Below are the injuries to the face and neck of Cheri Jo Bates detailed at autopsy. .

Although emergency medicine providers commonly describe any break in the skin as a laceration, this terminology is forensically and technically incorrect. A laceration is defined as a tear in tissue caused by a shearing or crushing force. Therefore, a laceration is the result of a blunt-trauma mechanism. A laceration is further characterized by incomplete separation of stronger tissue elements, such as blood vessels and nerves. These stronger tissue elements account for “tissue bridging” which is seen in lacerations. In addition, lacerations commonly occur over bony prominences and tend to be irregularly shaped with abraded or contused margins. Lacerations are typically caused by hard objects like a pipe, rock, or the ground. Link to ACEPNow.

Unfortunately, F. Rene Modglin detailed the autopsy findings of Cheri Jo Bates incorrectly, when he labeled "incised wounds" as "lacerations" when describing the stab wounds to her torso. Therefore, we are presented with the injuries to her face as lacerations - and have to determine whether any of these wounds were caused by a knife blade or the mechanism of blunt force trauma, such as a hard object, punch or kick to the head, or from impact with the driveway floor. The analysis above shows that lacerations are commonly found over bony prominences and tend to be irregularly shaped with abraded margins. The three wounds described at autopsy (excluding the discoloration of the right lip) are found over the bony prominences of the zygomatic bone (cheekbone), the mentum (chin) and left side of the maxilla (upper jawbone}, where we have two accompanying abraded areas on the left cheek and chin, and an irregular (ragged edge) wound to her left upper lip. These wounds are all consistent with blunt force trauma, bearing in mind we have a dark blue-grey discoloration (probable bruising) present on the left cheek and chin. We have to discern whether these proposed blunt force injuries were caused through kicking (as claimed in the Confession letter), or by impact with the driveway floor.

The below image shows the 5 incised (stab) wounds to the front torso and right arm of Cheri Jo Bates (denoted by the blue circles). Wound 6 is described as two abraded lacerations, so it's unclear whether this injury was caused by a knife blade.
Wounds 7, 8 and 9 to the dorsal side of the left hand and lateral aspect of the right index finger are congruent with Cheri Jo Bates using her hands and arms in a defensive posture while being secured from behind. The absence of prolonged screaming and the close grouping of these 9 wounds, can be argued from the standpoint of a killer restraining Cheri Jo Bates around the neck while stabbing backwards into her chest region.

Without more information it is difficult to ascertain whether the injuries to her hand and finger were separate stab wounds that never struck her torso, or were injuries created as the knife passed by. Discounting wound 6, we have 5 knife wounds to the upper region of her body in close proximity to one another. It must be pointed out that I have placed the 2 wounds to her left breast slightly off-center to avoid showing the blue circles over her right hand and confuse the observer. If the right hand of Cheri Jo Bates was more centrally positioned when injury 9 occurred, it can be seen how the grouping of stab wounds narrows. This grouping would be much more difficult to achieve if no restraint was applied by the killer and the interaction was much more dynamic in nature. If we change the position of Cheri Jo Bates' hands, with her right hand protecting her right side, and her left hand protecting her left side, then the incised wounds to each hand would mirror the stab wounds to her left and right breast. For these to be related it would require three knife strikes cutting her hands and finger as the blade passed by. With the final stab wound to her back possibly being administered after she was forced forward onto the driveway floor, with the killer kneeling over her.

In conclusion, we have between 6 and 10 stab wounds in total, with the seven knife slices across her neck being the final horrific act that night. The close grouping of the stab wounds, the lack of screaming, and the consistency of the wound widths to her breasts and right armpit of 1.4 cm, 1.5 cm, 1.7 cm and 1.9 cm (with her back wound 1.5 cm), could suggest restraint rather than a dynamic moving target, in which more shearing type wounds may be expected (as observed in the Cecelia Shepard autopsy). This can be seen on the arms of Cheri Jo Bates by the two somewhat abraded wounds to her left arm (of 3.5 cm and 4.0 cm), and the 4.0 cm wound to her right arm, which would have exhibited greater motion than her torso, assuming she was restrained by the neck region. These observations are consistent with the claims of the Confession letter author.  PART TWO. 

Several earwitnesses described hearing screams the night of Cheri Jo Bates' murder in Riverside on October 30th 1966, such as this one reported in the newspapers; "A neighbor heard an awful scream between 10:15pm and 10:45pm, and then about two minutes of silence, and finally the sound of an old car starting up. A man returning to the area at 10:30 pm told us he heard two screams then". Another report stated "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". Both earwitnesses (a man and girl) highlighted two screams at about 10:30pm, but no more. None of the 6 incised wounds to the torso (3 to chest, 1 to back and 2 to the right arm) of Cheri Jo Bates were fatal - and wouldn't have interfered with her ability to run and scream incessantly, yet these were the only two screams reported. 

