Follow along as I deconstruct the Z32.
The Z32 is 32 characters long but not 34. The preceding long ciphers had 17 character lines. The second line of the Z32 is only fifteen characters long. I am not in the camp of the folks that believe that the Zodiac added extra characters for filler. If he did, why not add two additional characters and create the Z34 instead. Each of the characters have a meaning, even though we may not know what that meaning is.
The Z32 contains two lines. The first line starts with a ‘C’. The first nine characters of the first line look similar to a Zodiac character version of the state in which the crimes took place: ‘CALIFORNIA’. Sure it was one character short (missing the ‘N’) and the ‘J’ must be made into an ‘L’ and the backwards ‘K’ into an ‘R”. But somehow, I was hung up on this being California. Who knows, maybe the Zodiac intended this but I now have to assume that this was a simple case of pareidolia. The second line starts with an ‘X’. Possibly the most important clue in the cipher.
The next thing I got hung up on was the last five characters of the first line. These five characters resemble the word ‘NORTH’. I believe this was intentional. The word ‘NORTH’ at the end of the first line combined with the ‘X” at the beginning of the second line leads to the basic form of the Z32 and on to the location of the bus bomb. It took me about two hours to get this far and realize that I was on to something. It took weeks to get to a viable location and then even more weeks to validate that location.
I believe that it is a very fair assumption that the Zodiac would place the bomb in the San Francisco Bay Area. The bomb would not be located in a school for the blind in Nigeria, on an ice cap in Greenland, in the middle of the Pacific Ocean or on top of Mt Diablo. Since the Bay Area is located in a ‘North’ latitude and a ‘West’ longitude and I assumed the word ‘NORTH’ is the last five characters of the first line, would I find four characters representing ‘WEST’ at the end of the second line? Well it works out yes but not exactly. If you assume the Zodiac character in the second line is a signature and not just a Zodiac character standing for some other character, the preceding four characters are ‘HCEL’. ‘HCEL’ does not look anything like ‘WEST’ but suspend belief just a bit longer as I explain about delimiters.
In computer science a delimiter is a character in a string of characters that separate significant information. In most written languages, the ‘space’ character is a delimiter. A space delimits a word. A period delimits a sentence. Looking at the Z32 and you can see the symbols for ‘NORTH’ and the symbols for ‘WEST’ are bounded by delimiters. Once you recognize the delimiters the entirety of the Z32 construct becomes evident. The word ‘North’ is preceded by a solid triangle and followed by the end of the line. The word ‘WEST’ is preceded by a half-filled square and followed by the Zodiac’s signature. The Zodiac used the geometric shapes of a filled square, a filled triangle and a half-filled square as delimiters. In the Z32, just as in written English, delimiters are not optional they are required.
Withoutdelimitersitwouldbedifficultorimpossibletodeterminethemeaningofasentence. Likewise the delimiters in the Z32 let the reader know where the numeric values for the longitude and latitude start and end.
The Z32 is a simple longitude and latitude location for the bomb.
The Z32 takes the simple form of something like:
CALI <delimiter> <numeric latitude value> NORTH
X <numeric longitude value> <delimiter> WEST <Zodiac signature> <post-script>
So what is left to decipher? Do I really know that the first four characters of the first line are really ‘CALI’? No. Just a guess. Maybe the Zodiac wanted to limit the location of the bomb to California. As far as solving the bomb location the first four letters are not really relevant. The last three characters are not just fill. For if they were fill there would be five characters there and line two would have 17 characters just like the Zodiac’s longer ciphers. If they are significant and follow the Zodiac’s signature then they are a postscript. Postscripts were common in written letters, including the Zodiac’s letters. Perhaps P, W, delta stood for PWD? Again just a guess. But the post-script is not significant to the bomb location either.
I had worked on the cipher a few days to come to the above conclusions. This is the simplest form for the Z32 that I have seen suggested in the fifty years since the Zodiac created the Z32.