An analysis of the Button letter map and code can be found towards the foot of this page, giving us the correct solution to the 32 character code of Estimate: Four Radians and Five Inches, which is 246 degrees (inc. Magnetic North) from Mount Diablo. Druzer (Andrew Gray), a contributor to both Zodiac forums, offered the correct solution to Zodiac Ciphers News, which not only satisfies the requirement stipulated by the Zodiac Killer that "The Mt. Diablo Code concerns Radians & # inches along the radians", but correlates the three plaintext letters to the only three repeating ciphertext characters in the code, thereby providing a perfectly valid key (see the solution above right). The use of an arrow pointing upwards at the hashtag is clearly instructing us to insert a number value before inches, just like we had to insert a number value before radians. Any solution without "radians and inches", each preceded by a number, will not be correct. The bomb was to be set alongside Ingleside Police Station (SFPD) on the embankment of the Southern Freeway. See The Blast Estimate of Zodiac, The Blast Estimate of Zodiac (Part Two) and The Blast Estimate of Zodiac (Part Three). Here is a condensed version of the location of the bomb and the code solution in eleven simple steps.
 Sgt Richard Radetich
The Button letter was mailed to the San Francisco Chronicle on June 26th 1970, with the Zodiac stating he was not pleased that the citizens of San Francisco had not adorned "some nice" Zodiac buttons. He acknowledged that he had promised to punish them if they didn't comply by annihilating a full school bus. However, because school was out for the summer, he had instead "shot a man sitting in a parked car with a .38".
The only event that tallied with the Zodiac's claim was the murder of police officer Sgt Richard P. Radetich (25) on June 19th at 5:25 am, who was gunned down by three shots from a .38 caliber revolver at point blank range through the driver side window of his vehicle while in the process of serving a parking ticket. He was sat in his police car near 643 Waller Street, San Francisco in the Lower Haight District, resulting in devastating injuries that claimed his life approximately 15 hours later. Local residents heard a vehicle speeding away from the scene, but the number of assailants involved is unknown. Not far from the crime scene a gas station attendant recalled seeing a white Cadillac racing down Oak Street and entering Divisadero Street only 0.3 miles from the murder scene. His murder shocked the community, as he left behind a wife, Nancy, and an eight-month-old daughter Janine. See crime bulletin below right. This was almost certainly the murder that the Zodiac Killer was referring to in his correspondence, but because newspaper reports of the crime had already been released, the inability of Zodiac to supply any unique details of the crime in the letter known only to him and the police, it is believed by many observers that the Zodiac Killer was simply laying claim to another crime he never committed. However, he did claim that "there is more glory in killing a cop than a cid because a cop can shoot back" in a communication mailed on April 20th 1970,.just two months earlier, Other crimes around that time bore hallmarks of the Radetich slaying, notably that of Sgt John Young killed in 1971, who was shot while tending the reception desk at Ingleside Police Station - a crime linked to the Black Liberation Army - a group violently anchored away from the ideological Black Power movement. This group also employed the use of bombs in their arsenal to create terror on the streets of US cites between 1970 and 1981, culminating with the Brink's Robbery. In total, in the years 1970-1971, there were six police homicides in San Francisco, in what was to ultimately become the most violent decade in US history. In 2007, the San Francisco Office of the Mayor offered a $100,000 reward for any information leading to a successful arrest in the Richard Radetich murder. The Button letter also contained a 32 character code, the fourth and final cryptic offering by the killer, which also included a map of 'San Francisco and Vicinity', both of which allied together were to reveal a bomb buried at a specific location. However, no bomb was ever found, if indeed it was ever laid. Phillips 66 Road Map of the San Francisco Bay Area 
The Dragon card was the immediate correspondence before the Button letter (pictured above) and mailed to the San Francisco Chronicle on April 28th 1970 .