The Confession letter author claimed "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". None of the newspaper articles described Cheri Jo Bates being restrained around the neck, and her mouth being obstructed prior to the Confession letter on November 29th 1966, because this would only have been known to the killer (and possibly through examining the autopsy report). This claim by the author of the Confession letter would explain why Cheri Jo Bates didn't immediately scream when initially attacked. The grabbing of the neck and obstruction of her mouth, claimed to be the first actions by the killer that night, prevented the young woman from doing so. As explained in an earlier examination of the autopsy report, this is when the author of the Confession letter stated "she died hard", and when the killer likely began thrusting the knife backwards into the breast region and right arm of Cheri (which she may have used in a defensive motion across her chest). The close grouping of wounds to her breast region and upper right arm being the "only" 5 stab wounds to her front upper body. In an unrestrained scenario, in which Cheri Jo Bates had freedom of movement, one might expect more screams and less wound grouping. 

The Confession letter author then concedes that Cheri Jo Bates had shifted position when he claimed he "kicked her head to shut her up". He cannot do this while still choking her. The author stated he kicked her because "she let out a scream once". This could very well have occurred when he released his grip on her throat and thrust her forward onto the driveway floor. The author then claimed he "plunged the knife into her". A killer grabbing Cheri Jo Bates from behind, who then pushes her to the ground and delivers a sixth strike from the knife, would ultimately deliver one knife wound to her back (which is the only wound noted to her rear torso at autopsy). A second, muffled scream during this part of the attack may have been all Cheri Jo Bates could muster at this point, restricted by being pressed into the ground while the sixth and final knife blow was administered. The remainder of the attack being the 7 slices drawn across the neck of Cheri Jo Bates to prevent any more screams. The petechia described on the forehead at autopsy, along with the 2cm ragged edge non-gaping laceration to her upper lip, is consistent with a killer choking and kicking Cheri Jo Bates.

The author of the Confession letter may have weaved his story around the screams reported by earwitnesses in the newspapers, and inadvertently (and somewhat) matched the autopsy report by sheer luck. Regardless of this argument, it is important to give some weight to the notion of the author and killer being one and the same. Previously, it has been stated on this website that the murder of Cheri Jo Bates was a prolonged and brutal attack, probably lasting upwards of one minute. However, the 6 stab wounds to her upper torso and right arm, along with the 7 neck injuries described at autopsy, could have been inflicted in as little as 20 seconds (or less). Would we have expected more screams from Cheri Jo Bates if the attack was dynamic and absent of restraint? There were 5 knife wounds to her front upper region (2 left breast, 1 right breast, 2 upper right arm) and a maximum of 3 possible knife wounds to her hands described at autopsy. That is 5 knife strikes and a potential 3 defensive wounds as the blade glanced her left and right hand as it passed by. If her right and left hand were shielding her respective breast region, then it must be noted that her left breast received 2 stab wounds and her left hand received 2 stab wounds, with her right breast receiving 1 stab wound and her right hand receiving 1 stab wound (see below). All the remaining injuries to her hands were described as abrasions at autopsy (likely as a result of impact and struggling while lying on the driveway floor).   
​ 
[1] A curved and interrupted moderately deep laceration (2 cm overall} in the skin of the base of the lateral aspect of the right index finger.
[2] A more or less Y shape laceration in the skin of the dorsum of the left hand medially and at the junction of the wrist and hand.
[3] An irregular laceration of the skin of the dorsum of the left hand in line with the middle finger and is about the mid area.

F. Rene Modglin used the term "laceration" rather than "incised wound" or "stab wound" when describing the injuries at autopsy, thereby confusing its interpretation. 

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

WAS THE CONFESSION LETTER AUTHOR THE KILLER OF CHERI JO BATES?
WAS THE CONFESSION LETTER AUTHOR THE KILLER OF CHERI JO BATES? [PART TWO]

The following examination is not a claim to the factual dymamics of the crime committed on October 30th 1966, but one interpretation regarding the senseless murder of Cheri Jo Bates in the driveway alongside the Riverside City College library.​ 

On the left there is an approximate set of measurements of the female anatomy, and the only five incised and non-abraded wounds to the front side of Cheri Jo Bates' upper body. The five wounds are clustered in an area measuring 20cm horizontally and 10cm vertically. While these could be caused by an individual standing in front of Cheri Jo Bates, it is evident that none of these wounds inflicted by a knife had significant depth penetration to prove immediately fatal.

