This is the image supplied to us by the Zodiac Killer on the Phillips 66 Mount Diablo map on June 26th 1970. By placing the numbers 0, 3, 6 and 9 around the crosshairs, akin to a clock face, and instructing us that 0 is to be set to Mag. N, the Zodiac Killer is telling us that we have to travel a certain amount of degrees around the clock face from point zero (set to magnetic north, which was 17 degrees in 1970).

The Zodiac Killer realized that the information he provided in the Button letter was insufficient to discover where he was planning to set the bomb. He also realized it was insufficient to solve the 32-Symbol cipher. That is why he placed two crosshairs in his next communication on July 26th 1970. One of the crosshairs contained the radians value, while the other crosshairs contained the inches value. Zodiac wrote:

"P.S. The Mt. Diablo code concerns Radians + # inches along the radians".

It was that simple, all we had to do was place the first crosshairs (shown on the right) over a compass rose. The center of the little black circle with SFPD next to it, landed exactly at 246 degrees, which is 4 radians and magnetic north. That is the answer to the radians value. The target was SFPD.

The second crosshairs had the phrase "P.S. The Mt. Diablo code concerns Radians + # inches along the radians" written over it. Why would the Zodiac Killer place an arrow pointing before the inches value, if he didn't intend for us to place a number here? The answer could only ever be 5 inches, because using the Phillips 66 map scale of 6.4 miles to the inch, only 5 inches falls over San Francisco (4 & 6 falls into the sea).
The target of SFPD was therefore 4 radians and five inches from Mount Diablo. The target was the Southern Freeway by Ingleside Police Station, explained in greater detail here.

Whatever target the Zodiac Killer chose, it was extremely unlikely his radians and inches values would form whole numbers. This is why he gave us an estimate. On December 3rd 2020, David Oranchak, Sam Blake and Jarl Van Eycke solved the infamous 340 cipher after 51 years. On December 27th 2020, just twenty-four days later, Druzer (a regular contributor to both mainstream Zodiac forums) solved the 32-Symbol cipher. When four radians and five inches was placed into the 32-Symbol code with the word estimate, it married perfectly the three repeating ciphertext characters, giving us the complete solution to the code. The simplicity of this solution is its strength, because it doesn't require an explanation longer than the idea. I have zero doubt his solution is correct, which is why I am satisfied that the search for answers to the 32-Symbol cipher is over.

The Zodiac Killer mailed the Little List letter on July 26th 1970 setting out his search for "society offenders", but this lengthy communication was withheld from publication in the newspapers until October 12th 1970. Despite a comprehensive article in the San Francisco Chronicle on September 26th 1970 featuring the disappearance of Donna Lass from Lake Tahoe on September 6th 1970, the Zodiac Killer never raised his victim total of 13 from July 26th 1970 to October 5th 1970, when the 13-Hole postcard arrived. He never previously needed any prompting to falsely inflate his victim total in previous communications, yet a month after the abduction and likely murder of Donna Lass from the Sahara Tahoe Hotel & Casino, the Zodiac Killer kept his victim total static, suggesting at this juncture he was not claiming the young nurse as victim 14. That is, because he never murdered her. Besides, he would later retrospectively claim he had sought her as victim 12 in the March 22nd 1971 Pines card, while she was still present in San Francisco and working at the Letterman General Hospital by the Presidio.

Donna Lass would have been working as a nurse in the Presidio park in the relevant time period for her to be sought as victim 12. Bearing in mind that the Zodiac Killer was last seen entering the Presidio park after the murder of Paul Stine on October 11th 1969, he knew that by retrospectively claiming he had targetted Donna Lass in San Francisco before her eventual disappearance, it would carry more weight to his suggested involvement in her demise through the Pines card.

The punched hole in the top right corner of the Pines card was never a hint towards her burial location, because the Zodiac Killer had no idea where her body was located. The vague and cryptic phrases pasted on the Pines card were just designed to identify the name of Donna. When the "Sierra Club" was aligned over the Sierra Club of Clair Tappaan Lodge, the punched hole landed over the "Donner" of the Donner Memorial State Park. This was shown to be likely true when a similar pasted card, dubbed the Monticello card, arrived at the San Francisco Chronicle on July 13th 1971, again hinting at the identity of a murdered woman, that of Kathy Bilek. This time, the author pasted "Woods", "April" and "near Monticello" as a clue to her name. However, on this occasion, the sender would actually direct us to a burial site.

Buried in the Oak Hill Memorial Park & Cemetery in the Monticello neighborhood of San Jose was the resting place of Kathy Snoozy, claimed as a victim by the Zodiac Killer in the Dripping Pen card on November 8th 1969. She was the namesake of Kathy Bilek, who along with Deborah Furlong, were all victims of the real murderer, Karl Francis Werner. The Monticello card followed the exact pattern of the Pines card, in which the Zodiac Killer retrospectively claimed the April 11th 1971 murder of Kathy Bilek in the Villa Montalvo woods of Saratoga, by pasting "shought victim 21" on the card. He never murdered Kathy Bilek and he never murdered Donna Lass. When Karl Francis Werner was credited with two of Zodiac's previously claimed victims, that of Snoozy and Furlong, he doubled down and more, by adding Kathy Bilek retrospectively in a vain attempt to discredit the notion of Werner being responsible for all three. This belated tactic was used to claim Donna Lass as a victim also, with the Zodiac Killer selecting a time period between the 10 victims on April 20th 1970 and 12 victims on June 26th 1970, while Donna Lass was still working at the Letterman General Hospital for a large chunk of this time. He knew this would add credence to his claim of involvement in her disappearance and likely murder, particularly when he noticed the proximity of her profession to the Washington and Cherry intersection in Presidio Heights.

In fact, the Halloween card, Pines card and Monticello card may have all been retrospective communications, with the Halloween card incorporating the murders of Kathy Snoozy and Deborah Furlong into its design by the addition of two skeletons and the 4-TEEN on the card inner. The Zodiac Killer was only claiming four teenagers as murder victims by October 27th 1970, that of David Faraday, Betty Lou Jensen, Deborah Furlong and Kathy Snoozy. We know that the Zodiac Killer wasn't responsible for the three victims eventually attributed to Karl Francis Werner, despite him valiantly trying to retrospectively claim all three on numerous occasions. Therefore, we should place little credence to his suggestion of involvement in the untimely disappearance of Donna Lass through the Pines card, especially when he had every chance to elevate his victim total on October 5th 1970. This should give you pause for thought when the Zodiac Killer retrospectively inferred his involvement in Riverside on March 13th 1971, four and a half years after the fact.

Druzer and I have recently been working on the Mount Diablo map code solution, using the measurements of four radians and five inches supplied by the Little List letter crosshairs. Druzer came up with a solution to the 32-Symbol cipher that satisfied the three repeating ciphertext characters in the code, giving us an estimate of where the Zodiac Killer was threatening to "set his bomb". The target was the Southern Freeway alongside Ingleside Police Station, stated in a previous article as 4.03 radians (4 radians} and 4.84 inches (5 inches) from Mount Diablo, indicating that the Zodiac Killer was rounding off his values and giving us an estimate.

