The most detailed description of the Zodiac Killer was presented in the days after the murder of Paul Stine in Presidio Heights, likely arrived upon by an amalgamation of two sets of eyewitnesses. The final age range estimated at between 35-45 years of age and semi-corroborated by Officer Donald Fouke, who described the suspect as 'graying in the rear' in his November 12th 1969 memorandum. The age of the killer may be relevant, when we consider the dramatic change in writing style from November 29th 1966/April 30th 1967 to the beginning of the Zodiac letters in 1969, just two years later. Is it possible to examine the linguistics from correspondence in the Cheri Jo Bates murder to the later writings and determine if they were authored by the same individual?  

The Zodiac Killer never bragged or labored the point about his four canonical attacks or five murders with respect to the victims. The closest he came was describing the attack on Michael Mageau, stating "When I fired the first shot at his head, he leaped backwards at the same time, thus spoiling my aim. He ended up on the back seat then the floor in back thashing out very violently with his legs; that's how I shot him in the knee."  But on this occasion he was prompted for more details about the crimes by Vallejo Police Chief Jack Stiltz, and duly responded. 
However, in the 'Confession' and Bates letters, just 2 to 3 years earlier, the author seemed to be relishing in the pain and misery he inflicted on Cheri Jo Bates and her family.
With statements such as "I said it was about time for her to die, she squirmed and shook as I chocked her and her lips twiched, and I then finished the job out cutting her throat," it had all the hallmarks of a killer who enjoyed reliving the events of that night, as well as exacerbating the heartbreak and suffering felt by family and friends. The author, not only named his victim in both letters, something the Zodiac Killer always steered away from, but he also mailed a letter to the father of the victim, Joseph Bates.
The addresses of the victims in the Zodiac crimes were routinely published in the newspapers, yet the Bay Area murderer failed to make contact with any of the victims families through mailed correspondence. The killer seemed to almost depersonalize the victims, only referring to them as kids, teenagers, boy, girl, woman, man, taxicab driver and people. When it came to his adversaries such as newspaper reporters, columnists, attorneys and police, then he had little problem naming Paul Avery, Marc H Spinelli, Herb Caen, Melvin Belli and David Toschi (depending on the validity of the correspondence).
Were the crimes simply his requirement to be taken seriously, so he could begin his letter writing campaign? In other words, they were not his primary focus, and why the attacks apparently ended after only 10 months.  

The most sexually explicit reference in the confirmed Zodiac letters was his statement of "man is the most dangerous animal of all to kill something gives me the most thrilling experience it is even better than getting your rocks off with a girl" in the deciphered 408 cryptogram. However, even this is downgrading sex below murder.
The 'Confession' letter is altogether different, referencing lying awake thinking about beautiful women, stating "Her breast felt very warm and firm under my hands, her lips twiched, keep your sisters, daughters and wives off the streets and alleys, I shall cut off her female parts and deposit them for the whole city to see and I am stalking your girls now." 
The emphasis of the letter is based solely on women, not couples, men or children. It also has a sexual component, not particularly evident in the Zodiac letters.
On March 13th 1971 the Zodiac Killer part-indicated his involvement in the Riverside murder of Cheri Jo Bates, but even then he couldn't refer to her by name - something he supposedly had no problem doing in both the Riverside correspondences a few years earlier. So, was the Riverside murderer really the Zodiac Killer?    ​

On the morning of October 31st 1966 at 6:30 am, Cleophus F. Martin (49), a groundskeeper at the Riverside City College discovered the stricken body of Cheri Jo Bates in an alleyway between two vacant properties. He was also described as a janitor on the website Find A Grave. Cleophus Martin died in 1975. Whether or not he is the same person who discovered the 'Riverside Desktop Poem' is open to speculation.
Four years earlier on February 28th 1962 the San Bernardino County Sun ran an article entitled 'San Bernardino Youth Knifed in Wild Attack on Redlands Road'. Somebody contacted me and pointed me in the direction of the source on Youtube, to which I will provide a link at the foot of this article. Here is the article text.    

"Three men were held for questioning in the knifing of a 19-year-old San Bernardino youth Monday after a highway incident that wound up in a wild, four-mile chase with occupants of one vehicle throwing rocks and debris at the other vehicle.
Charles Albert Schuler, 19, of 7695 Merito Avenue, was treated at Community Hospital for cuts on the shoulder, right elbow and left hand that he said was inflicted by a curved flooring knife.
His companions, Perry Lee Thomas and Bill Roan, both of San Bernardino, and Robert Claude Cockrell said they were attacked at Highway 99 and Alabama Street on the outskirts of Redlands about 5 pm Monday.
They said their three assailants, occupants of a pick-up truck, pushed in the windows of the hardtop in which the four were riding, and one of the assailants shoved in a pocket knife and started swinging it.
The four said they then got out of their car, but were chased by the other three, all of whom had knives. Witnesses said that Schuler was chased through heavy traffic. His shirt was cut to ribbons by his knife-swinging assailant.
After dodging knives for a while, the four youths got back in their car and fled. They said the three in the pick-up truck loaded the truck bed with rocks and debris, and chased the car four miles to Tippecanoe and Central.
One of their assailants rode in the truck bed and the other on a running board, hurling rocks and debris at the car, the four said. The truck was identified through a license number and three men were later picked up by Detective Jay D. Hughes.
Booked in the County Jail for questioning were Booker T. Washington (47), his son, John T. Washington (26) and Cleophus Martin (43) of 1577 Vine Street, all of San Bernardino. Detective William Paterson of the homicide division is investigating."   
Cleophus Martin was born on 15th October 1917, which would have him 44 years of age on February 28th 1962, not 43, as referenced in the newspaper. Due to the rarity of the name and the location of San Bernardino, it could be argued that this was the groundskeeper/janitor who discovered the body of Cheri Jo Bates. This man likely had nothing to do with the murder of Cheri Jo Bates, and was unfortunate enough to discover the terrible events of the previous night, but it begs the question of how familiar the perpetrator was of the Riverside campus.
Was the murderer of Cheri Jo Bates familiar enough with the Riverside City College campus to know that the two properties either side of the attack site were empty? Did he have access to the Riverside library storage room to write on the underside of the desktop in relative anonymity? Did he use paper acquired from the Riverside college?  
"A photocopying machine, where students could secure 8 1/2 X 11 inch black and white copy of printed or typed material, was available at the library for ten cents."
The photocopying machine would have been acquired by the college library in respect to the paper likely used by the college staff and students. The three Bates letters mailed on April 30th 1967 measured 8 1/2 X 11 inches, identical to the size offered by the photocopier in the library. 

Credit to ZodiacKillerIdentified on Youtube.

When Stephanie Guttman turned down the opportunity to accompany Cheri Jo Bates to the Riverside City College library on the afternoon of October 30th 1966, did she make alternative arrangements that ultimately led to her early demise. Despite entering the library to acquire her reading material shortly after opening time, she left within minutes. Nobody remembers seeing the young girl from 6:30 pm to 9.00 pm that evening, indicating she exited the library and went elsewhere. She wasn't murdered until approximately 10:30 pm that night, when screams were heard in the vicinity of the alleyway. At approximately 9:30 pm a female student purportedly noticed a man standing in the fateful alleyway smoking a cigarette and exchanged brief greetings with him. It is therefore clear that Cheri Jo Bates had been murdered subsequent to this encounter. 
The following observations take a new approach to the murder of Cheri Jo Bates, based upon the structure and wording of the 'Confession' letter mailed one month later. 

Everything contained in the 'Confession' letter was information readily available in the newspapers, however, this doesn't necessarily indicate that the author of the letter wasn't the killer. But there is a narrative in the letter that completely flies in the face of what was possible. The author of the 'Confession' letter described the middle wire of the distributor being pulled, the small knife and the cutting of the throat, which were all reported in the newspapers and totally correct, yet gave the impression that everything happened in one continuous timeline, which was impossible.
The impression given, is of a woman who enters the library while her vehicle is being disabled, and then exits to find her car won't start. The good Samaritan then offers her assistance and escorts her to a promise of a lift in his vehicle just down the street, before stabbing her. We know Cheri Jo Bates wasn't murdered between 6:00 pm and 9:30 pm, so why does the author cover all his bases in convincing the reader he is the killer, but fail so horribly with the timeline. 
Many details of the crime were printed in the newspapers, including an "awful scream between 10:15 pm and 10:45 pm and then a loud sound like an old car starting up." The author of the letter uses this scream in his letter, stating "she let out a scream once and I kicked her in the head," along with the presence of his vehicle: "I told her that my car was down the street and that I would give her a lift home."  However, if he knew she had exited the library to find her car disabled, then his story doesn't work from the standpoint of a 10:15 pm to 10:45 pm attack, as the library closed at 9:00 pm. Besides, he stated he followed her out of the library after about 2 minutes, and we know she left prior to 6:30 pm. Why is the author (if the killer) trying to give the impression that Cheri Jo Bates never left the campus that evening, when clearly her movements were unknown for approximately 4 hours. 
The author blatantly disregards the time of 10:15 pm and 10:45 pm in his continuous timeline, but certainly makes use of the scream and vehicle, to give us the impression he had killed Cheri Jo Bates moments after she exited the library. Does he weave his vehicle into the story to convince us he had to travel a reasonable distance to arrive near the alleyway, and therefore lives a reasonable distance away, when in actual fact he lived within walking distance of the Riverside campus.
If the author of the 'Confession' letter was the Zodiac Killer, he may have used this tactic nearly three years later, when using his vehicle as evidence he didn't live close to the payphone at Springs and Tuolumne after the attack at Blue Rock Springs.
If Cheri Jo Bates had left the library annex voluntarily before 6:30 pm and hooked up with somebody who lived nearby, who then escorted her back to her vehicle at around 10:30 pm, then the disabling of her vehicle could have taken place while she was present during an altercation. This would explain both windows rolled down, the right door being possibly ajar and the keys present in the ignition. A murder at approximately 10:30 pm with little passing traffic is an altogether more likely scenario, particularly when we consider the screams heard by eyewitnesses.
The author and killer would have been unaware at the point of writing, of a female student and man present in the alleyway with no body, and was desperate to shift the timeline 4 hours earlier, thereby ruling out any possibility of Cheri Jo Bates having ever left the campus to a nearby residence with somebody she knew. The use of his vehicle in the letter was the window dressing, to paint a completely different picture to the one that really happened that night - that Cheri Jo Bates was escorted from the campus on foot at around 6:30 pm by somebody she trusted. Somebody that would eventually betray that trust a mere 4 hours later.