If the killer had been holding or choking Cheri Jo Bates around the upper chest or neck from behind, then this compression could increase intra-capilliary pressure by restricting the venous return of blood, and thereby creating the petechial haemorrhaging evident on the forehead of the young woman. A killer securing her from behind, holding the knife in his right hand (or possibly left) and stabbing backwards toward her heart region, has the potential to produce this grouping of injuries to her breast region and upper arms in the initial phase of the attack. The natural response by a victim would be to raise their arms and hands to protect this vital region, in addition to attempting to grab the wrist of the attacker (possibly resulting in the watch being ripped from her assailant) and could have caused the only three described "laceration" wounds to the dorsal side of Cheri Jo Bates' left hand (2) and right index finger. This may also have been the moment that Cheri desperately clawed backwards at her assailant's hair, ripping out some head hairs that collected in the blood at the base of her right thumb. 
​
Cheri Jo Bates, at this juncture, would have received eight strikes from a bladed instrument (5 to her front upper body and possibly 3 to her hands/fingers) in an attack that was likely mere seconds in duration, followed by her being thrust forward into the hard driveway floor. However, it must be noted that the two injuries to her left hand described as lacerations by F. Rene Modglin (24 & 25 in the autopsy report) could be injuries sustained through impact with the driveway floor. One is a Y-shaped laceration at the junction of the wrist and hand, often caused by the blunt force trauma of a weapon or impact from a hard surface. The other injury was an irregular laceration in the mid area, in line with the middle finger. Both these lacerations to her left hand were to the dorsal side, so could be sequential injuries as she was thrust forward and down. Therefore, it's possible only the "laceration" to the lateral aspect of her right index finger was caused by a knife blade (2cm, interrupted and moderately deep). Cheri Jo Bates had a 2cm non-gaping cut to her left upper lip, a series of three non-gaping lacerations to her left cheek and an area of blue-gray discoloration to the skin of her left cheek, all of which could be caused by an impact across the driveway floor as she was thrust from behind. Some abrasions and discoloration to the midline of her chin possibly received in the same motion. The slightly swollen discoloration to her upper and lower lips on the right side could have resulted from Cheri Jo Bates shifting her head position and further force being applied by her assailant. Although petechial haemorrhaging can be caused by choking or compression of the chest cavity, it can also be caused when excessive pressure is applied to tissue (e.g., when a tourniquet is applied to an extremity or the person is struck across the face with an open palm of the hand). In the case of Cheri Jo Bates, the forehead petechiae noted at autopsy could have been caused as a result of her head being pressed into the hard uneven ground.. 

The entirety of the abrasions to her hands and fingers were located on her right hand (possibly her dominant hand), that could have been received as she was forced to the driveway floor, as she attempted to arrest her descent (and some caused by subsequent struggling while being pinned to the ground}. There were no abrasion-type injuries detailed on her left hand at autopsy, suggesting her right hand was the dominant force when in contact with the driveway floor. 

The final phase of the attack may have been the solitary knife wound to her back and the seven lateral knife wounds across her neck, ultimately severing her right common carotid artery and right superficial jugular vein, resulting in death in several minutes. The attack could have lasted less than 30 seconds.  PART ONE  PART THREE

WAS THE CONFESSION LETTER AUTHOR THE KILLER OF CHERI JO BATES?
WAS THE CONFESSION LETTER AUTHOR THE KILLER OF CHERI JO BATES? [PART TWO]

An archived forum post on May 4th 2000 from ZodiacKiller.com concerning the once Riverside Detective Steve Shumway stated "Until now, a key piece of evidence supporting RPD’s claim has been withheld. With permission from lead detective Steve Shumway, I am revealing a fact that directly points to the Bates murder as being a classic “crime of passion:” Cheri Jo Bates was stabbed 42 times.

Where Steve Shumway acquired this information is irrelevant, because it is pure fiction. In fact, Cheri Jo Bates was stabbed less than one-quarter the amount of times put forward by Steve Shumway. A cursory glance across the 26 entries from the external examination by autopsy surgeon F. Rene Modglin shows that Cheri Jo Bates received no more than 6 incised wounds to her torso and arms (discounting the two abraded lacerations to her left forearm). Her neck received 7 incised wounds that transected the thyroid cartilage, right common carotid artery and right superficial jugular vein, indicative of a blade being drawn across the neck (they were not stab wounds). Claims that Cheri Jo Bates was nearly decapitated is another wild dramatization of an already brutal and senseless murder. Also, attempting to manufacture an argument that this crime was possibly committed in an act of rage by somebody who had a relationship or was known to the victim, cannot be credibly argued based on the number of stab wounds the victim received.

