1] Of all the possible locations in San Francisco, why did the Zodiac Killer choose to murder Paul Stine in the region of Presidio Heights. Whether his initial intention was Laurel or Maple Street, why did he choose this specific part of San Francisco rather than a more remote location- and why did he remove a section of Paul Stine's shirt in arguably the most risky of all his four settings (or did he)?
2] On November 16th 1970 Paul Avery wrote an article about a persuasive link between Riverside and the Zodiac Killer. Four months later the murderer mailed the March 13th 1971 'Los Angeles' letter and then 'disappeared' for nearly three years. What, if anything, does this say about the killer. One month after the Los Angeles letter, a Zodiac film was released on April 7th directed by Tom Hansen, and later that year the blockbuster 'Dirty Harry' movie based on the Zodiac Killer was released on December 23rd 1971, directed by Don Siegel- but still nothing from the killer.
3] Zodiac basked in the attention of writing to the newspapers. So why did he wait just over seven months after the double murder of David Faraday and Betty Lou Jensen to put pen to paper?
4] The mailing of letters to police from killers is not commonplace. The Bates letters and July 31st 1969 letters were both mailed as a trinity of communications. This is extremely rare, if not unheard of. Bearing in mind the suggestion of a Zodiac link to Riverside, does this rare occurrence indicate that a trinity of consecutive communications is compelling evidence for such a link? If not the Bates murder, then certainly the Bates letters.
5] If the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald had refused to print any of the Zodiac Killer's communications and given him limited publicity, do you believe Zodiac would have committed the Lake Berryessa attack and Presidio Heights murder. Would the path of the Zodiac Killer have changed course. Did the publicity fuel the fire?
6] A vehicle pulled up beside Darlene Ferrin's brown Corvair approximately 5-10 minutes before the shooting. Was this the Zodiac Killer, and if so, why did he pull away and return?
7] If the murderer of Cheri Jo Bates disabled her vehicle shortly after she entered the library at 6 pm, why were greasy palm and fingerprints reported by detectives as being found on her car door, when it was totally unnecessary for the killer to ever have touched her car door while disabling the vehicle or offering her assistance- also bearing in mind the murder likely occurred 4 hours after the disabling of the vehicle. How did these greasy prints end up here?
8] A vehicle was spotted by James Owen heading toward Vallejo as he passed the Borges Ranch on his approach to the turnout at Lake Herman Road. The occupant of this vehicle never came forward. If we make the assumption this was the killer, how can we reconcile this with what James Owen said in his statements to police?
9] Why did the Zodiac Killer separate his 408 cipher into three parts, but left the 340 whole. Did his choice of Dripping Pen have any significance. And what is his Thing?
10] Why did the Zodiac Killer (if not the hoaxer/s) flip the text on the 13 Hole postcard and Pines card. Does either have any significance or any correlation to one another?