The idea that the murderer of JonBenet Patricia Ramsey on 25/26th December 1996 would break into the Ramsey household, write a two and a half page ransom note using a notepad and pen found within the house (taking in excess of 22 minutes to compose), rather than write the note beforehand, and then not actually kidnap the young girl, but kill her in the basement, beggars belief.
Analysis of the note and the language contained within it, tends to indicate that it was written by a female.

Mr. Ramsey,
Listen carefully! We are a group of individuals that represent a small foreign faction. We do respect your bussiness but not the country that it serves. At this time we have your daughter in our posession. She is safe and unharmed and if you want her to see 1997, you must follow our instructions to the letter.
You will withdraw $118,000.00 from your account. $100,000 will be in $100 bills and the remaining $18,000 in $20 bills. Make sure that you bring an adequate size attache to the bank. When you get home you will put the money in a brown paper bag. I will call you between 8 and 10 am tomorrow to instruct you on delivery. The delivery will be exhausting so I advise you to be rested. If we monitor you getting the money early, we might call you early to arrange an earlier delivery of the money and hence a earlier delivery pick-up of your daughter.
Any deviation of my instructions will result in the immediate execution of your daughter. You will also be denied her remains for proper burial. The two gentlemen watching over your daughter do not particularly like you so I advise you not to provoke them. Speaking to anyone about your situation, such as Police, F.B.I., etc., will result in your daughter being beheaded. If we catch you talking to a stray dog, she dies. If you alert bank authorities, she dies. If the money is in any way marked or tampered with, she dies. You will be scanned for electronic devices and if any are found, she dies. You can try to deceive us but be warned that we are familiar with law enforcement countermeasures and tactics. You stand a 99% chance of killing your daughter if you try to out smart us. Follow our instructions and you stand a 100% chance of getting her back.
You and your family are under constant scrutiny as well as the authorities. Don't try to grow a brain John. You are not the only fat cat around so don't think that killing will be difficult. Don't underestimate us John. Use that good southern common sense of yours. It is up to you now John!
Victory!
S.B.T.C  Youtube.

This will be an exploration into the premise that the November 29th 1966 'Confession' letter, the Riverside 'Desktop Poem' and the three Bates letters were written by a female, consumed with hatred and jealousy towards her fellow womenfolk, and not by the murderer of Cheri Jo Bates, brutally stabbed and beaten in a Riverside alleyway on October 30th 1966.
Here is the wording contained within the typed 'Confession' letter:
​
She was young and beautiful. But now she is battered and dead. She is not the first and she will not be the last. I lay awake nights thinking about my next victon. May'be she will be the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven. Maybe she will be the shapely blue eyed brunett that said xxx no when I asked her for a date in high school. But maybe it will not be either. But I shall cut off her female parts and deposit them for the whole city to see. So dont make it to easy for me. Keep your sisters, daughters and wives off the streets and alleys. Miss Bates was stupid. She went to the slaghter like a lamb. She did not put up a struggle. But I did. It was a ball. I first pulled the middle wire from the distributor. Then I waited for her in the library and followed her out after about two minutes. The battery must have been about dead by then. I then offered to help. She was then very willing to talk to me. I told her that my car was down the street and that I would give her a lift home. When we were away from the library walking, I said it was about time. She asked me "about time for what". I said it was about time for her to die. I grabbed her around the neck with my hand over her mouth and my other hand with a small knife at her throat. She went very willingly. Her breast felt very warm and firm under my hands. But only one thing was on my mind. Making her pay for all the brush offs that she had given me during the years prior. She died hard. She squirmed and shook as I chocked her. And her lips twiched. She let out a scream once and I kicked her in the head to shut her up. I plunged the knife into her and it broke. I then finished the job out cutting her throat. I am not sick. I am insane. But that will not stop the game. This letter should be published for all to read it. It just might save that girl in the alley. But that's up to you. It will be on your conscience. Not mine. Yes I did make that call to you also. It was just a warning. Beware....I am stalking your girls now.
CC.
Chief of Police Enterprise.

Although not wholly scientific, the wording from the 'Confession' letter was placed into two online tools to determine the gender of its author.
Textgain, a web service for predictive text analytics, predicted a female of 25 years or over, with 75% confidence.  
Hacker Factor, in formal genre, scored 849 for female and 428 for male, and a weak emphasis for European origin.
This analysis is not pushing the idea that the author of the Riverside communications was a female, simply considering it a possibility based on the language used- particularly within the 'Confession' letter and Riverside 'Desktop Poem'. 
The 'Confession' letter author appears to be reveling in the murder and demise of Cheri Jo Bates, a trait not exhibited by the Zodiac Killer, who, not only never mentioned his victims by name, but didn't dwell on the nature of the murders themselves. Here, the author is positively wallowing in the details of their achievement, opening with the lines "She was young and beautiful. But now she is battered and dead." In addition to being morally bankrupt, the author is going out of their way to exhibit a spiteful and malicious streak in the tone of the letter. Providing details of the crime to prove their connection to it, which they ultimately failed to do, appears of secondary importance to the author.  
Scouring any piece of text to discover the gender of its author is similar to handwriting comparison- it's subjective and dependent on the observer, and therefore cannot be scientifically validated. This is important to remember when reading the following observations.
Would a male individual have used the language contained within the 'Confession' letter? Just like the JonBenet Ramsey ransom note, the author appears to be selling a story- how "the shapely blue eyed brunett said no when I asked her for a date in high school" or maybe they will kill "the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven." 
Phrases such as "the shapely blue eyed brunett," "the beautiful blond that babysits near the little store," "she went very willingly. Her breast felt very warm and firm under my hands," "keep your sisters, daughters and wives off the streets and alleys" and "it just might save that girl in the alley. But that's up to you. It will be on your conscience. Not mine" raises some questions as to the gender of the 'Confession' letter typist, who is adding superfluous detail into the story behind the murder of Cheri Jo Bates. In addition to this, making sure we understood that 'he' was rejected "by the shapely blue eyed brunett" and was "brushed off" by Cheri Jo Bates many times in 'his' pursuit of a heterosexual relationship. 
For those who believe a Riverside connection to the Zodiac Killer, another factor must be considered- despite the addresses of the Bay Area victims being widely publicized in the newspapers, not once did the Zodiac Killer write to the family members of the victims, such as David Faraday, Betty Lou Jensen and Darlene Ferrin, to name but three- as typified by the author of the Joseph Bates letter, in what can only be described as a cruel and unnecessary act.
The mailing of the Joseph Bates letter, again exemplified the callousness of an individual who seemingly bathed in the misery of the murder itself, something evidently absent from the Zodiac communications.
Are these observations, particularly regarding the 'Confession' letter, suggestive of a female author, or a male of effeminate tendencies or inadequacies who just got "brushed off." Or possibly a complete stranger. Your thoughts on either the 'Confession' letter or the JonBenet Ramsey ransom note would be welcome.      

Without a DNA or fingerprint connection apparently linking Riverside and the Zodiac Killer, many have tried to link the two through his correspondence. Was the Zodiac Killer responsible for the murder of Cheri Jo Bates in Riverside on October 30th 1966, and if so, was he a well-read individual with connections to the campus library.
David Oranchak of ZodiacKillerCiphers highlighted the text of Edward Hyde, Earl of Clarendon, present in the 408 Cipher, in his article entitled 'Throw the book at him, Part 3'. The section of text is from a book called 'The life of Edward, Earl of Clarendon, lord high chancellor of England: Volume 2':
​Forty-six consecutive letters from this text corresponds with a section of the 408 cipher. Dave Oranchak, the foremost expert on the Zodiac ciphers, commented on this "So, only one piece of text, from a vast collection of eleven billion pieces of text, fit into this chunk of cipher text. A one in eleven billion chance seems to suggest some significance. But don’t be fooled by this. Just because this rare event occurred, doesn’t mean it is anything more than a simple coincidence. If we didn’t already know the real solution to the 408, how do we know that this chunk of old and obscure text isn’t the correct solution?"  
I wanted to validate or refute whether this was a simple coincidence or not by examining whether the works of Edward, Earl of Clarendon featured anywhere else in Zodiac or Riverside correspondence. One wouldn't envisage many American criminals using the writings of a seventeenth century English statesman to form part of their serial murder exploits, and certainly not without access to a comprehensive library of books.
This is when I noticed another piece of obscure text from Edward, Earl of Clarendon and flew back to the last piece of notable text from the presumed Zodiac Killer on the Riverside desktop- the title of which was "sick of living/unwilling to die."  
One of Edward Hyde's quotes was “They who are most weary of life, and yet are most unwilling to die, are such who have lived to no purpose, — who have rather breathed than lived.” http://izquotes.com/quote/385232.
​Although not perfect, I couldn't help wondering if the Zodiac Killer was recalling from memory, as he did with 'The Mikado.'
Had he plagiarized "weary of life, unwilling to die" to "sick of living, unwilling to die," and would then later hide another section of Edward Hyde's text in the 408 cipher, as a form of link between the murder in Riverside and the Bay Area.
Edward Hyde, Earl of Clarendon was also an avid user of ciphers as revealed here in literary manuscripts; 
"Naturally a substantial portion of Clarendon's surviving manuscripts comprises his personal correspondence — both letters received by him from numerous correspondents and his own letters, written or signed by him, whether drafts, retained copies, or the letters actually sent. Among many notable examples are his letters written in August 1646 to William, Lord Widdrington, and to Sir John Berkeley, announcing the beginnings of his History of the Rebellion, and the letter he wrote on 12 November 1646, to Sir Edward Nicholas, describing his plan for the work and stating that he had already completed sixty sheets of it. Some of his letters, particularly those dating from the Civil War period, are wholly or partly in cipher or make use of pseudonyms in both salutations and signatures. The codes to sixteen such ciphers used by the Royalists are written out in Bodleian, MS Clarendon 94, and see also British Library,"
However, are there any alternatives to Edward Hyde- someone that possibly connects the 'Confession' letter and Riverside 'Desktop Poem' together, using the title of each communication.   

