In 2020, the Zodiac Killer's 32 character code was solved by Druzer, who put forth the answer of "Estimate Four Radians and Five Inches". The Zodiac Killer, knowing the code was unsolvable with only three repeating characters, pretty much gave us the answer on July 26th 1970, when he wrote "PS. The Mt. Diablo Code concerns Radians & # inches along the radians". The "code concerns Radians & # inches" meant using "radians and inches" in the answer, with the hashtag key the obvious giveaway.

Once "four radians and five inches" was placed in the code from character 9 to 32, only the word "estimate" satisfied the three repeating ciphertext characters in the 1 to 8 position in the code. The four radians and magnetic north of 246.2 degrees (229.2 + 17 degrees), fell slightly shy of Ingleside Police Station (SFPD), which was the target highlighted by the black circle within the crosshairs. You may come across a disingenuous individual cloaking his identity under the pseudonym of VT Squire, who insists that I manipulated the overlays to achieve a preconceived and desired result. However, as you can see in the 2020 article linked above, the accuracy was never exact. Four radians and magnetic north measured 246.2 degrees, while Ingleside Police Station sat at 251 degrees. Manipulating the overlays to produce an exact result would completely negate the point of having "estimate" in the Z32 code. 

​The Zodiac Killer once again used radians in his Bus Bomb letter approximately 7 1/2 months earlier (November 9th 1969), when he threatened to target Salesian High School (likely with a bomb). The crosshairs he provided in this instance, highlighted the numbers 6, 8, 9, 10 and 11 on a clock face, which when tilted close to magnetic north in 1970 and centered over Mount Diablo, landed over the five attack sites he was claiming at Lake Herman Road & Blue Rock Springs (line 10), Lake Beryessa (line 11), Presidio Heights (line 8) and San Jose (line 6). See below. The Zodiac Killer falsely claimed the murders of Snoozy & Furlong in San Jose a day earlier in his Dripping Pen card. Only line 9 remained unanswered. Next to his crude crosshairs "clock face", shown here, he wrote "PS. Be Shure to print the part I marked out on page 3 or I shall do my thing". His "thing" seemed to be the targeting of schoolchildren, so it wasn't surprising that line 9 fell over the Salesian High School where Daniel Williams worked as a school teacher. Daniel Williams had received numerous threats from somebody identifying themself as the Zodiac Killer in the preceding weeks.

One has to remember when looking at the crosshairs on the Bus Bomb letter (and Little List letter), that these are crude designs not meant to be totally accurate. The 9 o' clock position is 270 degrees on a compass rose, therefore, 9 o' clock and magnetic north (of 17 degrees) is 287 degrees. One radian is approximately 57.3 degrees, so 5 radians is 286.5 degrees. Therefore, 5 radians equals line 9 tilted to magnetic north.

With the crosshairs "clock face" tilted close to magnetic north, line 9 falls over the Salesian High School.(9 o' clock position). Not only did somebody identifying as the Zodiac Killer target Daniel Williams with arsenic on November 2nd 1969, but the school where he worked was also targeted on November 9th 1969 by the Zodiac Killer, using a measurement of 5 radians. That's because the Zodiac Killer was responsible for both. The Zodiac Killer did exactly the same thing on June 26th 1970 (Button letter), when he used 4 radians to target the San Francisco Police Department (SFPD) with a bomb. On both the Phillips 66 map (mailed with the Button letter) and the Bus Bomb letter, the Zodiac Killer utilized the numbers on a clock face. In both instances, the 9 o' clock position has to be rotated clockwise by magnetic north to identify the target.

USING MOUNT DIABLO ON NOVEMBER 9TH 1969

The Zodiac Killer appeared to be using Mount Diablo as a reference point as early as November 9th 1969, when he mailed the Bus Bomb letter and supplied us with some crosshairs and five X's on its circumference. Using this diagram it is possible to determine that the Zodiac Killer was identifying Mount Diablo as his initial or center point. Mount Diablo was used for the purpose of land boundaries in the majority of Northern California and Nevada, with the summit used as the "initial point", the north/south meridian and the east/west baseline intersection point. However, because of the vastness of California, surveying required three "initial points" of Mount Diablo, Mount Pierce and the San Bernardino Mountain to form grid lines. The Zodiac Killer knew the prominence of Mount Diablo from an elevation standpoint, but very likely knew some of the history from a navigational perspective  - and why he chose this mountain as his "initial point".

In the Dripping Pen card the Zodiac Killer was claiming the brutal stabbings of Kathie Reyne Snoozy & Debra Gaye Furlong on August 3rd 1969. On November 12th 1969, somebody featured in the San Francisco Chronicle used the San Jose double murder in their analysis of the Bus Bomb letter crosshairs, very likely concluding the "initial point" was Mount Diablo, without actually referring to the mountain by name. When you look at the five X's around the circumference, it's fairly obvious that they all sit on the left side of the crosshairs center (from 180 degrees to 330 degrees). They were positioned at 6, 8, 9, 10 and 11 on a clock face. Therefore, the "initial point" must be to the east of all the confirmed attack sites. When we attempt to line up the uppermost X with the Zodiac Killer's uppermost crime at Lake Berryessa, it becomes quickly apparent that only one position satisfies four of the X's on the circumference, and that one X represents both Lake Herman Road and Blue Rock Springs. If we draw a line through the Lake Herman Road and Blue Rock Springs attack sites, the line passes directly over the summit of Mount Diablo and beyond. By moving the crosshairs "initial point" along this line, we can see that only one position satisfies at least four of the X's.     

