On November 29th 1966, one month after the murder of Cheri Jo Bates alongside the Riverside City College library, two confession letters were delivered to the Riverside Homicide Detail and Riverside Press Enterprise containing a sinister message. They read in part "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". If the good Samaritan, as he claimed in the letter, was offering to give her a lift home from his nearby vehicle, then it's fairly obvious that Cheri Jo Bates isn't going to willingly travel 3.5 miles back to her 4195 Via San Jose home with this individual and leave her prized Volkswagen Beetle with the windows rolled down, her keys in the ignition and the doors unlocked. Therefore, the idea that her killer promised her a lift home doesn't tally with the condition her vehicle was found the following morning. 

The January 1969 Inside Detective magazine described the crime scene, stating "The victim of the savage attack was clad in faded red capris, a long-sleeved pale yellow blouse with a ribbon tied at the throat. Her feet were encased in white sandals. A large red and tan woven straw bag was half covered by the body". This large bag can be seen in the crime scene photographs. If Cheri Jo Bates had arrived back at her vehicle after exiting the library and placed her library books on the passenger seat, one might have expected Cheri Jo Bates to have first removed this straw bag from her shoulder prior to rolling the windows, placing her key in the ignition and preparing to drive away (especially if the bag was slung over her right shoulder). This oversize straw bag would certainly have impaired her ability to shift gear in a comfortable manner while driving. If she had removed this bag to prepare to drive home and was forcibly removed from her vehicle in a surprise attack under the threat of a knife or gun, why under any circumstances, would she have placed the bag back on her shoulders under duress (for it to be later found under her body in the driveway) The Confession letter author claimed she was very willing to talk and leave with him, which would explain her grabbing her bag before leaving - but not the condition her vehicle was ultimately found the next morning. If the author was her killer, she had two minutes (according to the Confession letter) to remove the straw bag from her shoulder before he arrived and offered the young woman assistance. 

Recently I looked at the autopsy report of Cheri Jo Bates, which may suggest her being placed in a choke-hold at the moment the attack began, while the killer stabbed backwards into her upper body and right arm, before thrusting her forward (face down) into the hard driveway floor and "finishing the job out" by stabbing her in the back and slashing her throat. This would explain why her straw bag remained in contact with her body throughout (although not slung over her head as a method of carrying it). A vicious attack from the front, by a knife wielding assailant facing Cheri Jo Bates, is less likely to have her retaining control of a large straw bag throughout.

​None of the knife wounds to her front torso were immediately life threatening, so a savage attack with somebody thrusting a knife towards her (and into her) while she is mobile and able to run, is unlikely to create a scenario where her bag remained on her shoulder during this period. Her bag is likely to be dropped - and she is likely to move away. The chances that she would be coincidentally reunited with that bag later in the attack is extremely unlikely. The position of the straw bag under her body, on the right side, could suggest she had the bag on her right shoulder when the killer grabbed her around the neck with his left arm and stabbed backwards with his right hand. Her right arm would naturally come upwards to defend herself, with the straw bag remaining in relatively close contact with her body while upright. When the killer thrust her face down into the driveway, her straw bag fell from her right shoulder to the position shown in the crime scene. In other words, she was grabbed and killed in virtually the same spot in the driveway. 

To listen to a comprehensive discussion on the Cheri Jo Bates murder in Riverside on October 30th 1966, with contributions from Druzer and Michael Morford, please visit the Citizen Detective podcast on Youtube (running time 3hr 10 mins). 

Despite having reservations that the murderer of Cheri Jo Bates was the author of the Confession letter, let us look at certain aspects of the Confession letter in relation to the published details of the crime and the unpublished details of the autopsy report by November 29th 1966. Many of the newspaper articles prior to November 29th 1966 mentioned the stab wounds to her arms, back and face, along with her throat being slashed, but I could find none that mentioned stab wounds to her breasts, or any mention of Cheri Jo Bates being choked or strangled (unless you know better). The autopsy did show she had at least seven incised wounds across her throat and one stab wound to her right arm, although no concrete evidence of any stab wounds to her face (rather, blunt force lacerations and abrasions to her lip, chin and left cheek). The following snippet is the relevant part of the Confession letter pertaining to the autopsy report.

It seems unusual that Cheri Jo Bates received three stab wounds to her breasts, with no other stab wounds to her front torso, bearing in mind the author of the Confession letter infused a sexual element into their typing, by stating "Her breast felt very warm and firm under my hands" and mentioned "cutting off female parts to deposit for the whole world to see". The author was claiming contact with her breast region just before stating that "she died hard". The author also stated that he initially grabbed Cheri Jo Bates around the neck and mouth, and choked her. This could explain the petechial haemorrhaging visible on her forehead at autopsy. The Confession letter then mentioned her lips twitching before he kicked her in the head, which could explain the 2cm ragged non-gaping oblique laceration to the left side of her lip, and the dark blue-gray slightly swollen discoloration of the mucocutanous portions of the upper and lower lips to the right side - both consistent with a kick to her head while in close contact with the driveway floor - and to the claims in the Confession letter.