Cheri Jo Bates had received three wounds to her breast region and one to her back (4 in total to her torso), none of which were life threatening (disregarding prolonged blood loss). She had two moderately superficial cuts to the anterior and medial upper left lobe of her lung, with no.pulmonary embola significant atelectasis (collapse of lung tissue with loss of volume). The three incised wounds to her breast region measured 1.9cm (0.75 inches), 1.7cm (0.67 inches) and 1.4cm (0.55 inches). F. Rene Modglin had calculated, based on the entirety of the wounds, that the minimum knife dimensions would be half inch wide and three and a half inches long. The wounds may have measured slightly more than half an inch at autopsy, but this is dependent upon the angle of delivery and removal of the knife as it entered and exited the body. But the incised wounds to her breast region and back (0.59 inches) suggest a blade of half an inch wide or fractionally bigger. Her right upper arm had only one gaping wound measuring 4cm (1.6 inches), suggestive of an angled strike with the blade, with another wound measuring 1.5cm to her right axillary fold (right armpit). Her left arm carried two "somewhat abraded lacerations" of 3.5cm and 4cm, that were not necessarily indicative of a knife wound. A laceration is caused by blunt force trauma (crushing or ripping blow) with evident tissue bridging and minimal blood loss (except for the scalp). An incised wound (by a knife in this case) exhibits no tissue bridging and greater blood loss.

​Unfortunately, the autopsy uses the word laceration throughout to show the knife wounds in this case, making it difficult to disseminate what is meant when describing the wounds to the face and hands of Cheri Jo Bates. The "2 cm oblique ragged edge fresh non gaping laceration of the upper lip on the left side, that angles laterally from above and extends completely through the thickness of the lip", is likely a blow from either the fist or foot of the murderer, or contact with the ground. As were the "series of three fresh lacerations of the skin of the left cheek, angling from above in front slightly downward and posteriorly". These injuries to her face were interspersed with abrasions (possibly received from the driveway floor). Her hands received numerous abrasions, but only three of the wounds to her hands were described as lacerations by F. Rene Modglin. There were twelve injuries to her hands described at autopsy (10 presumably to her dominant right hand and two to her left hand). F. Rene Modglin described two lacerations to her left hand and one to her right, leaving nine abrasion type injuries remaining (and so making the twelve described injuries). One entry in the autopsy described a few light linear criss-crossing abrasions of the right hand (I attributed this as one injury). If F. Rene Modglin used lacerations to describe incised wounds from a blade, then Cheri Jo Bates only had three defensive wounds to her hands. The numerous abrasions to her hands most likely received from contact with the driveway floor.     

As a consequence of the above findings we can determine that none of the knife wounds to her torso, arms and hands would have proved fatal had she escaped at this point and received fairly prompt medical assistance. Assuming the "lacerations" to her hands were not caused by crushing or tearing blows (and were knife wounds), then Cheri Jo Bates received just three incised wounds to her hands, of which, two were to the dorsal side (knuckle side) of her left hand, and one to the medical aspect of her right index finger. So was Cheri Jo Bates placing her hands over her breast region attempting to protect that vital area during the initial phase of the attack, thereby receiving these wounds to the back of her hands? (and possibly the two abraded lacerations to her left forearm).

​However, discounting these two abraded lacerations, which were on the volar surface (palm side) of her forearm (and assuming Cheri Jo Bates had her hands in front of her chest for some time during the attack), then she received eight incised wounds from a knife blade while standing, likely delivered by an assailant securing Cheri Jo Bates from behind during this period. Can we conclude that Cheri Jo Bates had been thrown or forced to the ground during the next phase of the attack, then punched and kicked, before being stabbed once in the back with a knife as she lay struggling on the driveway floor? All the abrasions and lacerations to her hands described at autopsy by F. Rene Modglin were to the dorsal side of her hand (knuckle side). Her fingers received injuries, but none were detailed to the palms of her hands in the autopsy report. 

We have a killer who failed to deliver any imminent life threatening injuries to the front of Cheri Jo Bates' body, with limited knife penetration to any part of her torso (whether delivered standing up or kneeling over her). Although not proven, it appears the final part of the attack occurred when Cheri Jo Bates was lying face down, with one stab wound to her back, followed by the knife blade being drawn across her neck seven times. Was this attack the product of a youthful and inexperienced lightweigt, who failed to deliver any killer blows during the initial phase of the attack, who ultimately resorted to attacking her neck region? Or is it impossible to conclude the maturity and experience of the murderer based on anything contained within the autopsy report generated by F. Rene Modglin?   PART TWO  PART THREE

WAS THE CONFESSION LETTER AUTHOR THE KILLER OF CHERI JO BATES?
WAS THE CONFESSION LETTER AUTHOR THE KILLER OF CHERI JO BATES? [PART TWO]

