On October 20th 1969, nine days after the murder of Paul Stine in Presidio Heights, somebody made a threatening phone call to the Palo Alto Times newspaper saying he intended "to pick the kids off as they get on the school bus". The San Bernardino County Sun reported on the threat, stating "Patrol cars convoyed school buses around Palo Alto yesterday after a telephoned murder threat by a man claiming to be the Zodiac Killer of five persons. The weird slayer who signs himself "The Zodiac" made a similar threat in a letter to the San Francisco Chronicle last week after the Oct 11 shooting of a taxi driver. The district transportation supervisor said an armed guard might ride with each of the system's 25 buses. Officers in Napa and Vallejo, areas of the first three murderous attacks, some 45 miles north of Palo Alto, have been convoying police officers. Palo Alto Police Chief William Hydie called the new threat "extremely serious," but warned against over reaction to what might be a crank call".

On November 8th 1969, the Zodiac Killer mailed the 'Dripping Pen' card and 340 cipher to the San Francisco Chronicle claiming the "Aug" murders of Debra Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found brutally stabbed on August 3rd 1969 in the Bay Area of San Jose.

On November 21st 1969, somebody claiming to be the Zodiac Killer wrote to the San Jose Police Department​ threatening the life of a widow, accompanied by the words "There's no doubt I will do my Thing". The brief text in the letter clearly contained enough information for police to identify the woman and implement 24-hour surveillance on her residence.

On December 7th 1969, a letter was mailed from Fairfield stating "I just need help. I will kill again, so expect it any time the will be a cop".

On December 16th 1969, another letter arrived from Fairfield threatening to kill "government life" and "cops" in Sacramento, Fairfield, Napa, Vallejo, Oakland, San Francisco and San Jose. A future geographic profiling technique was applied to the locations in which he 'threatened murder' (as detailed in the Fairfield letter), and noted that "Interstate 80 begins at an interchange with U.S. Route 101 (US 101) in San Francisco, and then crosses the San Francisco–Oakland Bay Bridge into Oakland. It then heads northeast through Vallejo, Fairfield, Sacramento, and the Sierra Nevada mountains before crossing into Nevada". The idea was to identify the areas the Zodiac Killer was prepared to target, based on their accessibility to him using a main commuter route he regularly traveled. If he regularly used the I-80 for his profession, then six of these seven destinations are directly passed by the I-80, with Napa only a few miles off route.

On December 19th 1969, somebody claiming to be the Zodiac Killer again threatened cops, making a phone call to Sergeant Robert Rengsdorff of the San Jose Highway Patrol (see article above), stating "I am going to kill five of you officers and a family of five between now and Monday". This threat towards San Jose police and a family of five was issued on a Friday, exactly as was the November 21st 1969 letter, mailed to San Jose police threatening harm on a widow. After the threat on the widow was thwarted by 24-hour police surveillance on her residence, was this the response, to once again instigate fear in the San Jose community? Were the widow and 'family of five' of the same residence? We know he was threatening the lives of numerous police officers, but the threat on five members of a family appears rather specific.           

On December 20th 1969, the Zodiac Killer mailed the 'Melvin Belli' letter containing a piece of murdered Paul Stine's shirt, effectively proving the author was the murderer of the taxicab driver on October 11th 1969. This letter mimicked the December 7th 1969 Fairfield letter by stating "please help me", which in some way helps to authenticate both Fairfield letters not released to the newspapers.

​The purpose of this article is to show the targeted areas of the Zodiac Killer (if responsible for these letters and phone calls) from the standpoint of geographic profiling. These events spanned from the October 11th 1969 murder of Paul Stine, to the mailing of the 'Melvin Belli' letter on December 20th 1969 (71 days). The areas shown in red above, highlight the locations the Zodiac Killer targeted by murder, proposed murder, as well as by his threatening phone calls and letters - and they are all connected by one direct route of travel.

During these 71 days in October, November and December the Zodiac Killer focused his attention on Sacramento, Fairfield, Vallejo, Oakland, San Francisco, Palo Alto and San Jose. Interstate 80 and U.S. Route 101 provide one seamless journey from Sacramento to San Jose. Was the Zodiac Killer a traveling salesman which took him through each of these locations - and therefore he had a familiarity with? Do these commuter route tell you anything about his home residence during this time period? 
When you commit, or intend to commit these acts, accessibility to and from a main commuter route could be invaluable.