The stab wounds (as explained in the previous analysis) to her left breast (2), right breast (1), right axillary fold (1) and right upper arm, grouped on an approximate 10cm vertical plane, is also consistent with an assailant holding the victim around the neck (possibly with their left arm) from behind, and stabbing backwards into the upper torso and upper right arm of Cheri Jo Bates, thereby resulting in the relatively close grouping of stab wounds to her frontal region. Her right arm being motioned across her body for protection would explain the two stab wounds to the upper right arm and right axillary fold. In fact, had she been stabbed here while using her right arm for protection over her chest, it would further narrow the horizontal plane width of the incoming knife. After thrusting Cheri Jo Bates to the driveway floor and kicking her in the head, the author of the Confession letter then claimed he "plunged the knife into her". This, too, is consistent with the one knife wound to her back detailed at autopsy. The word "plunged" maybe suggestive of a downward strike as she lay face down on the driveway floor, before he "finished the job out cutting her throat". The limited details given in the Confession letter are consistent with the previous analysis and the autopsy report, yet insufficient to fully claim that the author and murderer are one and the same.
PART ONE  PART TWO

Many have considered the Riverside Desktop Poem is that of somebody exhibiting suicidal tendencies from a first person perspective, with the "just wait till next time" writing at the end of the poem, a promise these tendencies will be revisited. However, there is a realistic argument to be had that this "poem" was written within days of the Confession letter (postmarked November 29th 1966), with both composed with the murder of Cheri Jo Bates in mind. The Riverside Desktop Poem may have been structured by reminiscing in the present tense, reflecting on an attempted murder in the first part of the poem, followed by a boast of the 'successful' murder of the Cheri Jo Bates in the second part, stating "just wait till next time", before confirming the discovery of her body in Riverside on Halloween (hence the rh attribution). The phrase "just wait till next time" could be expected to have a subsequent date (or time) following it. 

When you consider there was an attempted murder by knife on the Riverside City College campus just a year earlier (April 1965), in which a young girl escaped from an assailant who stabbed her, followed by the newspaper headlines stating Clean-Cut Youth Sought For Stabbing, it's easy to see the correlation in wording to the Riverside Desktop Poem, which opened with the words "cut, clean, if red/clean, blood spurting, dripping, spilling; all over her new dress. Oh well, it was red anyway". The following "She won't die this time, someone'll find her" testimony to the fact she survived the stabbing and sought help nearby. There is every chance the author of the Riverside Desktop Poem was contemporising this attack, before reflecting on the murder of Cheri Jo Bates, implying the next victim wouldn't be so lucky in riverside on halloween (rh). This would date the Riverside Desktop Poem subsequent to October 30th 1966. Rolland Taft was arrested for the attempted murder of the girl in 1965, and was incarcerated at the time Cheri Jo Bates was murdered.      

The correlation between the newspaper headline in The Press and Daily Enterprise on April 17th 1965 of Clean-Cut Youth Sought For Stabbing and the Riverside Desktop Poem of "Cut, Clean", is not the only linguistic connection. The Riverside Desktop Poem was entitled "Sick of living/umwilling to die". Despite being only 45 words in length and unreleased to the public in 1966, the wording in its title featured heavily in the Confession letter (its full transcript also not released). The Confession letter stated  "I said it was about time for her to die", just like the three Bates letters mailed on April 30th 1967, which again, despite being only 8 words in length, thrice used the phrase "to die". The phrase "to die" having now been used in three sinister sets of communications spanning just 5 months. In fact, the phrase had been used six times in total (3 Bates letters, 2 Confession letters and one poem), along with "She died hard" in the Confession letter..

​The title of the Riverside Desktop Poem also contained the adverb of "unwilling", the root of which is used twice in the Confession letter, when the author typed "She was then very willing to talk to me" and "She went very willingly". The use of the word "sick" in the Riverside Desktop Poem title was also present in the Confession letter when the author typed "I am not sick". Therefore, we have several words in the title of the Riverside Desktop Poem that featured heavily in the Confession letter. Another feature of the Riverside Desktop Poem was the use of "just wait till next time", implying an impending death. This would mirror the promise of impending death 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". The Riverside Desktop Poem also stated "she won't die, this time someone'll find her". The word "time" used five times in total through two communications. 

Bearing in mind the linguistic correlation between the Riverside Desktop Poem, Confession letter and Bates' letters, the latter two of which referenced the murder of Cheri Jo Bates by using her name, it could be argued that the Riverside Desktop Poem was also inferring her murder through "riverside" and "halloween" in the form of rh, along with phraseology of "cut" bleeding into the Confession letter with the wording "I then finished the job out cutting her throat". Two stabbings in consecutive years on the same campus may have been the inspiration behind the Riverside Desktop Poem, with all three sets of communications crafted by the same individual. Knowledge and awareness of the knife attack in April 1965, and the delivery of the Bates' letters on April 30th 1967 spanned two years. So it's perfectly plausible, bearing in mind the writing on the desktop was discovered inside the Riverside City College, that the author of these three sets of communications was a long standing resident of Riverside County, or its neighboring areas. Although there is no way to prove which came first, it appears that the Riverside Desktop Poem was the precursor to the Confession letter (and therefore written between October 31st 1966 and November 29th 1966). The Confession letter the offshoot of the "just wait till next time" threat. 

In 2016, investigators received a communication from an individual in San Bernardino who claimed that he had authored the three Bates letters on April 30th 1967, stating he was a troubled teenager at the time he sent the trinity of malicious handwritten letters to the Riverside Police Department, Riverside Press-Enterprise newspaper and Joseph Bates. However, this individual did not take responsibility for the Riverside Desktop Poem and Confession letter, indicating he was likely the author of none. 

