: ​An imposter by the name of Eric Weill called into the Jim Dunbar KGO-TV station on the morning of October 22nd 1969 and attempted to pass himself off to the host and Melvin Belli as the infamous Zodiac Killer. During the phone call Eric Weill pleaded with Melvin Belli, stating "I want help".  On October 23rd 1969, the Desert Sun newspaper claimed that Melvin Belli told the caller “All of San Francisco wants to help you. The hand is out, you can feel the hands out.” The Zodiac Killer clearly latched onto this plea for help, when in mocking fashion he wrote to the residence of Melvin Belli on December 20th 1969 and stated "please help me" on three occasions, in accompaniment to the phrase "I cannot reach out for help". However, this wasn't the first time the Zodiac Killer would mock the spectacle of the Jim Dunbar Show, when on December 7th 1969 he mailed a letter from Fairfield to the San Francisco Chronicle stating "I just need help. I will kill again so expect it any time soon the will be a cop". Thirteen days later, the Melvin Belli letter would replicate this plea for help, despite the fact the December 7th 1969 correspondence was never released to the newspapers. But here's the kicker.

After the Zodiac Killer communication, postmarked December 7th 1969, a phone call was received later that night by the host of commercial radio station KTOK in Oklahoma City claiming to be from the Zodiac Killer. KTOK news director Larry Lamotte told the San Francisco Chronicle that a man rang the station and declared that he had to leave California because "it got too hot for me", remarking that the man did an awfully good impression of the man who rang the Jim Dunbar Show on October 22nd 1969. This is the crucial part. On the same day of December 7th 1969, we have a man mailing a letter to the San Francisco Chronicle mocking the call to the Jim Dunbar Show by stating "I just need help", followed a few hours later by a call to an Oklahoma radio station by a man doing an awfully good impression of the man who rang the Jim Dunbar Show on October 22nd 1969. This impressionist caller could possibly be the Zodiac Killer mocking the Jim Dunbar Show, just as he had done in the letter earlier that day - and would do thirteen days later when he thrice pleaded "please help me". There is no way of finding out the full transcript of the phone call to the Oklahoma radio station, but it wouldn't be too far-fetched to believe he mockingly asked for help on this occasion too.   

The caller to the Oklahoma radio station, doing an impression of the Jim Dunbar Show caller, claimed he left California because "it got too hot for me". A few hours before the October 22nd 1969 Oakland Police Department phone call requesting that either Melvin Belli or Francis Lee Bailey, high profile lawyers at the time, appear on a chat show hosted by Jim Dunbar later that day, somebody rang the Palo Alto Times newspaper claiming to be the Zodiac Killer and stated that he had left San Francisco because "because I'm too hot there". Two similar pieces of phraseology connected by two phone calls and the Jim Dunbar Show.

​In addition, we have the December 7th 1969 letter stating "I will kill again so expect it any time soon the will be a cop", followed by the December 16th 1969 Fairfield letter listing 38 "cops" as potential victims, and a December 19th 1969 payphone call to Sergeant Robert Rengsdorff of the San Jose Highway Patrol threatening "I am going to kill five of you officers and a family of five between now and Monday". Three threats to kill cops within twelve days of December. Then came the mocking Melvin Belli letter just one day later. Neither of the Fairfield letters were released to the newspapers, making the December 19th 1969 payphone caller just another lucky chap if it wasn't the Zodiac Killer. It is fairly evident that the Zodiac Killer was responsible for many more phone calls than the two he has been accredited with, including a phone call to the Santa Rosa Police Department on October 15th 1969. 

The apparent familiarity with the KTOK radio station, by choosing to call one of its hosts over 1,000 miles from the Bay Area, could suggest an affinity to their style of broadcasting. During the 1960s KTOK radio station featured news, sport and adult music, with the 1960 Broadcasting Yearbook describing its content as "toe tapping music (no rock and roll) and all the announcers are adults". That music included such artists as Tony Bennett, The Mills Brothers and Al Martino. This may give an insight into the maturity and age of the Zodiac Killer when the phone call was made on December 7th 1969, in a year when all three sets of eyewitnesses at Presidio Heights described the Zodiac Killer as 40 years or above. Was the Zodiac Killer an avid listener to this radio station, or did he once have roots in Oklahoma?   