Equidistant (as the crow flies) to Sacramento and San Jose is the waterfront city of Vallejo, believed by many to be the home residence of the Zodiac Killer. It is 53 miles from Sacramento and 57 miles from San Jose. The Springs and Tuolumne payphone, where Zodiac placed a call to police dispatcher Nancy Slover on the morning of July 5th 1969, sits 728 metres from Interstate 80.

On Monday, October 12th 1970 the San Francisco Chronicle ran an article entitled Gilbert and Sullivan Clue to Zodiac. Just two weeks later, the Zodiac Killer would respond when he mailed the Halloween Card to Paul Avery, a prominent San Francisco Chronicle reporter. This card, containing two skeletons, opened with the phrase "I feel it in my bones, you ache to know my name. And so I'll clue you in". This on the face of it seemed like a direct response to the Chronicle article, but what clue was the Zodiac prepared to give us in this card regarding his identity or name? Before we tackle this problem, we shall fast forward to the Exorcist Letter, mailed to the Chronicle on January 29th 1974 and investigate any possible clues within this correspondence. This first part has been covered previously, however, this will be expanded upon as we delve a little deeper.
The Exorcist Letter appeared a curious blend of two productions; The Mikado (1885), a satirical portrait of Victorian England, and the horror classic The Exorcist (1973), ironically labeled "the best saterical comidy that I have ever seen" by the Zodiac Killer. The Exorcist Letter appears a mismatch of genres containing an unholy alliance of mixed messages - unless of course - it was designed this way to provide us with a hidden clue to his identity or name.   

After a line such as "Signed, yours truley" one would expect the sender to provide us with a name, yet here the Zodiac Killer gives us a line from The Mikado's On a tree by a river, part of Act Two. Is his name concealed within these lines? In the article 'The Best Saterical Comidy,' this idea was explored. The name William can be abbreviated to Will, Bill, Billy, Willy, or Willie. It can be seen that these lines contain the names 'Bill and Will' several times. This of course is meaningless on its own, until you wrangle with the unusual alliance of The Exorcist and The Mikado. 

The Exorcist is 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 Mikado was created by Gilbert and Sullivan, however, one half of the duo was Sir William Schwenck Gilbert, which effectively gives us the three William's in the excerpt above and tempt us with the phrase "Signed, yours truley, William".  The inspiration for William Peter Blatty's novel The Exorcist (1971) was the real life exorcism of Roland Doe, a 13-year-old Maryland boy, in 1949. Father William S. Bowdern, S.J. was central to this exorcism, assisted by Walter Halloran and William Van Roo, a third Jesuit priest, bringing our total to five.

​In the San Francisco Chronicle article Gilbert and Sullivan Clue to Zodiac, Paul Avery wrote "Sheriff's detective sergeant Kenneth Narlow of Napa County has fruitlessly followed up another 900 tips to Zodiac's identity since September 27th 1969". Did the Zodiac take this line and incorporate it into the Halloween Card, using the pumpkin fruit to effectively reveal his identity, by deliberately placing the pumpkin over the groin and then removing it to expose his identity. The groin becomes fruitless, yet reveals a name? I'm afraid you've guessed it - Willy. While this is highly improbable, the Zodiac Killer did present a rather immature element in much of his correspondence. In an attempt to reinforce this identity we shall proceed. The Halloween Card is obviously a reference to the Western Christian celebration of All Hallows Day on October 31st, hence the use of the spiders web, skeletons and pumpkin within the card. The most notable addition to the card was the pumpkin, so other than its deliberate positioning, has it any further significance to the Zodiac Killer's identity? The pumpkin itself is carved out on Halloween to create a spooky or ghostly face and lit on the inside to create a menacing glowing effect. This is termed a 'Jack o' lantern' or 'Will o the wisp' - an atmospheric ghost light seen by travelers at night.    