The Zodiac Killer only gave us a rough drawing of his crosshairs, so any interpretation must take this into account. The above diagram, centered over Mount Diablo, lines up the five locations the Zodiac Killer was claiming as his murders (Lake Herman Road, Blue Rock Springs, Lake Berryessa, San Francisco and San Jose). The (unaccounted for) red line above, travels directly over the Salesian High School of Daniel Williams, who Zodiac targeted from October 23rd 1969 to November 5th 1969 by prowling his house, poisoning his drink, making malicious phone calls, and threatening to shoot him via the Martinez Police Department. His subtle threats continued in the Dripping Pen card and Bus Bomb letter, explained thoroughly in the article The Quest For Number Eight. This is why he wrote "PS. Be Shure to print the part I marked out on page 3 or I shall do my thing" next to the crosshairs on the Bus Bomb letter. That "thing" was a threatened attack on Salesian High School, depicted by the red line on the map. The orange line shows Magnetic North of 16.5 to 17.0 degrees in 1969. The tilted crosshairs are slightly shy of this mark. But remember, the Zodiac Killer only drew us a rough guide in his correspondence. These Bus Bomb crosshairs were the precursor to the Mount Diablo map on June 26th 1970, when the Zodiac Killer again used the mountain's "initial point" as a directional tool, but this time to locate a proposed bus bomb on the Southern Freeway by Ingleside Police Station, using four radians and five inches. The Mount Diablo Map and Code Solution.     

During the height of Zodiac activity, sandwiched between the murder of Paul Stine in Presidio Heights on October 11th 1969 and the mailing of the infamous 340 cipher on November 8th 1969, one man stared pensively out of the window in search of a prowler that was stalking his house, equally disturbed by the inevitability that his phone at some point would burst into life, threatening death at the other end. That man was Daniel Williams, a Salesian High School teacher in the city of Richmond, living at 1234 Bush Street in Martinez.

Almost certainly one and the same, this prowler had been calling Daniel Williams' residence from October 23rd 1969 to November 2nd 1969, which culminated in his pursuer lacing his 7-Up soft drink with more than enough arsenic to kill. Police had been summoned to his residence on November 2nd 1969 when he noticed the screen door of his house had been pried open, however, they left shortly thereafter when it was determined nothing had been stolen. A short time later, Daniel Williams went to his refrigerator for some light refreshment and took a swig of 7-Up. Had he swallowed after noticing the metallic tasting drink, he most certainly would have died alone on his kitchen floor. The person who called Daniel Williams on numerous occasions threatening his murder claimed to be none other than the Zodiac Killer. Somebody pretending to be the Zodiac Killer by phone or mail is one thing, but this person had intended to kill.

Daniel Williams was a 24-year-old school teacher at the very beginning of his life, so one can only wonder how it came to pass that somebody felt the persistent need to target this man over a period of thirteen days, when finally, on November 5th 1969, somebody rang the Martinez Police Department at 12:30 am stating "There's going to be a shooting at 1234 Bush Street", before immediately hanging the receiver up.

If Daniel Williams had a hidden enemy with a grudge, not only was he apparently unaware of this animosity toward him, but why would this person telegraph his intent over a two week period by way of malicious phone calls. The notion of somebody attempting to kill the school teacher, while passing it off as a Zodiac crime over a prolonged period, appears a rather convoluted approach, when the perpetrator could simply have killed Daniel Williams and then made a phone call or mailed a letter taking responsibility as the Zodiac Killer. Ringing a police department and making threats to kill, in advance of comitting the act, seems to negate the opportunity of surprise and allows the intended victim to take preparatory steps. When we consider the contents of the November 8th and 9th communications by the Zodiac Killer, only three days after the phone call to the Martinez Police Department on November 5th 1969, another possibility begins to materialize.    

The person behind the phone calls to Daniel Williams' house and the Martinez Police Department, along with the prowling incidents, had also made threats toward a Martinez school. When he rang the school teacher, the caller stated he "had gone to a Martinez school in search of victims but left when he found police there". In light of the Zodiac Killer's desire to murder schoolchildren during the month of October, the claim of searching for victims at a nearby school should have raised significant alarm bells.

The persistence of this stalker may not have stopped on November 5th 1969, when the Zodiac Killer's Dripping Pen card arrived at the San Francisco Chronicle, stating "I though you would nead a good laugh before you hear the bad news. You won't get the news for a while yet". This phrase had all the hallmarks of activity ongoing, which had yet to reach its conclusion, backed up by the letter which arrived at the Chronicle the following day. In the Bus Bomb letter mailed on November 9th 1969, the Zodiac Killer made obvious that his victim count was only totalled "up to the end of Oct", suggestive of ongoing action between October 31st 1969 and the current mailing date. This apparent desire to add an eighth victim to his total, in light of a man claiming to be the Zodiac Killer and ringing the Martinez Police Department on November 5th 1969 with the threat of murder, appeared to indicate he was not finished yet. Or at the very least, this is what he wanted us to believe.

The nature of the attack on Daniel Williams by way of arsenic poisoning, seemed to fit with the opening paragraph of the November 9th 1969 letter, in which the Zodiac Killer vented his frustration and promised to alter his approach to murder. He directly addressed law enforcement, remarking that "I have grown rather angry with the police for their telling lies about me. So I shall change the way the collecting of slaves. I shall no longer announce to anyone. When I committ my murders, they shall look like routine robberies, killings of anger, + a few fake accidents, etc". However, it's what he said next that may link the Zodiac Killer to the malicious phone calls perpetrated on Daniel Williams. The caller to 1234 Bush Street claimed he was thwarted by police outside a Martinez school during his search for victims, but they wouldn't catch him because, as he stated “I’m too smart for them". The next line of the Bus Bomb letter, after promising to change his way of collecting slaves, was to ridicule police by asserting that "The police shall never catch me, because I have been too clever for them". This could be argued as the Zodiac Killer reading the newspapers and mimicking the wording in the written text to plant a seed of his involvement in the Daniel Williams stalking. If this was his intention, it was so subtle, it went ignored for 51 years. The police probably believed this prolonged attack on Daniel Williams was just another successor in a long line of Zodiac hoaxers, but this supposed hoaxer was not only determined, he was prepared to kill to imitate the Zodiac Killer.      