I have always believed the Zodiac Killer was driven by some form of warped religion- one that drove him to the confession box after each crime and manifested in the form of letters mailed to the newspapers and police.
Using the Riverside library as our primary focus once again, did the works of an early Christian theologian and philosopher influence the writings of Zodiac. 
'Peter A Fiore concludes that John Milton (an English poet, author of Paradise Lost, polemicist, man of letters, and civil servant for the Commonwealth of England) like many humanists, Christian philosophers, Reformers, and theologians of every variety in the early seventeenth century, drew widely from Augustine and that such indebtedness gave a richer and fuller theological dimension to his epic of lost paradise and enhanced the meaning of the poem.' 
link  
The Augustine he is referring to is St Augustine of Hippo (13 November 354 - 28 August 430), a Roman African, Christian theologian, whose writings influenced the development of Western Christianity and Western Philosophy. 
His work was translated by many individuals, but here are a few examples:
1] "Now is not the time for asking questions but for confessing to You. I was wretched, just as every mortal soul is wretched who is bound to the friendship of mortals. We are torn to pieces when we lose them, and so become aware of how wretched we were, even before we lost them. This is the way it was with me. I wept bitterly, and found rest only by weeping. I was so wretched that I held that life of wretchedness to be more dear to me than the friend for whom I wept. Even though I wanted to change it, I was more unwilling to lose it than I had been to lose my friend. Actually, I doubt that I would be willing to lose it even for him, as it is said of Orestes and Pylades, if that is true, that they would have gladly died for each other, or both died at the same time, rather than living part from each other. But I had begun to be afflicted with a strange kind of feeling, different from theirs. I cannot explain it, but I was tired of living and yet, I was afraid to die." link.​

2] "I do not know whether I would have been willing to die for him in the way that Orestes and Pylades, if the story is true, were willing to die together for each other. And yet a strange feeling had grown in me, and it was very different from theirs; I was sick and tired of living but I was too afraid to die." link.
​3] "But in me there was an odd kind of feeling, the exact opposite of theirs, for I was at once utterly weary of life and in great fear of death." link.
4] "I was at the same time thoroughly tired of living and extremely frightened of dying.”
link.
Was this a case of the Zodiac Killer recalling the literary work of another, as he did with the Gilbert and Sullivan Mikado, but paraphrasing it. However, in this instance, the author chose sick of living/unwilling to die as his title of the 'Desktop Poem'. 
On its own, this connection could appear a little unconvincing, but the author of the Riverside 'Desktop Poem' may have mailed correspondence to the Riverside Homicide Detail and Riverside Press Enterprise on November 29th 1966, in the form of letters entitled 'The Confession.'
Two weeks after the October 30th 1966 murder of Cheri Jo Bates, the Riverside Police staged a library reconstruction of the crime on November 13th 1966. The probable murderer then mailed the 'Confession' letters. St Augustine of Hippo wrote the Confessions (in which the above examples of text are contained), an autobiographical piece of work consisting of 13 books. "The Confessions of Saint Augustine in order to distinguish the book from other books with similar titles. Its original title was Confessions in Thirteen Books, and it was composed to be read out loud with each book being a complete unit.
Confessions is generally considered one of Augustine's most important texts. It is widely seen as the first Western autobiography ever written, and was an influential model for Christian writers throughout the Middle Ages. Professor Henry Chadwick wrote that Confessions will "always rank among the great masterpieces of western literature." link.  
St Augustine of Hippo was born on November 13th, the exact date of the library reconstruction. 
"The City of God Against the Pagans (Latin: De civitate Dei contra paganos), often called The City of God, is a book of Christian philosophy written in Latin by Augustine of Hippo in the early 5th century AD. The book was in response to allegations that Christianity brought about the decline of Rome and is considered one of Augustine's most important works, standing alongside The Confessions, The Enchiridion, On Christian Doctrine and On the Trinity. As a work of one of the most influential Church Fathers, The City of God is a cornerstone of Western thought, expounding on many profound questions of theology, such as the suffering of the righteous, the existence of evil, the conflict between free will and divine omniscience, and the doctrine of original sin."
"Shortly before Augustine's death, the Vandals, a Germanic tribe that had converted to Arianism, invaded Roman Africa. The Vandals besieged Hippo in the spring of 430, when Augustine entered his final illness. According to Possidius, one of the few miracles attributed to Augustine, the healing of an ill man, took place during the siege. According to Possidius, Augustine spent his final days in prayer and repentance, requesting that the penitential Psalms of David be hung on his walls so that he could read them. He directed that the library of the church in Hippo and all the books therein should be carefully preserved. He died on 28 August 430. Shortly after his death, the Vandals lifted the siege of Hippo, but they returned not long thereafter and burned the city. They destroyed all of it but Augustine's cathedral and library, which they left untouched."  Wikipedia.
​Was the murderer of Cheri Jo Bates somehow connected to the Riverside library, a well-read individual, who subtly introduced sections of text from St Augustine of Hippo into the titles of both the 'Riverside Desktop Poem' and 'The Confession' letter in order to give himself a feeling of superiority over the police and newspapers, as he would ultimately do several years later. 

"SICK OF LIVING, UNWILLING TO DIE" 

In light of the possible capture of the Golden State Killer on April 24th 2018, there has been renewed excitement in recent weeks concerning the possible DNA left by the Zodiac Killer when he mailed his many correspondences. Other sources that may have harbored DNA have been mentioned, such as the car door, bottle and Zodiac bindings at Lake Berryessa, the gloves from Presidio Heights, along with potential blood from the killer deposited on the clothing of Cheri Jo Bates at Riverside on October 30th 1966. This may or may not be a Zodiac crime, but it is still an avenue that must be pursued. 
Michael Cole, who runs the 'Zodiac Revisited' website, details the mitochondrial DNA findings of 1999, obtained by Michael Morford and pertaining to the case of Cheri Jo Bates. But the hope is now, that a full DNA profile can be obtained and cross checked using genealogy websites and familial DNA linkage. Separating any blood from the killer on Cheri Jo Bates clothing by locating Y-markers has always presented a challenge to forensic investigators in a mixed sample, however, there is a possibility that we may, or could have had the blood of the killer at Riverside from somewhere other than the clothing of Cheri Jo Bates.
"The Y chromosome is currently by far the most popular marker in genetic genealogy that combines genetic data and family history. This popularity is based on its haploid character and its close association with the patrilineage and paternal inherited surname." PubMed.
Riverside Police were meticulous in their evidence gathering, performing a library reconstruction of events the night of the murder and taking fingerprints and hair samples from attendees of the library on Sunday October 30th 1966. They retrieved a hair sample from a blood clot at the base of Cheri Jo Bates' right thumb, recovered a cigarette butt from the alleyway floor and took fingernail scrapings from the victim. They also clearly considered the possibility that the killer of Cheri Jo Bates may have cut himself during the attack with a less than sturdy knife, described by Captain Cross as a pocket knife with a "3-inch blade or less." Even the author of the 'Confession' letter on November 29th 1966 (whether the killer or not) claimed that the knife broke towards the end of the attack. Was this the pivotal moment that ended the callous attack on the defenseless young woman.
The 'Inside Detective' magazine revealed one crucial piece of evidence from the Riverside alleyway crime scene. It stated "The driveway adjacent to 3680 Terracina Street was so churned up it looked like a tractor had been over the ground. The girl, who was very athletic, put up a terrific struggle. At the murder scene, drops of blood leading from the body to Terracina Street indicated to the detectives, that the murderer had walked back to the street following the slaying."
Using an old overhead view of the campus in 1966 (not shown here) and the fact she was positioned between the two vacant properties of 3680 and 3692 Terracina Drive, it is possible to calculate how far Cheri Jo Bates' body lay up the alleyway from Terracina Drive. Below I have placed all the relevant distances.     

Cheri Jo Bates was lying approximately 100 feet southwest of Terracina Drive, shown in relation to the football field and scoreboard in the distance. That is an extensive blood trail leading away from the body, if the interpretation of the police statement is correct. 
​The 'Confession' letter stated "When we were away from the library walking, I said it was about time. She asked me "about time for what". I said it was about time for her to die. I grabbed her around the neck with my hand over her mouth and my other hand with a small knife at her throat. She went very willingly." If the attack began in the vicinity of where her body was discovered, we are left with two possibilities: The blood trail to Terracina Drive was the victim's blood, dripping from the killer, or the killer's blood dripping from a cut hand. The blood trail, if significant enough to be noticed by detectives, was continuous to the sidewalk of Terracina Drive, then it could be argued to be blood secreted from a continuously bleeding hand, as opposed to a killer having blood on his person (absorbed by his clothing) or a small knife. Presumably, the killer would have pocketed the knife in advance of reaching the street. This must have been considered by investigators who visited the crime scene. But, was this blood gathered from the alleyway floor and stored for 'future use'? 
Cheri Jo Bates' blood type detailed at autopsy is rare in the USA population. It was AB RhD positive, which accounts for only 3.4% of the American population. Even with the limited forensic capabilities in 1966, this testing was a simple affair, and could have determined whether the blood trail extending toward Terracina Drive was that of the killer's or from the victim.
The pattern or tail of the blood drops could certainly have determined the direction of the killer within the alleyway. Since detectives concluded that the "drops of blood leading from the body to Terracina Street indicated to the detectives, that the murderer had walked back to the street following the slaying," then it remains a possibility that the killer injured himself during the attack, allowing the trail of blood to extend the full 100 feet in distance, as opposed to the limited blood secretion possible from a small pocket knife or clothing. 
If the murderer of Cheri Jo Bates cut himself when he delivered the stab wound to the young woman's back during the latter part of the attack, there may be limited blood transfer to her clothing, however, there may be have been far more present in the vicinity of the crime scene, during his 100 foot journey to exit the alleyway. By odds alone, it is unlikely the killer had an AB RhD positive blood type, making it easy to determine the origin of the blood on the alleyway floor, and whether it was from Cheri Jo Bates or even the Zodiac Killer himself. 

Here we will take one final look at the October 30th 1966 Cheri Jo Bates murder in Riverside, utilizing the 3D graphics of Google maps to give an overview of the crime scene that evening or night. Cheri Jo Bates lime green Volkswagen Beetle was discovered on October 31st 1966 parked 30 yards past the library entrance, and 75 yards east of the ill-fated alleyway. Whether it remained in this position from the moment she arrived at the library just before opening time, until being discovered by investigators the following day, is open to question. Below is a representation of the Volkswagen Beetle, library annex, the alleyway (drawn into its approximate position), and the movements of Cheri Jo Bates (1 to 5) from the perspective of the November 29th 'Confession' letter.        