It has been stated on this site and elsewhere, that the 32 character code is unsolvable using conventional cipher techniques without the killer supplying us with a key. There are 29 unique characters within the code, making any solution practically unprovable. The solutions offered by using the 408 and 340 keys have produced less than convincing results, particularly when we consider that this code contains an "anchor" and "omega" symbol, not used in the 408 and 340 ciphers. Attempting to correlate the letters used in the code to written text in both the Button letter (June 26th 1970) and Little List letter (July 26th 1970) also produces negative results. Therefore, it could be argued, that a code containing 29 unique characters must have an alternative meaning, in accompaniment to the code solution of "estimate:four radians and five inches".

The Zodiac Killer gave us an estimate of 4 radians, but the actual figure (shown above) was 4.084 radians. That is, 4.084 multiplied by one radian value (57.3 degrees) to equal 234 degrees. When we add in the magnetic north which Zodiac instructed us to do (17 degrees in 1970), we get 251 degrees and the location of Ingleside Police Station. Could the 32 character code contain the value of 234 degrees, which once set to magnetic north, now identified the exact location of Ingleside Police Station? If we resort to basic numerology where A=1, B=2, C=3 etc, and add up the values of the alphabetical characters in the Zodiac Killer's 32 character code, we arrive at a total of 234 (or 234 degrees). When set to magnetic north, it gives us the value of 251 degrees, which when subtended from the peak of Mount Diablo passes directly over Ingleside Police Station and the Southern Freeway. "The map (set to 17 degrees magnetic north) coupled with the code of 234 will tell you where the bomb is set".

Nikki Alexandra Benedict (14) had left her friend Kathie Gomski's house in Halper Road, Poway on May 1st 1967 shortly after 6:00 pm, to walk the 2 1/2 mile journey to her home at 13530 Olive Tree Lane, when approximately 20 minutes into her journey her life was cruelly snatched away.

She was just passing the intersection of 12784 Poway and Carriage Road, traveling along a dirt pathway that straddled the Poway Road, when it is speculated that somebody laying in wait leapt from a grassy depression and viciously attacked the young teenage girl with a short-bladed knife. She had a knife wound to her neck and bruises on her elbows and knees, but the fatal injuries were two stab wounds that penetrated her heart.

The young girl did not succumb to her injuries immediately, with a trail of blood extending 200 yards to the west side of Carriage Road as she desperately sought help near a local shopping center. At approximately 6:30 pm, an 11-year-old boy, Ronald Fisk, discovered the critically injured girl and raced away on his bicycle to seek help from his father, who worked at a nearby market store. Unfortunately, despite the best efforts of responding personnel, Nikki Benedict would be pronounced dead upon her arrival at Palomar Hospital.

Much speculation has followed this case for 54 years and theories surrounding the murder of Nikki Benedict are far reaching, that include the infamous Zodiac Killer. Everybody is entitled to their opinion, but I see very little in this murder that points towards the Bay Area murderer of five. It is certainly possible that this could be an early attack perpetrated by the infamous Zodiac Killer, but other than an attack with a knife at a location 82 miles south of the Riverside murder of Cheri Jo Bates, that may or may not have been committed be the Zodiac Killer, there is little else. The injuries detailed in the murder of Nikki Benedict suggest a brief encounter, before the suspect fled on foot from the pathway. From the reports in the newspapers, it appears that no sexual interference took place on the young girl, and no eyewitnesses have testified to viewing the attack as it unfolded. What we do know (which is limited), is the assailant inflicted a wound to her neck (as though a knife was pressed against her skin) and two fatal stab wounds to her chest, in what has been described as a brief struggle. Then there are reports of an individual running away from the crime scene.  

It is extremely difficult to form any certainties surrounding this crime, based on snippets of information gleaned from the newspapers, but it appears that the encounter between Nikki Benedict and her murderer was short in duration. Sunset was over an hour away, so this attack with a short-bladed knife would have occurred in daylight hours in an open field, close to the intersection of 12784 Poway and Carriage Road, with a shopping center nearby.

Bearing in mind that this attack wasn't viewed in progress by any eyewitnesses, why would a grown man with ulterior motives, fail to achieve his objective of overpowering a 14-year-old girl at this location, or fail to drag her away to a waiting vehicle? Nikki Benedict traveled at least 200 yards after the attack in a desperate bid to seek help, that not only showed the attacker's inability to kill her on the spot, but based on her described injuries, appeared to corroborate the notion of a brief encounter before the assailant ran away on foot. Using this speculatory analysis, it could be argued that her killer was extremely inexperienced and inadequate. This tallies with the description given in one newspaper of a young man seen running away from the crime scene. Another newspaper detailed a witness, who "reported seeing a white male running from the area but it was from a considerable distance and the description was broad, investigators said". From these limited eyewitness descriptions, it is certainly possible her attacker was an inexperienced youth of similar age to Nikki Benedict.  

“Could it be a local? Yes, it could be. Could it be an outsider? Yes, it could be", said Detective Will Altenhof with the San Diego County Sheriff's Dept. "We don’t really have evidence to suggest one way or another".

There is every chance her killer was local, every chance he knew Nikki, and every chance he was either a classmate of the young girl, or he waited for her that day as she left school and visited her friend's house. Nikki Benedict would usually travel the 2.3 mile journey from Meadowbrook Junior High School on the school bus to her home at 13530 Olive Tree Lane, however, on this Monday she visited her friend Kathie in Halper Road to discuss an art project.

Meadowbrook Junior High School is situated just off Halper Road, and her attacker struck just 20 minutes after she left the home of her friend. Not only are the three locations of school, friend's house and attack location extremely close to one another, but was it really just bad luck that the only day she didn't travel home using the school bus, was the day an attacker just happened to be lurking in a depression alongside the pathway she chose that evening? Or was her attacker connected to Meadowbrook Junior High School, who followed Nikki to her friend's house and waited for her to leave to walk home? It wouldn't be the first time a young man pestered and stalked a young girl. In absence of any eyewitnesses before the attack, had the young man walked with and spoken to Nikki Benedict? When he didn't get or hear what he wanted, could he then have lashed out in a brief, but deadly attack, from which he may have been seen running away from? His flight path could tell us so much as to what area of Poway he lived. 

Sadly, Nikki Benedict passed away during the ambulance ride to Palomar Hospital without uttering a word, but my guess had she done so, would have identified somebody she knew of similar age, who deliberately lay in wait in the field opposite Halper Road that evening. It's certainly possible this could be a random assailant unknown to the young girl, but the proximity of Meadowbrook Junior High School, Kathie Gomski's house in Halper Road, the pathway alongside the Poway Road, the seemingly inexperienced attack which was initially survived by Nikki Benedict and the young white male seen running away from the crime scene, appears like a targetted attack of somebody known to the young teenage girl. This, coupled with the fact she usually caught the school bus home, could indicate prior knowledge of her intentions and movements that day.