In the early morning hours of October 22nd 1969, somebody claiming to be the Zodiac Killer called the Oakland Police Department and requested that Francis Lee Bailey or Melvin Mouron Belli appear on the Jim Dunbar Show at KGO Radio in San Francisco, to which he would ring in. Somebody did ring the chat show, but this caller was later identified as mental patient, Eric Weill. However, we still don't know to this day whether the original caller to the Oakland Police Department was the Zodiac Killer or not, because the genuine Zodiac Killer only stated "That wasn't me on the TV show" in his now decrypted 340 cipher. At no point did he deny being the caller to the Oakland Police Department.

Probably the most important question to ask, is why would the Zodiac Killer choose to ring the Oakland Police Department above any other. There appeared no connection between the Zodiac Killer and Oakland prior to October 22nd 1969. However, this was also the case on October 15th 1969, when the Zodiac Killer almost certainly phoned the Santa Rosa Police Department to threaten schoolchildren on buses, who then implemented the routine checking of every school bus for hidden bombs. This caller, claiming to be the Zodiac Killer, was threatening schoolchildren two days before the details of "School children make nice targets, I think I shall wipe out a school bus some morning" was released by the San Francisco Chronicle, and one day before it was released by the Los Angeles Times. .

On October 21st 1969, the day before the Oakland Police Department call, somebody claiming to be the Zodiac Killer rang the Palo Alto Times newspaper. The Palo Alto Times reported on October 22nd 1969, that Patrol cars convoyed school buses around Palo Alto yesterday after a telephoned murder threat by a man claiming to be the Zodiac killer of five persons. The caller to the Palo Alto Times said he intended to "pick the kids off as they get on the school bus". The weird slayer, who signs himself "The Zodiac", made a similar threat in a letter to the San Francisco Chronicle last week after the Oct. 11 shooting of a taxi driver. This would come only six days after the Santa Rosa threat on schoolchildren. The caller also stated to the Palo Alto Times that he had left San Francisco "because I'm too hot there". On December 7th 1969, somebody claiming to be the Zodiac Killer rang commercial radio station KTOK in Oklahoma City, claiming he left California "because it got too hot for me". There was a further call on December 19th 1969, the day before the Melvin Belli letter, threatening "I am going to kill five of you officers and a family of five between now and Monday". This call was received by Shirley Searey, a police dispatcher at the San Jose Highway Patrol.

Captain Martin Lee stated, after the Zodiac Killer's October 13th 1969 letter: "His boast of being in the area we were searching was a lie. We had the whole area flooded with lights. We had seven police dogs and a large number of patrolmen searching the area tree by tree and bush by bush. The dogs are the best in the country". Captain Lee added that Zodiac's failure to mention the dogs and floodlights was proof "he wasn't anywhere in the vicinity". The Zodiac Killer responded on November 9th 1969 with "I have grown rather angry with the police for their telling lies about me. The dogs never came with in 2 blocks of me + they were to the west + there was only 2 groups of parking about 10 min apart then the motor cicles went by about 150 ft away going from south to north west".

However, this ire likely began on October 15th 1969, when the San Francisco Chronicle failed to publish his threat on schoolchildren, resulting in his phone call to the Santa Rosa Police Department. The call to Oakland Police Department on October 22nd 1969 may have been triggered by these perceived slights from law enforcement. By avoiding the San Francisco Police Department and calling the Oakland Police Department on October 22nd 1969, the Zodiac Killer could request a prominent attorney to represent him on the Jim Dunbar Show, and set the record straight on the misinformation and lies spoken about him by Captain Martin Lee to the San Francisco Chronicle. This TV audience on the popular Jim Dunbar Show in San Francisco may have been the ideal way to set the record straight, circumventing the San Francisco Police Department and San Francisco Chronicle and receiving maximum exposure. Ultimately, the Zodiac Killer may have had second thoughts, surmising that it could have led to somebody identifying him. This hesitancy opened the door to hoaxer Eric Weill.

Despite the phone call to the Jim Dunbar Show having been roundly dismissed as the Zodiac Killer "by three who knew", the murderer of five still felt compelled to disassociate himself from being the caller to the TV show, by mailing a cryptogram and greeting card on November 8th 1969. If the Zodiac Killer had rang the Oakland Police Department on October 22nd 1969 with the intention of appearing on the Jim Dunbar TV show and setting the record straight concerning Captain Martin Lee and the San Francisco Police Department - then having not done so - one would have expected his next communication to do exactly that. Therefore, it's no surprise that the Bus Bomb letter on November 9th 1969 was the Zodiac Killer's longest communication of them all, attacking the police with the venom he so wanted to do with a captive TV audience. The two communications on November 8th 1969 and November 9th 1969, inextricably bound by his failure to appear on the Jim Dunbar Show just over two weeks earlier.

The phone calls wouldn't stop there, when Daniel Williams (24), a Salesian High School teacher, started to receive malicious phone calls to his 1234 Bush Street, Martinez residence on October 23rd 1969. These calls continued for ten days and culminated with somebody breaking into his residence on November 2nd 1969 and lacing his 7-Up soft drink with enough arsenic to kill. The caller, claiming to be the Zodiac Killer, told Daniel Williams over the phone that he "had gone to a Martinez school in search of victims but left when he found police there", mocking law enforcement by stating “I’m too smart for them". This was considered particularly relevant because of the language Zodiac adopted on November 9th 1969 in the Bus Bomb letter mailed to the San Francisco Chronicle of "The police shall never catch me, because I have been too clever for them".