A Mexican-American student noticed Cheri Jo Bates close to opening time and shortly after: who stated "he knew Cheri Jo Bates and had noticed her in the library the night in question. He said he saw the girl "writing something with a ball point pen" in her blue spiral school notebook." The boy told us he was outside about 5.30 pm, waiting for the library to open at 6, and it was then he saw the girl."
Other students who were acquainted with Cheri Jo said they were in the library between 6.30 pm and 6.40 pm, and did not see the girl during that time.
Walter Siebert stated that "he and a few friends were in the library from 7.15 pm until 9, but did not see Miss Bates, whom they all knew. They said they saw four men dressed in work clothes sitting on a fence across from the spot where Miss Bates' car was found, but they did not know them." ​
If we believe the 'Confession' letter and tie it alongside these statements, a picture unravels of a woman who likely discharged her books and left the library within a very short time- leaving prior to 6.30 pm. However, according to the author of the 'Confession' letter, he would have effectively disabled her vehicle extremely close to the library entrance sometime between 6.00 pm and when she exited the library. She would then have discovered her disabled Volkswagen and taken up the offer of assistance by this unknown person, walking back past the library entrance, completely dismissing the option of assistance from anybody inside the library, including making a phone call, and traveling into a dark alleyway (despite being afraid of the dark), while simultaneously leaving her car keys in the ignition, windows rolled down and car doors unlocked. Not withstanding the fact, a female eyewitness saw no body in the alleyway circa 9.30 pm, and screams were heard from that location by two earwitnesses around 10.30 pm. One could argue, that if these observations make no sense, then the story depicted by the 'Confession' letter is fiction regarding the timeline it suggests.       

There is no guarantee that the Volkswagen Beetle remained in this position upwards of 12 hours until its discovery on the morning of the 31st. Since detectives seemingly operated upon the assumption it did, one could infer that eyewitnesses leaving the library on the evening and night of the murder, saw the Volkswagen Beetle in exactly the same position it was ultimately discovered on the Monday. 
If this were the case, and with screams heard around 10.30 pm- then other than abduction- she must have left willingly on foot after departing the library to a secondary destination, either on her own or with an unknown person or party. The problems began four hours later just before the screams were heard. The 'Confession' letter gives the impression of a good Samaritan "offering to help" when Cheri Jo Bates failed to start her vehicle, and she blissfully wandered off with him into a dark alleyway. The added suggestion of "brush offs" in the letter may have wanted to infer that the killer and victim were known to one another and hence her willingness to walk alongside him. Yet this seems too obvious a conclusion to be drawn, focusing the investigation inward to friends and relations, and thereby would not have been wholly relied upon as the truth by investigators- who could easily have formed an opposite stance. 
But if Cheri Jo Bates willingly left the library with somebody she knew or had arranged to meet shortly after opening time, and had returned to her vehicle circa 10.30 pm with this person, then it is conceivable the confrontation or disagreement began by her vehicle, and the disabling of her vehicle was integral to it. The condition of her vehicle the following morning may suggest she was preparing to leave for home that night when things took a turn. The sabotaging of her distributor not distinct and separate to her discovering her disabled vehicle, but part of one continuous sequence. Left with little option but to seek help, she headed off to ring for assistance, leaving her vehicle in a condition she otherwise would never have done. She is dragged or forced into the alleyway and the rest is history. 
The 'Inside Detective' magazine stated 'Two young girls who said they knew Cheri Jo, gave a taped interview to a crew from a Los Angeles television station. The girls in the interview, said that Cheri Jo had told them Sunday that she was "going to the library to meet her boyfriend." However, Sgt Gren said that while Cheri Jo had met her boyfriend in San Francisco the weekend prior to her murder, the boy was still in the Bay Area at the time of her death. The statements of the two girls were based on hearsay and not on fact Captain Cross told newsmen.'
However, were the two young girls referring to Dennis Highland or somebody else. If Cheri Jo Bates had made alternative plans to meet somebody that evening, could this be our murderer. He may certainly have been known to the young girl and more crucially to the friends of Cheri Jo Bates.   

Many have toyed with the idea of a Zodiac Killer in Riverside, California, responsible for the murder of Cheri Jo Bates on October 30th 1966 or at the very least the author of the Confession and Bates letters. There are tantalizing threads in regards to the three Bates letters allying with his 'trinity' of communications mailed to the Vallejo Times-Herald, San Francisco Chronicle and San Francisco Examiner on July 31st 1969, just over two years later. The double postage was evident, and the threat of "more victims " was apparent in both. The April 30th 1967 Bates letters stated "Bates had to die, there will be more." The Vallejo Times-Herald communication carried a similar threat: "I will cruse around and pick of all stray people or coupples that are alone then move on to kill some more untill I have killed over a dozen people." 
It is also pointed out that the Zodiac Killer was responsible for the Bates letters because he signed off two of the letters with a Z-like alphabetical character. The Z representing Zodiac. The following will cast some doubt on this supposition and hopefully give us the exact date the Zodiac Killer first thought up his pseudonym Zodiac. In other words, the pseudonym Zodiac didn't exist for this individual in 1967 and therefore the alphabetical Z wasn't representative of Zodiac, or the precursor to it.​ 

On the right is an excerpt from the San Francisco Sunday Examiner and Chronicle dated August 3rd 1969. The Vallejo Police Chief Jack E Stiltz "urged the writer yesterday to send more letters with more facts to prove his connections with the crimes." The Bay Area murderer duly obliged with the 'Debut of Zodiac' letter, received by the San Francisco Examiner on August 4th 1969. It was called the "Debut" letter for good reason- it was the day the Bay Area murderer revealed his pseudonym to the world, opening with the now infamous line "This is the Zodiac speaking." But if Chief Jack E Stiltz had not requested more details, it is extremely unlikely this correspondence would have been mailed at all. We would have had to wait over two months until the October 13th 1969 Paul Stine letter for Zodiac to introduce his pseudonym into the public domain, if ever at all. 
The 'Debut of Zodiac' letter only existed because of Chief Jack E Stiltz- and this communication is the only reason our knowledge of the killer as Zodiac existed at this point in time. The choice of the pseudonym being revealed in this letter was not a choice made by the killer, because he wouldn't have written it, if not pressed into action by reading this newspaper column. 
In fact, the Zodiac Killer may never have existed under this name, if it wasn't for this publication by the San Francisco Sunday Examiner and Chronicle on August 3rd 1969. There is further evidence that the American public played a key role in igniting the killer's choice of pseudonym 
If the Z on the Bates letters really stood for Zodiac, then the murderer of Cheri Jo Bates, David Faraday, Betty Lou Jensen and Darlene Ferrin had almost three years to create an appropriate pseudonym before the July 31st 1969 'trinity' of communications proclaiming his collection of slaves for the afterlife. He had six and a half months from the December 20th 1968 double murder until the attack at Blue Rock Springs Park. He had 27 days from the July 4th 1969 attack until the mailing of the July 31st 1969 'trinity.'  This was his arrival to the world, yet he didn't sign off any of these letters with 'Zodiac' or even a 'Z'.
If he was surreptitiously operating under the name of Zodiac at this point, he clearly didn't give this impression when he opened up two of his communications with the rather unoriginal opening line of "I am the killer of the 2 teen-agers last Christmass at Lake Herman and the Girl last 4th of July" to the Vallejo Times-Herald and San Francisco Examiner. The San Francisco Chronicle was equally devoid of any pseudonym or initial, beginning with "This is the murderer of the 2 teenagers last Christmass at Lake Herman + the girl on the 4th of July near the golf course in Vallejo." 
The reason behind this, being that he hadn't formulated the pseudonym Zodiac at this juncture. The prompt was to come just three days later on Sunday August 3rd 1969- the day the 'Zodiac Killer' was born in the mind of the killer. 
The San Francisco Sunday Examiner and Chronicle opened with the lines "A self-accused killer failed to keep a threat of mass murder here, but there was no slackening of tension or mystery caused by the warning. The police department telephone system was clogged at times by anxious callers asking if the "cipher killer" had been caught."
The killer read this publication and was probably dismayed at the pseudonym of "cipher killer" attributed to him. He sat back in his armchair and was likely sparked into action to create his own pseudonym. He thumbed through the San Francisco Sunday Examiner and Chronicle of August 3rd 1969 during the day, until he arrived at the Zodiac horoscope page, and a light went on. This was the day the 'Zodiac Killer' was born.    

We will take a look at the 'Confession' letter- and with the consideration of one murderer in mind, examine its contents in relation to the autopsy findings by pathologist Rene Modglin, in respect to the brutal murder of Cheri Jo Bates in Riverside on October 30th 1966. This may go someway to determining whether or not the 'Confession' letter was authored by the killer. 

On the right is a representation of the wound pattern inflicted upon Cheri Jo Bates. One can see that all the lacerations noted in the post-mortem findings were effectively delivered by the killer from the breasts upwards, with the ferocity of the attack centered around the neck and face (the hands and arms raised to protect these vital areas). Some may say, that with six injuries to the face and seven lacerations to the neck, the killer's intention was to wipe away the identity of the pretty young student in a distinctly personal attack, but I will leave that to the observer to consider.
The lacerations and their directions have a story to tell- one that doesn't indicate an overhand knife attack from the front, in a downwards motion. Or an underhand grip from the front in a straight, or upwards motion- an argument  strengthened somewhat by the evident lack of injuries to the area of the abdomen.
The 'Confession' letter stated "I said it was about time for her to die. I grabbed her round the neck with my hand over her mouth and my other hand with a small knife at her throat." The killer was effectively gaining control from the beginning of the attack, rather than performing an uncontrolled full frontal assault, stabbing wildly. If we base this analysis on one assailant, as the letter implies, it is reasonable to deduce the assailant had grabbed Cheri Jo Bates around the neck and mouth with his left arm, in a form of choke-hold.
Cheri Jo Bates' autopsy findings showed numerous petechiae in the forehead (broken capillary blood vessels). Petechiae are commonly present in the eyes or eyelids as a result of manual compression of the neck area, but not always, and can also be present on the face, especially the forehead. The manual force compressing the neck increases the vascular pressure, causing the blood vessels to rupture. 
The assailant can now use his right hand to stab and slash the young girl, in effect, reaching over her right shoulder and directing the knife back towards himself (possibly an underhand grip), causing the three injuries to her breast region and several to her face. Clearly, at this point, Cheri Jo Bates is using her hands and arms in a defensive motion to protect her upper torso and face (eleven injuries noted to her hands and fingers, including lacerations and abrasions), as noted in the diagram. The small knife is being deflected as it's delivered, resulting in lacerations running laterally across her body. There must have been a violent struggle at this point, with Cheri Jo Bates trying desperately to secure her release, and the attacker resisting her escape, resulting in the alleyway floor being disturbed by their footwear, described in the 'Inside Detective' magazine by law enforcement: "The driveway adjacent to 3680 Terracina Street was so churned up it looked like a tractor had been over the ground. The girl, who was very athletic, put up a terrific struggle."      