Irrespective of my take on the murder of Nikki Benedict, the overarching priority is to identify the killer no matter who he turns out to be. If you have any information pertaining to this case, please call the Sheriff’s Homicide Unit at (858) 974-2321 or the Crime Stoppers anonymous tip line at (888) 580-8477. Or use the online tip form.

"In this, the most awful day in our lives, we have been kept afloat and have been given the strength to bear the senseless tragedy we have had, by our new friends in Poway. You have come to us with your real understanding, and you have given us food to eat when we could not cook, and you have gone out and searched in the fields with the sheriffs. In spite of our awful loss, we cannot say we are sorry we moved here. This senseless thing could have happened in any town in America - a sick person stabbed a girl who came down a country path. It happened to be our daughter, and not yours. If he should read this, we want the person who killed our Nikki to know that we pity him, for he is alive (as Nikki is not) and he has a great burden and a great debt to pay. If he comes forward and tells the sheriff he did it, we promise we will not hate him, and we will try to help him. To everyone in the sheriff's department and fire department, to everyone who tried to save our Nikki, and to the volunteers, we are deeply appreciative". Russell and Julie Benedict. 

Poignant words from the grief-stricken parents after their beloved daughter was brutally stabbed by an unknown assailant in Poway on May 1st 1967. Nikki Alexandra Benedict (14), a carefree young teenager, was walking home by the intersection of 12784 Poway and Carriage Road shortly after 6:00 pm, when the embodiment of evil cruelly cut short the young girl's life with two stab wounds to her heart. As of writing, the perpetrator of this heinous crime has yet to be identified, as we approach the 54th anniversary of her untimely death.

The picture on the left shows a caring young girl tending to her pet rabbits, hopeful of a bright future, in stark contrast to the malevolence that exists in some people to destroy the dreams of others. In the words of her parents, Nikki was just an innocent young girl walking down a country path, never believing for a moment she would never reach home.

If you have any information on the murder of Nikki Benedict, then call the Sheriff’s Homicide Unit at (858) 974-2321 or the Crime Stoppers anonymous tip line at (888) 580-8477. Russell and Julie Benedict died without any justice for their daughter, so if you know anything that may push this case forward, please don't hesitate to contact the appropriate authorities. Above all, remember the photograph of a smiling young girl with so much to give, who never got to cuddle her pet rabbits again.

On August 3rd 1969, cyclists made the grim discovery of the bodies of Kathy Snoozy and Deborah Furlong from San Jose, each stabbed in excess of a hundred times and found beneath an oak tree in Almaden Valley. The Chief of Detectives, Barton Collins spearheaded an investigation that eventually saw the arrest of Karl Francis Werner in the April of 1971.

The Zodiac Killer on August 6th 1969, after viewing the extensive front page coverage of this crime that he believed he deserved, very likely switched to a knife for his brutal attack on Bryan Hartnell and Cecelia Shepard at Lake Berryessa on September 27th 1969. The Zodiac Killer would indirectly refer to Kathy Snoozy and Deborah Furlong through multiple communications spanning two years, most notably the "by knife" attribution on Bryan Hartnell's car door and the Dripping Pen card, when he inflated his victim total to seven by adding the month of "Aug". He may also have done this in the December 16th 1969 Fairfield letter when he drew the Bleeding Knife of Zodiac with seven drops of blood falling from the blade. He wasn't responsible for the murders of Kathy Snoozy and Deborah Furlong on August 3rd 1969, but he wanted us to believe he was. 

This leads us to the Halloween card on October 27th 1970, approximately one year after the Dripping Pen card. The greeting card contained an eye peeking from the knothole of a tree with the circled wording of "peek-a-boo you are doomed". It is this childlike terminology of "peek-a-boo" used by parents when playing with their children, that could reveal an alternative meaning to the Halloween card. There are many variations of "peek-a-boo", such as where trees are involved: "Hiding behind that tree" is sometimes added. Wikipedia. Kathy Snoozy (15) and Deborah Furlong (14) were extremely young victims, with Kathy Snoozy described by investigators as much younger looking than 15 years. The Halloween card depicting a tree with somebody hiding behind it, in accompaniment to the two skeletons adorning the card (one purposefully added}, seemed to mirror the attack on the two young girls by an oak tree. The Halloween card deliberately designed to signify two victims, explaining why the Zodiac Killer went to the extra effort of adding a second skeleton to the card inner, and featuring "by knife" on the rear of the card, just like he did on the car door of Bryan Hartnell at Lake Berryessa.  

The San Francisco Chronicle on August 6th 1969 stated "Dr. Hauser, so shaken by the brutality of the crime he could scarcely find words, said the Snoozy youngster had 150 wounds on her back, 50 on the front and a "storm" of punctures on her neck. Deborah's body had about 100 wounds on her back and upper front and a dozen on her neck. Dr. Hauser said he was "puzzled" by many aspects of the brutal slaying. He said neither girl had been sexually molested; neither had suffered any wounds below her waist, neither gave evidence of having struggled to escape. Only the Snoozy girl, he said, had one small mark on her hand, suggesting she may have tried vainly to deflect the plunging knife". The Zodiac Killer placed a pumpkin over the groin/waist region of the first skeleton, giving rise to the notion that this communication had a malevolent undertone attached to it. But these observations are backed up by the Zodiac Killer's running victim total presented in three forms. He wrote 14 on the first skeleton's hand, he wrote 4-TEEN over the skull of the second skeleton, and may have written "Zodiac Fourteen" at the base of the card inner by combining two features, adding 4 dots to signify "four" once again.

The Zodiac got creative by listing seven victims with the addition of "Aug" on November 8th 1969 and adding seven drops of blood on December 16th 1969 on the Bleeding Knife of Zodiac drawing, so did he get creative in the Halloween card? The Zodiac Killer didn't write 4-TEEN as his victim total for no reason, therefore we have to examine why he did it. The number 4 is self evident, meaning 4 victims. The word TEEN is short for teenager or teenagers. This indicates that the Zodiac Killer has incorporated 4 teenagers into his victim total of fourteen. At this juncture, he was claiming the murders of Betty Lou Jensen (16), David Faraday (17), Darlene Ferrin (22), Cecelia Shepard (22), Kathy Snoozy (15), Deborah Furlong (14), Paul Stine (29), Richard Radetich (25) and Donna Lass (25). That is nine claimed victims of the fourteen he had placed on the Halloween card, but only four were teenagers, hence the wording of 4-TEEN. The two skeletons may sadly have represented Snoozy and Furlong, adding the two teenagers from San Jose to the existing two teenagers from Lake Herman Road in Benicia, that we already knew for certain. 

Halloween is a time when the children venture out into the night, dressed in costumes to play trick or treat in the neighborhood. The Zodiac Killer, on the other hand, may have played the sickest game of all, when he mailed the Halloween card on October 27th 1970, claiming yet again his involvement in two murders he had no hand in.