On Wednesday, November 5th 1969, somebody rang the Martinez Police Department at 12:30 am stating "There's going to be a shooting at 1234 Bush Street", before immediately hanging up. The threat to find victims at a Martinez school, coupled with the menacing phone calls, were not dissimilar to recent Zodiac activity during the month of October. After the threat to shoot Daniel Williams at his residence, police instigated surveillance in the immediate area of Bush Street for the remainder of that morning, but no suspicious activity was detected. The next Zodiac Killer communications would be postmarked just two and three days later, with the promise of more bad news and a victim count left dangling at the end of October. If the perpetrator of the crimes inflicted upon Daniel Williams wasn't the Zodiac Killer, then it was a pretty determined hoaxer claiming to be him. The call to Oakland Police Department was made on October 22nd 1969, with the threats on Daniel Williams beginning just a day later, on October 23rd 1969. The Salesian High School where Daniel Williams worked, only thirteen miles north of the Oakland Police Department. When we place all of this in context, does it indicate that the Zodiac Killer was likely the caller to Oakland Police Department on October 22nd 1969, or did Eric Weill just spontaneously call law enforcement because he had nothing better to do at the time? 

Daniel Williams (24), a Salesian High School teacher, started to receive malicious phone calls to his 1234 Bush Street, Martinez residence on October 23rd 1969. These calls continued for ten days and culminated with somebody breaking into his residence on November 2nd 1969 and lacing his 7-Up soft drink with enough arsenic to kill. The caller, claiming to be the Zodiac Killer, told Daniel Williams over the phone that he "had gone to a Martinez school in search of victims but left when he found police there", mocking law enforcement by stating “I’m too smart for them". This was considered particularly relevant because of the language Zodiac adopted on November 9th 1969 in the Bus Bomb letter mailed to the San Francisco Chronicle of "The police shall never catch me, because I have been too clever for them".

The Zodiac Killer's wording was also considered suspicious in the Dripping Pen card, when on November 8th 1969 he stated "This is the Zodiac speaking. I though you would nead a good laugh before you hear the bad news. You won't get the news for a while yet". The wording smacked of unfinished business, especially when you consider that he wrote "up to the end of Oct I have killed 7 people" in the following communication. It was now November 9th 1969, but he made a point of claiming seven victims only up to the end of October. These sections of text highly suggestive he was in the process of acquiring victim number eight. That victim could very well have entailed the ongoing pursuit of the Richmond High School teacher, Daniel Williams, to which this number had been reserved. These ideas may be speculative, but the story doesn't end there.

After the November 2nd 1969 attempted poisoning, Daniel Williams reported to police that the prowlings he had experienced around his residence during the time of the sadistic phone calls, continued after the break-in and failed poisoning. The persistent threats on the life of Daniel Williams would also fail to cease.

On Wednesday, November 5th 1969, somebody rang the Martinez Police Department at 12:30 am stating "There's going to be a shooting at 1234 Bush Street", before immediately hanging up. The threat to find victims at a Martinez school, coupled with the menacing phone calls were not dissimilar to recent Zodiac activity during the month of October. After the threat to shoot Daniel Williams at his residence, police instigated surveillance in the immediate area of Bush Street for the remainder of that morning, but no suspicious activity was detected. The next Zodiac Killer communications would be postmarked just two and three days later, with the promise of more bad news and a victim count left dangling at the end of October. If the perpetrator of the crimes inflicted upon Daniel Williams wasn't the Zodiac Killer, then it was a pretty determined hoaxer claiming to be him.

In the sadistic phone calls to Daniel Williams the caller also promised to "kill the lady in the blue house". On November 21st 1969, San Jose Police had to provide 24-hour surveillance for a woman, after somebody claiming to be the Zodiac Killer mailed a threatening letter identifying her as the target. The letter was accompanied by the wording "There's no doubt I will do my Thing!" reminiscent of the Dripping Pen card of "I could do my Thing". Of course, we don't know whether the threats in Martinez and San Jose were the infamous Zodiac Killer, but they certainly could have been.  

From October 23rd 1969 to November 2nd 1969, Daniel Williams, a Richmond High School teacher received a series of sadistic phone calls that culminated in somebody attempting to kill him by lacing his soft drink with arsenic. Had he not noticed the metallic taste and spat it out, Daniel Williams would have been a "dead duck" as the caller had promised.

In a letter to the San Francisco Chronicle postmarked October 13th 1969, the Zodiac Killer threatened to "wipe out a school bus some morning. Just shoot out the front tire + then pick off the kiddies as they come bouncing out". A telephone threat to bomb a school bus and kill children from somebody claiming to be the Zodiac Killer was targeted at Santa Rosa on October 15th 1969, prior to the details about "wiping out a school bus and picking off the kiddies" had been released by the newspapers. There were reports of a possible gunshot being heard by a Santa Rosa bus driver on October 17th 1969. These threats on schoolchildren brought a massive response from school officials and law enforcement, who laid out extensive measures to combat the perceived threat by the Zodiac Killer. Extra security to the buses also came in the form of police vehicles shadowing the schoolchildren to and from their respective schools.

On October 21st 1969, the San Francisco Chronicle released an article entitled Fear Rides the Yellow Bus, stating "A climate of fear hangs over the Napa Valley. The fear is over "Zodiac" and his terrifying boast to "wipe out a school bus". No one takes the threat lightly, Zodiac has already struck here. The task of trying to insure the safety of 10,000 youngsters who ride the Napa Valley Unified School District is immense".  It was two days later that Daniel Williams started receiving menacing phone calls from a caller claiming to be the infamous Zodiac Killer. The caller stated that "he intended to kill several persons" and on one occasion said he "had gone to a Martinez school in search of victims but left when he found police there". Bearing in mind the heightened security around school buses and therefore school premises, this was entirely plausible. This could easily have been interpreted as an empty threat from another hoaxer, but it's a fair assumption that the phone caller and arsenic poisoner were one and the same. There were probably many idle hoaxers latching onto the Zodiac case during this period of uncertainty, but I doubt many were prepared to back up their threats with murder, as was the case in the attempted poisoning of Daniel Williams. If this person was prepared to kill a school teacher, then it's not beyond the realms of possibility he was prepared to kill schoolchildren in Martinez (where Daniel Williams lived) or the city of Richmond, where Daniel Williams taught at Salesian High School.   

