On October 14th 1969 a letter arrived at the San Francisco Chronicle laying claim to the murder of taxicab driver Paul Stine, in addition to a further ominous threat of "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". 

​In compliance with the wishes of the San Francisco Police Department, the Chronicle withheld the threat on a school bus when this latest Zodiac letter was published in the newspaper on October 15th 1969. It wasn't until October 17th 1969 that the Chronicle published the threat on a school bus (and October 16th in the Los Angeles Times). Therefore, the threat delivered by telephone to Santa Rosa by somebody claiming to be the Zodiac Killer on October 15th 1969 promising to blow up a school bus, was made before the Zodiac Killer's threat in his letter was ever released in the newspapers. This suggests it was the Zodiac Killer who telephoned the school bus threat in Santa Rosa on October 15th 1969. This is what was reported in the Chronicle on October 21st 1969: "Someone hinting he might be Zodiac has telephoned such a threat in Santa Rosa. The man responsible for the safety of the students who ride the buses is Fred Sowash, the district's transportation director. Since last Wednesday, when he learned of Zodiac's threat, Sowash has been devoting 18 to 20 hours a day to blunt it".  Last Wednesday was October 15th. 

On October 17th 1969, a female school bus driver was traveling southeast towards Yulupa Elementary School in the morning, when she claimed she heard a shot ring out, stating "As I came around this bend I heard a loud shot from the left hand side of the bus. The children heard it too. Now I don't know if anything struck the bus. We can't find anything that struck the bus". Looking at the October 17th 1969 KRON News footage, it appears she may have been traveling along Bennett Valley Road in Santa Rosa, with relatively low density housing dotting the route and the Sanoma Mountains in the distance. This route would have provided the perfect cover for the Zodiac Killer to shoot out the tires of a school bus in relative seclusion. Assuming a shot was fired at the bus and heard by the driver and/or schoolchildren, either he missed, or his intention was merely to create panic on the school bus to ensure the shots were heard and reported - and thus lend credibility to his telephone threat two days earlier. After the shot, the woman driver "hit the foot feed and started going on", realizing there were no other cars in the vicinity she could get the attention of. "So I just kept going fast to the Yulupa School" she added.   

Unfortunately, investigators were skeptical because they could find no evidence of any bullets striking the bus. One would have thought that a Santa Rosa telephone threat from the Zodiac Killer directed at a school bus, followed by a woman driving a school bus in Santa Rosa reporting what she described as "a loud shot", would have stimulated less skepticism  It seemed that Fred Sowash took it seriously, because when he learned of the threat on Wednesday, October 15th 1969, he devoted 18 to 20 hours a day to repel the threat. Yet it appears that no police vehicles were trailing this school bus on October 17th 1969 as it approached Yulupa Elementary School in Santa Rosa, despite the Zodiac threat to shoot out the front tires of a school bus and "pick off the kiddies as they come bouncing out", and the direct threat to Santa Rosa itself.  

​FOLLOW UP ARTICLE: THE SPOTLIGHT ON SANTA ROSA 

It has been stated that one of the keys depicted in the Eureka card mailed in December 1990 was traced to its once owner, Chester Clark Klingel. The question that has arisen is: if the Eureka card was mailed by the Zodiac Killer, how did he acquire the post office box key of Chester Clark Klingel in order to photocopy it? If the Zodiac Killer didn't find the key and trace its owner, then the logical conclusion is that at some point he may have crossed paths with Chester Clark Klingel. After Chester married his wife, Blandina, in 1965, they visited relatives regularly in Turlock, before they purchased property at 6413 E Keyes Road in Hughson, California in 1973 (now Alpine Pacific Nut Company). They eventually sold this property and bought a 20-acre ranch from walnut huller, Glenn DeLay in 1976. This is the only tenuous link that can be forged between Chester Clark Klingel and the Zodiac Killer, who, if we believe abducted Kathleen Johns on March 22nd 1970, may have been traveling back to Vallejo from the Turlock or Hughson area that night. Additional link.