It contained a picture of a dragon and donkey, with the reverse side requesting the wearing of Zodiac buttons like other counterculture buttons of Peace, Black Power and Melville Eats Blubber (see below). A failure to do so would risk Zodiac placing his bomb. The card read: "If you dont want me to have this blast you must do two things. Tell everyone about the bus bomb with all the details. I would like to see some nice Zodiac butons wandering about town. Everyone else has these buttons like, black power, melvin eats bluber, etc. Well it would cheer me up considerbly if I saw a lot of people wearing my buton. Please no nasty ones like melvin's. Thank you." The card itself was a Jolly Roger brand greetings card of a prospector riding on the back of a dragon. A similar card can be viewed on archive news footage of Bryan Hartnell during his recovery in hospital, as one of the many greetings cards displayed on the wall of his room. It can be seen on the extreme right of image at 3 minutes and 32 seconds by following this link. The reference to "melvin eats bluber" is based on the creation of buttons in the mid to late 1960s by Irwin Weisfeld, in the form of counter-culture expressionism. The actual pin button says "Melville Eats Blubber" (see newspaper article below), which is in fact referring to Herman Melville, the creator of Moby Dick published in 1851. In this correspondence it appears the Zodiac is poking fun towards Melvin Belli, who himself received correspondence from the killer in the form of a letter approximately four months prior to this card on December 20th 1969, which contained a third piece of shirt taken from the murdered taxicab driver Paul Stine at Presidio Heights on October 11th 1969. 
The 3 counterculture buttons that featured on the Zodiac Killer Dragon card
 Click to enlarge
It has been suggested the Dragon card was depicting elements of the book Don Quixote, a novel by Miguel de Cervantes Saavedra.
At the beginning of the novel Alonso Quijana, a prolific reader of books, became so mesmerized by the chivalry contained within them, he sets out under the assumed name of Don Quixote, recruiting Sancho Panza as his squire in his quest to revive chivalry. Don Quixote sets off on his mission bedecked in an old suit of armor, in the form of a knight upon his horse Rocinante, while Sancho Panza makes do with a nameless donkey, sometimes referred to as el rucio on account of its color. It is thought the Dragon Card is depicting these two central characters, with the dragon element being part of heraldic folklore. A statue of Miguel de Cervantes, Don Quixote and Sancho Panza can be found in Golden Gate Park in San Francisco. See above left. |
The answer to the 32-Symbol cipher was given to us by the Zodiac Killer after just 30 days when he mailed the Little List letter on July 26th 1970. He gave us part of the answer when he wrote PS. The Mt. Diablo Code concerns Radians & # inches along the radians (all we had to do was add the number 5 where he placed the arrow and hashtag}. The code solution identified was "estimate: four radians and five inches". The 32 character code wasn't the complete solution, because the Zodiac Killer explicitly stated "the map coupled with the code will tell you where the bomb is set", which included magnetic north of 17 degrees in 1970. The code contained "four radians and five inches", to be coupled with the map which incorporated the magnetic north, giving us a total of 246.2 degrees.
See The Answer to the Mount Diablo Code 
The murder of taxi driver Larry Hargis June 25th 1970
Larry Hargis (27) was on duty on June 25th 1970, when he informed the taxicab company dispatcher of a client asking to be driven to the Spring Valley area from downtown San Diego, California. San Diego is situated near the coast in Southern California, about a two-hour drive south of Los Angeles and Riverside County.
These words, in the early hours of June 25th 1970, unfortunately were some of the last spoken by taxicab driver Larry Hargis, his body later discovered in a field near Galopago Street where he had been shot and had his wallet taken. His taxicab, presumably commandeered by the murderer(s), was later discovered back in downtown San Diego, which by car is approximately 20 minutes traveling time. No suspect or suspects have ever been identified and the case remains unsolved to this day. This murder took place the day before the Button letter was mailed to the San Francisco Chronicle on 26th June 1970, but the location and traveling distance makes any connection to the Button letter - as well as the Zodiac Killer - extremely unlikely. But nevertheless, it provides a significant timeline between the murder of Larry Hargis and the mailing of the Button letter to the San Francisco Chronicle.. This case has been placed here for consideration, although any link to the Zodiac case remains small. However, if you can help authorities with any details that may lead to the identification of any suspect in this case, or any other cases in the San Diego region, please use the contact details on the San Diego County Sheriff's Department website here. |
April 20th 1970 Bus Bomb Diagram
On April 20th 1970 the Zodiac Killer mailed a letter to the San Francisco Chronicle with three key components. [1] The Zodiac Killer stated "I hope you do not think that I was the one who wiped out that blue meannie with a bomb at the cop station. Even though I talked about killing school children with one. It just wouldn't doo to move in on someone else's teritory". The Zodiac Killer was referencing the murder of San Francisco police officer Brian McDonnell on February 16th 1970, who suffered devastating and sadly fatal injuries two months earlier, when a bomb packed with fence staples exploded on an outside ledge of Park Police Station in the Upper Haight neighborhood. He continued [2] "But there is more glory in killing a cop than a cid because a cop can shoot back". [3] The Bay Area murderer also included a bus bomb diagram, with a school bus traveling south in the morning and the sun rising to the east. The bomb was positioned on a steep embankment.