Part Two: Then came the ridiculous statements in the Lodi News-Sentinel by a detective sergeant and KTOK news director, Larry Lamotte. The detective sergeant told the Sentinel that "Major Miller told us it was a hoax. I don't know if we even looked into the case". Apparently the police ended their investigation inside of one day - and according to Larry Lamotte they didn't even come to collect recordings of the man's voice when offered the tapes. Larry Lamotte remarked "I don't see how it can be anything but a hoax. The caller was too familiar with Oklahoma City. He knew the name of our shopping centers and mentioned our high rate of traffic fatalities and even the governor's 'Live for the 70s program". Well, maybe he had visited Oklahoma recently, and/or had possibly lived there at some point Larry. Maybe he read newspapers and magazines.   

When the caller was asked if he was the Zodiac Killer, he stated "I could be", and added that "I don't need to kill. There are too many people killed on the highways and that's legal". The conversation continued with the caller remarking "You're going to try and trace it" - and when met with the affirmative - replied "then I better hang up". The caller added one final thing, threatening more killings by stating "There are plenty of parking lots" - mentioning one large Oklahoma shopping center by name. This call to Oklahoma City on December 7th 1969 came forty-seven days after the Jim Dunbar Show, yet it mimicked the October 22nd 1969 call to KGO-TV station the very same day a Zodiac letter was postmarked to the San Francisco Chronicle, also mimicking the Jim Dunbar Show hoaxer by stating "I just need help". Again, predating the Melvin Belli letter on December 20th 1969 that thrice pleaded "please help me". The caller to the Oklahoma radio station stated he had to leave California because "it got too hot for me", just like the caller to the Palo Alto newspaper just hours before the Oakland Police Department call in the early morning hours of October 22nd 1969. On that occasion the caller stated that he left San Francisco "because I'm too hot there". So, the notion the Oklahoma City caller was an isolated hoaxer that was currently resident in Oklahoma doesn't stack up, especially when you consider the December 7th 1969 letter was postmarked Fairfield, California. This Oklahoma City recording could reveal the true voice of the Zodiac Killer. At the very least, it should have been played to Bryan Hartnell, Nancy Slover and David Slaight, who had all heard the Zodiac Killer's voice a matter of months earlier.       

Additional Information: On October 19th 1969, the San Francisco Examiner ran an article entitled "Message to the Zodiac Killer". It read: "Five people are dead. Let there be no more killings. Police say you are intelligent. If you are, then listen to reason. You are being hunted everywhere in the state, and nation. You are alone in this world. You can share your secrets with no one. No friend can help you. You are as much a victim of your crimes as those whose lives you snuffed out. You cannot walk the streets a free man. There is no safety for you, anywhere. And you will be caught, there is no doubt. You face life as a hunted, tormented animal - unless you help yourself. We ask that you give yourself up to the Examiner. We offer you no protection, and no sympathy. But we do offer you fair treatment, the assurance of medical help and the full benefits of your legal rights. And we offer to tell your story. Why have you killed? How has life wronged you? Call the City Editor of the Examiner any time, day or night. The telephone number is (415) 781 24 24. Call collect. Your call will not be traced".

This message may have inspired the Zodiac Killer to ring the Oakland Police Department on October 22nd 1969 requesting that either Melvin Belli or Francis Lee Bailey, two high profile lawyers at the time, appear on a chat show hosted by Jim Dunbar later that day. The San Francisco Examiner article was published on October 19th 1969 with the assurance of "legal rights" if the Zodiac Killer phoned in - and requested the murderer to "give yourself up". It was reported in a magazine article in August 1971 that after the caller to Oakland Police made contact, the main thrust of the conversation was that the Zodiac Killer wanted to give himself up, but only if he could be represented by a famous lawyer. Approximately six weeks after the Oakland call, a letter mailed on December 7th 1969 to the San Francisco Chronicle (now validated as Zodiac correspondence), mocked the dialogue in the Jim Dunbar Show by opening his communication with "I just need help", but after threatening to kill a cop he stated "I will turn myself in". This was the only time the Zodiac Killer offered to turn himself in, other than the caller to the Oakland Police Department. To the best of my knowledge no newspaper articles immediately subsequent to the Jim Dunbar Show mentioned the Oakland caller offering to turn himself in - and neither did the Jim Dunbar Show hoaxer. This last section will be deleted if fresh information proves otherwise.  

