The Zodiac modus operandi, if any can really be established, involved attacks where he tended to seek out couple's in cars, the only deviation being the Presidio Heights slaying of taxicab driver Paul Stine on October 11th 1969, yet still a vehicle was integral to the crime. In searching for crimes based upon the threats outlined in the 1987 letter, where the author had used his car as a potential weapon, we shall examine the murder of a young girl in Wichita on October 31st 1987. But first, we will take a look at the brutal attack on a lone woman in Marin County who had a terrifying encounter one dark night in 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, in his early 40s, 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 - and that April 7th 1972 once again fell on a Friday. The Zodiac crimes of Lake Herman Road, Blue Rock Springs Park, Lake Berryessa and Presidio Heights were on Friday, Friday, Saturday and Saturday respectively.
The October 28th 1987 letter is questionable as to whether it was authored by the Zodiac Killer, but did anything occur on Halloween night 1987 that would substantiate anything the author alludes to in the letter.
On October 31st 1987, three days after the mailing of this correspondence, Shannon Olson (15) disappeared from the South East Wichita area after she had decided to venture out with friends on All Hallows Eve. Within hours she was found floating in a pond by two fishermen in an industrial area by the now I-35 and K-96 in North Wichita. Shannon Olson had been repeatedly stabbed over forty times, discovered with her hands bound behind her back by her own bra. It was presumed that her body had been dumped there, having been abducted from a secondary location. The letter and the murder were within days of each other, with the crime occurring on Halloween night.
The killer could have used his car to temporarily disable the young girl before whisking her away to the area of her murder - which may have been the malicious intent of the perpetrator of the Tamalpais Valley attack on Isobel Watson .
Shannon Olsen, in the eyes of somebody like the Zodiac Killer would have been viewed as a kid, as she was only 15-years-old. She was bound and brutally stabbed in what can only be described as a frenzied attack consisting of over 40 knife wounds. There are loose similarities to the attacks at Lake Berryessa, the Hood/Garcia murders and the Domingos/Edwards slayings - all discovered near water. October 31st 1987 was also a Saturday, in alignment with the Zodiac's four confirmed attacks at Lake Herman Road, Blue Rock Springs Park, Lake Berryessa and Presidio Heights which all took place on a Friday or Saturday.
Was the Zodiac Killer an integral member of the Church of Satan, or was he part influenced by the Anton LaVey movement and the resulting press coverage? In a television interview, reporter Paul Avery, who had become the subject of the Zodiac Killer's Halloween card received a phone call from Anton LaVey stating that he thought the Zodiac Killer may have attempted to become one of his parishioners, subsequently providing Paul Avery with some material. This created a comical response from Paul Avery who stated that the "Zodiac was so bad even the Church of Satan didn't want him". As stated earlier, the Zodiac Killer mentioned the 1977 film The Car, about a satanically possessed vehicle that embarks on a murderous rampage, Anton LaVey was awarded the title of Creative Consultant in the movies credits with a quote from his Satanic Bible.
The murder of Shannon Olson may be unlikely a Zodiac crime - with many people suggesting the BTK Killer, Dennis Rader as the possible murderer - as his crimes were committed in the area of Wichita, Kansas between 1974 and 1991 where he claimed 10 victims. However, the majority of his murders involved strangulation or suffocation, with only one of his victims, Kathryn Bright, having been stabbed. Dennis Rader has never confessed to the murder of Shannon Olson and the case remains unsolved to this day.