The 'Confession' letter continued: "Her breast felt very warm and firm under my hands, but only one thing was on my mind. Making her pay for all the brush off's that she had given me during the years prior. She died hard. She squirmed and shook as I choked her, and her lips twitched." The squirming being her attempt to break free from his clutches. The sheer terror and exertion, coupled with the compression applied to her neck, resulted in the petechial hemorrhaging to her forehead. It may have been at this point (or quite possibly later), that the assailant, in an attempt to gain control, shifted his grip from around her neck and started to slash (or stab) her throat.
One must also note the correlation between the wounds inflicted to her breasts, his reference in the letter to "her breast felt very warm and firm" and his promise to "cut off her female parts and deposit them for the whole city to see." In addition, if her breast felt very warm, was this indicative of an assailant who was not wearing gloves, and who had earlier deposited fingerprints on her lime green Volkswagen Beetle. 
The 'Confession' letter then stated: "She let out a scream once and I kicked her in the head to shut her up." If this were true, then clearly, he cannot kick her in the head standing upright behind her, while she is upright too. Bearing in mind the position she was found in the turnout the following day- face down- she may likely have been thrust forward at this point, onto the alleyway floor, causing abrasions to her hands (noted at autopsy). Free from the choke-hold, she is able to let out a scream, which resulted in the assailant kicking her in the face. Whether this action ever took place is debatable- but here are three excerpts from the autopsy to consider: [1] "A 2 cm oblique ragged edge gaping laceration of the upper lip on the left side that angles laterally from above and extends completely through the thickness of the lip. The teeth behind are not loose or broken." [2] "A dark blue-gray, slightly swollen discoloration of mainly the mucocutaneous portions of the upper and lower lips on the right side involving a 2 cm greatest diameter." [3] "An area of dark blue-gray discoloration of the skin of the left cheek angling from above in front slightly downward and posteriorly. The overall length is 3 cm.
None of the injuries thus far, despite being extensive, are necessarily terminal at this juncture.
With Cheri Jo Bates having been forced, face-down into the alleyway floor, the 'Confession' letter kicks in again: "I plunged the knife into her and it broke." The assailant, likely atop and astride the young woman, plunges the knife into her left upper back (shown in blue in the diagram above). The back region being very firm, coupled with an extensive attack using a small pocket knife, may well have caused the hinge mechanism to fail, resulting in the blade closing and quite possibly injuring the hand or fingers of the assailant. The History Channel documentary 'The Hunt for the Zodiac Killer,' alluded to the fact the killer's blood may have dripped onto the attire of Cheri Jo Bates. This is a very real possibility and likely resulted in the end of the attack on the young woman, but for the final coup de grace: "I finished the job by cutting her throat."  

The cause of death listed in the autopsy was laceration of the right carotid artery. There was in fact extensive marking to the neck, all of which may have played a factor. The full description in the report was as follows: "The anterior neck skin extensively and irregularly lacerated with marked gaping. A deep cut is in the thyroid cartilage on both sides and the right common carotid is completely transected as well as the right superficial jugular vein."
​If this cut (shown on the right) originated on the left side of the thyroid cartilage near the midline and extended in one motion to the right side of the neck, this would be indicative of a right-handed assailant kneeling above Cheri Jo Bates (who is lying face down) and drawing the blade from left to right. This ultimately, is where her valiant fight for life abruptly ended.
However, she would before this happened, reach back with her right hand and grab the hair of her attacker. The autopsy stated "Considerable partially dried blood over the hand and especially about the fingers and under the unpainted moderately long but not carefully manicured fingernails."  When Cheri Jo Bates grabbed her assailant's hair, the extensive blood on her dominant hand trapped the hair at the base of her right thumb- crucial evidence that would later be used to extract mitochondrial DNA from her murderer.    
There is one more important thing to consider, other than finding foreign DNA on the clothes of Cheri Jo Bates, and that is blood tying. 
In the 'Inside Detective' magazine it stated "At the murder scene, drops of blood leading from the body to Terracina Street indicated to the detectives, that the murderer had walked back to the street following the slaying." 
This may have been the blood of the victim dripping from the knife or assailant. But, there surely must have been consideration from investigators that this may have been blood from the murderer's cut right hand, which is common during attacks with bladed instruments. This blood was either collected and stored, or completely disregarded as originating from the victim, which could have been a big mistake.
Cheri Jo Bates' blood type detailed at autopsy is rare in the USA population. It was AB RhD positive, which accounts for only 3.4% of the American population. Even with the limited forensic capabilities in 1966, this testing was a simple affair, and could have determined whether the blood trail extending towards Terracina Drive was that of the killer's, and subsequently stored appropriately for future testing. Different samples could also have been retrieved from the clothing of Cheri Jo Bates and stored separately. What are the chances the killer also possessed this very rare blood group? 
Whether or not this trail of blood was tested and stored in controlled conditions, and ruled out, we may never know. But if it wasn't, then this story could possibly have had a very different ending from the one it's likely to have.

Inspired by the first episode of the Zodiac Killer docudrama, which aired on November 14th 2017, we will take a completely fresh look at the Cheri Jo Bates murder using only newspaper and magazine articles as our guide, and completely disregard anything contained in the material provided by Robert Graysmith.
It will also disregard any preconceptions of the crime formulated by investigators and the 'Confession' letter sent on November 29th 1966, approximately one month after the brutal murder.
​The 'Confession' letter author likely played into the suppositions of investigators, who almost immediately ran with the narrative that Cheri Jo Bates had her Volkswagen Beetle tampered with while she was in the library, despite the fact little supports this conclusion.
Let us start in and around the library annex just before opening time.
The 'Inside Detective' magazine recalled that a Mexican-American student noticed Cheri Jo Bates close to opening time and shortly after- who stated 'he knew Cheri Jo Bates and had noticed her in the library the night in question. He said he saw the girl "writing something with a ball point pen" in her blue spiral school notebook." The boy told us he was outside about 5.30 pm, waiting for the library to open at 6, and it was then he saw the girl.'
It clearly states he had 'noticed her in the library the night in question'- therefore presumably after 6.00 pm. 
The 'Inside Detective' Magazine also stated "The participants in the reenactment at the detectives' request, wore the same clothing and sat in the same seats that they had occupied the Sunday night of the murder. They were also asked to park their cars in the same places they had on the night of October 30. It had been determined that Cheri Jo (or a girl resembling her and in similar clothes) had arrived at the library about 5.40 pm and waited for about 20 minutes for the doors to be opened. The girl apparently entered the library as soon as the doors were opened at 6.00 pm, and checked out the books she had come for."

Taking this completely at face value, and the fact her library books were discovered on the passenger side seat of her vehicle, we will assume she entered the library at opening time and discharged her reading material.
Sergeant Gren stated "The girl was definitely in the library as she checked out the books. She must have been contacted by the murderer as soon as she received her books." The key words here, are she "checked out her books." 
The article continued "However, other students who were acquainted with Cheri Jo said they were in the library between 6.30 and 6.40 pm- and did not see the girl during that time." Neither did Walter Siebert, who stated that "he and a few friends were in the library from 7.15 pm until 9, but did not see Miss Bates, whom they all knew. They said they saw four men dressed in work clothes sitting on a fence across from the spot where Miss Bates' car was found, but they did not know them."  
It is therefore extremely likely Cheri Jo Bates entered the library at 6.00 pm and left before 6.30 pm, having checked out her books. The four men in work clothes are crucial. 
They stated to investigators that "they had seen Cheri Jo near her car the previous night." But what time and where?
It is reasonable to assume it may have been slightly before 5.30 pm, since the Mexican-American student and the female eyewitness saw Cheri Jo Bates at 5.30 pm, 5.40 pm and the time she entered the library at 6.00 pm.
​The Riverside City College was undergoing renovation at the time, so these four men may have been passing the area of the college campus around this time- probably working within the college campus on a Sunday, at a time when certain areas were free from student activity. This may be a reasonable supposition, because they were still in the vicinity when Walter Siebert arrived at 7.15 pm, at which time they were sitting on a fence on the north side of Terracina Drive. They may have been taking a break.
Walter Siebert and friends never laid eyes on Cheri Jo Bates that evening, nor did they, or any other person familiar with the young girl, spot her striking lime green Volkswagen Beetle (or at the very least was it reported), despite the fact it was supposedly parked only 30 yards or 90 feet east of the library entrance. Walter Siebert and friends said "they saw four men dressed in work clothes sitting on a fence across from the spot where Miss Bates' car was found, but they did not know them." They only said the four men were located across from the position the vehicle "was found", not from the position of the vehicle that evening. Indicating they never saw her vehicle on the evening of October 30th 1966. In fact, not one of the attendees to the library that evening or night stated they spotted Cheri Jo Bates' vehicle in the position it was found. "They were also asked to park their cars in the same places they had on the night of October 30", yet apparently not one parked near the lime green Volkswagen Beetle, or noted its position on Terracina Drive.​  

Is it possible they didn't notice her vehicle because it wasn't there? Cheri Jo Bates parked her vehicle up that evening, and was noticed by the four men (but not necessarily exactly 30 yards east of the library), who said "they had seen Cheri Jo near her car the previous night." 
She then entered the library, "checked out her books," left before 6.30 pm and possibly drove away, bucking the supposition of detectives, who assumed the perpetrator disabled her vehicle while she was in the library, and wrongly concluded her vehicle remained idle from the moment she parked up, to the following morning, when her vehicle was ultimately discovered. 
A perpetrator disabling her vehicle, would had to have done so approximately 90 feet from the library entrance, risking being spotted and then killed her within minutes, despite the fact the young woman's body would have lain in the alleyway for around 4 hours that evening, without anybody walking down the alleyway, and completely negating the screams being heard around 10.30 pm by at least two earwitnesses. It makes little sense, and therefore is highly unlikely.
This is why the 'Confession' letter is highly suspect. It is simply parroting what investigators immediately concluded after discovering the disabled Volkswagen Beetle, and what was widely reported in the newspapers in the aftermath of the murder. The 'Confession' letter revealed no details only privy to the murderer, and even if its author was the killer of Cheri Jo Bates, he was only too happy to concur with the conclusions of the police investigation, especially if it steered the investigators away from what really happened on October 30th 1966, and even more importantly, centered the focus around the library annex and college campus. The 'Confession' letter should have been called the 'Confirmation' letter, as it effectively confirmed to police what they already believed, whereas the truth likely lay elsewhere. 
The 'Inside Detective' magazine also stated 'Two young girls who said they knew Cheri Jo, gave a taped interview to a crew from a Los Angeles television station. The girls in the interview, said that Cheri Jo had told them Sunday that she was "going to the library to meet her boyfriend." However, Sgt Gren said that while Cheri Jo had met her boyfriend in San Francisco the weekend prior to her murder, the boy was still in the Bay Area at the time of her death. The statements of the two girls were based on hearsay and not on fact Captain Cross told newsmen.'
It is clear this statement was prematurely dismissed by police, because according to the two girls, Cheri Jo Bates was supposedly "going to the library to meet her boyfriend." This cannot be misinterpreted as going to San Francisco to meet her boyfriend Dennis Highland, unless she was meeting him at a library in San Francisco.    
This is from Zodiackiller.com: "The relationship between Barnett and Cheri soured after Cheri returned from San Francisco, where she had visited her steady boyfriend. Cheri informed Barnett that she had accepted this boyfriend's wedding proposal and that she and Barnett could no longer date. (This conversation with Barnett occurred less than a week before her murder.)"
It is clear that the relationships of Cheri Jo Bates were less than clear cut, so it is by no means out of the question that Cheri Jo Bates may have made alternative plans that Sunday evening, once her friend Stephanie Guttmann declined her officer at 3.45 pm that day, to accompany her to the library. Cheri Jo Bates may have originally planned to meet a "boyfriend" after the library closed that evening, but her plans could have changed when Stephanie decided not to go to the library.     