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

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

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

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

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

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

The image on the left is described by Wikipedia as the "typewritten confession received by Riverside police and the Riverside Press-Enterprise November 29, 1966". This statement is seemingly at odds with what has been released, because the typewritten message shown in the image on the left was sent to the Riverside Press-Enterprise, and is different to the typewritten message shown on most of the websites and forums on the internet. The Confession letter widely shown on the internet, stamped as having been submitted to the FBI laboratory, is not the same letter shown in the image on the left. When you enlarge and examine the letter on the left, there are at least ten major differences in text compared to the one widely viewed on the internet. The whole structure and sentencing is also different.

In other words, we have to contemplate that the author of the two Confession letters typed two individual correspondences on plain white paper to the value of fourth or fith generation, using carbon paper. A quick look at the image on the left compared to the one with FBI laboratory stamped on it, will show three noticeable differences immediately. The length of underscores after BY are different in each instance. THE CONFESSION title above is underlined, which isn't the case on the FBI laboratory image shown by clicking the link above. The CC. CHIEF OF POLICE ENTERPRISE list of recipients is further from the left margin and a line further down in the image shown above, compared to the image stamped with FBI laboratory. The image widely shown on the internet (and in the link above), should in theory have been addressed to the Riverside police because it is different to the Riverside Press-Enterprise version. Below is the image of the Confession letter widely viewed on the internet (which should have been addressed to the Riverside police). Beneath that is the Confession letter sent to the Press-Enterprise, highlighting ten major differences. The only other explanation for two versions, is that the widely shown Confession letter is a product of having been retyped for greater clarity by law enforcement personnel, but somehow was retyped incorrectly, adding spelling mistakes, correcting spelling mistakes, attempting to correct spelling mistakes but replacing the word with another misspelling, removing sections of typing such as the XXX on the fifth row, and altering words such as "finished the job out" to "finished the job by". One would have thought this would have been done professionally, had the Riverside Police Confession letter sent by the author been the same as the Press-Enterprise version.  

THE CONFESSION LETTER - RIVERSIDE POLICE ​

Therefore, attempting to fit an author's name after BY to align to a particular suspect may be negated by the differing lengths of the underscores in each Confession letter. The author of the Confession letters would also have gained and lost the ability to spell (as well as misspelling the same word twice) between each communication. But why would the author bother to type out two separate and unique communications, when they could have sent the fourth and fifth generation carbon copies from the first typing? Whatever the case, the "ripped at both ends" version sent to the Press-Enterprise (shown in the photograph with the scissors) is an unadulterated version typed by the author. The other version has either been retyped by law enforcement (or under instruction from law enforcement), or was a completely different version sent by the original author.

The three Bates letters have become very topical at the moment based on Riverside police claiming an individual hoaxed the three handwritten communications. They stated "In April 2016, investigators received an anonymous letter postmarked from San Bernardino, California. This letter was typed and appeared to have been generated from a computer. The author of the anonymous letter admitted to writing the hand written letters. The author apologized for sending the letters and said it was a sick joke. The author admitted that he was not the Zodiac killer or the killer of Cheri Jo Bates and was just looking for attention. In 2020, the Homicide Cold Case Unit and the FBI Los Angeles Investigative Genealogy Team, submitted the stamp from the letter for additional DNA analysis and subsequent interviews were conducted. The individual linked to the DNA evidence on the stamp admitted to writing the letter and sending it to Riverside Police Department. The author was a young teenager at the time and had a troubled youth. He said he wrote the letter seeking attention and was remorseful for his actions".

​However, we cannot say with certainty based on this statement, whether the individual in 2016 was telling the truth. Recently I made a comparison between the Riverside Desktop Poem, the Confession Letter and Bates Letters, as follows: If the wording of the Confession letter had been withheld from the newspapers in 1966, it would make any similarities between the Confession letter and Riverside Desktop Poem more significant. It appears that the majority of the text from the Confession letter wasn't released until November 1968, when it was published in the Press-Enterprise newspaper. The title of the Desktop Poem was "Sick of living/unwilling to die".  When we look at the Confession letter the author types two sentences carrying the similar wording of "She was then very willing to talk to me" and "she went very willingly".  The Confession Letter author also typed "I am not sick. I am insane". In other words, the Desktop Poem title is embedded in the story of the Confession Letter. The Desktop Poem concludes with the wording "She won't die, this time someone'll find her. Just wait till next time", suggestive of an impending death - and mirrored in the Confession Letter when the author types the word "time" on a further three occasions and utilizes the word "die" in the same string of wording, by stating "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".  The Riverside Desktop Poem contained the words "to die". The Confession Letter harbored the wording "I said it was about time for her to die" (meaning Bates had to die). Then, five months later, the three Bates Letters contained the wording "Bates had to die there will be more" and "She had to die there will be more".  

