The Zodiac Killer, would eventually, on November 9th 1969, promise to "change the way the collecting of slaves". Was this the first step in that direction, attempting to kill remotely after his fortunate escape subsequent to the murder of Paul Stine in Presidio Heights on October 11th 1969, buoyed by the publicity he received during the Jim Dunbar Show circus?
Daniel Williams residence was situated at 1234 Bush Street in Martinez, so why would police have visited a Martinez school, when Daniel Williams was a school teacher at Salesian High School in Richmond? Wouldn't police more likely have placed protection in and around the Richmond school where he worked? Isn't it more likely the sadistic caller to Daniel Williams may have planned to target the Richmond school, with police pre-empting this eventuality? The newspaper may have made an error, and should have read "he had gone to a Richmond school in search of victims but had left when he found police there".