It therefore shouldn't be any surprise that his next letter on June 26th 1970 contained all three of these components in its design: [1] He claimed he had set a bomb by Ingleside Police Station, [2] claimed his "glory" by insinuating his involvement in the shooting death of Officer Richard Radetich and [3] his bus bomb diagram matched perfectly the bomb to be set by Ingleside Police Station.
In the June 26th 1970 Button letter he stated "The Map coupled with the code will tell you where the bomb is set*. It is clear the bomb was to be set in San Francisco, the target for the majority of his communications and ire toward police. The code provided the inches and radians value, and the map was to provide the magnetic north value of 17 degrees in 1970 ("to be set at Mag. N" from his zero point clockwise). This was plainly evident when he provided the extra two clues in the following Little List letter on July 26th 1970.
It therefore shouldn't be any surprise that his next letter on June 26th 1970 contained all three of these components in its design: [1] He claimed he had set a bomb by Ingleside Police Station, [2] claimed his "glory" by insinuating his involvement in the shooting death of Officer Richard Radetich and [3] his bus bomb diagram matched perfectly the bomb to be set by Ingleside Police Station.
In the June 26th 1970 Button letter he stated "The Map coupled with the code will tell you where the bomb is set*. It is clear the bomb was to be set in San Francisco, the target for the majority of his communications and ire toward police. The code provided the inches and radians value, and the map was to provide the magnetic north value of 17 degrees in 1970 ("to be set at Mag. N" from his zero point clockwise). This was plainly evident when he provided the extra two clues in the following Little List letter on July 26th 1970.
The first clue was the first set of crosshairs, where he placed the bold, black circle at 4 radians and magnetic north (246 degrees} around the circumference. This was to be placed over the Mount Diablo map of San Francisco & Vicinity, centered over Mount Diablo to give us the radian value. The second crosshairs on the Little List letter contained the inches value - where he placed the hashtag and arrow for the number 5 to be inserted. Therefore, we had to travel approximately 5 inches along a line subtended at 246 degrees from Mount Diablo. This is why he used the phrase "The map coupled with the code will tell you where the bomb is set". The code supplied the 4 radians and 5 inches, to be coupled with magnetic north from the map.
The bomb was to be set close to Ingleside Police Station, which to a high degree of accuracy fell extremely close to 4 radians and magnetic north, and five inches from Mount Diablo. The inches subtended from Mount Diablo at 246 degrees couldn't be more or less than 5, because a bomb (set at 4 or 6 inches) would have fell into the sea on the east and west side of San Francisco. The bold, black circle (above right) with SFPD next to it, should be evidence enough that the target was squarely focused on the San Francisco Police Department. Not withstanding the fact, that the geography of San Francisco is such, that 4 radians and 5 inches are the only measurements capable of falling within San Francisco. The Zodiac Killer gave us a zero pointer (facing north) on his Mount Diablo map, to be set to Magnetic North of 17 degrees, with a clock face around the circumference. This clearly indicated that the radians were to be measured in a clockwise fashion - and therefore no surprise that the bold, black circle was positioned at approximately 4 radians and magnetic north (see below). The Zodiac Killer only gave us a crude drawing.