On December 3rd 2020, David Oranchak (USA), Sam Blake (Australia) and Jarl Van Eycke (Belgium) solved the Zodiac Killer's 51-year-old 340 cipher, laying waste to the countless other solutions proposed by amateur sleuths down the years. Now, Jarl Van Eycke has done it again, solving the 386-year-old Code of Langren created by Michiel Florentius Van Langren (1598-1675) in the 17th century. Van Langren was an engineer, cartographer and astronomer from the Netherlands, known for his mapping of the moon. In 1634, he enciphered a solution for determining the longitude of a ship at sea for help with navigation, which had remained unbroken for nearly four centuries. His story attracted the interest of Jos Pauwels, an Antwerp amateur astronomer who studied his work, and mathematician Dirk Huylebrouck, who would contact Jarl Van Eycke after reading about his success with the Zodiac Killer's 340 cipher. Jarl Van Eycke, after being contacted by Dirk Huylebrouck, managed to crack the 386-year-old code in just one week.

The code, enciphered in the French language (despite its introduction), decoded to "Michel Florencio van Langren says that one should make two cylindrical copper vessels of equal volume that have a conical end at the bottom, in which a hole is made in the middle so that when they are filled with seawater, they let a line of water run until they empty. The stars know in how much time they must be empty. This noted, the first barrel is run on departure, while recording which known star is on the meridian. This vessel will be empty when this star is back on the same Earth meridian, knowing that it is empty in 24 hours of sidereal time. At the same time as when the first vessel stops flowing, the second vessel opens, which will also be empty when the said star is back on the meridian of departure. This careful operation will be done daily during the trip mentioned here if one wishes to know how many degrees of longitude one has traveled from the meridian of departure. One has only to determine this difference from the stars in the sky each time one of the vessels is empty. Not to be surprised, a cylindrical float floating on cork is used to indicate".

On July 26th 1970, the Zodiac Killer mailed the Little List letter with the important clues to the Mount Diablo mystery, stating "PS. The Mt. Diablo Code concerns Radians & # inches along the radians". The answer would be about radians and inches. With the northern section of the map crosshairs positioned at zero and to be set to magnetic north, the Zodiac Killer gave us the value of 4 radians and magnetic north (246 degrees) by the placement of the bold, black circle within the first crosshairs on the Little List letter.

The target was the San Francisco Police Department at Ingleside (SFPD). The second set of crosshairs on the Little List letter contained the hashtag (number sign) in the phrase above, with an arrow placed underneath, beckoning us to insert a number before inches. Only 4 radians and magnetic north, coupled with 5 inches could ever fall over San Francisco, constrained by its land mass. No other values can meet the requirement of targetting SFPD. To an overall accuracy in excess of 98%, the location of the bomb was to be set on the embankment of the Southern Freeway just 274 feet from Ingleside Police Station. For the full story, read The Answer to the Mount Diablo Code.

My solution to the 32-Symbol code in the above article did not marry up the ciphertext to the plaintext adequately, however, Druzer, an invaluable contributor to both Zodiac Killer forums, supplied a solution that married up the three repeating ciphertext characters with corresponding plaintext characters. His solution took "PS. The Mt. Diablo Code concerns Radians & # inches along the radians". into "four radians and five inches" that satisfied the requirement of the Zodiac Killer's Mount Diablo code. This would ultimately provide us with 24 of the plaintext characters for the solution, leaving us 8 ciphertext characters to decode. Druzer came up with the answer, but how was this achieved?     

The problem that materialized, was where to place "four radians and five inches" within the 32-Symbol array. We needed an entry point. The clue had to exist within the ciphertext characters themselves. Two of the most notable ciphertext characters were the Anchor and Omega symbols (the latter of which had never been used before), so possibly it was this symbol that held the key of where to insert "four radians and five inches".

The Omega symbol can be written two ways (shown on the left), with a quick search on Wikipedia revealing information on the radian per second. The radian per second (symbol: rad⋅s−1 or rad/s) is the SI unit of angular velocity, commonly denoted by the Greek letter ω (omega). The radian per second is also the SI unit of angular frequency. The radian per second is defined as the change in the orientation of an object, in radians, every second. 

Using this as the entry point in our ciphertext characters, the word "radians" was placed at the beginning of the Omega sign in the code, hoping that the 24 plaintext characters of "four radians and five inches" would travel to the end of the code. Inserting "four" before "radians", It fell into the code seamlessly (as shown below).

Now we can add in the three plaintext characters represented by O, C and ∆ to the three repeating ciphertext characters in the first section of the code, like so.

Ingleside Police Station is actually 4.03 radians (4 radians} and 4.84 inches (5 inches) from Mount Diablo, so the Zodiac Killer was rounding off his values and giving us an estimate. As can be seen in the above diagram, the word "estimate" fits perfectly into the first eight characters of the code, giving us the final answer to the 32-Symbol code of "estimate: four radians and five inches". The Zodiac Killer was informing us that the answer to the Mount Diablo code of "four radians and five inches" was just an estimate to the location of the bomb at Ingleside Police Station (SFPD). The Merriam-Webster dictionary defines "estimate" as a rough or approximate calculation, which is exactly what it is.

The following are a few extracts from the newspapers regarding the murder of Anthony Vincent Bruno on November 2nd 1975.

According to Police Captain George Stephenson, Bruno and his girlfriend (16 years) had been parked on Monte Cresta Drive, above Barclay Way in an isolated area of western hills when a man opened the driver's side door and apparently without saying anything fired the shotgun. The girl, who was not identified by police, pushed Bruno's body aside and drove the car to her home from where police were notified. She described the assailant as white, 5 feet 5 inches tall, 140 pounds and wearing an Army green parka with hood, according to police. Stephenson said also that a late model brown pick-up truck, possibly a Dodge or Chevrolet, had been seen in the area at about the time of the shooting. The killer then ran south on Monte Cresta from the dark hillside area, past a streetlight 50 yards away, and then possibly to a late model Dodge or Chevrolet pick-up truck.

Belmont police today are attempting to find a man who shotgunned a 17-year-old Carlmont High School student to death in a parked car early Sunday morning. The youth, Anthony Vincent Bruno of 213 Bayview Drive, San Carlos, died instantly, his body sprawled on the seat of the parked car beside his terrified 16-year-old girlfriend. The killer then turned, dropped the sawed-off stock of his weapon on the ground, perhaps by accident, and fled. It was disclosed Wednesday that about an hour and a half before the brutal slaying, a man was seen struggling to drag a box about two feet long and 18 inches wide up a steep rise about 100 feet from the slaying site. A rod, or perhaps a rope, protruded from the box, according to police, and the dragging was being done by a man in mechanic's overalls with longish, dark brown hair. Stephenson also confirmed that police are searching for the driver of a maroon pick-up truck, equipped with blackwall tires and white wheels; a vehicle which they have information to believe may have approached the parked couple 15 minutes before the slaying, stopped a distance away, made a u-turn, and apparently drove off. The girl gave a follow up description "She saw a face but couldn't identify him. She couldn't see whether he was black or white, or anything other than he was 5'5", 140 pounds and wearing a green army-type parka". One has to consider that under the circumstances, this description may be less than reliable.  

