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. 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.
There may be many 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 on January 29th 1974, but equally there may be none. Isobel Watson fortunately rejected the offers of the 'good Samaritan' and lived to tell the tale.