After his displeasure that the citizens of San Francisco would not wear "some nice buttons", the List Letter on July 26th 1970 continued with a future tense narrative from The Mikado's As Some Day it May Happen, proclaiming how the Zodiac Killer was set to torture his slaves in paradise, by stating "some I shall tie over ant hills and watch them scream and twich and sqwirm". Despite the Little List letter being unreleased to the public on October 5th 1970, the 13-Hole postcard continued the narrative, now proclaiming in the past tense he had effectively succeeded in torturing his slaves, claiming "Some of them fought it was horrible". It can be argued that this goes a long way to authenticating the 13-Hole postcard as a Zodiac communication. This communication, mailed on October 5th 1970, was followed by another pasted postcard from Berkeley, California on October 17th 1970, which also used cuttings to convey the message, and threatened "Adams You Are Next Zodiac".  It was addressed to Dr. Edward C. Adams, who resided at 102 Camino Don Miguel, Orinda, California. It appears that this postcard was mailed by the same individual as the 13-Hole postcard, but with the October 5th 1970 communication having already been published in the newspapers, we cannot be sure this latest postcard was not created by a copycat. An examination of the adhesive used on both communications would be highly beneficial in determining joint authorship. This determination could be crucial, because if we can prove both were authored by the Zodiac Killer, we may be able to physically place the Zodiac Killer in San Bernardino, alongside Riverside,  in 1969. We could place the Zodiac Killer mailing a letter just 19 miles from the murder site of Cheri Jo Bates.

A letter postmarked Montclair, California on November 10th 1969 and addressed to an individual in Clarinda, Iowa, carried the message "Mr. (redacted) Your Next. The Zodiac". This format was nearly identical to the Edward C. Adams postcard, again using cuttings from a newspaper or magazine. The Montclair mailing was also sent during the hub of Zodiac activity. No communications had apparently been mailed by the Zodiac Killer since the October 13th 1969 Paul Stine letter, but this inactivity was broken by the November 8th 1969 and November 9th 1969 Dripping Pen card and Bus Bomb letter, shortly followed by the Montclair mailing on November 10th 1969 from San Bernardino. If the Adams postcard was the Zodiac Killer, then how high a probability do we place on the Montclair mailing being from the Zodiac Killer, bearing in mind this was addressed to another male individual, with a near identical message, using cuttings from a publication - and more crucially - not released into the public domain when the Edward C. Adams postcard was mailed nearly one year later. If the Montclair mailing was Zodiac, we can place him extremely close to Riverside three years after the Cheri Jo Bates murder. A murder that hadn't been publicly linked to the Zodiac Killer on November 10th 1969.    

Another fascinating aspect of the Montclair, San Bernardino mailing, was that it was fashioned using school notebook paper, just like the three Bates' letters mailed in Riverside on April 30th 1967, later claimed to have been authored by an individual from San Bernardino in 2016. These too, contained an extremely succinct message. If we can link the Montclair mailing to the Adams postcard, and therefore the 13-Hole postcard, we can almost certainly place the Zodiac Killer mailing a letter close to Riverside in November 1969, placing new emphasis on the three Bates letters mailed in April 1967, and shedding further doubt on the lacklustre claims of the individual in 2016. Unless of course, he is the Zodiac Killer. which I seriously doubt as a viable option. A Freedom of Information (FOIA) request for an unredacted version of the below FBI file may unearth the identity of the individual in Clarinda, Iowa, and uncover any commonalities between him and Edward C. Adams. If this individual was a certified psychiatrist, just like Dr. Adams, it could be an extremely interesting avenue of research. And placing the Zodiac Killer mailing a letter close to Riverside at the beginning of his campaign of terror in the Bay Area, could shed a whole new light on the murder of Cheri Jo Bates in 1966 and the communications associated with the case.  

Although I believe the Cheri Jo Bates murder and accompanying communications have nothing to do with the Zodiac Killer, it would be foolish to unequivocally rule out of any of the commonly mentioned pre-canonical crimes suggested as possibly being the work of the Bay Area killer. So let us once again examine the Halloween card on October 27th 1970, that inspired Phil Sins to contact American journalist, Paul Avery, shortly after its arrival at the San Francisco Chronicle, and point out his thoughts on the relationship between the Halloween card and the murder of Cheri Jo Bates on October 30th 1966. Even though a link between the Zodiac murders and Riverside had been considered the previous year by investigators, this wasn't common knowledge on October 27th 1970. Phil Sins was also unaware that three letters had been mailed to the Riverside Press Enterprise, Riverside Police Department and Joseph Bates on April 30th 1967 by somebody claiming to be the killer of Cheri Jo Bates.