If this was the Zodiac Killer, how did it come to be that Daniel Williams was selected as a possible target by the Bay Area murder? The Zodiac Killer may have selected Daniel Williams by staking out his school and following him home. He now has a credible victim who police won't dismiss as an attention seeker. Daniel Williams also teaches schoolchildren, making him the ideal target for the Zodiac Killer. When Daniel Williams relays the details of the "Zodiac" phone calls to police, such as the man claiming he "had gone to a Martinez school in search of victims but left when he found police there", it adds veracity to the threats in the current climate. In the mind of the Zodiac Killer, he knew that these phone calls would be readily dismissed as just another hoax by police, so he needed to elevate these threats to the next level and show law enforcement he wasn't just playing games.

The Zodiac Killer, by poisoning the soft drink of Daniel Williams with arsenic, having previously stated he "had gone to a Martinez school in search of victims but left when he found police there", must have concluded that his visit to a Martinez school, in accompaniment to Daniel Williams being a Richmond school teacher, was more than enough to occupy law enforcement on several fronts. He may have thought that if the police didn't take the threat of murder seriously, then they would likely take nothing seriously.

With the failed poisoning on November 2nd 1969, the Zodiac Killer wrote in the Bus Bomb letter "up to the end of Oct I have killed 7 people", possibly indicating he hadn't yet finished with Daniel Williams (or possibly wanted us to believe that). When the phone caller to Daniel Williams mentioned his visit to a Martinez school, he concluded that police would never catch him because he was "too smart for them". In the Bus Bomb letter on November 9th 1969, the Zodiac Killer stated "The police shall never catch me, because I have been too clever for them". The Zodiac Killer was certainly a clever wordsmith, but was he responsible for the attempted murder of Daniel Williams? 

The Zodiac Killer often responded to the newspaper articles written about him, usually in close proximity to their release. The Dripping Pen card had likely been purchased subsequent to the morning of October 25th 1969 in response to the last San Francisco Chronicle article by Paul Avery. If the 340 character cipher had been specifically designed to compliment this card, then it too was crafted subsequent to October 25th 1969. As the title attributed to this communication suggests, this greeting card featured a dripping pen on its front face, accompanied by the wording "Sorry I haven't written, but I just washed my pen". The Avery article read "Zodiac struck last on October 11 when he gunned down cab-driver Paul Stine on Washington Street in Presidio Heights. He revealed himself the killer in a letter sent to the Chronicle three days later. Since then he has remained silent".

Bearing in mind the wording "since then he has remained silent", it could be argued that the chosen card of "Sorry I haven't written" was purposefully selected in response to this article - and therefore chosen by the Zodiac Killer after October 25th 1969. The paragraph in the newspaper article also referred to Washington Street, thereby completing the phrase on the card "but I just washed my pen". The last observation is probably a little far-fetched, and heavily reliant on the Zodiac Killer being able to find a greeting card apologizing for being silent, as well as containing a word related to Washington Street. Extremely unlikely, but not impossible.

Then, the day before the November 9th 1969 'Bus Bomb' letter, came the newspaper article detailing the attempted murder of Richmond school teacher, Daniel Williams. Somebody claiming to be the Zodiac Killer made sadistic phone calls spanning October 23rd 1969 and November 2nd 1969, and culminating in a soft drink in his refrigerator being laced with arsenic. This failed murder plot may have inspired the Zodiac Killer (if the poisoner) to insinuate his continued pursuit of Daniel Williams, by stating "I though you would nead a good laugh before you hear the bad news" and "up to the end of Oct I have killed 7 people". On November 12th 1969, the San Francisco Chronicle released information on the Dripping Pen card and Bus Bomb letter under the banner of I've Killed Seven, The Zodiac Claims.

This newspaper article featured the observations of an individual with respect to the X's on the Bus Bomb crosshairs (see right). This observation was suggested in the article The Promise of Murder on Line 5.

I believe the person who initially made this suggestion was almost certainly correct. However, when I floated this idea on November 23rd 2020, I was fully aware of the Mount Diablo map and crosshairs accompanying the Button letter, which was mailed to the San Francisco Chronicle on June 26th 1970. I positioned the Bus Bomb crosshairs over Mount Diablo and rotated them slightly clockwise, so that a line drawn from the peak of Mount Diablo through four of the five X's passed directly over Lake Berryessa, Vallejo (where two attacks occurred), San Francisco and San Jose.

When we consider that this person made the observation on November 12th 1969, seven-and-a-half months before the Mount Diablo map was mailed by the Zodiac Killer (on June 26th 1970), the interpretation by this individual is extremely intriguing.  

The five cross marks cannot directly pinpoint the five claimed attacks in Benicia, Vallejo, Lake Berryessa, Presidio Heights and San Jose by superimposing them over a map. If you arrange any two X's over Lake Herman Road and Blue Rock Springs, the other three X's will never fall over Lake Berryessa, Presidio Heights and San Jose. The only way it is possible, is by placing the crosshairs over Mount Diablo (rotated clockwise} and drawing lines through the X's on the circumference. But this still leaves the 9 o' clock line unaccounted for. This is where Daniel Williams, the Richmond school teacher comes in. The sadistic phone caller to Daniel Williams may have wanted to target schoolchildren at the Richmond school where he worked (Salesian High School falls over the line drawn through the 9 o' clock position}. This is covered in the article A Killer on Line Five.

The newspaper article stated "Zodiac's letter contained five cross marks which possibly refer to attacks. Comparing these markings against a map, one interpretation that can be drawn is that they pinpoint Lake Berryessa, Vallejo (where two attacks occurred}, San Francisco and San Jose". It was effectively saying that five cross marks could pinpoint four locations (identifying Vallejo as the location where two attacks occurred). Despite classifying Lake Herman Road as Vallejo, the tight grouping of the first two attacks on the map would allow the observer to reach the same conclusion as shown in the above map. After all, this person didn't say "Zodiac's letter contained five cross marks which possibly refer to five attacks".