"We've never had a case like this before. This is the bloodiest, most brutal killing I've ever seen", Belmont Police Chief William R. Singer said as he surveyed the scene of Belmont's first potential murder case in over two years. "It could be another Zodiac", he added.  Wednesday afternoon, Juvenile Division Detective Gary Sickman drove this reporter to the scene of the slaying and replayed what police have linked together about it so far. "This is a little-known lovers' lane", Sickman said. "Many of the kids I've talked with at Carlmont were unaware of it." Sickman drove the patrol car down a narrow dirt road connecting with Monte Cresta Drive; a chuckhole-pocked stretch traversing a ridge high above Belmont Canyon. At the end of the road, a half-mile from the slaying site, a teenaged couple embraced in a parked car. Sickman checked their identification and jotted their names in his notebook after giving them a little fatherly advice.

The image on the right shows Belmont Police Chief William Singer and Captain George Stephenson examining the scene of the crime. To visit the location, click the image to enter Google maps.  

This crime has similarities to the two attacks at Lake Herman Road and Blue Rock Springs, particularly the latter (highlighted above in blue). The couple in this instance were 16 and 17 years of age just like Betty Lou Jensen and David Faraday, attacked on what was described as a lovers' lane area. The killer, without uttering a word, fired into the vehicle in similar fashion to the shooting at Blue Rock Springs, this time in the early morning hours of Sunday, November 2nd 1975. The assailant at Monte Cresta Drive may have driven up to the vehicle of the young couple just prior to the murder, driving away and returning a few minutes later, before unleashing his deadly assault. Had the gun not broke apart, we could again have been looking at a repeat of December 20th 1968.

The following day, on November 3rd 1975, it was reported by KGO-TV that a possible Zodiac letter was discovered near to the crime scene in a phone booth. Michael Morford, a researcher at the Zodiac Killer Site forum, also remembered a cassette tape accompanying the letter. The attack happened early Sunday morning, with the newspapers carrying the story on Monday, November 3rd 1975, so when the letter (and possibly tape) were placed in the phone booth is an important factor. If the letter was placed there in the minutes after the crime (or Sunday night) and not discovered until Monday morning, the greater the possibility that the letter was written by the murderer of Anthony Vincent Bruno, who hadn't read or heard any reporting of the crime.

The reporting in the San Mateo Times of a letter alleged to have been written by the Zodiac Killer appears to carry weight, when you consider the wording of Chief William R. Singer, who stated "It could be another Zodiac". If this letter existed, then it is fairly obvious that law enforcement and Chief William R. Singer would have been aware of it.

There are three main possibilities regarding the letter: [1] Somebody read or heard the details of the crime, noted the similarities to the Zodiac attacks, and decided to hoax a letter. [2] The person who murdered Anthony Vincent Bruno prepared a Zodiac-style letter to shift the emphasis away from the fact it was personal attack. [3] The person who committed the murder and wrote the letter was the Zodiac Killer, however unlikely this option may seem. The Zodiac Killer hadn't conclusively been linked to a murder for six years at this point, and hadn't written a confirmed letter for well over a year, which undoubtedly weakens the intent of a person attempting to shift the blame onto the Zodiac Killer. The last widely accepted letter from the Zodiac Killer was the Exorcist letter mailed on January 29th 1974, probably mailed from San Mateo County. If this was "truly" a Zodiac letter, it too would have a San Mateo connection.

Two and a half years later, a cryptic letter was mailed to the San Francisco Chronicle on July 19th 1978, in what can only be described as unintelligent ramblings. With respect to the 1975 letter (and possibly cassette tape) placed in the phone booth near the crime scene, a certain section of text in the July 19th 1978 was of particular interest. It may have no connection whatsoever to the Anthony Vincent Bruno murder, but read "I have my real name on a small metallic tape. You see, while you have it in your possession, I want you to know it belongs to me and you think I may have left it accidentally".  Was this "small metallic tape", a ferric cassette tape, which was deliberately placed in the phone booth and was now in the possession of law enforcement? The murder of Anthony Vincent Bruno in San Mateo on November 2nd 1975 is a difficult crime to connect to the Bay Area murders of the Zodiac Killer without access to this letter (and tape), but the broken stock of the shotgun found ten feet from the murder scene could contain valuable evidence if stored correctly.

Thanks to Zodiac Killer Site forum.

One would presume the only person who knew that Leona Roberts wasn't going to be killed immediately after being abducted was the killer, which is why the two "forecast" letters on December 10th 1969 and December 11th 1969 are extremely interesting. The two pasted horoscope communications entitled Day-By-Day Forecast For Cancer and Day-By-Day Forecast For Leo, bearing in mind the latter could easily be interpreted as Day-By-Day Forecast For Leona Roberts, is extremely perintinent when we consider the timing of the communications and her abduction. The December 10th communication also came with the pasted pseudonym of "ZODIAC" emblazoned across its face. The fact that these communications were a forecast (a prediction of what will happen), coupled with a Zodiac horoscope and the distinct possibility that "Leo" was chosen for purpose, then the discovery of her body eighteen days later at Bolinas Lagoon in Marin County, is rather curious.

The coroner concluded that she had likely been dead "4 to 7 days prior to recovery, and he theorized that she had been alive 10-14 days after her abduction". She was abducted on Wednesday December 10th 1969 and found at Bolinas Lagoon on December 28th 1969, so that places her murder between December 20th 1969 and December 24th 1969, allowing for a small margin of error. The longer between death and discovery, the more difficult it is to make an accurate determination. 

The Zodiac Killer mailed the Fairfield letter on December 16th 1969, but he made no update to his running total of seven victims. In this communication he added a supplemental drawing of a "Bleeding Knife" with seven drops of blood, possibly fashioned to incorporate the two extra victims he was claiming, that of Kathy Snoozy and Deborah Furlong murdered in San Jose on August 3rd 1969, by knife. Just four days later, the Melvin Belli letter arrived at the San Francisco Chronicle stating the Zodiac Killer was resisting the temptation to murder his ninth and tenth victim. This appears to indicate that victim number eight was secured between December 16th 1969 and December 20th 1969, which falls around the approximate time the corner determined that Leona Roberts was murdered. If the above interpretation is correct, we would have three Zodiac communications on December 11th 1969, December 16th 1969 and December 20th 1969, giving us a "forecast for Leo", a failure to update the running victim total five days later, followed by an update to eight victims just four days later, around the time Leona Roberts was killed.         

The phrases on the Cancer and Leo communications are difficult to interpret, but when we consider the random phrase of "BIRDS FLY SOUTH" (pasted between the 18th and 24th) and the location where her body was discovered, on a north to south Pacific Flyway for migratory birds, one can't help thinking that the pasted clues were cryptic in nature. Irrespective of their correct meanings or otherwise, the "forecast" letters and the timing of Leona Roberts abduction should not be overlooked. It is likely only one person knew the day-by-day forecast for Leona Roberts, and his identity remains a mystery to this day. 