The Zodiac Killer placed numerous eyes on the Halloween Card, accompanied by the words "peek-a-boo you are doomed" which was wrapped around the knothole in the tree. This, on the face of it, appeared a veiled threat towards San Francisco Chronicle reporter Paul Avery, but was it yet another clue to his identity?
 
​'Blind Bat', a member on the Zodiac Killer Site forum, found an interesting connection to the Halloween Card involving the "peek-a-boo" phrase the author added to the greeting card. The picture on the right demonstrates this perfectly with the Zodiac-like letter K, with the eyes and eyelashes eerily similar to the depiction on the Halloween Card itself. ​William V. Peekaboo Pennington Senior was a San Francisco private detective, described as a cattle man, private investigator, theater owner, building contractor, oil man and member of the Eastern Star, a freemasonry related order established in 1850 by Rob Morris. He moved to San Francisco in 1924 and performed investigative duties for prominent lawyers and attorneys, including Melvin Belli, who became closely embroiled in the Zodiac Killer case. The Halloween Card provides us with two full, and two abbreviations of William, when we consider the following.

​The Halloween Card is the only time the Zodiac Killer used the letter Z on his correspondence. He placed the letter Z on the envelope and the inside of the card - but in addition to this - the Zodiac Killer placed a Zorro style mask on the skeleton. Is this a further clue? Had the Zodiac spent his formative years in the 1950s, Zorro would have been a high profile television series, made into two Walt Disney films, The Sign of Zorro (1958) and Zorro, the Avenger (1959). The Disney television series ran from 1957 to 1959, and this, along with the two movies, starred Guy Williams.  
  
Revisiting the subject of Melvin Belli, the Zodiac Killer wrote a personal correspondence to the prominent lawyer on December 20th 1969. In this correspondence he stated "I will loose all controol of myself and set the bomb up. Please help me I can not remain in control for much longer". This phrase is remarkably similar to a message scrawled on the wall of murder victim Frances Brown, who was discovered on December 10th 1945 at her 3941 North Pine Grove apartment, in Edgewater, Chicago. She had multiple knife wounds, with the actual knife found protruding from the victim's neck, along with a bullet wound to the head. The killer had left a calling card, in the form of a message written in lipstick on the wall. See here. It said: "For heavens Sake catch me Before I kill more. I cannot control myself". The Zodiac Killer wrote (edited) "I will loose all controol of myself. Please help me. I can not remain in control for much longer".  The killer William Heirens, known as the 'Lipstick Killer', was convicted of the murders of three females over a seven-month period. Was the letter mailed to Melvin Belli a plea for help or just another subtle clue to his identity.

Paul Avery extensively covered the Patty Hearst affair, along with San Francisco Chronicle reporter Tim Findley, something the Zodiac was unlikely to miss. The Zodiac Killer has been credited with the 'SLA Letter' mailed on February 3rd 1974, the day before the kidnapping of Patty Hearst by the Symbionese Liberation Army on February 4th 1974. There are two links here, in that Patty Hearst was the granddaughter of American publishing magnate William Randolph Hearst, who gained control of the San Francisco Examiner from his father. But more importantly, the Symbionese Liberation Army (SLA) leaders were Donald De Freeze and William Harris. One of its founding members was Willie Wolfe. 

​In the article 'Gilbert and Sullivan Clue to Zodiac', Paul Avery wrote "Zodiac is still at large today. And he is now claiming he has murdered thirteen persons. Homicide detectives who've been hunting Zodiac for nearly two years frankly admit he is as much an enigma now as he was on December 20th 1968, when he chalked up his first two victims". In chalk-like writing, the Zodiac would now be claiming a potential fourteen victims in the Halloween Card, but was it revealing a lot more than initially thought?

The Little List letter mailed on July 26th 1970 heavily featured two portions of The Mikado. The seventh line of Mikado Act One Part 5a  As some day it may happen reads "All children who are up in dates, and floor you with 'em flat". The Zodiac Killer paraphrases this verse to "All children who are up in dates and implore you with im platt". It could simply be that he was attempting to write the letter F, and accidentally formed the letter P - but if not. I don't subscribe to the techniques employed in this article, but I thought it worthwhile for those who have William as a suspect.  