The Zodiac Killer likely chose Mount Diablo because of its use when surveying land boundaries in Northern California, with the summit used as the "initial point". Was it possible that the person behind the interpretation on November 12th 1969 had correctly identified Mount Diablo as the "initial point" to center the crosshairs over, by using the same reasoning as Zodiac? The Zodiac Killer himself classified Lake Herman Road and Blue Rock Springs under the banner of Vallejo (evident on Bryan Hartnell's car door), so when he provided five cross marks to signify four general locations, he was deliberately leaving the 9 o' clock line as a puzzle to the location of his next attack. He employed exactly the same technique, when substituting the X around the crosshairs with a bold, black circle around the circumference of the crosshairs on July 26th 1970, again designed to pinpoint the location of his next attack. On this occasion, it would be a school bus traveling on the Southern Freeway by Ingleside Police Station, positioned at 4 radians and magnetic north.   

An unknown caller claiming to be the Zodiac Killer threatened Daniel Williams, a Richmond high school teacher, from October 23rd 1969 to November 2nd 1969. It was reported that the sadistic caller stated he was going to "kill the lady in the blue house". Despite previous exploration of this subject, here we will examine two new ideas related to the lady in the blue house. One will be a simplistic approach, while the second may understandably be regarded as far-fetched.

It could be argued that it would be rather meaningless for the sadistic caller to threaten a woman in a blue house, had this woman got no connection whatsoever to Daniel Williams. The caller was clearly targeting Daniel Williams and attempting to unnerve him. When Daniel Williams left his house on November 2nd 1969, the killer gained access by prying open his screen door and placing some arsenic in his soft drink. There is every chance that the perpetrator had followed Daniel Williams to some extent and was aware of his departure from his Martinez home that day. Had this person also seen Daniel Williams visit or converse with a woman in a blue house, possibly on Bush Street where he lived - and knowing that he was friendly with this woman - he knew that a threat to kill her would resonate with the school teacher? Threatening an unknown woman to Daniel Williams, plucked from nothing more than his imagination, appears rather pointless. However, there is a more unlikely alternative.  

The newspapers stated that the caller gave no explanation regarding the lady in the blue house, so either he expected Daniel Williams to work it out, or he had planned a future attack on a woman unknown to Daniel Williams, but hoped that Daniel Williams would relay his intention to "kill the lady in the blue house" to police. When his next attack was then threatened or carried out, police would understand that he was responsible for both events. It was suggested in the previous article that the sadistic caller may have had unfinished business with Daniel Williams after the failed poisoning, hence his statement of "up to the end of Oct I have killed 7 people" in the November 9th 1969 Bus Bomb letter, thereby leaving investigators to speculate upon his intentions during the beginning of November and the likelihood of murder for the remainder of the month. Since nothing materialized with respect to Daniel Williams in this window of time and subsequent to November 9th 1969, it could be reasoned that it was just another idle, but menacing threat from the Zodiac Killer (assuming he played any part in the Daniel William affair). But what of his threat to "kill the lady in the blue house". 

The next possible letter by the Zodiac Killer arrived at the San Jose Police Department on November 21st 1969, threatening a woman and accompanied by the wording "There's no doubt I will do my Thing!". In the Dripping Pen card the Zodiac Killer wrote "I though you would nead a good laugh before you hear the bad news. You won't get the news for a while yet. PS could you print this new cipher in your frunt page? I get aufully lonely when I am ignored, so lonely I could do my Thing !!!!!!  Des July Aug Sept Oct = 7". Was the communication on November 21st 1969 the bad news he had promised us, and the culmination of the threat to "kill the lady in the blue house"? In this communication the author threatened a widow, with enough detail in the letter that police were able to identify her. They took the threat extremely seriously, instituting 24-hour surveillance on her and her property. It is impossible, fifty-one years after the fact, to establish whether any connection existed between this woman and Daniel Williams. The likelihood of a connection is extremely remote, but it would have been interesting to find out the color of her house. 

Daniel Williams, a Salesian High School teacher in Richmond, received ten days of sadistic telephone calls beginning on October 23rd 1969 from a man claiming to be the Zodiac Killer. These calls were probably dismissed as the genuine Zodiac Killer because of the language adopted in the calls, mimicking the hoax caller who addressed Melvin Belli on the Jim Dunbar Show on October 22nd 1969. Daniel Williams would recall that the menacing caller would also "sob and complain of headaches". However, the calls to Daniel Williams shouldn't be ruled out on this basis, because two months later the real Zodiac Killer did speak of "losing control" and having difficulty "holding it in check" when writing to Melvin Belli on December 20th 1969. In previous articles covering this topic, the city of Richmond was identified as a possible future target on his Bus Bomb crosshairs. Also, the phraseology of “I’m too smart for them" by the sadistic caller to Daniel Williams was compared to the passage in the Bus Bomb letter of "I have been too clever for them". However, there is a little bit more.

It was November 2nd 1969 when Daniel Williams received the final call from the man presumably impersonating the Zodiac Killer, with the menacing threat of “You’re the dead duck". He would then leave his house in Martinez and return later, only to find his screen door pried open and arsenic in his soft drink. Fortunately for Daniel Williams he noticed the metallic taste and spat it out, which undoubtedly saved his life. Clearly the murder of Daniel Williams had been thwarted, meaning the perpetrator had unfinished business. This is why I find the Zodiac Killer's opening statement in the Bus Bomb letter particularly unusual. The opening line of the November 9th 1969 communication began "This is the Zodiac speaking up to the end of Oct I have killed 7 people".  But why didn't he just declare "This is the Zodiac speaking. I have killed 7 people to date", or "This is the Zodiac speaking. I have murdered 7 people". He deliberately chose to say "up to the end of Oct", almost like there was a murder he was still engineering or was attempting to complete between the end of October and November 9th 1969. In other words, he had unfinished business. Bearing in mind the murder attempt on Daniel Williams took place on November 2nd 1969, he may have been signalling by the statement of "up to the end of Oct" that he wasn't finished with Daniel Williams just yet. Especially when we consider that just a few lines later he issued the statement of "The police shall never catch me, because I have been too clever for them", in extremely similar fashion to “I’m too smart for them" spoken over the phone to Daniel Williams.    