​Although the Kathleen Johns abduction occurred three years before the Klingels purchased the property in E Keyes Road and six years before the second purchase, the Zodiac Killer could have had family or friends, or had business dealings in Turlock or Hughson, that required him traveling there from the Bay Area before and after the Kathleen Johns abduction. If he had visited this area of California in 1970, he could have visited it regularly pre and post March 22nd 1970 - possibly into the 1980s and 1990s, where he may have crossed paths with Chester Clark Klingel in a personal or professional capacity. The route that Kathleen Johns took on March 22nd 1970 had her traveling northwest on Highway 99, through Turlock and near Hughson, California, before reaching Modesto and heading west on Highway 132. In fact, E Keyes Road passed over the top of Highway 99, with the 15-acre farm at 6413 E Keyes Road in Hughson situated less than two miles from Highway 99.

If the Zodiac Killer was responsible for the Kathleen Johns abduction in 1970, and had lived in the Bay Area during this period, it's very unlikely he would have taken a 170-mile round trip to an isolated stretch of road just to commit this type of crime, that he could have committed anywhere. This opens up the possibility he may have had reason to be in Turlock or Hughson pre and post 1970 (possibly business related). However slim, is there a chance that the Zodiac Killer trailed Kathleen Johns from Highway 99 somewhere in the region of Turlock or Hughson, or could he have traveled from this area and randomly come across Kathleen Johns as they both drove along Highway 132 at approximately 11:15pm?. Any continuing journeys to the Turlock region subsequent to the night of March 22nd 1970 may have facilitated the opportunity for the Zodiac Killer and Chester Clark Klingel to have crossed paths with one another. According to the obituary of Chester Clark Klingel, he remained in Turlock until the death of his wife Blandina on September 9th 1993, when he sold the farm and moved to Eureka. Therefore, it is entirely plausible that the Zodiac Killer 'acquired' and photocopied the post office box key from Chester in the years up to and including 1990, while Chester lived in Turlock, California.

On January 29th 1974, a letter was mailed from either San Mateo or Santa Clara County to the San Francisco Chronicle by the Zodiac Killer for the first time. The letter (minus the Asian symbols) was published in the San Francisco Chronicle newspaper on January 31st 1974, but the envelope was not released into the public domain prior to the arrival of the April 24th 1978 letter. Up to 1978, every single Zodiac communication that carried the *Please Rush to Editor" message on the reverse side of the envelope was either written in diagonal fashion or not contained on one line - except for one - which was written using a single line and was parallel to the upper and lower edges of the envelope. That was the Paul Stine envelope (containing the shirt piece) mailed on October 13th 1969, which was also withheld from the public domain prior to April 24th 1978.

​The only available envelope addressed to the San Francisco Chronicle newspaper that the 1978 letter author had available for them to mimic, was the November 8th 1969 envelope released in a newspaper article on November 16th 1970. This newspaper article clearly shows the front and back of the envelope, with "Please Rush to Editor" written in level fashion on the front of the envelope and in diagonal fashion on the rear of the envelope. The author of the 1978 envelope seemingly did an excellent job mimicking the handwriting on the front side of the November 8th 1969 envelope, yet inexplicably failed to write "Please Rush to Editor" in level fashion on the front of their 1978 envelope. Additionally, the author of the 1978 envelope failed to write "Please Rush to Editor" in diagonal fashion on the rear of the envelope, again failing to mimic the November 8th 1969 envelope - instead opting to mimic the Paul Stine letter which was never released into the public domain. In fact, the 1978 envelope was the only communication connected to the Zodiac Killer with the writing "Please Rush to Editor" in diagonal fashion on the front of an envelope. This copycat certainly wasn't very observant - apparently losing his train of thought from one side of the envelope to the other. Also, according to investigators, the author of the 1978 letter managed to mail the communication from either San Mateo or Santa Clara County, just like the Exorcist letter, four years earlier. Strange how he apparently never forgot that.