We have spent nearly fifty years studying the Zodiac Killer, delving into the mind of a murderer and attempting to unlock the driving force behind his reign of terror to uncover the reason behind the madness - and we are by no way short of ideas. As many observers have pointed out, our killer may have had a military connection, had theatrical links either professionally or personally, including an oriental link, born out by three references to the Mikado and the symbols portrayed on the Exorcist Letter, as well as an affinity towards movies and a penchant for the cryptic. However, on the flip side he portrayed an illiterate, egotist with a flair for a lack of subtlety, displayed in unstinting fashion in his 408 Cipher, in which he states candidly "to kill something gives me the most thrilling experience it is even better than getting your rocks off with a girl". The thing is, he may have been telling the truth, if the San Francisco Chronicle reporter Paul Avery was to be believed.

On October 18th 1969 he ran a piece in the San Francisco Chronicle describing the Zodiac Killer as a 'latent homosexual'. Under the banner Zodiac-Portrait of the Killer  he stated "The killer of five who calls himself 'Zodiac' is a clumsy criminal, a liar and possibly a latent homosexual". How close this description is to reality is open to question, but it has some legs and is worth investigating. The Zodiac Killer addressed Paul Avery personally when he sent the Halloween Card on October 27th 1970 approximately one year after this article was written - and bearing in mind the killer's ability to reduce everything to base level and the aforementioned characteristics he displayed in his missives, this is how we shall approach this card.        

Two notable features of this card were the two skeletons, one of which had a pumpkin placed over the genital area. It was after all four days before Halloween, so the pumpkin and skeletons were not unusual - but why would the Zodiac Killer choose a pumpkin, of all the things he could have chosen, and in particular, place it in such a fashion. The Zodiac Killer also underlined the 'lav' in the misspelled reporter's name Paul Averly. These two features of the card, along with the phrase 'peek-a-boo', implied a suggestion of something hidden.
 
Some Zodiac researchers have explored the possibility the Zodiac was of English origin, on account of his word usage, such as 'shall', infrequently used in American English, but by the same token a word frequently used by thespians. Peek-a-boo  
is known as Peep-bo in British culture and is the act of concealing ones face behind the hands or other object, before suddenly appearing back into view and uttering the words peek-a-boo or peep-bo. It can be seen in Wikipedia that many variations involve trees, similar to the depiction on the Halloween Card, where 'Hiding behind that tree' is added. See here. Whether or not it is a significant phrase by the Zodiac Killer is open to question, but Peep-Bo is a character that features during Act I of The Mikado.

The eyes peering from the tree, peek-a-boo and the hidden gender, may just have been the start of a form of 'toilet humor' backlash or closet acceptance that the Paul Avery reference to Zodiac possibly being a 'latent homosexual' had been officially noted. After all 'lav' is a colloquialism used in English speech for lavatory or 'water closet'. A 'closet homosexual' is used for people who have not disclosed their sexual orientation or gender identity, and ties in nicely with the English phrase 'skeleton in the closet', coined in the 19th century, a colloquial phrase and idiom used to describe an undisclosed fact about someone which, if revealed, would have a negative impact on perceptions of the person.

​Falling back to the theatrical connection and The Mikado, 'Skeleton in the Closet' was a 1965 Japanese 'Pink Film', also called 'Secrets Behind the Wall'. A 'Pink Film' deals with Japanese theatrical films of nudity, almost exclusively shot on 35mm film - but in order to circumvent censorship restrictions, Japanese directors carefully positioned props over the actors private parts, although one doubts a pumpkin found its way on to set very often. Incidentally pumpkin seeds have long been used in parts of Asia for boosting sexual performance and prostate health.

The Zodiac Killer is indelibly linked to San Francisco. Most of his mailings were to the Chronicle, along with his final confirmed murder, a marked deviation from his previous attacks on lone couples across the bay. Paul Stine was believed to have picked up his final passenger from the theater district near the intersection of Mason and Geary Street, while some believe it may have been around the area of Nob Hill or the Tenderloin District.