On Tuesday, April 21st 1970, the San Francisco Chronicle ran an article entitled The Bloody Satan Murder stating "An autopsy yesterday morning showed Salem was slain sometime last Wednesday", which was April 15th 1970. The introduction to the article highlighted the murder of Robert Michael Salem in his 745 Stevenson Street, San Francisco apartment, describing the "macabre mutilation of the renowned lighting designer" found Sunday evening (April 19th). On Monday, April 20th 1970, the San Francisco Chronicle produced their first article on the murder, stating "A bizarre murder - with the words Satan Saves Zodiac written in blood on the expensively decorated hippie-style pad - was discovered last night at 745 Stevenson Street". The pseudonym "Zodiac" and the drawing of a religious Ankh was also found scrawled in blood on the apartment wall. It is clear, that despite Robert Salem being murdered on April 15th 1970 (or thereabouts), his murder was not discovered until Sunday, April 19th 1970. The story not released publicly until it appeared the following morning in the San Francisco Chronicle newspaper.

If the Zodiac Killer was not the murderer of Robert Salem - and didn't have inside knowledge of the discovery on April 19th - the first time he would have become aware of his pseudonym being found at a murder scene was when he bought his morning newspaper on April 20th 1970. The very same day, a letter arrived at the San Francisco Chronicle stating "PS I hope you have fun trying to fiygure out who I killed" and "I have killed ten people to date". After four months of not writing, was the timing of this letter really a coincidence - falling on the same day his bloody pseudonym was reported on the wall of a murder victim. The Zodiac Killer could easily have just written the victim count once, next to his crosshairs, but specifically added "I have killed ten people to date", suggesting that we should include the month of April into the equation. The Zodiac Killer was seemingly attempting to push us into concluding he was the murderer of Robert Michael Salem. By including a short code of thirteen characters, which included the three number eights (Christ the Redeemer in Christian numerology, and the opposing value of 666, the number of the beast), was the phrase of "I hope you have fun trying to fiygure out who I killed" trying to lead us to "Satan Saves" on the wall of the apartment?                    

What is crucial here, is the timing of this Zodiac communication in relation to the newspaper article reporting the murder of Robert Salem. If the letter was insinuating he was responsible for the 745 Stevenson Street murder, then after reading the San Francisco Chronicle on Monday, April 20th 1970, the Zodiac Killer would have had to access (or buy) his writing paper, envelopes and stamps - create a thirteen character code, recall the Officer Brian McDonnell murder on February 16th 1970, compose the letter and draw his "string of bombs" diagram almost immediately - before mailing the letter in time for it still to be collected, processed and postmarked AM on the morning of Monday, April 20th 1970 (before noon),. Is that a reasonable proposition? If this were the case, it could imply that the 13-Symbol cipher was created with no forethought, was contemporary in nature and possibly related to the murder of Robert Salem (hence the numbers).

The alternative could be that the April 20th 1970 letter was created in advance of the San Francisco Chronicle article reporting the murder of Robert Salem. This could mean that the Zodiac Killer knew of the murder prior to the details being released in the newspaper, because he was the murderer of Robert Salem at 745 Stevenson Street. It just depends on what credence you place on the timing of this letter and the emphasis you place on "I have killed ten people to date" to mean "I have killed ten people to April 20th 1970", thereby highlighting the importance of April to the victim count.

On April 24th 1978, a letter arrived at the San Francisco Chronicle declaring "I am back with you", authenticated by documents examiner, Sherwood Morrill. Then came the arrival of San Francisco Chronicle columnist, Armistead Maupin, who joined the San Francisco Associated Press in 1971, and went on to launch nine novels that included the popular Tales of the City series. He caused a stink when he revealed that Inspector David Toschi had forged fan mail in regards to his character in the Tales of the City series, which resulted in Inspector David Toschi being demoted to pawn shop detail despite no solid evidence he crafted the 1978 letter.