​In 2012, Mike Morford of Zodiac Killer Net interviewed Phil Sins, who stated that despite going to the Riverside Police Department with Paul Avery "where the letters & desktop were discussed or shown", he himself did not get to see them. Therefore, he had no knowledge regarding the contents of the Bates' letters when he drew his original conclusions between the Zodiac and Riverside cases. And neither, have we yet proved, did the Zodiac Killer. This is why the Halloween card and the Zodiac Killer's previous letter, the Little List letter mailed on July 26th 1970, are so curious. If not responsible for any of the Riverside activity, the Zodiac Killer could have been aware of the Cheri Jo Bates case and the Confession letter when he mailed both the Little List letter and Halloween card, because the Inside Detective magazine published on January, 1969 featured both. However, he wouldn't have been aware of the three Bates' letters (had he not been the author).  

Had the Zodiac Killer read the Inside Detective magazine and thought now is the time to plant the seed in investigators minds that he may have been responsible for the Riverside murder? The Confession letter mailed on November 29th 1966 read "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". The Little List letter on July 26th 1970 read "Some I shall tie over ant hills and watch them scream + twich and sqwirm". Did the Zodiac Killer deliberately group this sequence of words together (including the misspelling of twich) to encourage individuals to draw the comparison between both communications and force investigators to strongly consider his involvement in the Riverside murder (and authorship of the Confession letter)? Or were these word comparisons sheer coincidence? Before you draw any conclusions, it is important to consider the Halloween card, which followed three months later.

The whole premise of the Halloween card cover was seemingly chosen on the understanding that when the card was opened it would reveal his name. One notable feature of the card was the prominence of the word "By", followed by the four methods of death. The Zodiac Killer had written "By Fire, By Gun, By Rope and By Knife". The 1966 Confession letter also tempted us with a name, when the author began his typewritten letters with "The Confession", followed by the word "By" and several underscores. The word "By" playing a significant role in both communications. We also have the Halloween theme running through the 1970 card and the Riverside murder of Cheri Jo Bates, whose lifeless body was discovered on Halloween morning. But it's the addition of the "Z" symbol (meant to infer "Zodiac") placed at the foot of the Halloween card that conjures the most interest. The Zodiac Killer had mailed 15 confirmed communications prior to October 27th 1970 (probably in excess of 20), yet he had never once used the letter "Z" to sign off a communication. In fact, no communication subsequent to October 27th 1970, verified or otherwise, ever signed off with the letter "Z".​

​The only time the Zodiac Killer used the letter "Z" as a signature, was in conjunction with Halloween on October 27th 1970. This is what is so interesting about the potential "Z" like signatures accompanying the April 30th 1967 Bates' letters, concerning the murder and discovery of Cheri Jo Bates' body on Halloween morning. Of course, the signatures on the Bates' letters may not have been the letter "Z", and the "Z" signature on the Halloween card may just have been a fortunate coincidence, but these three letters would have been unknown to Phil Sins when he contacted Paul Avery about a Zodiac connection. So, I suppose the discovery of the Bates' letters was an added bonus to Paul Avery when he entered the Riverside Police Department in 1970, and ultimately made the "Z" connection between the cases. Was it extremely fortunate for the Zodiac Killer to tie together Halloween, the prominent wording of "by" and the perceived "Z" signature - in combination with the common phraseology between the Little List letter and Confession letter, just three months previously - or did the Zodiac Killer deliberately place these markers on the Halloween card to plant a seed in the mind of investigators - or was he involved in the murder and/or letter writing in Riverside four years earlier?

The Zodiac Killer may have done exactly the same thing on November 8th 1969 when he claimed seven victims within the Dripping Pen card, forcing investigators to draw the conclusion he was responsible for the murder of Kathie Snoozy and Debra Furlong in San Jose on August 3rd 1969 by the addition of "Aug" in his chronological list of months. As he did on March 22nd 1971, mailing us another cryptic card, this time encouraging investigators to connect him to the Donna Lass disappearance on September 6th 1970 by the addition of "Lake Tahoe areas" and "Sought Victim 12". Once Paul Avery had connected the Riverside and Zodiac murders together, the Zodiac Killer then cemented that notion by giving "credit for stumbling across his Riverside activity". However, not once did he ever categorically claim or prove these murders were his. He only let investigators draw such a conclusion.  

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. 

A letter on school notebook paper was mailed from Montclair, San Bernardino County, California on November 10th 1969 (one day after the Bus Bomb letter) to an individual in Clarinda, Iowa. The letter read "Mr. (redacted) your next The Zodiac". The text was created by using scotch tape to affix cuttings from a magazine. Two weeks earlier (estimated: October 27th 1969) a similar letter bearing the same message had been mailed (from where to where is unknown).