​Just over one year later, somebody wrote a series of 5 handwritten letters to Edward Kennedy, Joseph P. Kennedy, Ethel Kennedy and Adlai Stevenson in the June and July of 1968 with various threats. One of which was addressed to Mr. Joseph P. Kennedy, Brookline, Massachusetts and postmarked West Palm Beach, Florida on June 17th 1968. The Confession letter author remarked that "I lay awake nights thinking about my next victom", and seemingly deliberately misspelled the word "victim" by typing "victom" instead. The handwritten note to Joseph Kennedy followed a similar pattern to the Confession Letter, stating "Do you propose "Tedd" to be the next victum", but this time spelling "victim" as "victum".. 

A short time earlier, on June 14th 1968, a handwritten letter to Mrs. Ethel Kennedy, Hickory Hill, McClean, Virginia, postmarked Boston, Massachusetts was received at Senator Kennedy's offices, stating that "Jack had to die. Bobby had to die. Teddy has to die". The three Bates letters contained the threats of "Bates had to die", "Bates had to die" and "She had to die". The author below wasn't "sick of living" however, he was sick of the Kennedy's. The author of the five Kennedy communications is very likely different to the author of the Riverside communications, but I thought it was a noteworthy addition to ponder in light of recent developments.  

If the wording of the Confession letter had been withheld from the newspapers in 1966, it would make any similarities between the Confession letter and Riverside Desktop Poem more significant. It appears that the majority of the text from the Confession letter wasn't released until November 1968, when it was published in the Press-Enterprise newspaper. Here is a brief section from a previous article:making a comparison between the Desktop Poem and Confession letter, both of which begin with a title.

​The title of the Desktop Poem was "Sick of living/unwilling to die".  When we look at the Confession letter the author types two sentences carrying the similar wording of "She was then very willing to talk to me" and "she went very willingly".  The Confession letter author also typed "I am not sick. I am insane". In other words, the Desktop Poem title is embedded in the story of the Confession letter. The Desktop Poem concludes with the wording "She won't die, this time someone'll find her. Just wait till next time", suggestive of an impending death - and mirrored in the Confession letter when the author types the word "time" on a further three occasions and utilizes the word "die" in the same string of wording, by stating "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".   

Is this enough correlation to point to one author of the Riverside Desktop Poem and Confession letter? And could the author of the Bates letters (whoever that may be) be responsible for the two previous communications. Recently, the Riverside Police Department have stated that somebody contacted them via a letter in 2016 claiming responsibilty for the three Bates letters postmarked April 30th 1967. "The author apologized for sending the letters and said it was a sick joke. The author admitted that he was not the Zodiac killer or the killer of Cheri Jo Bates and was just looking for attention". But was the individual who made this admission in 2016 telling the truth? Despite the three Bates letters containing only eight words, they managed to continue the theme of the previous two communications in 1966. The Desktop Poem was titled "Sick of living/unwilling to die". The Confession letter harbored the wording "I said it was about time for her to die" (meaning Bates had to die). Then, five months later, the three Bates letters contained the wording "Bates had to die there will be more" and "She had to die there will be more". In addition, all three communications ended with the threat of further murder. The ending of each carried the wording "Just wait till next time", "I am stalking your girls now" and "There will be more". It is also noteworthy that the Zodiac Killer never wrote the wording "to die", "die" or "died" in any of his communications spanning eighteen years.

Here is some additional information regarding the Confession letter. Before the development of photographic copiers, a carbon copy was the under-copy of a typed or written document placed over carbon paper and the under-copy sheet itself (not to be confused with the carbon print family of photographic reproduction processes). When copies of business letters were so produced, it was customary to use the acronym "CC" or "cc" before a colon and below the writer's signature to inform the principal recipient that carbon copies had been made and distributed to the parties listed after the colon. With the advent of word processors and e-mail, "cc" is used as a merely formal indication of the distribution of letters to secondary recipients. A sheet of carbon paper is placed between two or more sheets of paper. The pressure applied by the writing implement (pen, pencil, typewriter or impact printer) to the top sheet causes pigment from the carbon paper to reproduce the similar mark on the copy sheet(s). More than one copy can be made by stacking several sheets with carbon paper between each pair. Four or five copies is a practical limit. The top sheet is the original and each of the additional sheets is called a carbon copy. A sheet of carbon paper is placed between two or more sheets of paper. The pressure applied by the writing implement (pen, pencil, typewriter or impact printer) to the top sheet causes pigment from the carbon paper to reproduce the similar mark on the copy sheet(s). More than one copy can be made by stacking several sheets with carbon paper between each pair. Four or five copies is a practical limit. The top sheet is the original and each of the additional sheets is called a carbon copy. Wikipedia. .

Robert Graysmith in Zodiac Unmasked stated "November 29, 1966. Two carbon copies of a "confession" letter sent to the press and Riverside Police. Zodiac typed on a sandwich of Teletype paper and carbon paper and mailed the faintest, the fourth and fifth impressions. The original typed top page was never sent". Ordinarily it is wise to double check anything Robert Graysmith claimed, however, in this instance his claims appear to concur with Wikipedia that four or five copies is perfectly feasible in this instance. The fact that the Confession letter was cut at the top and bottom suggests the paper used was taken from a Teletype roll