​Then came further handwriting experts claiming that the 1978 letter looked traced and too similar to previous correspondence. In the San Francisco Examiner on August 3rd 1978, four experts, Keith Woodward (head of Los Angeles documents department), John Shimoda (Postal Service crime laboratory), Robert Prouty (Chief documents section/Bureau of Criminal Identification and Investigation) and Terry Pasco (also Criminal Identification and Investigation), all deemed the 1978 letter a fake. Keith Woodward described the 1978 letter "a carefully drawn copy of the true Zodiac printing". He concluded it "was a poor attempt by an unknown writer". John Shimoda declared it "an attempt to duplicate Zodiac letters and is not authentic". Robert Prouty and Terry Pasco said basically the same thing. 

The experts concluded that the 1978 was effectively a "copy", attempting to duplicate authentic Zodiac letters. So how did the author of the 1978 letter duplicate the Melvin Belli letter introduction, when an image of this communication had never been published in the newspapers. If the author of the 1978 letter was attempting to imitate previous Zodiac communications so precisely, then why didn't he duplicate the introduction of "This is the Zodiac speaking" from at least four letters published in the newspapers?. He couldn't have been imitating the Zodiac Killer very well. Here is an excerpt from a previous article. ​

​From August 4th 1969 to March 13th 1971 the Zodiac Killer mailed 12 authenticated letters (inc. Fairfield letters} that carried the introduction of "This is the Zodiac speaking" on the first line of the message. Of these 12 letters, only the Melvin Belli letter on December 20th 1969 failed to keep the "This is the Zodiac speaking" introduction exclusively on the main first line (ignoring the "Dear" intro). It was written "This is the Zodiac speaking I". The San Francisco Chronicle published at least four of these introductions, which included the October 13th 1969, November 8th 1969, April 20th 1970 and March 13th 1971 letters (shown here).

The author of the April 24th 1978 "I am back with you" letter (if a hoaxer) had every opportunity to just mimic any one of these published introductions, yet he chose to mimic the Melvin Belli letter on December 20th 1969, which broke with tradition. The Melvin Belli message began with "This is the Zodiac speaking I", but was grammatically incorrect in failing to place a comma or full-stop between "speaking" and "I". Therefore, the author of the 1978 letter (if a hoaxer) managed to imitate the message on the opening line of the Melvin Belli letter (including the punctuation error) despite the fact an image of the Melvin Belli letter was not published in any newspapers (to my knowledge). One would have expected a Zodiac copycat to mimic any one of the four introductions available in the San Francisco Chronicle  - but they didn't. The 1978 author mimicked the only one not publicly available in the Chronicle. Both letters also began with the author addressing the receiver by way of "Dear Melvin" and "Dear Editor". From August 4th 1969 to March 13th 1971, this "addressing of the receiver" within the letter was only performed twice (8/4/69 and 12/20/69). These observations may suggest the Zodiac Killer authored the 1978 letter after all. When you consider the same introduction present in the Melvin Belli and 1978 letter, was it just coincidence that the Melvin Belli letter stated "I can not remain in control for much longer", to which the 1978 letter replied with "I am now in control of all things"? 

According to Mike Rodelli, Alan Keel, Criminalist at the San Francisco Police Department "revealed that there were two letters in possession of the department that had abundant saliva and DNA-containing oral epithelial cells on them, and that the DNA extracted from these two letters matched between them". The San Francisco Police Department DNA chart concurred that a DNA sample was obtained from the 1978 letter. Zodiac researcher, Michael Butterfield, curator of the Zodiac Killer Facts website, wrote in an article entitled The Magic Bullet, that In the late 1990s San Francisco police obtained DNA from a suspected Zodiac letter, and the DNA did not match Allen’s DNA. That communication was the 1978 letter, described in comments in the DNA chart as "DNA Sample Obtained". The evidence above, strongly points to the 1978 letter being a genuine Zodiac letter, unless of course, the hoaxer just happened to ignore the widely publicized letters in the newspapers carrying the usual introduction, and instead opted to mimic the introduction and error in punctuation in the Melvin Belli letter, which they could never have seen an image of.  

