There is without doubt some interesting connections between the Zodiac and Riverside, in particular, the trinity of consecutive communications from April of 1967, to the three July 31st 1969 letters that began the letter writing campaign by the Zodiac Killer. It is therefore understandable that many observers want to interpret the symbol at the foot of the Bates letters as an alphabetical Z to bridge the connection between the Bay Area and Riverside, and bolster an argument for it. However, was this symbol seriously considered to be an alphabetical Z before the arrival of Zodiac just over two years later, or was it just a convenient reappraisal.
Two years later, on July 31st 1969, the killer we now know as Zodiac, announced himself to the world when he wrote to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald newspapers, but yet again, despite supposedly masquerading as the Zodiac Killer he was still apparently reticent to reveal his pseudonym to the world, only introducing himself as "the murderer of the 2 teenagers last Christmass at Lake Herman + the girl on the 4th of July". For a egotistical murderer so bold, he seemed rather reluctant to reveal his identity. Had Vallejo Police Chief Jack E. Stiltz not questioned the July 31st 1969 letter writer in the August 3rd 1969 San Francisco Examiner, stating he was "still not convinced the letters and codes were written by the actual killer, and urging the writer to send more letters, with more facts to prove his connections to the crimes," then the August 4th 1969 Debut of Zodiac letter would not have been written by the killer. In other words, the Zodiac Killer would still not have been born. How can we reconcile this reluctance to announce the pseudonym Zodiac to the world, with the fact he had supposedly concocted this pseudonym by the time of the Bates letters in April 1967?
"In 1882, Ariste Calame founded a workshop for the production of special watches in Le Locle, Switzerland. The original name of the company was Ariste Calame and would later become Zodiac. The name "Zodiac" was used early but was not registered until 1908. The founder's son, Louis Ariste Calame, was sent to watchmaking school, and then began to participate in the business in 1895, and took over the business that year". Wikipedia.
If the Zodiac Killer was inspired by a watchmaker, then one has to ask the question - why did he only use the crosshairs in his three July 31st 1969 letters and seemingly abandon the name Zodiac, if an advertisement such as the one on the right was the trigger? Again, he only introduced himself as the Zodiac Killer four days later when the Debut of Zodiac letter arrived at the San Francisco Examiner, and even that wouldn't have arrived if the killer had not been prompted by Vallejo Police Chief Jack E. Stiltz.
The idea of gunsight crosshairs, proposed by many, may be the likely inspiration for the murderer of three young people at Lake Herman Road and Blue Rock Springs Park. The standalone crosshairs at the foot of each of the July 31st 1969 letters appear to be the logical conclusion to the threat that preceded it. The San Francisco Chronicle, for example, finished with an ominous threat: "I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend". So it isn't particularly illogical that this threat may be followed by a "target" sign or the crosshairs of a gun, without the need for the pseudonym Zodiac or a connection to a famous watchmaker. The killer is simply signing off his letters by indicating he has more people in his sights.
If there ever was the perfect opportunity to announce himself to the American people under the name Zodiac, this was the perfect time - in accompaniment with a trinity of letters and his opening coded message - in which he actually promised to reveal his identity. However, this opportunity was spurned. The reason for this, one could argue, was the pseudonym Zodiac had not been conceived by the killer at this juncture.
The San Francisco Sunday Examiner and Chronicle of August 3rd 1969 opened with the lines "A self-accused killer failed to keep a threat of mass murder here, but there was no slackening of tension or mystery caused by the warning. The police department telephone system was clogged at times by anxious callers asking if the "cipher killer" had been caught". In this short snippet of text, probably lay the inspiration behind the pseudonym Zodiac, as he was not prepared to be labelled the "cipher killer" by anybody. This was the push he needed. The following day the Zodiac was etched into the minds of police and newspapers alike, and has remained so for nearly half a century.
On the contrary, had the Swiss watchmaker been the original inspiration behind the Zodiac's pseudonym and logo, then why did he fail to introduce the name "Zodiac" in his July 31st 1969 letters. He delayed the introduction until his August 4th 1969 letter to the San Francisco Examiner, in direct response to the San Francisco Sunday Examiner and Chronicle article of August 3rd 1969. Therefore, this newspaper had to be the driver behind the name Zodiac, not only because of his lack of affection for the "cipher killer" pseudonym, but because the name Zodiac probably lay somewhere within its folded pages.