When we couple these observations with his Dripping Pen card on November 8th 1969, the story becomes a little more intriguing. It too gives the impression of unfinished business. The card read "This is the Zodiac speaking. I though you would nead a good laugh before you hear the bad news. You won't get the news for a while yet. PS could you print this new cipher in your frunt page? I get aufully lonely when I am ignored, so lonely I could do my Thing !!!!!!  Des July Aug Sept Oct = 7".

The wording of "I though you would nead a good laugh before you hear the bad news". appears to indicate that the Zodiac Killer has, or is actively seeking to generate some bad news - which would usually involve murder. He then qualifies this statement by adding "You won't get the news for a while yet". This could indicate that he had plans for murder, but was yet to complete his mission. If he was the caller and poisoner of Daniel Williams, his failed murder attempt may have inspired the statement of "up to the end of Oct" and "You won't get the news for a while yet" in reference to his continued pursuit of the Richmond school teacher. Ironically, the Dripping Pen card would be accompanied by the Zodiac Killer's second lengthy cryptogram, the first of which was cracked by a Salinas High School teacher.


RELEVANT ARTICLES: THE PROMISE OF MURDER ON LINE 5    A KILLER ON LINE FIVE

The above story broke in the San Francisco Chronicle on November 8th 1969, the day before the Zodiac Killer's Bus Bomb letter was postmarked. The previous two articles [1] [2] explored the idea that the Zodiac Killer may have positioned one of the X's on the Bus Bomb crosshairs to signify an impending attack/murder in Richmond, based upon the fact Daniel Williams was a school teacher at Salesian High School. How the police came to the conclusion this wasn't the genuine Zodiac Killer by virtue of relayed phone messages, appears rather speculative. If this wasn't the Zodiac Killer, then it becomes a distinct possibility that somebody known to Daniel Williams was trying to kill him, using the Zodiac Killer as a convenient fall guy.

However, there are crucial parts of the Daniel Williams story that were not covered in the San Francisco Chronicle article above. The day after this article was published, the Bus Bomb letter was postmarked, meaning it was out of the Zodiac Killer's hands by November 9th 1969. The Bus Bomb letter continued the theme of threatening schoolchildren by means of a bomb. But the November 9th 1969 letter contained one important line, after his introduction of "changing his way of collecting slaves". He stated "The police shall never catch me, because I have been too clever for them".

The following day (November 10th), the Desert Sun newspaper would expand on the details of the sadistic phone call to Daniel Williams. It read "MARTINEZ (UPI)—A young scoolteacher who received threatening telephone calls for 10 days thought the caller was a crank who was pretending to be the Zodiac Killer. But police took the threats seriously after 24-year-old Daniel Williams found a lethal dose of arsenic in a bottle of soft drink in his refrigerator. Williams, a teacher at Salesian High School in Richmond, told police the caller talked of how he intended to kill several persons, then last; Sunday said: “You’re the dead duck.” Williams went out and when he returned home found someone had pried open the screen on a back door. However, a police search showed nothing was missing. But after the officers left and Williams took a drink from a bottle of opened soft drink in his refrigerator, he found it tasted “metallic” and immediately spat it out. Police reported Friday that the bottle contained more than enough arsenic to kill a human being. Williams said the caller identified himself as the still sought Zodiac killer of five, but police discounted the idea. The caller would “sob and complain of headaches.” Williams said, and on one occasion said he had gone to a Martinez school in search of victims but left when he found police there. Williams said the caller told him: “I’m too smart for them". This story was also published (word for word) in the San Mateo Times on November 8th 1969.

The sadistic phone calls to Daniel Williams began on October 23rd 1969 and lasted 10 days until November 2nd 1969, with the caller mocking police by stating “I’m too smart for them". The Zodiac Killer in reference to the police on November 9th 1969 (Bus Bomb letter), stated "The police shall never catch me, because I have been too clever for them". Very similar phraseology aimed towards the police by the real Zodiac Killer and somebody claiming to be the Zodiac Killer, separated by approximately one week. The expanded story of Daniel Williams (in the Desert Sun on November 10th) was copied from an identical version in the San Mateo Times newspaper, published on November 8th 1969, which covered the details of the phone call boasting “I’m too smart for them". But if the Zodiac Killer only read the Chronicle article (which didn't cover the phrase), then it's rather fortuitous that he would also use the near identical wording of "I have been too clever for them" at the beginning of the Bus Bomb letter on November 9th 1969. If they were not the same person, then there is a possibility that the Zodiac Killer read the version of Daniel Williams story, covered in the San Mateo Times or another newspaper prior to the mailing of the Bus Bomb letter, and used the phraseology of the sadistic caller detailed in the newspapers in his latest letter, so as to convince the police he was the caller and poisoner of Daniel Williams. Does the phraseology suggest one perpetrator as sadistic caller and Bus Bomb letter author, a Zodiac Killer mimicking the newspaper articles, or is the wording just a simple coincidence?

RELEVANT ARTICLES: THE PROMISE OF MURDER ON LINE 5    A KILLER ON LINE FIVE

Daniel Williams (24), a young school teacher from Martinez, California started receiving sadistic calls from a man claiming to be the Zodiac Killer, beginning on October 23rd 1969 (the day after the Jim Dunbar Show call). While this was initially passed off as just another copycat by Daniel Williams, he and the police took it extremely seriously when a lethal dose of arsenic was discovered in a soft drink inside his refrigerator. Many copycats forging communications and phone calls would not be considered unusual in a high profile case such as the Zodiac Killer, but I doubt many would take it to the next level and commit murder in the name of impersonating the murderer of five. The phone calls spanned a period of ten days, culminating in somebody breaking into his house and spiking his drink. Had Daniel Williams not noticed the metallic taste in his drink, the young teacher would have been a "dead duck" as the phone caller had promised.