In late 2017 there was optimism regarding a new round of testing of the Zodiac letters. In early 2018, the Sacramento Bee reported that "Vallejo police Detective Terry Poyser, who has worked the Zodiac case for four years, said his agency has submitted two envelopes (in late 2017) 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". But according to the above sources and the "DNA Sample Obtained" comment by the San Francisco Police Department laboratory, we already have a DNA sample from the 1978 letter. Therefore, with little doubt, we have DNA from the Zodiac Killer - and have done for many years. This DNA from the 1978 letter should now be run through the genealogy database to generate fresh information in this long-standing case. If Alan Keel is correct, then we definitively have a full DNA profile of the Zodiac Killer from the 1978 letter, that he claimed matched one of the 1974 letters (which could very well be the Exorcist letter, as this was the only 1974 letter processed for DNA according to the chart). This sounds plausible, because recent information has shown that the Exorcist letter is probably genuine Zodiac correspondence based on comparisons between envelopes. All of this should exonerate David Toschi of having any involvement in forging Zodiac letters, and exclude Arthur Leigh Allen once and for all. But if the Exorcist letter and 1978 letter matched in DNA - and the 1978 letter was considered a forgery by investigators - why hasn't the Exorcist letter been more heavily questioned as authentic? Irrespective of any matches noted by Alan Keel, if the 1978 letter provided a DNA sample, then we may be able to identify the Zodiac Killer if the arguments made using the Melvin Belli letter stack up.

ADDITIONAL READING: A PATTERN OF WRITING  

Many people believe that the Zodiac Killer's "terroristic" exploits didn't begin with Lake Herman Road on December 20th 1968 and the subsequent letter writing campaign - and have searched in the Editor's columns of newspapers for any hints of Zodiac type language. The following does not claim this is a Zodiac communication, but it is worthy of a mention because it involves a threatening letter to Mr. Melvin Belli prior to the inception of the Zodiac Killer.

A typewritten letter was postmarked Starkville, Mississippi on March 24th 1964, addressed to Mr. Melvin Belli, Attorney at Law, San Francisco, California, with a return address of R. A. Wagner, 1302 E. Capitol Street, Jackson, Mississippi. Investigators could find no such number on E. Capitol Street and no R. A. Wagner by searching the Polk Directory in Mississippi. The letter read:

"Old Dago Belli says of Dallas, 'This city stinks', We have news for you jelly belli -- that's your upper lip you smell. Furthermore, if you're not careful some-body's going to put a slug of hot lead between those beady eyes of yours". It was signed "The Commitee" and followed by "Remember, San Francisco is no sanctuary."         

This letter was in response to the conviction and death sentence imposed on Jack Ruby on March 14th 1964 for the killing of Lee Harvey Oswald, and Melvin Belli's response to the verdict. Melvin Belli, who defended Jack Ruby, was quoted in a newspaper article: "ANOTHER MAN ON THE STREET, L. D. ENNES, DECLARED: "I THINK IF IT. HAD GONE ANY OTHER WAY, IT WOULD HAVE BEEN A DISGRACE TO OUR LAWS." THERE WERE THOSE, HOWEVER, WHO SIDED WITH BELLI. BESIDE HIMSELF WITH RAGE AT THE VERDICT, THE NORMALLY SUAGE SAN FRANCISCO LAWYER ROARED IN COURT WITH RAGE AT THE VERDICT, THE NORMALLY SUAVE SAN FRANCISCO LAWYER ROARED IN COURT: "THIS IS A VICTORY FOR BIGOTRY. DON'T WORRY JACK, WE'LL APPEAL THIS AND TAKE IT OUT OF TEXAS." THE 55-YEAR-OLD BELLI WAS EQUALLY VEHEMENT TODAY IN ASSERTING, "THIS CITY STINKS." 

Mississippi was a hotbed of racial tension in the civil rights movement era, with the murders of Chaney, Goodman, and Schwerner, also known as the Freedom Summer murders, the Mississippi civil rights workers' murders or the Mississippi Burning murders, which occurred in the latter half of 1964. The reason I bring this up, is the name adopted by the sender from Mississippi. Why would the sender choose this name? Richard Wagner was a German composer,  theater director, polemicist, and conductor who is chiefly known for his operas. "The self-taught 19th-century German composer was born into a performing family – several of his sisters became opera singers and actresses. A vehement anti-Semite, Wagner is one of the most controversial figures in the history of classical music. The Ku Klux Klan-glorifying 1915 silent film, The Birth of a Nation, featured music from one of Wagner’s operas, Ride of the Valkyries". Post Magazine.. Adolf Wagner was a German soldier and high-ranking Nazi Party official born in Algrange, Alsace-Lorraine, and appointed by Adolf Hitler. So, did the roots of racism play any part in the fictitious name chosen by the sender from Mississippi.  

