FBI's Secret Fingerprint Request in the Zodiac Case

# The FBI's Secret Fingerprint Request in the Zodiac Killer Case

In the fall of 1969, the Zodiac Killer had already terrorized Northern California for over a year. He had claimed at least five lives, taunted police with cryptic ciphers, and written mocking letters to newspapers daring investigators to catch him. Law enforcement at every level — local, state, and federal — was under enormous pressure to produce a name, a face, a set of fingerprints that matched. On November 1, 1969, a declassified FBI teletype shows exactly how urgently the bureau was working one particular lead — and how carefully they were keeping it from public view.

The document is a teletyped memo sent from the FBI's San Francisco field office to the Director of the FBI in Washington, D.C., specifically addressed to the Identification Division. Marked urgent and transmitted encrypted — the document header reads "ENCIPHERED" before transitioning to "PLAINTEXT" for the operative content — the message is brief, bureaucratic, and heavily redacted. But even through the black bars and clipped government prose, it reveals something significant: federal agents had a specific individual in their sights and were formally requesting that the FBI's fingerprint experts compare that person's prints against latent fingerprints already on file in the Zodiac case.

The case number referenced throughout the document is 9-49911, with the specific latent fingerprint submission logged as 9-49911-38. The San Francisco field office had been working this case file in parallel with local investigators, and by the time this memo was sent, the bureau had already received and catalogued dozens of evidentiary submissions. The "38" suffix suggests this latent print comparison was far from the first such request — the investigation had been generating forensic leads for months.

What makes the document particularly striking is the subject line. The memo categorizes the case under "UNSUB" — FBI shorthand for "Unknown Subject" — and lists the Vallejo Times-Herald newspaper as the victim in what is described as an extortion matter. This framing is notable. The Zodiac had been sending letters and coded ciphers to Bay Area newspapers, including the Vallejo Times-Herald, demanding they publish his messages under the implicit threat of continued killing. The FBI's classification of this as an extortion case — rather than a homicide investigation — reflects the legal jurisdictional reality of the time: serial murder was not a federal crime, but extortion, especially across communications channels, most certainly was. This was the bureau's formal entry point into one of the most infamous unsolved cases in American criminal history.

The routing list at the top of the memo reads like a who's who of the FBI's senior leadership in 1969. Names like Tolson — Clyde Tolson, J. Edgar Hoover's longtime deputy and confidant — appear alongside Mark Felt, who would later become infamous as the Watergate source known as "Deep Throat." The presence of this many senior officials on a single routing slip underscores just how seriously the FBI was taking the Zodiac investigation at the highest levels, even as the bureau maintained a publicly low profile on the case, deferring outwardly to local California authorities.

The core request itself is maddeningly incomplete thanks to redactions — almost certainly applied under Exemption 7(C) of the Freedom of Information Act, which protects the identities of individuals mentioned in law enforcement records. The name of the person whose fingerprints are being compared has been scrubbed, as has what appears to be an assignment notation. What remains is the procedural skeleton: someone, assigned somehow to something, needed to have their fingerprints run against the Zodiac's latent prints on file.

The note at the bottom of the document adds a chilling bureaucratic flourish: "ARMED AND DANGEROUS." This designation, standard FBI procedure when flagging a subject considered a physical threat, confirms that whoever this redacted individual was, agents in the field believed they were dealing with someone potentially violent — or at minimum, someone who warranted that level of caution. In the context of the Zodiac investigation, the phrase carries particular weight.

The document is also dated with a slight internal discrepancy worth noting. The teletype header reads November 1, 1969, while a timestamp embedded in the transmission reads November 8, 1969, and a routing notation at the bottom references November 18, 1969. This layering of dates is consistent with how FBI teletypes of the era worked: a message could be drafted, transmitted, received, and then formally logged and routed to relevant divisions over the course of days or even weeks. The November 18 notation likely reflects when the memo completed its internal routing through the Washington bureaucracy.

The reference to a prior San Francisco teletype from "November Six Last" — meaning November 6, 1969 — suggests this fingerprint request was part of an ongoing back-and-forth between the field office and headquarters. Something had happened, or been discovered, in the days prior that prompted this formal comparison request. Whatever that triggering event was, it remains hidden behind the redactions.

For researchers and investigators who have spent decades trying to unmask the Zodiac, documents like this one are both illuminating and deeply frustrating. They confirm that the FBI was actively running down specific suspects in late 1969, using the full forensic resources of the Identification Division, and doing so with enough urgency to mark communications "ARMED AND DANGEROUS." They also confirm that the bureau knew more than it said publicly — and that the identities of those suspects remain officially protected more than fifty years later.

The central unanswered question this document leaves open is, of course, the one buried under that black redaction bar: whose fingerprints were they comparing, and did they match? The FBI's case files on the Zodiac remain only partially declassified. What sits in the still-sealed portions of file 9-49911 may yet hold an answer — or at the very least, the name of someone the FBI once considered dangerous enough to encrypt, urgent enough to route to the director, and sensitive enough to redact for half a century.

— DeClassX