On November 8, 1969, the Zodiac Killer mailed a mysterious “Dripping Pen” greeting card to the San Francisco Chronicle. Inside, a scrawled message hinted at some upcoming “bad news.”

Included was a cipher 340 symbols in length. Officially solved in December 2020 by computer and cryptology experts Dave Oranchack, Sam Blake and Jarl van Eycke, Zodiac’s message revealed nothing of significance to further the case along.

In his PS, Zodiac asked for “frunt-page” coverage of the cipher.

The next day, he mailed a six-page diatribe to The Chronicle that included, among other things, a second PS along with a similar request to have his material published. The postscript, conspicuously inserted on page 3 rather than the end of the letter, recounts the aftermath of the murder of San Francisco cab driver Paul Stine a month earlier.

It is noteworthy that Zodiac’s “PS. 2 Cops” passage contains 340 characters.

The identical lengths of the postscript and 340 cipher (along with Zodiac’s insistence over back-to-back days that both be published) suggest they are connected. This theory is not a new one, dating as far back as this 2014 Zodiackiller.com messageboard thread.

Since then, a key 2020 discovery may provide the missing link between the two items. In addition to being split in three parts (153, 153, and 34 characters, respectively) Zodiac’s solution is arranged diagonally and read downward, starting at the top-left corner.

A few sidenotes about the diagonal solution:

1. Several letter corrections and shift adjustments are needed, as highlighted above-right. They are explained in Sam Blake’s solution breakdown.
2. Horizontal exceptions emerge, most notably “life is” and “death”. Other horizontal words are spelled backwards, a phenomenon exclusive to the last two rows.
3. “Paradise” is spelled with a “c”. (The word frequently appears in other Zodiac correspondences, always spelled the same.)

In connection with Zodiac’s diagonal layout, several words in his “PS 2 Cops” passage stand out.

On the surface, his inclusion of ‘left,’ ‘down,’ ‘up’ and ‘over’ seems unremarkable in the context presented (e.g. “I left the cab”). However, upon closer inspection, surrounding words could expand/alter what Zodiac means.

(Note: ‘down hill’ and the opening number ‘2’ initially appear to be outliers compared with the other highlighted portions. These distinctions will be addressed momentarily.)

In the meantime, an interesting sequence emerges from the other word pairs, in order of appearance:

3 left — > up one — > over one

When applied to the 340 Cipher, the above pattern replicates the diagonal solution spacing discovered in 2020.

The cycle proceeds upward, seemingly at odds with the 2020 findings. However, Zodiac’s ‘down hill’ verbiage may not be an outlier after all. It potentially clarifies the 340 Cipher’s downward reading direction.

Then, there is still the number ‘2’ to consider. Unlike the other numeric values identified in Zodiac’s passage, it seems to stand alone.

However, its position immediately after ‘PS’ could distinguish the postscript as being ‘PS #2’ on the heels of the previous day’s ‘PS #1’.

Whether the totality of the arrangement was intentional or not, it is eye-catching that Zodiac’s “Postscript #2” contains, in order, the wording ‘3 left…up one…over one’ along with a “downhill’ reference in between.

It could be fairly argued that these findings are coincidental or the result of pareidolia. What makes them hard to dismiss, however, is where they are found: within the exact passage Zodiac demanded be printed, one day after he requested the same treatment for his 340 Cipher.

What’s more, from the opening ‘PS’ to the closing ‘one’, the entire sequence is constrained to the exact length of Zodiac’s top arrow.

Presuming the word pairs were indeed intentional, they support the theory that his master plan all along included leaving actual clues behind – not only in this particular passage, but possibly in other locations as well.

As such, upcoming Shake-The-Earth.com posts will explore multiple parts of Zodiac’s letters, cards, and ciphers where alternate intent possibly lurks beneath the surface.

Stay tuned.