Z13 Reality Check: The “Marvin Margolis (aka Marvin Merrill)” Claim Examined

February 23, 2026
Birch Bay, Washington

Every few years, someone claims to have cracked the Zodiac’s 13-symbol “My name is…” cipher. The latest headline-maker says it spells MARVIN MERRILL — reportedly an alias used by Marvin Margolis.

The name itself is unfamiliar to many readers, which makes it especially important to examine whether the cipher actually supports it.

Strip away the excitement and apply basic cipher rules, and the Merrill claim runs into immediate trouble. You don’t need advanced math to see why.

What the Zodiac Actually Gave Us

The Z13 cipher contains 13 symbols. Several of those symbols repeat in specific positions. That matters.

Because of those repeats, any valid solution must follow a fixed letter pattern if we treat the cipher the same way Zodiac’s solved ciphers work — one symbol equals one letter.

In plain English, any clean solution must obey these four rules:
• Letter 1 must equal Letter 12
• Letter 3 must equal Letter 11
• Letter 8 must equal Letter 13
• Letters 5, 7, and 9 must all be the same letter

Think of it like a combination lock. If a proposed name doesn’t match this pattern, it is not a clean fit.

Put “MARVIN MERRILL” to the Test

Write it out: MARVINMERRILL

Under normal Zodiac-style substitution, the Merrill name does not satisfy the cipher’s required structure. That is the central technical failure.

Regardless of statistical scoring or computational assistance, a proposed plaintext must first obey the symbol-repeat pattern. On that basic structural test, the Merrill reading falls short.

Why Frequency Matching Isn’t Enough

With only 13 characters, many different names can be made to share similar letter counts. This is a well-known trap in short ciphers.

Matching frequency alone is like saying: “The suspect is a six-foot male wearing shoes — it fits a lot of people.”

Experienced cryptanalysts understand that at this length, positional structure matters far more than raw counts.

About the “Leading Cryptologists” Claim

Media accounts have cited former NSA cryptographer Ed Giorgio, along with crypto-mathematicians Patrick Henry and Rich Wisniewski, as viewing the Merrill proposal favorably. However, the underlying methodology and verification process have not been publicly released for independent examination.

Reasonable experts can disagree — particularly with a cipher as short as Z13, which is mathematically underdetermined and prone to overfitting. However, regardless of statistical or computer-assisted approaches, any proposed solution must still satisfy the basic structural constraints imposed by the repeating symbols.

On that standard, the Merrill reading does not hold up.

The Larger Historical Reality

In his July 31, 1969 letters accompanying the 408 cipher, Zodiac explicitly claimed: “In this cipher is my idenify.” (Zodiac’s misspelling)

When the 408 was solved, no name appeared. No identity. Just more taunting.

Zodiac reinforced that posture in his November 9, 1969 letter, writing: “I will not give you my name because you will try to slow down or stop my collecting of slaves for my afterlife.” The statement is consistent with a pattern of deliberate concealment and misdirection.

Where My Investigation Stands

For the record, I have long argued — in Most Evil (2009) and Most Evil II (2015) — that the Zodiac and the Black Dahlia Avenger point to the same offender: Dr. George Hill Hodel.

That conclusion rests on a broad evidentiary foundation developed over decades, including documented LAPD interest in Hodel in 1950 and later re-examination of the case in 2003. It does not depend on any single cipher claim.

Whether Z13 ultimately yields a verifiable name — or proves to be another deliberate Zodiac tease — remains an open question.

The Bottom Line

The Merrill proposal does not withstand even basic structural scrutiny.

Until a solution emerges that uniquely and cleanly falls out of the cipher itself — rather than being fitted to it — the Z13 remains unsolved and very likely was meant to be.

— Steve Hodel