San Francisco in the 1960s had overseen a marked change - the Castro District being one - having transformed from a working class area to a prominent symbol of the lesbian, gay, bisexual and transgender movements. After World War II many military personnel courted the area, unwilling to return to a life incompatible with homosexuality and other forms of behavior, and areas like the Tenderloin and Castro Street became the home to many gay bars and sex clubs. As early as 1963 Castro Street opened its first gay bar, the 'Missouri Mule'. One such person was gay activist and entertainer Jose Sarria, who himself had served in World War II, but continued to fight against police harassment against not only gay people, but gay establishments as a whole, having performed in the 'Black Cat Bar' at 710 Montgomery Street, a north-south thoroughfare. 

The idea of a hidden body was extensively used in the Gothic novels of the Victorian period. Edgar Allen Poe was best known for his tales of mystery and the macabre, and one such example was this extract from 'The Black Cat' in 1845. "Gentlemen, I delight to have allayed your suspicions", and here, through the mere frenzy of bravado, I rapped heavily upon that very portion of the brick-work behind which stood the corpse of the wife of my bosom. The wall fell bodily. The corpse, already greatly decayed, stood erect before the eyes of the spectators". It has been suggested that the phrase 'skeleton in the closet' derives from the era of the notorious body snatchers, prior to 1832, when the UK's Anatomy Act allowed the more extensive use of corpses for medical research. The theory goes that, in a scenario similar to that of the concealment of Catholic priests in priest holes in domestic houses in Elizabethan England, doctors would conceal in cupboards the illegally held skeletons they used for teaching. Although there's no evidence at all to corroborate that theory. Concealed skeletons are occasionally found walled-up in houses, but they are usually those of unwanted infants. See here. 

In the early years of San Francisco it was against the law for men to dress up in women's clothing, but an exception was made for one night only on Halloween, a pagan celebration that would become the adopted day for gay celebrations. Sarria encouraged patrons to be as open and honest as possible, exhorting the clientele, "There's nothing wrong with being gay–the crime is getting caught," and "United we stand, divided they catch us one by one."  At closing time, he would lead patrons in singing "God Save Us Nelly Queens" to the tune of "God Save the Queen". Sometimes he would take the crowd outside to sing the final verse to the men across the street in jail, who had been arrested in raids earlier in the night. Raids on gay bars were routine, with everyone inside the raided bar taken into custody and charged with such crimes as being "inmates in a disorderly house". Although the charges were routinely dropped, the arrested patrons' names, addresses and workplaces were printed in the newspapers. When charges were not dropped, the arrested men usually quietly pleaded guilty. Sarria encouraged men to plead not guilty and demand a jury trial. Following Sarria's advice, more and more gay men began demanding jury trials, so many that court dockets were overloaded and judges began expecting that prosecutors have actual evidence against the accused before going to trial. One favored harassment technique, employed especially on Halloween after midnight, was to arrest drag queens under an old city ordinance that made it illegal for a man to dress in women's clothing with an "intent to deceive". In consultation with attorney Melvin Belli, Sarria countered this tactic by distributing labels to his fellow drag queens (hand-made, in the shape of a black cat's head)  that read "I am a boy". If confronted, the queen would simply display the tag to prove that there was no intent to deceive. Sarria's actions helped bring an end to Halloween police raids  Excerpt from Wikipedia.

The Zodiac Killer certainly seemed to have many things in common with San Francisco. Is it possible he was a 'latent homosexual' as described by Paul Avery, who harbored a resentment against police and officialdom, strikingly evident in his correspondence to the San Francisco Chronicle, not to mention his linkage to Melvin Belli through the 'Call to Chat Show' spectacle and the Dragon Card mailed on April 28th 1970 calling for people to wear his nice Zodiac buttons - possibly on their lapels, similar to the hand-made labels of protest above. And finally the Melvin Belli Letter mailed on the anniversary of Lake Herman Road, just before Christmas.  

Halloween in the Tenderloin grew in the early 1960s with the growing LGBT community and welcomed tourists – who many of the prostitutes and hustlers relied upon for income. By the late 1960s, a major celebration area during Halloween was along Grant Avenue in North Beach, on which there were many gay bars in the late 1960s between Broadway and Union. Excerpt from Wikipedia.