On August 26th 1976, a personal advertisement mentioning "The Imperial Wizard" and beginning with "ZODIAC" was placed in the San Francisco Chronicle to run for one week. This advertisement carried the initials R. A., just like the threatening letter from Mississippi addressed to Mr. Melvin Belli.

From August 4th 1969 to March 13th 1971 the Zodiac Killer mailed 12 authenticated letters (inc. Fairfield letters} that carried the introduction of "This is the Zodiac speaking" on the first line of the message. Of these 12 letters, only the Melvin Belli letter on December 20th 1969 failed to keep the "This is the Zodiac speaking" introduction exclusively on the main first line (ignoring the "Dear" intro). It was written "This is the Zodiac speaking I". The San Francisco Chronicle published at least four of these introductions, which included the October 13th 1969, November 8th 1969, April 20th 1970 and March 13th 1971 letters (shown below). The author of the April 24th 1978 "I am back with you" letter (if a hoaxer) had every opportunity to just mimic any one of these published introductions, yet he chose to mimic the Melvin Belli letter on December 20th 1969, which broke with tradition. The Melvin Belli message began with "This is the Zodiac speaking I", but was grammatically incorrect in failing to place a comma or full-stop between "speaking" and "I". Therefore, the author of the 1978 letter (if a hoaxer) managed to imitate the message on the opening line of the Melvin Belli letter (including the punctuation error) despite the fact an image of the Melvin Belli letter was not published in any newspapers (to my knowledge). One would have expected a Zodiac copycat to mimic any one of the four introductions available in the San Francisco Chronicle (images below) - but they didn't. The 1978 author mimicked the only one not publicly available in the Chronicle. Both letters also began with the author addressing the receiver by way of "Dear Melvin" and "Dear Editor". From August 4th 1969 to March 13th 1971, this "addressing of the receiver" within the letter was only performed twice (8/4/69 and 12/20/69). These observations may suggest the Zodiac Killer authored the 1978 letter after all. Up to and including 1978, the Melvin Belli and "I am back with you" letters were the only two letters that opened with the message "This is the Zodiac speaking I". Therefore, was it just coincidence that the Melvin Belli letter stated "I can not remain in control for much longer", to which the 1978 letter replied with "I am now in control of all things"?

This, along with the observations shown in a previous article, should help to authenticate a letter long believed to be a hoax by many in the Zodiac community. This could very well rule out David Toschi as the author of the 1978 letter and finally clear his name altogether. The San Francisco Police Department DNA report states that a "DNA sample was obtained" from the 1978 letter. Therefore, if the 1978 letter is genuine, we already have the Zodiac Killer's DNA. If anybody has information showing that the Melvin Belli letter was published in the newspapers prior to April 24th 1978, please let me know and this article will be amended or deleted.   

I would like to thank Zodiac researcher Druzer, whose initial insights into the structure of the Zodiac letters have made all this possible. Including the article "A Pattern of Writing".  

Here are some extracts from the Riverside Desktop Poem and the three Bates' letters, that bleed into the Confession Letter.
[1] SICK OF LIVING/UNWILLING TO DIE  [2] ALL OVER HER NEW DRESS  [3] SHE WONT DIE THIS TIME  [4] JUST WAIT TILL NEXT TIME  [5] SHE HAD TO DIE  [6] BATES HAD TO DIE  [7] THERE WILL BE MORE.

