ADVANCE BOOK EXCERPT: Zodiac’s Z13 Cipher—The GEORGEHODELMD Anagram and Its 2009 Origins
September 20, 2026
Birch Bay, Washington
The following is an advance excerpt from my forthcoming book, The Zodiac Murders: Fact vs. Fiction. In light of renewed public interest in Zodiac’s still-unsolved thirteen-character “My Name Is” cipher, known as the Z13, I am publishing this section ahead of the book’s release.

MYTH
The 2026 “Killer in the Code” podcast was the first to identify a suspect whose name fits the 3-2-2-2 repeat pattern in Zodiac’s thirteen-character “My Name Is” cipher.
FACT

“My name is” thirteen-letter cipher mailed by Zodiac to the
San Francisco Chronicle on April 20, 1970
Not so. I put two thirteen-letter forms of my father’s name in print back in 2009, more than eleven years before Zodiac’s Z340 cipher was solved:
DRGEORGEHODEL
GEORGEHODELMD
In Most Evil, I discussed Zodiac’s repeated use of the number thirteen. The October 5, 1970 “13-Hole Postcard” contained thirteen punched holes. Police and reporters saw them as a possible victim count. I suggested a double meaning: victims on one level, and thirteen letters spelling one of the above forms of my father’s name on another.
The point is simple. I did not arrive at the Hodel name after the Z340 solution or after the recent podcast. I published it in Most Evil in 2009, page 159.
Then, in December 2020, the Z340 was finally solved. Two longtime independent researchers of my father’s suspected crimes, James Valks and Dr. Luigi Warren, took a fresh look at the unsolved Z13 name cipher.
Valks made the first new connection. Using values from the Z340 key, he obtained the partial reading DREA*A*O*LEDO, treating Zodiac’s three unfamiliar “8-ball” symbols as wildcards. The opening DR and closing LEDO immediately suggested DR GEORGE HODEL. It was not a complete solution, but it independently pointed toward the same name I had published eleven years earlier.
Warren, who holds a Ph.D. in biology from Caltech, then took the analysis further.
He tested the Z13 as a possible combination of retained Z340 values, simple substitution and an anagram.
What he found is the part that got my blood up: GEORGEHODELMD has thirteen letters, but that is not all. Its repeated letters fall into the same groups as the repeated symbols in the Z13.
The 3 2 2 2 Pattern for Us Non Cipheretics
I am no cipher expert, so here is Warren’s finding the way I finally understood it. Think of the repeated symbols and letters as matching sets of blocks:

The cipher and GEORGEHODELMD both form the same repeat pattern: 3-2-2-2-1-1-1-1.
Warren then kept four proposed mappings from the Z340 key, assigned values to the remaining symbols, and obtained DRGHEMEOELGDO—an exact anagram of GEORGEHODELMD.
Does that prove GEORGEHODELMD is the one and only solution? No.
The Z13 is very short. Anagrams allow letters to be rearranged, and Warren had to make assumptions about symbols not established by the Z340 key. But this is more than squeezing a convenient thirteen-letter name under thirteen symbols. The letter count, the repeat pattern and the resulting exact anagram all point in the same direction.
For me, this is where intuition and science meet hand in hand. I saw the possible thirteen-letter signature in 2009. Years later, Valks and Warren arrived by a separate cipher-based route and strengthened it. Both men deserve full credit for their work.
There may be one more related clue, but I want to keep it separate from the Z13 analysis.
A Possible Aimee Semple McPherson Link


In September 1990, a “Celebrity Cipher” postcard showing Carmel’s “Sandy Beaches” was mailed to the Vallejo Times-Herald. It carried a Marianne Moore stamp. Warren applied the Z340 key and examined the letters as an anagram. Among the words he found was THE AVENGER. Because some symbols on the surviving image are unclear or hidden, I do not present this as a solved cipher.
Here is Warren’s 2021 email explaining what he saw:

The possible Aimee Semple McPherson connection is hard to miss. As I documented in The Early Years, Part I, her 1926 disappearance involved a Carmel seaside cottage, coded messages, “Miss X” look-alikes and a mysterious man calling himself “The Avenger.” The postcard was mailed two days before the September 27 anniversary of McPherson’s death, officially ruled as an “accidental overdose of Seconal.”
Is that proof? No. But the Carmel picture, the possible AVENGER wording, the date and my father’s suspected relationship with McPherson make it one more clue worth placing on the table.
My Conclusion
The Z13 is too short to identify any suspect conclusively. But the record is clear: I published the two thirteen-letter Hodel name forms in 2009; Valks later obtained a partial reading pointing toward DR GEORGE HODEL; and Warren produced an exact GEORGEHODELMD anagram with the same 3-2-2-2 repeat pattern. Standing alone, it is not proof. Standing beside the many non-cipher links connecting Dr. George Hill Hodel to Zodiac, I believe it is significant.
Steve
With ciphers, I’ve found that unless you have something that “clicks” (like the Z408 and Z340 solution), you don’t have very much — there just so many “free parameters.” You are just “working the problem.”
With that caveat noted…
In a substitution cipher like the Z408 or Z340, any symbol in the cipher translates to a fixed letter in the solution. Therefore, the letter frequencies in the Z13 solution are likely going to be the same as in the cipher (unless the 8-ball is to be taken as a wildcard, at least). Unfortunately, you cannot make either of the proposed GHH solutions work by assuming the Z340 key as there are known ciphertext letters here which just don’t fit.
It is interesting that, as Valks found, simply applying the Z340 key is “suggestive” of a GHH anagram solution, even if cannot be made to work as-is. It might be that this reflects GHH toying with a cipher scheme and tweaking it, e.g., to make it more difficult in case the Z340 were ever cracked.
Having the 8-ball stand for ‘E’ is a reasonable guess as ‘E’ is the most common letter in English text, as everyone knows. A reasonable guess, then, is the Z13 solution is a 13-letter anagram with three ‘E’s, three letters which occur twice, and four unique letters. If GEORGE HODEL MD is on your shortlist of Zodiac suspects — which he should be– then you might take the Z13 as “hint” he is the one. Perhaps that’s all we were ever going to get.
-LW