There is a reasonable argument to be had, that the Confession letter mailed on November 29th 1966 was created by the same author as the Riverside Desktop Poem, with both being created at around the same time by somebody who had access to the Riverside library photocopier and the desktops themselves - possibly a young student who lived in Riverside and attended the college. The author of the Riverside Desktop Poem may have split his poem into two parts: The first part reminiscing in the present tense about the April 1965 attempted murder of a young female student on the Riverside City College campus, who narrowly escaped death after being stabbed by Rolland Taft. A newspaper article entitled "Clean-cut Youth Sought In Stabbing" was released shortly after the attack, that seemed to mirror the opening two words of the Riverside Desktop Poem, and detailed on Ricardo Gomez's MK Zodiac website. The first part of the poem was correct when it asserted "she won't die, this time someone'll find her". The young woman fled the attack and sought help from a nearby residence and was rushed to hospital. The second part of the poem reminisced in the present tense that the next woman would not be so lucky, by stating "Just wait till next time. r h." That person may have been Cheri Jo Bates, brutally stabbed on October 30th 1966 close to the Riverside City College library annex and found on Halloween morning. The newspapers detailed that screams were heard on the night of October 30th 1966 but that her body was discovered the morning of Halloween, so the author of the Desktop Poem may have been using this date when he added Riverside, Halloween at the end of the poem.   

If the wording of the Confession letter had been withheld from the newspapers in 1966, it would make any similarities between the Confession letter and Riverside Desktop Poem more significant. It appears that the majority of the text from the Confession letter wasn't released until November 1968, when it was published in the Press-Enterprise newspaper. Let us make a comparison between the Desktop Poem and Confession letter, both of which begin with a title. The title of the Desktop Poem was "Sick of living/unwilling to die".  When we look at the Confession letter the author types two sentences carrying the similar wording of "She was then very willing to talk to me" and "she went very willingly".  The Confession letter author also typed "I am not sick. I am insane". In other words, the Desktop Poem title is embedded in the story of the Confession letter. The Desktop Poem concludes with the wording "She won't die, this time someone'll find her. Just wait till next time", suggestive of an impending death - and mirrored in the Confession letter when the author types the word "time" on a further three occasions and utilizes the word "die" in the same string of wording, by stating "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".   

There is every chance that the author of these two communications was a young prankster connected to the Riverside City College campus and library, who had knowledge of both attacks in 1965 and 1966, and gleaned everything about these two young women from the newspapers. The connection to both these attacks can be reasoned in the Riverside Desktop Poem, along with the claim of one author being responsible for both communications by the very wording they utilized.   

Rolland Taft was sentenced to 6 months to 20 years for the attempted murder of a young female student on the Riverside College campus in April 1965. She attended evening classes as a student of the college. Taft served 2 1/2 years and was released in 1968. The female victim suffered severe knife wounds in the attack but was able to escape and seek help from her neighbors. On April 17th 1965 The Press-Enterprise ran an article about the attempted murder, running with the headline Clean-Cut Youth Sought in Stabbing. This headline is extremely reminiscent of how the poem on the Riverside Desktop Poem began, with "clean" and "cut" used in each instance. So was the author of the Riverside Desktop Poem familiar with this crime, causing him to reminisce about it as he constructed the poem on the plywood desk?

If the author of the Desktop Poem was referring to this attempted murder, then he was clearly of the opinion that the young girl was stabbed while wearing a new red dress. The poem read "blood, spurting, dripping, spilling; all over her new dress. Oh well, it was red anyway".  The author was referring to past events, fully aware that she didn't die after the attack because someone found her bleeding outside their house and sought help.

Cragle, a regular poster on both forums, is attempting to locate some historic newspaper articles describing the attempted murder in the hope there is mention of the girl's attire that evening. If no newspaper articles or media coverage mentioned her new red dress, it may suggest that the author of the Desktop Poem knew Rolland Taft and the details surrounding the attack - or he knew the young victim and knew first-hand what she was wearing on that fateful evening in 1965. This could indicate that he attended the Riverside City College as a fellow student, with access to the plywood desk in order to write the poem. The most crucial aspect of the poem is the final section, which carries the foreboding message of "She won't die. This time someone'll find her. Just wait till next time. rh". In other words, this girl didn't die by knife, but the next girl will. The author may have written this poem prior to the murder of Cheri Jo Bates on October 30th 1966, with the rh at the foot of the poem a place and time prediction  - that of Cheri Jo Bates in Riverside on Halloween. The murderer of Cheri Jo Bates may have been attempting to lure her to a secondary location to kill her but her valiant struggle against her attacker may have thwarted his plans and resulted in the Halloween prediction falling short by 75 minutes.

The impressionable author of the Riverside Desktop Poem could conceivably have been a student of the college, who was inspired by the attempted murder of Miss Atwood. He could also have known the young woman and studied alongside her. Wherever she had been that fateful evening on April 13th 1965, possibly wearing a brand new red dress, he may have been present. This would be the only reasonable conclusion had she been wearing a red dress and these details were not mentioned in any media coverage (and he didn't know Rolland Taft). If the author of the Desktop Poem was the author of The Confession letter, then the mention of "brush offs" in a seemingly immature typed letter, could place the person responsible for both in the age range of Miss Atwood (19) and Miss Bates (18)- and very likely somebody connected to the Riverside City College. 