​These communications are extremely similar to a communication mailed from Berkeley, California on October 17th 1970, which also used cuttings to convey the message, was addressed to Dr. Edw. C. Adams, and threatened "Adams You Are Next Zodiac". Three weeks prior to the November 10th 1969 mailing (October 21st 1969), a note stating "You're Next - Z" was thrown from an automobile at an 8-year-old girl in Anderson Valley in Ukiah, California. A few months before the Edward C. Adams communication, somebody rang a woman, again in Ukiah, threatening "This is Zodiac - you're next".  This phraseology would be used five times from people claiming to be Zodiac (or Zodiac) from October 21st 1969 to October 17th 1970. 

San Bernardino was recently the focus of the Riverside Police Homicide Cold Case Unit, when they reported that 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. In 2020, four years after the admission in the 2016 communication, the Homicide Cold Case Unit and the FBI Los Angeles Investigative Genealogy Team submitted the stamp for additional DNA analysis and subsequent interviews were conducted. The individual linked to the DNA evidence on the (2016) stamp admitted to writing the (2016) letter and sending it to the Riverside Police Department. The Riverside Police Department further stated that "Additional information was developed regarding a separate set of letters sent to Northern California police agencies. The author claimed to be the "Zodiac Killer", but the author ultimately admitted to sending the letters to keep the investigation going". Montclair, San Bernardino is 19 miles west of Terracina Drive on the Riverside campus. The three Bates letters on April 30th 1967 were also composed using holed notebook paper, just like the November 10th 1969 communication mailed from San Bernardino. 

The communication on November 10th 1969 from Montclair (with the one mailed circa October 27th 1969), and the one mailed on October 17th 1970 from Berkeley, were both addressed to an individual person, both used cuttings from publications and both carried a near identical threat - and could very well be the same author (as all were unreleased to the public). The two communications using cuttings in October and November 1969 predated all other correspondences of this nature, including the two horoscope mailings on December 10th and 11th 1969, the 13-Hole postcard on October 5th 1970, the Berkeley mailing on October 17th 1970, the March 22nd 1971 Pines card and the July 13th 1971 Monticello card.. The horoscope mailings in December 1969 were sourced from a November edition of a magazine, so where did the author of the November 10th 1969 mailing source his material? Whether the author was the Zodiac Killer in any of the "Your Next" or "You Are Next" communications however, is open to question.  

"Edward C. Adams spent most of his life in the Bay Area where he attended the University of California Berkeley for his undergraduate work and Stanford University for his medical degree. His residency in psychiatry was received at the Menninger Clinic, Topeka, KS. During the Korean War he was an instructor in the Medical Field Service at Fort Sam Houston, San Antonio, TX. After retiring from an active practice in Psychiatry he devoted his energies to travel, fly fishing, the study of poetry and the enjoyment of his family and many friends. During the time spent at his Carmel home he volunteered as a docent at the Robinson Jeffers Foundation. He was a member of the San Francisco Psychoanalytic Society and an active supporter of many environmental groups". The November 10th 1969 communication was mailed to somebody in Clarinda, Iowa, located 121 miles (by crow) from where Edward C. Adams studied psychiatry at the Menninger Clinic in Topeka, Kansas.

Thanks to Cragle for sending me this document.

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. 

On October 30th 1966, several earwitnesses reported hearing screams between 10:15pm and 10:45pm from the vicinity of the driveway adjacent to Terracina Drive in Riverside. Robert Graysmith wrote in his Zodiac book that: 'A neighbor heard an awful scream between 10:15pm and 10:45pm, and then about two minutes of silence, and finally the sound of an old car starting up. A man returning to the area at 10:30 pm told us he heard two screams then'. Several people in a nearby apartment building heard screams about 10:30pm. It is clear that more than one person heard these screams. If these screams were a product of the murder of Cheri Jo Bates, then it is extremely unlikely the young woman could have left the library at 9:00pm, failed to start her vehicle, and been aided by a good Samaritan who ultimately lured her away and killed her between 9:15pm and 9:45pm in the nearby driveway. Many people will try to sell you this notion by using the daylight savings argument, when the clocks are turned back one hour. In other words, attempting to change an approximate 10:30pm murder into a 9:30pm murder, by claiming people failed to turn their clocks back. 

The clocks were scheduled to be turned back from 2:00am to 1:00am, very early morning, on Sunday, October 30th 1966. This would be 20.5 hours before a 10:30pm murder. Even accepting that most people will likely turn their clocks back when they wake up between, say 7am and 10am on Sunday morning - that still leaves 12.5 to 15.5 hours for the remainder of people to achieve this simple task. So, to believe that every earwitness who reported screams at Riverside failed to turn their clocks back, and made an error by stating 10:30pm rather than 9:30pm, is not realistic. If the screams were Cheri Jo Bates, the murder almost certainly happened at approximately 10:30pm.  