A man was seen running into Julius Khan playground shortly after the murder of Paul Stine on October 11th 1969, detailed by author Robert Graysmith, who stated "The detectives heard from neighbors that a stocky figure was seen dashing across Julius Khan playground and into the dense undergrowth of the Presidio. The dog patrol units, seven of the best search dogs in the country, gathered at the front entrance of the Presidio and were deployed one at a time in various directions. Armstrong and Toschi considered the possibilities. Had the killer gone quickly through the dark woods and emerged from the Presidio at Richardson Avenue, and taken Highway 101 past Fort Point onto the Golden Gate Bridge and vanished into Marin County".

It was speculated that had the Zodiac Killer exited the Presidio Park on its eastern edge to a waiting vehicle, with his escape via the Golden Gate Bridge into Marin County a matter of minutes away, providing separation from the San Francisco area. If the Zodiac Killer worked in San Francisco (near Presidio Heights), but commuted from Vallejo, then he may have used Highway 101 on a regular basis, passing through Marin County. Highway 101 straddles Shoreline Highway by just 724 meters, which we will return to shortly.

Here is an excerpt from Websleuths by Steph54 "On 28 December 1969, a man searching for driftwood on the beach at Bolinas Lagoon in Marin County found the nude body of Leona Roberts. It was later determined that a unique wristwatch was missing from the girl's wrist, but a Napa High School class ring given to her by a neighbor still remained on her finger. The tan dress she wore when last seen, along with two pairs of bell-bottomed pants, a blouse, a black purse and wallet, a key chain with car and house keys were also reported missing. There were marks on the wrists and ankles indicative of binding, but the coroner was unsure whether they occurred before or after death. The cause of death was reported as "due to viral infection of an unidentified species." It was also reported that there was "evidence of choking which could probably be linked to the virus." link. 

Leona LaRell Roberts had been abducted on December 10th 1969 from 749 Tormey Avenue in Rodeo. At about 5:50 pm a neighbor, Susan Clark, heard the sound of a girl screaming, followed by somebody running from the rear of the apartment. A suspicious male was observed many times between the front door and a blue station wagon, before he eventually drove away. The man was described as 25 years old, 5'8", short blond hair and wearing brown trousers and a jacket. A while later her boyfriend arrived home to find a disturbance inside the apartment, scuff marks near the back door and her red Volkswagen parked outside.

The same day, a potential Zodiac correspondence arrived at the Sacramento Bee newspaper containing a horoscope page with pasted wording. This communication entitled Day-By-Day Forecast For Cancer was pasted with the wording ZODIAC, WATCH, FLT 555 and BIRDS FLY SOUTH. The day after the Leona LaRell Roberts abduction, on December 11th 1969, a communication entitled Day-By-Day Forecast For Leo arrived at the San Francisco Newspaper Printing Company at Rincon Annex, again  with many pasted words, including FLT THREE OF A KIND. It was thought that the Day-By-Day Forecast For Leo may have been a sinister play on words for Day-By-Day Forecast For Leona Roberts, considering the date of her abduction and the mailing of this communication the following day.

A day-by-day forecast may have been an appropriate message considering her abduction on December 10th 1969, to the eventual discovery of her body eighteen days later at Bolinas Lagoon in Marin County. This is where Shoreline Highway comes into play, being just 724 meters from Highway 101, and a route that the Zodiac Killer may have commuted to and from work. Shoreline Highway runs alongside Bolinas Bay to Bolinas Lagoon, where Leona Robert's body was discovered. When we consider the December 10th 1969 communication containing the words ZODIAC and BIRDS FLY SOUTH, coupled with the December 11th 1969 Day-By-Day Forecast For Leo and her body being discovered at Bolinas Lagoon, the following information may become relevant.

Bolinas Lagoon is a tidal estuary, approximately 1,100 acres in area, located in the West Marin region of Marin County, California, United States, adjacent to the town of Bolinas. The Pacific Flyway is a major north-south flyway for migratory birds in America, extending from Alaska to Patagonia. Every year, migratory birds travel some or all of this distance both in spring and in fall, following food sources, heading to breeding grounds, or travelling to overwintering sites. Along the Pacific Flyway, there are many key rest stops where birds of many species gather, sometimes in the millions, to feed and regain their strength before continuing. Some species may remain in these rest stops for the entire season, but most stay a few days before moving on. Wikipedia.     

Four months later, on April 19th 1970, Pat Tan, a woman of Eurasian descent, was discovered hanging by rope and electrical cord from an oak tree near Bootjack Campground on Mount Tamalpais in Marin County. She was identified because of a key found in her pocket by Coroner, Keith Craig, which he traced to a Greyhound bus terminal and the eventual discovery of her address book. The question remains as to whether the death of Pat Tan was suicide or murder.

Bootjack Campground is located 553 meters from the Pantoll Campground along Panoramic Highway, which joins Shoreline Highway at its southern tip, Pat Tan's body was discovered hanging just 2.5 miles from the dump site of Leona Roberts at Bolinas Lagoon. Leona Roberts abduction was paralleled by two communications entitled Day-By-Day Forecast For Cancer and Day-By-Day Forecast For Leo, along with the pasted pseudonym of ZODIAC, as was the untimely death of Pat Tan, when the following day on the April 20th 1970, the Zodiac Killer mailed the 13-Symbol cipher containing THREE OF A KIND. However, this time it would be 888 instead of 555.

Two years later, on April 7th 1972, Isobel Watson (33) had just got off the bus on the evening of April 7th 1972, and was walking home along Pine Hill Road, Tamalpais Valley, Marin County at 9.00 pm, when a light colored vehicle veered towards her, knocking her to the ground. The driver exited his vehicle offering to take her home, but after she had refused his offer of apparent help a second time, the concerned citizen suddenly became enraged, pulling out a knife and stabbing the woman in the neck and shoulder. ​Her screams alerted the neighborhood, forcing the assailant into a hasty retreat from the scene. She was treated at Marin General Hospital and fortunately survived the brutal attack.

Her description of the man alerted investigators to a possible Zodiac connection, that of a man with heavy-rimmed black glasses, around 40 years of age, 5' 9" in height and short brown hair. It was not overlooked by police that the killer had attempted to lure the woman into his vehicle, not dissimilar to the method employed in the Modesto abduction of Kathleen Johns. Napa County homicide detective Kenneth Narlow believed in a greater than 50-50 chance of a Zodiac connection, bearing in mind the description given by Isobel Watson. Pine Hill Road, where the attack occurred, joins Shoreline Highway at its southern edge, just 4 miles from the Bootjack Campground and 7 miles from Bolinas Lagoon. Shoreline Highway joins Panoramic Highway only 1 mile from Pine Hill Road. So, had the attacker of Isobel Watson managed to lure her into his vehicle, would we have found her near Bootjack Campground or Bolinas Lagoon, just like Pat Tan and Leona Roberts? Of course, we don't know whether the Zodiac Killer had anything to do with the unfortunate events that befell these three women, but the location of Marin County and the proximity of Pine Hill Road, Bootjack Campground and Bolinas Lagoon is worthy of further investigation.     