It is common knowledge that in many knife attacks, such as the one perpetrated on Cheri Jo Bates in Riverside on October 30th 1966, the attacker will often cut themselves with their own knife. The Riverside Police Department (who for the most part did a thorough investigation) must have considered this a strong possibility bearing in mind the viciousness of the attack on the young woman. The Cheri Jo Bates autopsy findings showed extensive defensive wounds on her hands and arms, with the majority of the brutal attack focused on the upper part of her body (from the breasts upwards). The attack had all the hallmarks of somebody known to the victim, planned in advance by the disabling of her prized Volkswagen Beetle. Law enforcement stated that "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 driveway and the autopsy report undeniably proved that Cheri Jo Bates did not exit this world like "a lamb to the slaughter", rather a woman who fought valiantly to the last. The police scoured for clues in the alleyway and noted that "at the murder scene, drops of blood were leading from the body to Terracina Street, indicating to the detectives that the murderer had walked back to the street following the slaying". This being the case, they must have considered that the drops of blood could have originated from the killer, who may well have cut himself "when the knife broke".

Cheri Jo Bates was found lying face down in the alleyway, 100 feet from Terracina Drive by groundskeeper Cleophus Martin the following morning. The knife used in the attack was described by Captain Cross as a pocket knife with a "3-inch blade or less." Had the blood really dripped off this small knife leaving a trail all the way to Terracina Drive, or was the killer now nursing an injury.

Mitochondrial DNA was extracted from the crime scene evidence in 1999/2000, leading to a DNA concentration of  0.003 nanograms per microliter being retrieved from a discarded cigarette butt found in the alleyway, and 0.01 nanograms per microliter being retrieved from the hair discovered at the base of Cheri Jo Bates' right thumb. There is however, no mention of the blood from the alleyway floor. This blood trail could be a combination of blood from the knife and blood from the killer, but the longer the trail extends, the likelier it becomes that it originates from the bloodstream of the murderer.

Assuming that the blood was retrieved along the whole trail to Terracina Drive, it would have been extremely routine forensic work in 1966 to determine the blood group of the submitted samples. 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. Any samples submitted that were not an AB blood group were almost certainly from her killer. However, even if the submitted samples were of the same blood group as Cheri Jo Bates, it still doesn't eliminate the possibility of the samples having originated from her murderer. He may have had the same blood type.

The tail of the blood drops would have indicated the directional movement of the killer towards Terracina Drive (as opposed to away), but should also have revealed which side of the alleyway the killer was favoring as he headed towards Terracina Drive - and the likely location of his parked vehicle (assuming he had one). If he had no vehicle, then it could have told us which side of the city he was heading to reach his residence. The diameter of the blood drops (reducing in size or not) could also tell us whether this was a freshly dripping wound, or the gradually reducing volume of blood falling from a knife blade. If the killer was telling the truth when he stated "I plunged the knife into her and it broke", then it is quite possible there was no knife to be dripping. No broken blade was found at autopsy, so it is perfectly conceivable that the hinge mechanism of the small pocket knife may have given way when striking the back of Cheri Jo Bates.

A female earwitness described "an awful scream between 10:15 pm and 10:45 pm, and then about two minutes of silence, and finally the sound of an old car starting up". If the author of the Confession Letter was really the killer of Cheri Jo Bates, then we can estimate the location of his vehicle, assuming the earwithness was hearing the actual murder take place. By combining the direction of the blood trail to one side of Terracina Drive, with the two minute interval from "scream to vehicle starting up", we can use the details in the Confession Letter to pinpoint fairly accurately the location of his vehicle. 
The Confession Letter stated "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". If this is when he "finished the job out" before leaving the scene, then he had two minutes to "kick her in the head, plunge the knife into her, cut her throat" and walk to his waiting vehicle. Allotting about 45 seconds at the murder scene, he has approximately 75 seconds to negotiate the 100 feet to Terracina Drive, and the rest to reach his vehicle. Traveling at an average walking speed of 1.4 meters per second, the 100 feet (30.48 meter) journey would take about 22 seconds, leaving 53 seconds walking time on Terracina Drive. That would mean a vehicle parked 243 feet (74 meters or 81 yards) from the alleyway. Cheri Jo Bates' Volkswagen Beetle was parked 75 yards (68 meters) east of the alleyway, just beyond the library annex. This rough estimate, would place the killer's vehicle only 6 yards (18 feet) behind the vehicle of Cheri Jo Bates (had he exited the alleyway east) - the ideal spot to offer her assistance when her vehicle failed to start - and the near exact location of the Tucker Torpedo (or Studebaker) described in Robert Graysmith's book.       

It is clear that everything contained in the November 29th 1966 Confession Letter was harvested from the newspapers, and whoever created the typed letter was deliberately dragging orchestrated words from the newspapers into their narrative. Below I have used one particular article to demonstrate how the author used superfluous and unnecessary verbiage to flesh out the Confession Letter and convince us they were the killer of Cheri Jo Bates on October 30th 1966. 

The author begins by ladening their introduction with "young and beautiful" and "beautiful blond" just like the newspapers, in order to build the narrative of believability. The author then describes the disabling of the Volkswagen Beetle by disconnecting the "middle wire from the distributor" - another name for the coil wire described in the newspaper publication shown below. This was a key ingredient to convince investigators they were genuine, despite the fact they had approximately four weeks to uncover what the coil wire was. Quote from Liveaboutdotcom: "The ignition coil is the unit that takes your relatively weak battery power and turns it into a spark powerful enough to ignite fuel vapor. Inside ​a traditional ignition coil are two coils of wire on top of each other. These coils are called windings. One winding is called the primary winding, the other is the secondary. The primary winding gets the juice together to make a spark and the secondary sends it out the door to the distributor. You'll see three contacts on an ignition coil unless it has an external plug, in which case the contacts are hidden inside the case. The large contact in the middle is where the coil wire goes (the wire that links the coil to the distributor cap}. There is also a 12V+ wire that connects to a positive power source. The third contact communicates information to the rest of the car, like the tachometer". link.