Despite the Riverside communications not being in the public domain prior to November 1968 (only small parts of the Confession Letter were), the author of the typed Confession Letter carried wording similar to the Riverside Desktop Poem and Bates' letters. The wording "to die" featured in all three communications [1] "She/Bates had to die" [2] "I said it was about time for her to die" [3] "Sick of living/unwilling to die" (but "to die" or "die" never featured in any Zodiac communications). The Riverside Desktop Poem stated "over her new dress", whereas the Confession letter stated "over her mouth". The variation of the word "unwilling" in the Riverside Desktop Poem can been seen twice in the Confession Letter in "willing" and "willingly" (expressed as "unwilling to" die, she went "very willingly" and "willing to" talk to me). The Bates' letter thrice stated "there will be more", with the Confession Letter threatening "maybe she will be the beautiful blond". The Riverside Desktop Poem stated "she wont die this time" and "just wait till next time", whereas the Confession Letter stated "I said it was about time. She asked me about time for what. I said it was about time to die". The Confession Letter stated "I am not sick", in direct contrast to the Riverside Desktop Poem which declared "sick of living". The Confession letter stated "I waited for her in the library", whereas the Riverside Desktop Poem threatened "Just wait till next time". To a much lesser extent, the Riverside Desktop Poem refers to a knife by opening with "cut, clean, if red, clean", with the Confession letter also referring to the same action, by stating "I finished the job out cutting her throat". 

There is a strong possibility that all three Riverside communications were one author. In 2016 investigators received a communication from an individual in San Bernardino who claimed that he had authored the three Bates letters on April 30th 1967, stating he was a troubled teenager at the time he sent the trinity of malicious handwritten letters to the Riverside Police Department, Riverside Press-Enterprise newspaper and Joseph Bates. If he didn't also claim to have written the Riverside Desktop Poem and Confession Letter, I doubt he was responsible for any.

Druzer, an extremely intelligent Zodiac researcher, noted the indented lines on certain Zodiac letters as a way to help ascertain whether particular communications may be genuine or otherwise. The structure and composition of a letter may tell you more than the handwriting itself. There is a complete change in how the Zodiac letters were structured from 1969 to 1971, compared to how the letters were structured subsequent to 1971. As pointed out by Druzer, any hoaxer subsequent to 1971 has numerous early Zodiac letters from the newspapers to analyze with respect to their structure (in particular, how the killer opened with the introduction "This is the Zodiac speaking"). In every single Zodiac communication in 1969, 1970 and 1971 where the Bay Area murderer opened with "This is the Zodiac speaking", he began the introduction in line with the text below on all 12 occasions (including the Fairfield letters). Here are two examples:     

Subsequent to 1971, we have the 1978 letter (4/24/78), the Channel 9 letter (5/2/78), the 1986 letter (5/6/1986) and the 1987 letter (10/28/1987). All of these letters began with the introduction "This is the Zodiac speaking", but each time the introduction was offset from the left margin and the text below. If these were all different hoaxers, then it is rather uncanny how all these authors not only ignored how the Zodiac Killer structured his main opening line to conform with the text below, but they all structured the opening line in the same fashion. Of the 12 Zodiac letters in 1969, 1970 and 1971, only the Melvin Belli letter on December 20th 1969 failed to keep the "This is the Zodiac speaking" introduction exclusively on the main first line (ignoring the "Dear" intro). It was written "This is the Zodiac speaking I". One may have thought a hoaxer would adopt the introduction used the majority of the time, but instead the two 1978 letters, the 1986 letter and the 1987 letter followed a similar pattern to the Melvin Bellii letter, contrary to what would be expected of a hoaxer. 

You will notice below that three of the later letters failed to insert a full-stop or comma after the introduction, and before the rest of the text. Exactly the same as the authenticated Melvin Belli letter on December 20th 1969. All four of the communications below begin with either the subject of "I" or "You" after the introduction, rather than something non-personal. It has been shown extensively on this website how the 1986 and 1987 letters should be included as confirmed Zodiac correspondence. This being the case, the 1978 letter and the Channel 9 letter should be regarded as worthy contenders also. The change in style from 1969, 1970 and 1971, to 1978 onwards, shows a distinct pattern of "Zodiac" development in his style of writing. 

Another pattern that can be observed in the widely believed Zodiac letters, is that the August 4th 1969, October 13th 1969, November 8th 1969, November 9th 1969, December 20th 1969 and April 20th 1970 letters all have the introduction "This is the Zodiac speaking" with no significant gap to the second line. Then a seemingly conscious change, when the June 26th 1970, July 24th 1970, July 26th 1970 and March 13th 1971 letters all left a distinct gap between the first and second line (March 13th 1971 slightly less so). This shows a marked change in pattern by the Zodiac Killer. However, the latter four communications were pre-empted by both Fairfield letters on December 7tth 1969 and December 16th 1969, which both placed a noticeable gap between the opening introduction and the second line.