Cheri Jo Bates was spotted near her vehicle by the four workmen just before 5.30 pm. We don't know where exactly she parked. The men may simply have walked past her somewhere near the college, and noticed her alongside the vehicle. It may have been in the near area it was eventually found. This would make sense, because investigators presumably asked the four men where they spotted Cheri Jo Bates and her vehicle, and it likely near concurred with the position of the vehicle the following morning, thereby not raising any red flags 
​Later, Walter Siebert and friends noticed the same four men sitting on a fence, likely taking a break, around 7.15 pm, but they didn't notice Cheri Jo Bates or her vehicle. Therefore, it is unlikely the four men  spotted Cheri Jo Bates alongside her vehicle at 7.15 pm, because if they had, Walter Siebert and friends would likely have noticed her and the Volkswagen Beetle too, which they didn't. 
Additionally, if investigators tied the two stories together, and assumed the four men noticed Cheri Jo Bates by her vehicle at 7.15 pm, then she would have supposedly been leaving the library. Had she been arriving at the library, then Walter Siebert and friends would have seen her in the library between 7.15 pm and 9.00 pm. But she couldn't have been leaving the library either, because Cheri Jo Bates had apparently entered at opening time and wasn't even spotted in the library between 6.30 pm and 6.40 pm, 
If Cheri Jo Bates checked out her books prior to 6.30 pm, why would she still be next to her vehicle at 7.15 pm. Had it been tampered with while in the library, she could have simply sought assistance inside the library or from her arriving friends. The whole scenario doesn't stack up. 
The four men must have spotted Cheri Jo Bates on her arrival to the library just before 5.30 pm and relayed this to police, that "they had seen Cheri Jo near her car the previous night."  At 7.15 pm, when the four men were spotted by Walter Siebert, Cheri Jo Bates and her vehicle were gone. Investigators likely assumed Cheri Jo Bates' vehicle remained throughout, as they had done from the very beginning, and the vehicle simply went unnoticed by Walter Siebert and company.
​Originally her plans were to visit the library to study with Stephanie Guttmann, but possibly her plans changed and she decided to meet with this "boyfriend". The eventual murder had all the hallmarks of a spurned admirer and 'crime of passion'.
The problem we have, is why would Cheri Jo Bates' vehicle have left the library and returned to effectively the same position some 4 hours later. Had she arranged to meet the 'mystery man' outside the library just after checking her books out, gone to a secondary location, before returning her 'passenger' where she picked him up. If so, did he live nearby, and was familiar with the college campus, including the two empty houses along the alleyway. The fact that both windows were rolled down, with the keys in the ignition and doors unlocked, may suggest something erupted on their arrival back at the library.
​If he is carrying her books for her, the 'mystery man' may have exited the vehicle, placed the books on the seat, closed the right door, inadvertently leaving it slightly ajar, and then proceeded to disable her vehicle in the heat of the moment to prevent her leaving. This may explain her eagerness to vacate the vehicle and seek help. She is dragged into the alleyway, and the attack begins circa 10.30 pm. The author of the  'Confession' letter, if the killer, knew that by playing into the police narrative of the crime, the investigation would remain squarely around the college campus and make his confession completely worthwhile.      

In the aftermath of the Cheri Jo Bates murder in Riverside on October 30th 1966 a library reconstruction was performed on November 13th 1966, with fingerprints and hair samples taken from the attendees to compare to crime scene evidence. How many college students and personnel were ultimately screened can only be speculated, but it was likely extensive. But who on the fringes of Riverside City College slipped through the net. Riverside College was undergoing extensive renovation at the time and was likely a hub of activity, that included contractors employed for this very task. Who could travel unhindered around the college campus, with access to buildings usually considered off limits. The murder was committed at the end of October, with the Bates letters mailed on April 30th 1967. We are looking at a period of 6 months, before the Zodiac Killer disappeared and apparently resurfaced in Benicia just over one and a half years later. If the Zodiac Killer was responsible for the events in Riverside, then it is conceivable, that if he worked around or within the Riverside City College campus, he took his profession with him when he resumed his murderous activities in northern California.   
The focus of our killer seemed to centralize around the Riverside College campus. We shall therefore look at some key bullet points. 

#1. Cheri Jo Bates arrived at the campus shortly after 6.00 pm,  but screams were heard from the alleyway circa 10.30 pm. What  happened during this time period is unknown, but the killer  specifically targeted Cheri Jo Bates Volkswagen Beetle and may have remained on site for upwards of four hours.
Does this suggest he was comfortable in these surroundings and could travel around the campus largely unnoticed. Did the killer have access to a building in the vicinity of the library annex. Was he able to approach Cheri Jo Bates, only because he was familiar to her, yet he wasn't a close friend or fellow student.
#2. The two buildings either side of the crime scene were unoccupied. Would a killer lure a woman into this particular alleyway and commit a brutal attack, lasting possibly a minute or more, if he thought that these dwellings were inhabited by potential eyewitnesses, or even park his vehicle nearby.
This goes to the very heart of whether this perpetrator knew the status of these two buildings and the area he was operating in. Knowing in advance that nobody was overlooking the crime scene was seemingly fundamental to his escape from justice.
#3. A Timex watch was ripped from the murderer's wrist during the struggle. It carried white flecks of paint. Did this belong to a worker, somebody who was involved in the renovation of the campus facilities. 
#4. Here is a little background on the Riverside City College library: "The library is located on the Terracina Avenue side of the Quadrangle. Its collection included more than 35,000 books, 400 current periodicals and newspapers, 1,950 reels of microfilm and 2,000 pamphlets. Its indoor and outdoor facilities could accommodate 225 students. The library staff, included five professional librarians, who offered students and faculty individual assistance.
The services of the College Library were available to students and residents of the area without charge. Students had free access to any of the books and magazines in the collection and were encouraged to use the library for their recreational reading as well as for academic pursuits. The circulation period was flexible and was determined by the demand for the material in question. Usual loans were for three weeks, but shorter periods may have been required for assigned reading in limited materials. Longer loans could be made upon request. Borrowers were held responsible for any library materials which were lost or damaged while in their care. Hours of service were: Monday through Thursday 7:45 a.m. - 10:00 p.m.; Friday 7:45 a.m. - 4:30 p.m.; Sunday 1:00 - 5:00; 6:00 - 9:00 p.m."    

Did the killer have access to the library facilities outside of hours.
Somewhere he could write unhindered on the library desktop, without fear that his unsavory poem could link him back to any murderous deeds he may commit. If the Riverside Desktop Poem was a precursor to the murder of Cheri Jo Bates, then an absence of onlookers would be preferential.
#5. The murderer of Cheri Jo Bates may equally have used other facilities from the library. The 'Confession' letters mailed by the killer on November 29th 1966 were several generation copies.
"A photocopying machine, where students could secure 8 1/2 X 11 inch black and white copy of printed or typed material, was available at the library for ten cents."
Photocopying an admission of murder in public may have been perilous, unless you could access such a machine in relative obscurity, such as a library during closing times.
#6. The photocopying machine would have been acquired by the college library in respect to the paper likely used by the college, staff and students alike. The three Bates letters mailed on April 30th 1967 measured 8 1/2 X 11 inches, identical to the size offered by the photocopier in the library. 

​#7. "An unrelenting search had been in progress for the murder weapon, and that Tuesday detectives used a metal detector in shrubbery adjacent to the murder scene in an effort to find the knife used by the slayer. Captain Cross revealed to the news media that the autopsy showed that the murder weapon was probably a pocket knife with a 3 inch blade or less. The broadcast and published information about the knife caused the police switchboard to be flooded with calls reporting knives of similar description being found all over the city of Riverside." ​
On November 14th 1966, one day after the highly publicized library reconstruction, the police did get a call from a Riverside City College gardener: "That he had unearthed a hunting knife with his rake. The knife had apparently been buried near the murder scene. Detectives hurried to the campus and turned over the knife to the homicide detail. However, examination failed to show any evidence of dried blood on the knife blade. Also, its width did not compare with the incisions made by the stab wounds."
Did the killer plant this knife to play games with the police, possibly observing them from the campus grounds as a casual onlooker. Was the murderer familiar with the routine of the college gardener, knowing he would eventually unearth the knife, or did he make a call to police, something that was withheld from the newspapers.
#8. The 'Confession' letter stated "She was young and beautiful but now she is battered and dead. She is not the first and she will not be the last. I lay awake at night thinking about my next victim. May'be she will be the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven. Or may'be she will be the shapely brownette that said no when I asked her for a date in high school. But may'be it will not be either."
Was the killer referring to the alleyway where Cheri Jo Bates was murdered. Could he have been present on the Riverside College campus throughout this period, perfectly visible, yet at the same time inconspicuous because of his connection to the college. 
What, if anything, was significant about the month delay in claiming the crime in the 'Confession' letter. Was this indicative of how close he was to the college, or was the author a hoaxer, simply reading the newspaper reports and leading us on a merry Danse Macabre.

The 'Confession' letter purportedly typed by the hand of Cheri Jo Bates' murderer delivered a sense of foreboding: "She is not the first and she will not be the last. I lay awake nights thinking about my next victim. Maybe she will be the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven. Or maybe she will be the shapely blue eyed brownett that said no when I asked her for a date in high school. But maybe it will not be either....Yes I did make that call to you. It was just a warning. Beware...I am stalking your girls now."  
This was equally true of the Riverside Desktop Poem, discovered by a Janitor at Riverside City College in the December of 1966, after the murder of Cheri Jo Bates, and after the 'Confession' letter, but in all probability was written before the October 30th 1966 murder. It gave a chilling prelude to what may transpire, what may be denied, but ultimately the threat of more to come: "Just wait till next time. rh." 
If the Desktop Poem was written in the October of 1966 by the same mind who typed the 'Confession' letter, then it could be argued it was the prelude to the murder of Cheri Jo Bates, and equally argued as the first correspondence of the Zodiac Killer, if you believe a connection exists between the Bay Area and Riverside.    