The Confession letter continues with a vague reference to their car being down the street, which has been gleaned from the anonymous female earwitness account in the newspaper, telling us they heard a "car driving away". This anonymous earwitness account was further harvested for another part of the story, where the murderer apparently kicked Cheri Jo Bates in the head to stop her screaming, stating "she let out a scream once and I kicked her head to shut her up". The female earwitness described "a muffled scream" - almost as though it had been curtailed by a kick in the head.

An appeal for the weapon to be found was broadcasted by police almost immediately, describing it as a small knife or pocket knife, but it was never found. Why would a proclaimed big, brave, boasting killer add the phrase "with a small knife at her throat", if they were not using this to confirm the size of the knife described by police? The addition of the word "small" was totally unnecessary and devoid of any good reason, other than to convince the reader of the Confession Letter they were in fact the killer. If you read the multiple newspaper publications regarding the murder of Cheri Jo Bates, the overwhelming consensus is of a young woman "stabbed in the back, with her throat slashed", despite the fact that the autopsy showed far more wounds on the young woman's body, indicative of a prolonged and violent struggle between Cheri Jo Bates and her assailant. The Confession Letter just parroted these articles, stating "I plunged the knife into her, then finished the job out cutting her throat". The plunging of the knife was referencing the stab in the back, and the cutting of her throat just mimicked her throat being slashed. The fact that the author knew nothing about the intricacies of the crime was evident when they claimed "she went willingly, didn't put up a struggle and went to the slaughter like a lamb" - all of which were clearly untrue, and corroborated by not only the autopsy findings, but the freshly churned up driveway alongside the library.  

However, the most important feature of the newspapers at the time, was the reporting of the anonymous call from a female earwitness who described "an awful scream between 10.15 pm and 10.45 pm, and then about two minutes of silence, and finally the sound of an old car starting up". This earwithness was described as anonymous in several newspaper publications.

The author of the Confession Letter claimed they made a call to the police or newspaper. However, the Riverside Police Department and the Riverside Press-Enterprise could not confirm any phone call made to them by the claimed killer of Cheri Jo Bates. Zodiac Killer Facts wrote "Police could not confirm a phone call to the police or the local newspaper, The Press-Enterprise. The letter was considered most suspicious. Kinkead offered a disturbing conclusion: “The person who wrote the confession is aware of facts about the homicide that only the killer would know. There is no doubt that the person who wrote the confession letter is our homicide suspect.” There has been no confirmation or admission that the murderer of Cheri Jo Bates made any phone calls subsequent to the crime, and as shown above, there is no evidence whatsoever that the killer and Confession Letter author are the same person. In fact, there is no evidence the author of the letter was even a man. Running the wording through many software programs has comprehensively indicated female authorship.

The only phone call we know of, was the anonymous call by a female the following day, describing screams being heard nearby. So, was the author of the Confession Letter when stating "Yes I did make that call to you also. It was just a warning" referring to this call - and pretending they were the anonymous caller as some form of practical joke. If so, then they would be claiming they were female by association. However, what they would not have known, was the extended version of this 'anonmous call' story, elaborated upon in the Inside Detective magazine on January 1969.

Other detectives interviewed residents of a nearby apartment building, A girl tenant in an apartment only a few doors from the dirt driveway where the body was discovered, told the detectives that she heard screaming and yelling about 10:30 pm. "Then I heard a muted scream, and then a loud sound like an old car being started up - this was about two minutes after I heard the first scream", the girl informant said. However, the girl admitted she had not called police that night to inform them of the sounds of apparent violence she had heard.  Inside Detective, 1969. 

The woman/girl was not anonymous because detectives had interviewed her in person at her apartment, but to any newspaper reader in 1966 they could have been forgiven for believing the woman was simply phoning police while remaining anonymous and unknown. Was the author of the Confession Letter, as they had done for all the details typed above, simply taken this "anonymous telephone caller" from the newspapers and claimed "Yes I did make that call to you also"? - and why the Riverside Police and Riverside Press-Enterprise recollect no phone call being received by the killer. If this were the case, then the author of the Confession Letter is effectively admitting they are a female, and certainly not the Zodiac Killer. If the author of the Confession Letter was actually the murderer of Cheri Jo Bates, then the young Riverside City College student could conceivably have been murdered by another woman - a story that I doubt many would believe.

Some of the questioned Zodiac communications address certain individuals using the lower case format, and the March 13th 1971 'Los Angeles' letter refers to Riverside in the same fashion: "I do have to give them credit for stumbling across my riverside activity, but they are only finding the easy ones, there are a hell of a lot more down there". The Riverside Desktop Poem, written sometime in 1966 and believed to have been signed off with the author's initials, also featured two lower case letters. The clue to "rh" may lie in the poem itself and in the first correspondence by the Zodiac Killer on July 31st 1969 - assuming you believe a connection between Riverside and the Bay Area murders. That is because there is a real possibility the Riverside Desktop Poem was authored prior to the murder of Cheri Jo Bates on October 30th 1966. If you believe that Cheri Jo Bates was stalked surreptitiously in the weeks or months before her death, then the Desktop Poem is the precursor or warning, and the Confession letter is the completion of that threat. 

