Further exploration of the theory that the Zodiac was claiming his victims on the first day of the 13 Moon Calendar has unearthed further possibilities in the relevant time frame with noticeable Zodiac traits.
Without going extensively over old ground, three more victims, that of Robin Graham (18) who disappeared in the early hours of November 15th 1970 on the Hollywood Freeway after encountering car problems and noticed in the company of an unidentified dark haired male in possession of a pale Chevrolet Corvette.
The strangled body of Lynn Maureen Derrick (24) found on a Sausalito side street on July 26th 1972 believed to have been murdered elsewhere and dumped, with the sound of a speeding car leaving the scene.
Interestingly another woman contacted Robin Graham's parents stating she had refused a lift off a man claiming to be an off duty detective, again driving a Corvette and identified this man as Bruce Davis.
Coupling the Donna Lass disappearance on September 6th 1970 and Robin Graham disappearance just 5 weeks later on November 15th 1970, could this be the Zodiac's 14th victim he fortold in the Halloween Card on October 27th 1970.
All three dates of November 15th 1970, April 25th 1972 and more importantly July 26th 1972 all fell on or near a full moon and on the first day of the week of the 13 month moon calendar cycle, as did the Donna Lass disappearance, with all four having the possible use of a vehicle in the conveyance of the abductions.
The murder of Lynn Derrick fell on the two year anniversary of the Little List Letter, both marking the start date of the 13 Moon Calendar, also July 26th 1972 was a full moon and brought the potential list of Zodiac victims to 15.
For more information regarding these cases, follow these links
The possible List so far:
David Faraday December 20th 1968
Betty Lou Jensen December 20th 1968
Darlene Ferrin July 4th 1969
Cecelia Shepard September 27th 1969
Paul Stine October 11th 1969
John Hood February 21st 1970
Sandra Garcia February 21st 1970
Judith Hakari March 7th 1970
Thomas Dolan July 4th 1970
Homer Shadwick July 4th 1970
Donna Lass September 6th 1970
Nancy Bennallack October 25th 1970
Robin Graham November 15th 1970
Jeanette Kamahele April 25th 1972
Lynn Derrick July 26th 1972