Since this proclamation on November 9th 1969, the only tangible crimes linked to the Zodiac Killer appear to be the Modesto abduction of Kathleen Johns on March 22nd 1970, and the disappearance of Donna Lass from the Sahara Tahoe Hotel and Casino, Stateline, Nevada, on September 6th 1970.
Disabling the vehicle of Kathleen Johns was central to his plan in the Modesto abduction as the focus of attack. He chose not to kill Kathleen Johns the moment he approached her vehicle, as he could easily have done. Possibly his aim was to conceal the crime from being associated with the previous Lake Herman Road murders and Blue Rock Springs attack, and what he had in store for Kathleen Johns was ultimately thwarted. Her eventual escape from his clutches and subsequent identification of him as the Zodiac Killer from the composite sketch at the Patterson Police Station, may have forced his hand, to which he reluctantly owned up to a few months later. Unless of course he was laying claim to a crime he never committed.
Had the Zodiac Killer played a part in the disappearance of Donna Lass on September 6th 1970? The phone call subsequent to the crime, informing people that Donna Lass had been called away due to a family illness, could be telling. The caller was not boasting of murder like the Zodiac Killer exhibited after the Blue Rock Springs and Lake Berryessa attacks, he was seemingly trying to give the impression nothing sinister had happened, suggesting the act of the phone call was simply to 'buy time'. If the abductor was affording himself some extra breathing space, then the real possibility he was local to the area or known to Donna Lass is a credible argument, and he was either holding Donna Lass at this juncture, needed time to dispose of her body, or possibly needed to remove incriminating evidence from his home or vehicle before the police came knocking. This could have suggested that the responsible moved in the circle of Donna Lass, such as friends and work colleagues, who are inevitably the first people to be questioned in most police investigations.. However, the only viable links to the Zodiac Killer have been drawn from the unauthenticated 'Pines' card, mailed six and a half months after her disappearance.
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. [view on google maps] 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 40's, 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 Ken 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 more 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.
There may be countless crimes associated to the Zodiac Killer that we are unaware of, if we believe his boasts of ME-37 SFPD 0 in the 'Exorcist' letter, but equally there may be none. Isobel Watson fortunately rejected the offers of the 'good Samaritan' and lived to tell the tale.