The Zodiac Killer often ended his communications with an unbridled mockery of police, giving a running total of victims so far. He would often compliment this in correspondence, such as the November 9th 1969 'Bus Bomb' letter, stating "up to the end of Oct I have killed 7 people." In the November 8th 'Dripping Pen' card he added the months of his alleged attacks, stating "Des, July, Aug, Sept, Oct = 7."  On March 13th 1971 the Zodiac Killer referenced his exploits in Riverside by 'complimenting' the police on connecting the murder of Cheri Jo Bates to him: "I do have to give them credit for stumbling across my riverside activity, but they are only finding the easy ones."
Could the initials rh be offering us something similar. The author of the Riverside Desktop Poem warned us of a "next time," then gave us the initials. Could the author have instructed us on the time and place of his next murder, much like the unconfirmed 'Albany' letter mailed on August 1st 1973.
"Just wait till next time. riverside, halloween." The author was giving us the area of the crime and the exact date. The Riverside Desktop Poem was the ode to murder, the 'Confession' letter was its completion. The murder was believed to have taken place at approximately 10.30 pm on October 30th 1966, the day before Halloween. However, if we believe the author of the 'Confession' letter, then his original intention may have been the abduction of Cheri Jo Bates in his vehicle, before things unexpectedly changed course. He may have planned the murder of the young woman on October 31st 1966, the day she was ultimately discovered by groundskeeper Cleophus Martin.    

In the aftermath of the Cheri Jo Bates murder the police made appeals to the public to be on the lookout for the murder weapon, described as a small knife: "An unrelenting search had been in progress for the murder weapon, and that Tuesday detectives used a metal detector (see right) in shrubbery adjacent to the murder scene in an effort to find the knife used by the slayer. Captain Cross revealed to the news media that the autopsy showed that the murder weapon was probably a pocket knife with a 3 inch blade or less. The broadcast and published information about the knife caused the police switchboard to be flooded with calls reporting knives of similar description being found all over the city of Riverside."  
Was one of those callers the murderer, who did state in the 'Confession' letter "Yes, I did make that call to you." 
How many of these calls were followed up is hard to determine, but curiously on November 14th 1966, one day after the highly publicized library reconstruction, the police did get a call from a Riverside City College gardener: "That he had unearthed a hunting knife with his rake. The knife had apparently been buried near the murder scene. Detectives hurried to the campus and turned over the knife to the homicide detail. However, examination failed to show any evidence of dried blood on the knife blade. Also, its width did not compare with the incisions made by the stab wounds."
Did the murderer of Cheri Jo Bates plant the hunting knife and make a call to police, which ultimately got lost in the myriad of calls flooding the switchboard, and consequently was not followed through. Or did the killer make contact with the Riverside City College gardener to volunteer this information, while viewing the unfolding police presence from a distance. 
The police had thoroughly searched the crime scene with metal detectors in the days after the murder, so it seems likely the knife was planted subsequent to their search by either the perpetrator, or a misguided prankster. The planting of a larger hunting knife near the murder scene may have been another foreboding message by the killer, that "It was just a warning. Beware...I am stalking your girls now." Stalking them with a larger and more deadly knife. After all, he did claim that he "plunged the knife into her and it broke."

For many people, Cheri Jo Bates checked out her own library books. This being the case, we have approximately four hours in which her whereabouts are unexplained. Had she gone somewhere willingly, it is highly likely she traveled there by foot, having left her vehicle parked on Terracina Drive at about 6.15 pm.
Does this center the investigation close to the college campus?
The author of the 'Confession' letter was fond of referring to that "alley," when he stated "Maybe she will be the beautiful blond that babysits near the little store and walks down the dark alley each evening about seven" and "it just might save that girl in the alley." Was he referring to the alleyway in which Cheri Jo Bates was murdered, or some other alley in the vicinity of the Riverside City College campus. Somewhere he could monitor the comings and goings of young attractive women.
If he was able to go unnoticed, without drawing suspicion to himself around the college campus the evening of October 30th 1966, had composed the Desktop Poem earlier that month, and had subsequently planted the knife near the crime scene, was this indicative of somebody who worked at, or frequented the college on a regular basis. Somebody who could travel within the confines of Riverside City College unchallenged and blend into the background. 
The Timex watch discovered ten feet from the body of Cheri Jo Bates, apparently ripped off the wrist of the killer in the struggle, had white paint specks on its face. The Riverside City College was undergoing renovation at this point in time, so is this another small pointer. The attack on Cheri Jo Bates was fairly prolonged, evident by the wounds sustained by the young woman, inflicted on her in an alleyway bordered by two vacant properties. Is this yet further indication of prior knowledge to college affairs, that the killer was prepared to attack Cheri Jo Bates here, knowing that nobody resided within these properties. This again, reinforcing the idea that the murderer either worked within the college campus, or frequented it regularly. He would seemingly stick around until at least April 30th 1967, when three more virtually simultaneous communications were received from the alleged murderer, in similar fashion to the beginning of the Zodiac correspondence, just over two years later.   

Here we will take an even deeper look into the events of October 30th 1966, partially using the excellent timeline of Ray Grant from his book 'Zodiac Killer Solved.' We may disagree on certain aspects of the crime, but he makes extremely interesting observations regarding the movements of Cheri Jo Bates that evening, and the fact that the young woman would never have willingly left her prized Volkswagen Beetle in the state it was found the following morning. 
We can agree that Cheri Jo Bates left her 4195 Via San Jose residence at approximately 5.05 pm. The next important sighting was from a Mexican-American student, who later stated that "he knew Cheri Jo Bates and had noticed her in the library the night in question. He said he saw the girl "writing something with a ball point pen" in her blue spiral school notebook. The boy told us he was outside about 5.30 pm, waiting for the library to open at 6, and it was then he saw the girl." This statement can be interpreted in two ways. He either saw the girl at 5.30 pm or 6.00 pm. But on this occasion we will opt for around 5.30 pm. for reasons explained in 'Zodiac Killer Solved,' while adding a further component from the 'Inside Detective' Magazine.
​The journey time from her residence to Terracina Drive, where her vehicle was ultimately found 'abandoned,' is a journey time of about 12-15 minutes. She parked her vehicle 30 yards east of the library annex, as explained in the previous article, on the right hand side of the road. The time now is 5.20 pm. She walked the short distance to the library, where the Mexican-American student noticed Cheri Jo Bates "about 5.30 pm." It was likely a few minutes before, because as Ray Grant pointed out, she would eventually notice she wasn't in possession of her bibliography and ventured off to place a payphone call to her co-worker Donna at the Riverside National Bank at 5.30 pm, who said she hadn't seen the bibliography. This call probably lasted for approximately 5 minutes, because the next sighting of Cheri Jo Bates was at 5.40 pm, when she returned back to her vehicle by the library. This eyewitness was not 100% sure of the girl's identity, but there is a high probability it was Cheri Jo Bates, as she was returning to her vehicle, to make the journey back home to retrieve her bibliography.                

This is where the 'Inside Detective' Magazine comes in handy. It stated "The participants in the reenactment at the detectives' request, wore the same clothing and sat in the same seats that they had occupied the Sunday night of the murder. They were also asked to park their cars in the same places they had on the night of October 30. It had been determined that Cheri Jo (or a girl resembling her and in similar clothes) had arrived at the library about 5.40 pm and waited for about 20 minutes for the doors to be opened. The girl apparently entered the library as soon as the doors were opened at 6.00 pm, and checked out the books she had come for." This seemingly near corroborates everything before it- the sighting of the Mexican-American student just before 5.30 pm, the phone call to Donna at 5.30 pm, and her return to the library at 5.40 pm. There is one big problem however, pointed out by Ray Grant in 'Zodiac Killer Solved.'
Cheri Jo Bates was spotted by two eyewitnesses (a March Air Force Base man and a friend of Cheri's driving on Magnolia Avenue) that evening, arriving toward Terracina Drive at 6.10-6.15 pm. How could she be arriving at the college at 6.15 pm, when supposedly she was entering the library at 6.00 pm, having earlier arrived at the college library around 5.20 pm. Had she arrived at the college twice, then she must have returned home at some point to search for her bibliography. 
If we take the 5.40 pm eyewitness sighting as Cheri Jo Bates, this may corroborate her Volkswagen Beetle parked only 90 feet east of the library entrance. She was returning from the payphone, heading west to east, toward the library entrance, to consider a journey back home. Had her vehicle been parked 360 feet west of the library or 75 yards west of the alleyway, as asserted by Robert Graysmith, then this eyewitness would not have assumed Cheri Jo Bates was "arriving at the library at 5.40 pm." The magazine stated that apparently she entered the library at 6.00 pm, and had waited 20 minutes from arriving. It is highly likely this is supposition on behalf of the investigators, based upon the 5.40 pm sighting. As Ray Grant suggested, Cheri Jo Bates likely entered her vehicle at 5.40 pm or thereabouts, and drove the 24 minute journey to and from her residence to collect her bibliography. Allowing for the turnaround and locating her bibliography, 30 minutes is a reasonable estimate, placing her arriving back on Terracina Drive at 6.10 pm, where she was spotted by both the March Air Force Base man and her friend.