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.

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. In 2020, four years after the admission in the 2016 communication, the Homicide Cold Case Unit and the FBI Los Angeles Investigative Genealogy Team submitted the stamp for additional DNA analysis and subsequent interviews were conducted. The individual linked to the DNA evidence on the (2016) stamp admitted to writing the (2016) letter and sending it to Riverside Police Department. 

It appears from the wording in the statement that it was the additional DNA testing that unearthed the identity of the 2016 author. But why did it take four years from receiving the 2016 letter until further DNA testing identified the sender, when you consider that the Riverside Police Department have always had their sights set on an individual for the murder of Cheri Jo Bates, who went by the fictitious name of "Bob Barnett"? It isn't beyond the realms of possibility that when the Riverside Police Department received this 2016 communication from somebody alleging he was not the Zodiac Killer or the killer of Cheri Jo Bates, he may very well have been the murderer in the case of Cheri Jo Bates, playing more games with police as he did in 1967. Investigators obviously found the 2016 communication compelling enough to consider it for DNA testing in 2020, rather than just dismiss it as another hoax letter. They must have received many crank communications down the years regarding the murder of Cheri Jo Bates and the associated communications in the case, so what set the 2016 letter apart for the FBI Los Angeles Investigative Genealogy Team to get involved? Or do they routinely DNA every crank letter making claims or admitting some responsibility to the events in 1966 and 1967? I highly doubt it.

The Riverside Police Department further stated that "Additional information was developed regarding a separate set of letters sent to Northern California police agencies. The author claimed to be the "Zodiac Killer", but the author ultimately admitted to sending the letters to keep the investigation going". The wording here (like the rest of the statement) is extremely ambiguous, but the way it is constructed in contemporary fashion using "additional information was developed", appears to suggest that the author of the 2016 letter was ultimately claiming responsibility for several letters sent to Northern California police agencies. The reason for believing this to be the case, is that no known set of letters claiming to be from the Zodiac Killer in Northern California were ever mailed to police agencies to "keep the investigation going".

​All but two of the authenticated and unauthenticated Zodiac letters we know of currently, were mailed to newspapers not police agencies. The letters to a police agency in Northern California from 1969 to 2001 were mailed to the San Jose Police Department on November 21st 1969 (which threatened a widow), and the August 10th 1969 Concerned Citizen card to Sergeant John Lynch of the Vallejo Police Department. But this wasn't a set of letters, or letters designed to keep the investigation going. One way in which the Riverside Police Department could have judged the authenticity of the individual's claims in 2016 would have been to request details of the further hoax letters he mailed to Northern California claiming to be the "Zodiac Killer" and attempting to keep the investigation going. Had Riverside Police Department checked these further claims and verified them, it would have given more credence to this individual that he was a serial hoaxer involved in manufacturing the three Bates letters. These further hoax Zodiac letters and the way they were written and designed could be the key to the confidence displayed in the recent statement from the Riverside Police Department. 

The first time it was widely known of the Zodiac Killer connection to the Cheri Jo Bates murder case, was when Paul Avery wrote extensively about this in the San Francisco Chronicle on November 16th 1970 in an article entitled New Evidence in Zodiac Killings. It read "On April 30, 1967, exactly six months after the killing, three stamped letters - addressed to the Press-Enterprise, the police, and cruelly, to the slain girl's father - were dropped into a city mailbox. BATES HAD TO DIE THERE WILL BE MORE was printed in large scrawled letters on each of the notes penciled on pages of lined 3-hole school paper".  So any additional hoax letters created to keep the Zodiac investigation going, mailed by the 2016 claimant of the three Bates letters, likely came when he saw the connection between the Riverside and Northern California murders. This article may have been the incentive to project himself into the Zodiac case and mail additional hoax letters to Northern California police agencies. Assuming these further letters were retained, it could have been a simple case of interviewing the 2016 individual and asking him where he mailed these additional letters from (and their content), and cross-checking the postmark to verify his claims. Four months after the Paul Avery article, somebody claiming to be the Zodiac Killer decided to shift his letter writing from the San Francisco Chronicle to the Los Angeles Times, because "they don't bury me on the back pages like some of the others". The author of the March 13th 1971 Los Angeles letter begrudgingly  acknowledged the authorities for stumbling across his Riverside activity, adding that there was a hell of a lot more down there. Downtown Los Angeles is about 60 miles west of San Bernardino.