The bomb was to be set close to Ingleside Police Station, which to a high degree of accuracy fell extremely close to 4 radians and magnetic north, and five inches from Mount Diablo. The inches subtended from Mount Diablo at 246 degrees couldn't be more or less than 5, because a bomb (set at 4 or 6 inches) would have fell into the sea on the east and west side of San Francisco. The bold, black circle (above right) with SFPD next to it, should be evidence enough that the target was squarely focused on the San Francisco Police Department. Not withstanding the fact, that the geography of San Francisco is such, that 4 radians and 5 inches are the only measurements capable of falling within San Francisco. The Zodiac Killer gave us a zero pointer (facing north) on his Mount Diablo map, to be set to Magnetic North of 17 degrees, with a clock face around the circumference. This clearly indicated that the radians were to be measured in a clockwise fashion - and therefore no surprise that the bold, black circle was positioned at approximately 4 radians and magnetic north (see below). The Zodiac Killer only gave us a crude drawing.
The positioning of the bomb had to meet certain criteria. With a high degree of accuracy, Ingleside Police Station was situated 4 radians and magnetic north, and 5 inches from Mount Diablo. Even a line subtended from Mount Diablo passing over the neighborhood of Ingleside in San Francisco, when considered alongside the addition of SFPD=0, should have told us that the target for the bomb was likely the San Francisco Police Department in Ingleside. No other police station in San Francisco comes close to 4 radians and magnetic north, and 5 inches along the radians. The next task was looking for the exact location for the bomb to be buried. It most likely would have been set in the vicinity of the police station, just distant enough not to be observed.
The bus bomb diagram in the April 20th 1970 letter (shown above) depicted a school bus traveling from north to south in the morning, next to a steep embankment, with the sun rising to the east. This location is just 230 feet from Ingleside Police Station. School buses traveling from the northern and eastern edge of San Francisco to St.Thomas More Catholic School would travel the Southern Freeway, passing only 210 feet from Ingleside Police Station. From this location the bus would be traveling south in the morning to begin classes for the day, the sun would be rising from the east, and this location has a steep embankment mirroring exactly his bus bomb diagram of April 20th 1970. This portion of the Southern Freeway is flanked by the parking lot at the City College of San Francisco. This parking lot is the ideal location to access the embankment without parking on the freeway.
The bus bomb diagram in the April 20th 1970 letter (shown above) depicted a school bus traveling from north to south in the morning, next to a steep embankment, with the sun rising to the east. This location is just 230 feet from Ingleside Police Station. School buses traveling from the northern and eastern edge of San Francisco to St.Thomas More Catholic School would travel the Southern Freeway, passing only 210 feet from Ingleside Police Station. From this location the bus would be traveling south in the morning to begin classes for the day, the sun would be rising from the east, and this location has a steep embankment mirroring exactly his bus bomb diagram of April 20th 1970. This portion of the Southern Freeway is flanked by the parking lot at the City College of San Francisco. This parking lot is the ideal location to access the embankment without parking on the freeway.
Every criteria has now been met. The school bus, the route of the school bus on a freeway, the southerly direction, the steep embankment, the target of SFPD (San Francisco Police Department) and the 4 radians and magnetic north, coupled with 5 inches. The 32 character code wasn't the complete solution, because the Zodiac Killer explicitly stated "the map coupled with the code will tell you where the bomb is set". We had to add magnetic north. A bomb set here would have had maximum impact, striking a school bus as Zodiac had promised, but more importantly, right under the noses of the San Francisco Police Department for acute embarrassment. The location of a proposed bomb on the Southern Freeway by Ingleside Police Station, matches both the Mount Diablo map and code of 4 radians set to magnetic north, along with 5 inches along that 4th radian. The location also matches perfectly the bus bomb diagram within the April 20th 1970 letter.
The Ingleside Police District encompasses the area south of Cesar Chavez Street to the San Mateo County line and west from Highway 101 to Faxon Avenue. It is home to the San Francisco City College campus and many diverse residential neighborhoods including Sherwood Forest, Mt. Davidson, Glen Park-Sunnyside, Diamond Heights, Bernal Heights, Upper Noe, Mission Corridor, the Excelsior and St. Francis Wood, St. Mary's Park, Visitacion Valley, Precita Park, Cayuga, Outer Mission and Holly Park.