In one newspaper article it stated, "Some of her friends were at the library between 7 and 9 pm, but none can recall seeing Cheri. She had been there, however, because three books stamped that day were found in the front seat of her yellow-green Volkswagen found parked on Terracina, near the annex. Someone else was there too. Someone who police believe knew Cheri- knew her well enough to recognize her car. The distributor had been tampered with and there was evidence that the man had been in the car with her. The keys were still in the ignition when the car was found the next day. Both windows had been rolled down and the right door was ajar." ​
The 'Inside Detective' Magazine added that "the keys were in the ignition, but the car had been disabled and would not start. It was found that the distributor coil and condenser had been ripped out. Greasy finger and palm prints were discovered on the door of the car. Two school books and a notepad were found in the front seat." 
Ray Grant believes that Cheri Jo Bates was abducted from her Volkswagen Beetle shortly after arriving at the library at 6.10-6.15 pm, indicating she never entered the library that night. Had the Mexican-American student only spotted Cheri Jo Bates at "about 5.30 pm" outside the library, then no eyewitnesses at all that night had recalled Cheri Jo Bates inside the library. Ray Grant believes it wasn't Cheri Jo Bates that checked out the library books, but the perpetrators of the crime.
We may disagree on the events from 6.15 pm onward, but an abduction cannot be ruled out, as the young woman was 'missing' for just over 4 hours, until screams were heard coming from the alleyway, where Cheri Jo Bates would ultimately be found by groundskeeper Cleophus Martin the following morning.
She was almost certainly forcibly removed from her vehicle, particularly so, if only one assailant approached her vehicle that evening or night. If, as the 'Confession' letter intimated, she walked willingly away from her vehicle, then it is extremely unlikely a conscientious woman, who prided her Volkswagen Beetle, would leave the keys in the ignition, both windows rolled down and the doors unlocked, with one possibly ajar. The state of her vehicle clearly indicated she was under duress at this point.​  

We have to emphasize the fact that both her vehicle windows were rolled down. 'In October 1966 the average high temperature in Riverside, CA was 80.7°F, and this was 0.2°F cooler than the average of 80.9°F. The hottest day in October 1966 was 31 October when the temperature reached 91.9°F. Overnight the average temperature in October is 51.8°F.'
Had Cheri Jo Bates' vehicle been sitting idle for an extended period of time in front of her 4195 Via San Jose residence, earlier that day, then the temperature inside her Volkswagen Beetle would have been stifling. This certainly would have necessitated her rolling down both windows before her journey. On either journey, it's highly likely one would roll down both windows to circulate the air in temperatures exceeding 80 degrees Fahrenheit. This fact alone may support her abduction or forcible removal from her vehicle as she parked up on Terracina Drive, before she had chance to roll up the windows and exit the vehicle. It may also explain the keys still in the ignition and the doors unlocked, with one not fully closed, especially if more than one assailant was involved. This however, is where the library books come into play in Ray Grant's diversion theory, in 'Zodiac Killer Solved'. It is an extremely interesting read. 
If on the other hand she was forcibly removed, let's say under gunpoint or knife, shortly before 10.30 pm, when she arrived back from her 'missing' 4 hours, and then coerced into the alleyway, before being murdered, we have to ask ourselves the question. Would Cheri Jo Bates have arrived back at her vehicle at approximately 10.25 pm at night and rolled down both windows of her vehicle, before attempting to drive away. Or had she rolled down the passenger side window specifically, to converse with somebody on the sidewalk, who was offering her assistance with the stricken vehicle. Were the unlocked doors, greasy fingerprints and "evidence that the man had been in the car with her," a sign that she initially felt comfortable with the good Samaritan, or that it was somebody she knew.
All the evidence suggests that Cheri Jo Bates was forced from her vehicle that night, but was it around 6.15-6.20 pm, or shortly before 10.30 pm. Or is there another scenario, that may yet shed light on the events of October 30th 1966. 

http://www.zodiacciphers.com/zodiac-news/cheri-jo-bates-re-evaluating-the-crime-scene
 
Zodiac Killer Solved by Ray Grant.  

Here we will take a fresh look at the Cheri Jo Bates murder in Riverside on October 30th 1966, using the 'Confession' letter, excerpts from Robert Graysmith's book, details from police, and earwitnesses to pinpoint the location of Cheri Jo Bates' Volkswagen Beetle and the vehicle of her assailant.
The 'Inside Detective' Magazine from January 1969 stated "At the murder scene, drops of dried blood leading from the body to Terracina Street indicated to the detective that the murderer had walked back to the street following the slaying." This indicated the killer was walking back to his vehicle, parked on Terracina Drive. But which way did he head, east or west. The Riverside City College library annex was situated approximately 45 yards (135 feet) east of the alleyway, where the slain girl was discovered. There are, as always, conflicting versions of the same event.
​The 'Inside Detective' Magazine stated "The Riverside Sheriff's Department picked up the broadcast. Minutes later, Sheriff's Detective Sergeant Jack Reid and Detective Jack Elms discovered the little car. It was parked at the curb in front of the college library about 75 feet (25 yards) from the entrance of the roadway where the girl's body was found."  
Robert Graysmith, in his book Zodiac. stated "He probably came up and offered help, offered her a lift in his car. Then he got her to go down the unlit gravel road to the parking lot, about 75 yards east of her car."
The Riverside Police Department memorandum stated "She returned to her vehicle, which was parked on a city street a short distance from the library, placed her books in the vehicle, and attempted to start her vehicle, The vehicle had been tampered with so it would not start. This was evidently done by the suspect to keep the victim near her vehicle, so the suspect could make his approach. Our victim then left her vehicle, accompanied by the suspect, and walked approximately 200 feet (67 yards) into a dirt driveway between two houses."
Below I have interpreted the statements. One vehicle is placed between 67-75 yards west of the alleyway (which was "about 75 yards east of her car"). The second interpretation places the vehicle "in front of the college library" about 25 yards east of the alleyway. These appear the two options.  

Next we will examine the 'Confession letter' wording to pinpoint the location of the assailant/s vehicle, along with the true location of Cheri Jo Bates' Volkswagen Beetle. The 'Confession' letter stated "Then I waited for her in the library and followed her out after about two minutes. The battery must have been about dead by then. I offered to help. She was then very willing to talk to me. I told her that my car was down the street and I would give her a lift home. When we were away from the library walking, I said it was about time. She asked me "about time for what." I said it was about time for her to die."
If the author of the 'Confession' letter was honest in his directional movements that night, then his choice of words "when we were away from the library walking," seems to suggest he was walking away from the library, towards the alleyway and his vehicle, having already offered Cheri Jo Bates help in fixing her Volkswagen Beetle. This indicated that Cheri Jo Bates' vehicle was parked somewhere close to the library, and going by the above options, 25 yards east of the alleyway.
​If her disabled Volkswagen Beetle was parked 70 yards west of the alleyway, then his statement in the 'Confession' letter of "When we were away from the library walking, I said it was about time. She asked me "about time for what." I said it was about time for her to die," makes it appear he is heading in the wrong direction. Considering the relative position of the Volkswagen Beetle (70 yards west) and the alleyway in this instance, he would have been walking towards the library, not away from the library.
However, the Volkswagen Beetle being parked 25 yards east of the alleyway flies in the face of the Riverside Police Department memorandum, which indicated her vehicle was parked 200 feet (67 yards) from the alleyway. The Riverside Police Department memorandum and Robert Graysmith's book appear to corroborate one another in terms of distance from the alleyway.   

But what if the Volkswagen Beetle was parked 67-75 yards east of the alleyway, instead of 75 yards west, as Robert Graysmith stated in his book. This would literally place the Volkswagen Beetle very close to the library doors, using the measurement capabilities of Google maps, and corroborate the Riverside Police Department memorandum, which stated "her vehicle was parked on a city street a short distance from the library." This also tallies with the 'Inside Detective' Magazine, in which police said her Volkswagen Beetle "was parked at the curb in front of the college library." They did however, go on to state her vehicle was 75 feet from the alleyway, not 75 yards. But it's my guess they made a mistake or were misquoted.  
One wouldn't have imagined parking spaces that difficult to find on a Sunday evening, particularly bearing in mind Cheri Jo Bates had arrived at the library around opening time, before many of the other 65 attendees. This may also challenge the notion of her parking her vehicle 120 yards (360 feet) from the library entrance, along Terracina Drive, leaving her an unnecessary distance to walk. This revamped assessment now places her vehicle approximately 75 yards east of the alleyway, very close to the library, and "parked at the curb in front of the college library." Or "parked on a city street a short distance from the library."  Not on the west side of the alleyway as originally believed. 
But where was the assailant's vehicle parked? In the 'Confession' letter the author stated he "waited for her in the library and followed her out after about two minutes." We know that Cheri Jo Bates was not murdered until approximately 10.30 pm, so much of what the 'Confession' letter depicts is false, however his wording can still give us a clue to the location of where his vehicle was parked. It is extremely likely the killer either trailed Cheri Jo Bates to the library that evening, or pulled up near to the library on the expectation of her arrival, maintaining a visual on the entrance. Regardless of what time she entered the library, or where she went that evening, the assailant would have parked somewhere on Terracina Drive to facilitate his plan, hence the wording on the 'Confession' letter: "I told her that my car was down the street and I would give her a lift home." and "when we were away from the library walking." This indicated his vehicle was parked west of the library entrance, towards the alleyway. 

He clearly didn't want to park his vehicle by the Riverside City College library steps, as this would risk his vehicle being associated with the Volkswagen Beetle of Cheri Jo Bates. The wording on the 'Confession' letter of his vehicle "down the street," to lure her towards the alleyway, would suggest his vehicle was somewhere close to the alleyway. This would facilitate a speedy exit from the alleyway after the knife attack on Cheri Jo Bates, which would inevitably have left him with blood on his clothes. This was backed up by earwitnesses close to the alleyway, who likely heard the perpetrator's vehicle pulling away from the scene.
In the Robert Graysmith book it stated "A neighbor heard an 'awful scream' between 10.15 and 10.45 pm, and then about two minutes of silence, and finally the sound of an old car starting up." 
The neighbor's claim is backed up by the latter part of the 'Confession' letter: "She died hard. She squirmed and shook as I choked her, and her lips twitched. She let out a scream once and I kicked her head to shut her up. I plunged the knife into her and it broke. I then finished the job by cutting her throat." 
After Cheri Jo Bates screamed, according to the author, he kicked her and then used the knife twice to finally kill her. Taking this at less than 30 seconds, and assuming the killer and starting car are connected, what did the killer do for the remaining 90 odd seconds. If his vehicle was relatively close by (30 seconds journey)- so that the neighbor was able to hear it starting up, then we are probably looking for an unaccounted minute of time. Was this time used in searching for the Timex watch, wrenched off his wrist in the struggle with Cheri Jo Bates. 
Based on everything learned, the Volkswagen Beetle of Cheri Jo Bates was likely parked very close to the library annex, 75 yards east, or thereabouts from the ill fated alleyway. Her vehicle would have been parked approximately 30 yards (90 feet) east of the library entrance. The assailant's vehicle was also parked on Terracina Drive, within earshot of the alleyway, on either the east or west side. "At the murder scene, drops of dried blood leading from the body to Terracina Street indicated to the detective that the murderer had walked back to the street following the slaying."
But only a matter of yards from the alleyway, before driving away.    

FOOTNOTE: Newspaper article excerpt - Death on a Driveway, A life that ended too soon.  
"Some of her friends were at the library between 7 and 9 pm, but none can recall seeing Cheri. She had been there, however, because three books stamped that day were found in the front seat of her yellow-green Volkswagen found parked on Terracina, near the annex. Someone else was there too. Someone who police believe knew Cheri- knew her well enough to recognize her car. The distributor had been tampered with and there was evidence that the man had been in the car with her. The keys were still in the ignition when the car was found the next day. Both windows had been rolled down and the right door was ajar."