It is with little doubt that the 148 character cipher and letter mailed in May 1971 and the Albany letter and cipher mailed on August 1st 1973 were both created by the Zodiac Killer. Neither of the communications were published in the newspapers, yet both have overlapping features in not only the way they were written, but in the style and choice of ciphertext characters in each code. The Zodiac Killer ended his murder count on March 13th 1971 with 17+ victims, apparently updating this total to 37 victims on January 29th 1974 with the arrival of the Exorcist letter. The author of the 148 character cipher letter (which I will now refer to as the Skin letter) claimed he would murder again, stating "I done it 21 times", with the author of the Monticello card mailed on July 13th 1971 claiming he had "shought victim 21". The only communications between March 13th 1971 and January 29th 1974 referring to a progressing victim total, and both carried the same count of 21 despite both being unpublished. We know the Monticello card to be a genuine Zodiac correspondence because of the running theme of the Snoozy & Furlong murders in San Jose, that featured in the Zodiac communications over a two-year period, including the choice of Monticello and the Oak Hill Memorial Park in the neighborhood of San Jose. The Story of San Jose.

For the handwriting aficianados, the capital letter G present in both the 408 and 340 ciphers is noticeable in both the Albany letter and Skin letter, as is the threat of a "next time" and a "next victim". The Albany letter threatens to "start killing again", with the Skin letter threatening "I must kill more". However, all this is incidental when we consider the boxy style of both ciphers and the ciphertext characters the Zodiac Killer chose. Never before had the Zodiac Killer chosen the sun cross symbol, yet it featured in both the Albany letter cipher and the Skin letter cipher. I won't list all the correlations, because it's far easier to show the overlapping features contained in both unpublished ciphers.  

There are the same errors in coding in the 148 character cipher as displayed in the 340 cipher, with the 148 character cipher spelling simple words incorrectly such as "this" to "tis", "speaking" to "speacking" and "to" to "t". He also misses the word "is" out of the introduction entirely. There is also a scrubbed out letter in the 18th position on the top row. However, this time the cipher is created in such a way that no word runs from one row into another, making it 21, 21, 24, 23, 25, 23 and 11 = 148 characters. The revised message, with corrected sections, is:
"T(h)is (is) the Zodiac Speacking. Why can't you stop me. I can't stop killing. Stop listening t(o) phonys. If this is not on the front page in a week I will skin 3 little kids and make a suit from the skin".

The use of numbers in both sequences of ciphertext is evident, as is the use of a sun cross on both occasions. The number 7 in both ciphers is used to represent the letter A. The Skin letter and Albany letter are the only two letters mailed by a potential Zodiac Killer from May 1971 to August 1st 1973. We know of no other certain Zodiac communications during this period of time (other than the Monticello card), yet here we have two consecutive ciphers, both of which use the ciphertext number 7 as the letter A. If these two letters were mailed by two independent authors, then that is one hell of a coincidence. Because we can confidently link the Skin letter to the Monticello card through "21" and the Snoozy/Furlong murders, it is a fair statement to say that the Albany letter is a genuine Zodiac communication.

The best way of confirming the authenticity of potential Zodiac letters, cards and ciphers is to make comparisons between multiple communications, particularly through unpublished mailings which have no way of being copied by hoaxers. The alternative approach, is to just look at the handwriting and make a judgment based on nothing more than letter strokes which can easily be changed by the author. The third option, is to rely on the determination of others and remove independent thinking from the equation altogether.  

On December 3rd 2020, Dave Oranchak, Sam Blake and Jarl Van Eycke cracked the 340 cipher, revealing the Zodiac Killer's response to the Jim Dunbar TV show on October 22nd 1969. The Zodiac Killer stated "that wasn't me on the TV show", yet concealed it in a cipher that remained unbroken for fifty-one years. However, he didn't elaborate on whether he was the initial caller to the Oakland Police Department requesting that either Melvin Belli or Francis Lee Bailey appear on the chat show.

On September 25th 1990, a cipher was mailed to the Vallejo Times-Herald on the back of a beachfront postcard from Oakland, addressed Celebrity Cypher, Vallejo Times Herold, Vallejo, Ca. This communication arrived approximately six weeks after Robert Graysmith (author of two Zodiac books) and Pam Huckaby (sister of Darlene Ferrin) appeared on the tabloid talk show The Sally Jessy Raphael Show. The show ran from 1983 to 2002, featuring celebrity guests such as Robert Graysmith, along with ordinary members of the public, covering a wide range of social issues. 

Pam Huckaby appeared on the TV show in the August of 1990 alongside Robert Graysmith (who had published The Sleeping Lady earlier that year), claiming she feared for her life after a series of sinister events befell her, that included messages and Zodiac signs scrawled on her apartment door, mailed crytograms, a cross placed on her front lawn, a coffin delivered to her residence and bodily harm by an unknown individual, which she asserts could be the work of the infamous Zodiac Killer. These stories by Pam Huckaby are widely discredited, but could an interested viewer have took it upon himself to react to the TV show and mail the Celebrity Cypher postcard to the Vallejo Times-Herald. The name of the newspaper was incorrectly spelled as "Herold" on the postcard, just like the July 31st 1969 envelope, unpublished at the time. In fact, as of 2021, only three communications to the Vallejo Times-Herald have been publicly released, which includes the October 28th 1987 letter - and all may carry the misspelling of "Herold".         

Details of the TV show appeared in the Vallejo Times-Herald stating "A former Vallejo woman related to one of the Zodiac's victims told a national television audience Wednesday that she is being harassed with death threats from the serial killer. Huckaby does not have a listed telephone number in Antioch and couldn't be contacted after Wednesday's appearance. The killer is called the Zodiac because of his cryptic messages, loaded with astrological symbols, to the news media and police investigators". Therefore, it's rather curious timing, that after the celebrity appearance of Robert Graysmith on The Sally Jessy Raphael TV show in the August of 1990 featuring Pam Huckaby, that a potential Zodiac postcard would arrive on September 25th 1990 entitled the Celebrity Cypher, including a coded message. The Zodiac Killer responded to the Jim Dunbar Show soon after the TV show aired, encoding his message of "that wasn't me on the TV show" within the 340 cipher. Had he done something similar in the Celebrity Cypher just weeks after his name featured on the The Sally Jessy Raphael Show?

The postcard could be a veiled threat toward Pam Huckaby, with the hidden address on the left side of the correspondence being Antioch, CA, to insinuate he lived close by and could strike at any time. Or was the communication directed towards Robert Graysmith, hence the choice of a Celebrity Cypher, originally designed by Luis Campos, an inventor, poet and cryptographer who created six celebrity ciphers a week, featuring famous quotes from well-known people, past and present.