​Melvin Belli was a flamboyant showman and prominent attorney summoned to appear on the Jim Dunbar Chat Show supposedly by the Zodiac Killer, along with Francis Lee Bailey, well known for his involvement in the Patty Hearst SLA trial - something again the Zodiac seemed at pains to point out. Melvin Belli was famous for his use of 'Elmer' the skeleton, which he often used in his medical malpractice suits. After winning a court case, Belli would raise a Jolly Roger flag over his Montgomery Street office building in the Barbary Coast district of San Francisco (which Belli claimed had been a Gold Rush-era brothel) and fire a cannon, mounted on his office roof, to announce the victory and the impending party. See Wikipedia

The Dragon Card mentioned above contained these lines "If you dont want me to have this blast you must do two things. Tell everyone about the bus bomb with all the details. I would like to see some nice Zodiac buttons wandering about town. Everyone else has these buttons like, black power, melvin eats bluber, etc. Well it would cheer me up considerably if I saw a lot of people wearing my buton. Please no nasty ones like melvin's. Thank you". The card used was a Jolly Roger greetings card.- and we know that a Jolly Roger is a traditional English name used to refer to the flag depicting part of a skeleton and displayed on pirate ships. The links are there, but are they interconnected? Was the Halloween Card a form of base subtle humor, along with the Dragon Card that implied the Zodiac Killer did indeed harbor a deep felt resentment, against not only Paul Avery and the San Francisco Chronicle, but also the police in general - not only for the reasons we have become accustomed to, but for reasons far more personal to our killer, leaving us to wonder if the 'skeletons in the closet' may have been rattled loose just slightly and the 'mask' of the Zodiac Killer may one day fall to reveal his true identity.   

It has been widely considered that the Exorcist letter mailed on January 29th 1974 may have been the final correspondence from the infamous Zodiac Killer. But is its claim of 37 murders, if indeed this is what was meant, a realistic one. Firstly, we will take the unusual step of acknowledging the Zodiac Killer at his word, when throughout his campaign of terror he constantly informed the authorities of his murder count, displayed on each subsequent letter or card. But how accurate were his claims, and could a timeline of potential Zodiac victims be attributed to the periods in between each correspondence, bearing in mind that his declaration of seven murders on the Dripping Pen card of November 8th 1969 could be attributed with almost complete accuracy, albeit the missing murders in August, has still yet to be fully resolved. As stated previously, the months displayed at the foot of the Dripping Pen card could indicate the murder of David Faraday and Betty Lou Jensen in December, Darlene Ferrin in July, Cecelia Shepard in September, along with Paul Stine and Cheri Jo Bates in October. This meant six murders possibly attributed and one unaccounted for, due to his proclamation on November 8th 1969 indicating a total of seven victims up to this point.

So let us examine the period from this letter to the next confirmed Zodiac correspondence on December 20th 1969, that of the Melvin Belli letter, claiming he may lose control and claim a ninth and tenth victim. The suggestion of a search for a ninth and tenth victim, by inference, meant he had already claimed his eighth murder victim and it must have occurred between November 8th 1969 and December 20th 1969. So who was the most likely Zodiac victim, based on age, locality and nature of the crime during this time period. One possibility is Betsy Aardsma, murdered in the campus library of Pennsylvania State University on November 28th 1969 - although this crime has a number of question marks, including the locality - seemingly out of kilter with what we know of the killer to this point. There is, however, another interesting case that deserves closer scrutiny.          

Incidentally, a woman's body was discovered next to Paradise Drive, Belvedere, Tiburon in December 1966 - although the body, wearing a red dress had lain undiscovered for approximately three to four months, according to Marin County detectives. Also on December 1st 1969, Elaine Davis (17) disappeared from from her home in Walnut Creek, Contra Costa County, California. She was abducted during the evening hours through a sliding rear window. Two and a half weeks later on December 19th 1969 her body was discovered floating off  Light House Point, Santa Cruz, California, however, due to investigators misinterpreting the age of the victim at the time, her identity was only realized 31 years later when officials exhumed the body in 2000.
No link was ever ascertained between the murder of Elaine Davis and Leona Roberts, however, both victims fell within the correct age, area and timeline of the Zodiac Killer.    