The Zodiac Killer, would eventually, on November 9th 1969, promise to "change the way the collecting of slaves". Was this the first step in that direction, attempting to kill remotely after his fortunate escape subsequent to the murder of Paul Stine in Presidio Heights on October 11th 1969, buoyed by the publicity he received during the Jim Dunbar Show circus?

The Zodiac Killer may not be responsible for the phone calls or attempted murder of Daniel Williams during this period, however, it may be possible he was inspired by the reporting of this story. The case of Daniel Williams was reported in the Zodiac Killer's favorite newspaper, the San Francisco Chronicle on November 8th 1969, the day before the Bus Bomb letter was postmarked. One notable passage in the San Francisco Chronicle read "The string of sadistic calls began on October 23rd 1969 (the day after the Jim Dunbar Show call). On one occasion, the caller told Williams he had gone to a Martinez school in search of victims but had left when he found police there". Did the Zodiac Killer use this to his advantage? In the previous article, The Promise of Murder on Line 5, it was noted that the Zodiac Killer placed four X's around his Bus Bomb letter crosshairs, possibly denoting the seven victims he was claiming. Only line 5 (the fifth X) was unexplained. This line ran over the city of Richmond.   

On October 13th 1969, the Zodiac Killer mailed a letter with an ominous warning at its base, stating "School children make nice targets, I think I shall wipe out a school bus some morning. Just shoot out the front tire + then pick off the kiddies as they come bouncing out". The caller to Daniel Williams had continued this theme by claiming "he had gone to a Martinez school in search of victims but had left when he found police there".

Daniel Williams residence was situated at 1234 Bush Street in Martinez, so why would police have visited a Martinez school, when Daniel Williams was a school teacher at Salesian High School in Richmond? Wouldn't police more likely have placed protection in and around the Richmond school where he worked? Isn't it more likely the sadistic caller to Daniel Williams may have planned to target the Richmond school, with police pre-empting this eventuality? The newspaper may have made an error, and should have read "he had gone to a Richmond school in search of victims but had left when he found police there".

The Zodiac Killer, had he read this newspaper article the day before he mailed the Bus Bomb letter, would have known Daniel Williams taught kids at Salesian High School in Richmond (even if he wasn't the caller or poisoner). Bearing in mind the Zodiac Killer's recent fascination with targeting schoolchildren, the notion that line 5 on the Bus Bomb crosshairs runs directly over Salesian High School in Richmond and may have been chosen deliberately by the Zodiac Killer, is not out of the question. The Bay Area murderer may have been insinuating a continued threat towards the school where Daniel Williams taught, thereby attempting to lay credence to his involvement in the phone calls and poisoning. Or maybe he was just taunting the police. 

FOLLOW UP ARTICLES: DID ZODIAC POISON DANIEL WILLIAMS?   DID ZODIAC POISON DANIEL WILLIAMS? [PT2]

In the November 9th 1969 'Bus Bomb' letter the Zodiac Killer was clearly agitated by the response he received after mailing the Paul Stine letter on October 13th. In it he stated "This is the Zodiac speaking up to the end of Oct I have killed 7 people. I have grown rather angry with the police for their telling lies about me. So I shall change the way the collecting of slaves. I shall no longer announce to anyone. When I committ my murders, they shall look like routine robberies, killings of anger, + a few fake accidents, etc". The newspaper article that upset him featured Chief of Police Martin Lee, who stated in the San Francisco Chronicle article on October 18th 1969 entitled 'Zodiac Called a Clumsy Criminal,' that Zodiac possibly left his fingerprints on the taxicab, allowed himself to be spotted by three teenagers, and failed to kill all his victims. He went on say "His boast of being in the area we were searching is a lie. We had the whole area flooded with lights. We had seven police dogs and a large number of patrolmen searching the area tree by tree and bush by bush. The dogs are the best in the country. A mouse couldn't have escaped our attention".

The question was; had the Zodiac already attempted or carried out a crime after the October 18th 1969 article that was designed to look accidental or natural, but had possibly failed. After all, his victim count remained at seven by the end of October, which he corroborated in the Dripping Pen Card on November 8th. To do so, we would have to look at attempted crimes claimed by the 'Zodiac Killer' between October 18th and November 8th, in a relevant location.

As seen on the left, a Salesian High School teacher, Daniel Williams had his house broken into, but nothing was taken. A man claiming to be the Zodiac Killer made several threatening phone calls beginning on October 23rd 1969, culminating with the caller saying "You're the dead duck" on November 2nd 1969. Later that day, Williams took a drink from the refrigerator, but fortunately spat it out after noticing a metallic taste. The drink contained enough arsenic to kill.

This in all likelihood is not the Zodiac Killer, however, the targeting of a school teacher is interesting, bearing in mind a Salinas High School teacher, Donald Harden cracked his first cipher, and his 'Dripping Pen' card and second cipher was to arrive in just six days. It could also be argued that this attempted murder - had it been successful - may have looked 'accidental' as the Zodiac would state in the 'Bus Bomb' letter.

Daniel Williams residence was situated at 1234 Bush Street, Martinez, only 9 miles from the location of Zodiac's first crime at Lake Herman Road.
The mystery man during one of his calls talked of "killing the lady in the blue house," but as of yet the meaning behind this utterance is undetermined. 

Bearing in mind the October 22nd 1969 Jim Dunbar radio show, in which Zodiac was supposed to call in, it is hardly surprising we may get a crank call by somebody claiming to be Zodiac beginning on October 23rd 1969. The only difference here, was it appeared the caller was prepared to back up his threat with action. The original caller to the Oakland Police Department at 2:00 am on October 22nd 1969 may however, not be the same person as the hoaxer, who ultimately called the Jim Dunbar show and spoke to Melvin Belli.

​The phrase 'dead duck' may originate from "Never waste powder on a dead duck," first recorded in 1829. Bearing in mind the use of arsenic powder, an ironic choice of words.