Obviously, the Zodiac Killer has a very clear memory of the crime scenes and knows the compass points. His use of the stop word "Over" at list end in one of the letters would be consistent with the use of the same word at the end of the Z 148 Cipher and Letter of 1971 and the possible stop word "iti" at the end of the decoded text of the 408-character cipher Z 408 that the Zodiac attached to his July 1969 letters. The use of "over" as procedure word, particularly in view of the possible procedure words "This is" in later Zodiac Killer communications could indicate the Zodiac Killer's familiarity with military, naval and radio communications.
With the continuing text, coercion and extortion as the true purpose of the July 31, 1969 letters to force newspapers to publish the cipher parts become obvious. Here we would like to emphasize that, very clearly, the Zodiac did not request the publication of his letters but the publication of the cipher parts that he had attached to his letters. Therefore, it is reasonable to assume that, from the Zodiac Killer's perspective, his July 1969 letters as such where meant for the newspapers and possibly indirectly for the police, but that the ciphers where meant for the general public.
His request to make the front pages with his ciphers clearly shows the Zodiac's desire to communicate, to make news, and to bring his message across to a wide audience, including his identity, that some mistakenly expected to be equivalent to his name.
The Zodiac Killer's threat to "cruse around all weekend killing lone people" [sic] gives very strong hints on his modus operandi (M.O.). The words "cruse around" [sic] confirm the killer's (intended) use of a car for trolling. The words "weekend" and "at night" suggest weekend and night time crime activity, and "lone people", "stray people or coupples that are alone" [sic] and "people who are alone" suggest that the killer randomly targets victim that are separated from the crowd and in secluded areas. These modus operandi indications are fully consistent with actual and presumed Zodiac Killer crimes, with exception of the killing of cab driver Paul Stine in the Presidio Heights neighborhood of San Francisco on October 11, 1969.
The Zodiac gave inconsistent statements regarding his threat to kill people on the weekend of August 1-3, 1969. In two of his letters, he threatened to kill "a dozen people", while in the letter to Vallejo Times Herald he says "over a dozen people". This inconsistency might indicate that the threat was not firmly defined and was rather intended to impress than it was an concrete plan for action. The fact that the killings did not happen although the newspaper did not precisely follow his extortion attempt supports this assumption.