On March 22nd Kathleen Johns was abducted and taken on a terrifying journey by an assailant she later claimed to be the Zodiac Killer. Even the Zodiac himself claimed his involvement, when he mailed a letter to the San Francisco Chronicle on July 24th 1970. There were many murders and disappearances in California during the month of March, including Cosette Ellison on March 3rd, Patricia King on March 5th, Judith Hakari on March 7th, Marie Anstey on March 13th and Eva Blau on March 20th. However, the 'My Name is...Letter' and Bus Bomb Diagram claimed 10 murders on April 20th 1970, with the Melvin Belli letter on December 20th 1969 indicating that 8 murders had taken place. If we therefore take the Zodiac at his word, only two murders had taken place in this four month period. If John Hood and Sandra Garcia were Zodiac victims, then none of the disappearances and murders in March were anything to do with the Zodiac Killer. On the other hand, if the Hood and Garcia murders were not Zodiac victims, then only two of these victims in March remain a possibility, not more. Unless for some reason only known to the killer, he committed more murders, yet failed to attribute them to himself. 

Moving forward two months to the Button letter on June 26th 1970, the Zodiac claimed 12 murders. He also stated he had "shot a man sitting in a parked car with a .38". The only event that tallied with the Zodiac's claim was the murder of police officer Sgt Richard P. Radetich (25) on June 19th at 5:25 am, who was gunned down by three shots from a .38 caliber revolver at point blank range through the driver side window of his vehicle while in the process of serving a parking ticket. He was seated in his police car by 643 Waller Street, when it is believed another vehicle pulled alongside and an occupant opened fire. Officer Richard Radetich would die 15 hours later. However, the Zodiac Killer, who almost always gained extreme pleasure from his mockery towards the police and authorities, only referred to his victim in the Button letter as a 'man', apparently failing to capitalize on the situation. This appears to shed reasonable doubt that he was responsible for the murder of Sgt Richard Radetich, although the caliber of the weapon was correct. 

The disappearance of Donna Ann Lass (25) from the Sahara Tahoe Hotel on September 6th 1970 seemed to push the Zodiac's murder count to 13, with the Halloween card mailed on October 27th 1970 proclaiming a possible fourteenth victim, arriving just two days after the murder of Nancy Bennallack (27), a court reporter, on October 25th 1970. Nancy Bennallack had been slain in her own apartment on Arden Way and Bell Avenue, Sacramento , cut down by over 30 knife wounds, indicating the severity of the brutal murder - although she had not been sexually assaulted. The crime scene indicated that the killer may have used tape to mask over his fingertips during the attack.  

Finally, onto the Los Angeles letter, mailed on March 13th 1971, where he laid claim to an estimated 17 or more murders.
In this letter he stated "I do have to give them credit for stumbling across my riverside activity, but they are only finding the easy ones, there are a hell of a lot more down there". He was apparently referring to the fact that detectives had forged a link between the Zodiac Killer and the senseless slaying of Cheri Jo Bates in Riverside on October 30th 1966, claiming there were many more victims in that region. 

One such attack, was the Robert Domingos (18) and Linda Edwards (17) double murder on June 4th 1963. The young couple were gunned down on a beach near Tajiguas Creek, Lompoc, Santa Barbara County. The killer had initially attempted to bind the couple, reminiscent of the Lake Berryessa Attack on Bryan Hartnell and Cecelia Shepard on September 27th 1969. But clearly, if the Zodiac was responsible for this couple's murder, along with Cheri Jo Bates, then his murder total should have read 8, by the mailing of the Dripping Pen card on November 8th 1969, which clearly it didn't. The suggestion of "there are a hell of a lot more down there", seems to conflict with his declaration on the Dripping Pen card of seven murders. The only reasonable explanation being, that these murders were not committed under the Zodiac umbrella. A pseudonym he would only adopt just prior to the 'Debut of Zodiac' letter, received by the San Francisco Examiner on August 4th 1969. The killer may have belatedly attached the 1963 murders of Domingos and Edwards, and the Riverside murder of Cheri Jo Bate to the Los Angeles letter claiming 17+ murders. This may explain the increase from the 14 victims claimed in the Halloween card approximately five months earlier.