If we look at the wording on the Riverside Desktop Poem (below) from the standpoint of somebody stalking Cheri Jo Bates, then it is perfectly conceivable that at some point in time the wannabe killer has noticed the young woman wearing a red dress and fantasized about making her pay for the "perceived brush-offs" he has endured. But what is noticeable, is that the author states "she won't die this time, someone'll find her". If the young woman was to be stabbed, why would someone necessarily find her? If his mind is seeing his fantasy in the present during school hours and in the context of a busy Riverside City College campus, then one could easily see how she could be rescued and survive. However, in the next line he is projecting his mind to the future by stating "just wait till next time". The only way "next time" could conceivably have a different outcome, is if he lures Cheri Jo Bates away from the Riverside City College campus - and this is exactly what he said he was attempting to do when he typed the November 29th 1966 Confession letter, thirty days after Cheri Jo Bates' murder. He stated "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".  

If the murderer of Cheri Jo Bates had made a promise to seek her out "next time" in the Riverside Desktop Poem, and had some connection to the college, or was in her near or outer circle, is it really realistic he would give his true initials at the foot of the Desktop Poem to give law enforcement a helping hand? On the other hand, if they weren't really his initials and he had just placed two random letters together, then it is a rather pointless exercise. The Zodiac Killer wrote "riverside" in the 1971 'Los Angeles' letter and "halloween"/"Halloween" in the questioned 1987 correspondence, showing yet again his ability to ignore the upper case form of these titles. It is these two words that may give us the meaning to the "rh" at the foot of the Desktop Poem. The poem indicated the necessity of the killer to separate Cheri Jo Bates from the college campus so somebody wouldn't find her in time, thereby resulting in her death. Had he achieved such an objective, then her death may very well have occurred past the midnight of October 30th, rather than around 10:30 pm when screams were heard emanating from the campus alleyway. He was ultimately thwarted by Cheri Jo Bates, who likely fought back vigorously when she was being coerced towards his vehicle. The killer ultimately boasted that this was not the case by stating "I said it was about time. She asked me 'about time for what'. I said it was about time for her to die".  This was clearly a line pulled straight from his imagination, to give the impression he was in complete control throughout. Had Cheri Jo Bates not fought valiantly against her abduction, then the prophecy of "rh" would have been realized: "Just wait till next time, riverside halloween".

On July 31st 1969, the Zodiac Killer wrote "If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend". The Bay Area murderer was always promising more bloodshed in the future - and the Riverside Desktop Poem was no different. But on that occasion he gave us the exact time and place.    

Many attempts have been made to conclusively link the Riverside murder of Cheri Jo Bates on October 30th 1966, along with the accompanying communications, to the Zodiac Killer. The three 'Bates' letters, on April 30th 1967, ended the Riverside chapter, with the three July 31st 1969 letters to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald, beginning the Zodiac chapter. But is the hidden identity contained within the 408 cipher (if it exists) somehow connected to the hidden author of the November 29th 1966 'Confession' letter? It is paramount to make a distinction between name and identity when attempting to formulate any cohesive link between the Confession letter and 408 cipher, because the Zodiac Killer claimed he wouldn't give us his name in the decoded 408 cipher, but did claim it would reveal his identity.

​When we take a close look at the decoded 408 cipher, it can be argued that he made a fundamental error when he encoded his original message, accidentally omitting the word "people" in the ciphertext. This is explained in 'The 18 Unsolved Characters [Pt3]'  This effectively created a shortfall of 6 characters in his 408 cipher, which had he not done, would only have left 12 unsolved characters at the end of the message. In view of the Bay Area murderer identifying himself as "Zodiac" just four days later, it was considered that his impatience may have compelled him to reveal his identity earlier than he would have liked, and "Zodiac" was integral to his identity in the 12 characters at the end of the 408 cipher. The hidden identity, therefore being the "Zodiac Killer". 

Had the 408 cipher read "the best part of it, is that when I die I will be reborn in paradice and all the people I have killed will become my slaves", and the last 12 characters contained his identity, then by extension, we should be looking backwards to Riverside for the previous time he used a form of cryptic or hidden message. The only letter that contained such an instance, was the November 29th 1966 letter beginning "The Confession by - - - - - - - - - - - -".  The Confession letter to the Press-Enterprise contained 12 underscores of, presumably, the hidden name or identity of the killer. For those believing a connection from Riverside to the Bay Area, the potential murderer of Cheri Jo Bates may have cloaked his identity behind 12 underscores in this particular Riverside Confession letter and 12 characters in his communication with the San Francisco Chronicle on July 31st 1969.  The 'Bates' letters correlated via a trinity of letters, whereby the Confession letter correlated through the identity of twelve. However, the length of the underscores on the Confession letter to Riverside police appears notably longer. See here. 

This analysis fundamentally fails to successfully bridge the divide from Riverside to the Bay Area, as many arguments have before - and the connection between the murder of Cheri Jo Bates and associated communications, to the Zodiac Killer, will remain a hot button topic for many years to come no doubt - but the search goes on.

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?    ​