The Zodiac Killer had a propensity to tease us with his name, but he also mailed two communications in the form of postcards on March 22nd 1971 and July 13th 1971, where he teased us with the name of the victim he was claiming. The "Sierra Club" of the Pines card overlayed over the Sierra Club of Clair Tappaan Lodge on the northwest side of Lake Tahoe, left the punched hole firmly over the "Donner Memorial" State Park. The Monticello card of July 13th 1971 gave us the phrase "Near Monticello Shought Victims 21 ...... In The Woods Dies April". The card was insinuating the murder of Kathy Bilek in the woods of Villa Montalvo in Saratoga on April 11th 1971. The murder site was near the neighborhood of Monticello in San Jose, where one of Zodiac's previously claimed victims was buried. Kathy Snoozy was buried in the Oak Hill Memorial Park & Cemetery. The two pasted cards were clues to the victims he was claiming, both of which were inferred by the remembrance of a memorial park. The Eureka card mailed in the December of 1990 was likely suggesting a third name. But on this occasion, the Zodiac Killer may have known the living victim (or at least known his name).

First brought to our attention on Tom Voigt's message board, the photocopied keys of the Eureka card were traced by the numbers on them to a post office box and the eventual owner, who they called "Sam", but was later identified as Chester Clark Klingel who lived in Eureka. This is obviously relevant because the Christmas greeting card was postmarked Eureka, California. It has been speculated that the Zodiac Killer may have found the keys, which has some merit when you consider the Ancient Greek word of Eureka meaning "I have found". However, it's unlikely that these keys were just found on the street without the Zodiac Killer knowing the owner's identity, because the Eureka card was designed in such a way that it hinted at the name "Chester" by the contents of the card. He gave us clues to the names of Donna Lass and Kathy Snoozy in two previous cards, so why shouldn't he do it for a third time. Having noticed this possibilty, I was happy to see that somebody else had also touched on this idea on the Zodiac Killer message board, but it was sadly passed over. Nin stated "Another trivia, Chester Carlson, the inventor of xerography (xerox) spent 3 years at RCC, Riverside".   

The Zodiac Killer was directing law enforcement to the home of Chester Clark Klingel in Eureka, with the photocopied keys and postmark. The Eureka card has the pre-printed message "From your secret pal, can't guess who I am yet? Well, look inside and you'll find out", challenging us to discover the name inside the card. The only way to discover the name was to identify the numbers on the keys. But why did the Zodiac Killer photocopy the keys? It could have been another clue to the owner of the keys, because as Nin highlighted:

Xerox was founded in 1906 in Rochester, New York, as The Haloid Photographic Company. It manufactured photographic paper and equipment. In 1938, Chester Carlson, a physicist working independently, invented a process for printing images using an electrically charged photoconductor-coated metal plate and dry powder "toner". However, it would take more than 20 years of refinement before the first automated machine to make copies was commercialized, using a document feeder, scanning light, and a rotating drum. Chester Floyd Carlson is best known for inventing electrophotography, the process performed today by millions of photocopiers worldwide. Carlson's process produced a dry copy, as contrasted with the wet copies then produced by the mimeograph process. Carlson's process was renamed xerography, a term that means "dry writing".

How likely is it, that the not so common name of "Chester" would be the inventor of a process used by millions of photocopiers worldwide, and would be the owner of the two photocopied keys placed inside the Eureka card by the Zodiac Killer, while also living in Eureka, California in 1990. The card outer was now completed: "From your secret pal, can't guess who I am yet? Well, look inside and you'll find out". Chester. Chester Clark Klingel was ruled out as being the Zodiac Killer, so it's evident that this was just another game by the Zodiac Killer, intending to misdirect law enforcement on yet another wild goose chase. But if he knew the name of Chester Clark Klingel when designing the greeting card, it may bring us a little closer to finding out who he was.

Just over two weeks before the 340 cipher was mailed, Dr. D.C.B. Marsh of the American Cryptogram Association laid down a challenge to the Zodiac in the newspapers to reveal his name in a cipher, however complicated. The wording in the San Francisco Examiner on October 22nd 1969 invoked the name of Edgar Allan Poe, so possibly the designers of the article were hoping that the Zodiac Killer would invoke Edgar Allan Poe to give us his name, making any offering easier to crack. This appeared to influence the Zodiac Killer, because the first cipher mentioned in Poe's essay A Few Words on Secret Writing actually works in decoding the message in the 340 cipher. The second cipher technique in Poe's essay A Few Words on Secret Writing split the alphabet into two portions of 13 letters, so it was surprising that the Zodiac Killer's next code reduced dramatically to 13 characters just like Poe's design (beginning with A and ending with M). See here for essay.

Three years ago, it was suggested that the Zodiac Killer wouldn't again shy away from the challenge of giving us his name, having possibly given us it in an abbreviated format. That is why the cryptic reference of Fk, I'm crackproof caught my eye in the October 5th 1970 communication with 13 punch-holes in the fabric of the card. The punch-holes were separated into a 10 to 3 configuration, positioned in such a way that they mirrored the design of the 13-Symbol cipher. The only way to break the small code was to discover the entry point, and the three circled 8's seemed as good a place as any, especially when we consider Fk, I'm crackproof is split into three parts and fits around the existing K and M in the code. The crosshairs, anchor and Celtic Cross in the code are all religious symbols, with the number 8 representing rebirth, regeneration and a new beginning in Christianity. The figure 888 is also representative of Jesus Christ in Christian numerology. It was discovered that the first 8 began FK, the second 8 began IM and the third 8 began CRACKPROOF, which completed the circle of eternal life. The introduction to the April 20th 1970 letter was also completed, to "This is the Zodiac speaking. By the way have you cracked the last cipher I sent you? My name is Fk, I'm crackproof",

Anyway, this is to show that the Fk, I'm crackproof solution was found before the 340 cipher was cracked by Dave Oranchak, Sam Blake and Jarl Van Eycke on December 3rd 2020, along with its scytale links to Edgar Allan Poe's A Few Words on Secret Writing. This is extremely important when we consider the following. Edgar Allan Poe highlighted certain encipherment techniques in the essay regarding a split alphabet, which are outlined here: and, so placed, a might stand for n and n for a, o for b and b for o, &c. &c. This, again, having an air of regularity which might be fathomed, the key alphabet might be constructed absolutely at random. The next line was: Thus A might stand for P.

These examples can be summarized as;
[1] a might stand for n and n for a
[2] Therefore, r might stand for e and e for r
[3] Thus, a might stand for p (and vice-versa)
Using only these examples in the 13-Symbol cipher, I inserted the possibilities into the code, using the letters K and M as entry points, based on the aforementioned reasoning. The letters N, A and M (not boxed in blue) I have no explanation for. So the search goes on to discover whether the Zodiac applied something else to the encryption. Or whether a different technique was used entirely.

When you take into consideration that the Fk, I'm crackproof solution was suggested in 2017, before the scytale link of the 340 cipher to Edgar Allan Poe, coupled with the formation above using just Poe's examples shown in [1], [2] and [3], it shows a pattern receptive to the remaining letters in the solution. But the three remaining ciphertext characters would need explaining. 

The next encipherment technique described in A Few Words on Secret Writing were the two concentric circles (one fixed), where the outer wheel can be rotated around the inner wheel during the coding process. Here is a working cipher wheel.