FBI Case Files: Zodiac Killer (9-HQ-49911) Information and Investigations

Administrative Overview and Case Identification

• Subject: Unknown Subject (UNSUB); Zodiac Murder Cases, San Francisco, California.
• FBI File Numbers:   - Primary File Number: $9-HQ-49911$   - Supplemental Numbers: $9-2296$ (San Francisco Office), $9-68$ (Sacramento Office).
• Victims Named in Record:   - Vallejo Times-Herald: Victim of extortion.   - Cecelia Ann Shepard: Assault-murder victim, Lake Berryessa Area, Napa County, California ($September 27, 1969$).   - Unnamed Cab Driver: Murdered in San Francisco ($October 11, 1969$).   - Other Murders Referenced:     - Solano County ($December 20, 1968$): Two shot to death.     - Vallejo, California ($July 4, 1969$): Two shot; one survived.

Zodiac killer Communications and Modus Operandi

• Correspondence with Press: The assailant, labeled by the Press as the "Zodiac Killer," sent a series of letters and anagrams to newspapers, including the "San Francisco Chronicle" and the "Vallejo Times-Herald."
• Letters and Ciphers:   - On $August 6, 1969$, a cipher was submitted by the Sacramento Division.   - On $November 10, 1969$, the "San Francisco Chronicle" received two letters (one seven-page, one three-page with a cipher) postmarked $November 8$ and $November 9, 1969$.   - In a letter postmarked $November 9, 1969$, the subject claims to wear "transparent finger tip guards" to avoid leaving prints and discusses a bomb drawing for a "system" that "checks out from one end to the other."   - Another note begins with "There's no doubt I will do my Thing!" and ends with the symbol of a circle with a cross through it.
• Chiding Authorities: One letter explicitly chides local authorities for their failure to solve the Zodiac killings.
• Description of Assailant: Witnesses (including an eight-year-old witness to the cab driver murder) provided details leading to a composite sketch distributed by the San Francisco Police Department (SFPD).

Latent Fingerprint Examinations and Suspect Eliminations

• General Investigation: Latent fingerprints and impressions were developed from letters and evidence. The FBI Identification Division conducted numerous comparisons against suspect prints, but no matches were found in any of the following instances:   - Suspects from St. Paul and Brady, Texas: Identified as WMA, born in St. Paul, Minnesota, and WMA, born in Brady, Texas. Fingerprints were not identical to latents; palm prints were not available ($November 1, 1969$).   - Suspect from Napa Case $105907$: Not a match to latent prints ($October 31, 1969$).   - WMA Suspects residing in San Francisco: Two suspects (one born in San Francisco, one with birth details at St. Luke's) were requested for comparison on $November 3, 1969$. Results were negative.   - Suspects from Oakland and San Mateo: Fingerprints of individuals residing in Oakland and San Mateo, California, were checked ($November 6, 1969$). Results were negative.   - Suspect David Odell Martin ($793366D$): Shot and killed by SFPD on $November 21, 1969$. Press reports indicated Martin claimed to be the Zodiac on his deathbed. Subsequent examination by the Homicide Detail, SFPD, confirmed he was not the Zodiac ($November 21, 1969$).   - Veterans Hospital Patients: Fingerprints for several "seriously disturbed mental patients" from Palo Alto and Menlo Park VA hospitals, who were on weekend pass during relevant periods, were requested for comparison ($November 19, 1969$). No identifications were effected.

FBI Laboratory Reports: Handwriting and Cryptanalysis

• Handwriting Analysis ($D-691114053 LL$):   - Characteristics of hand printing on letters from $November 8$ and $November 9, 1969$, matched those on previous threatening letters in the case.   - A separate analysis of specimens from a suspect in Houston determined that standard samples were inadequate for a definitive conclusion ($October 30, 1969$).   - Handwriting of a suspect from Yosemite Park ($K4$) showed no significant evidence of involvement ($November 25, 1969$).
• Cryptanalysis Reports:   - Specimen $Qc33$: A handprinted note beginning "There's no doubt I will do my thing!" was analyzed. The ciphertext portion was deemed unreadable using previously recovered keys. Its brevity precluded further examination at that time.   - Interpretation of "$-+82+-": The theory that this code represents the number "$1620$" could neither be proved nor disproved analytically. The character "$\cdot$" between "November" and "$8$" was suggested to represent the number "$2$," but this inference was based on postmark dates rather than cryptanalysis ($November 28, 1969$).
• Cipher Decryption Claims:   - A resident of Missoula, Montana, claimed to have decoded ZODIAD messages. He asserted that a message named a specific Special Agent and cities like Minneapolis, suggesting the agent's daughter was a future victim.   - Missoula Police verified the individual was likely suffering from an overactive imagination ($November 25, 1969$).

Inter-Agency Cooperation and Specialized Leads

• Evidence Transfer via TWA: Fingerprint cards for a specific suspect were transported aboard TWA Flight $85$ from Friendship Airport near Washington to San Francisco to expedite comparison ($November 10, 1969$).
• Butte Division Lead: Authority was granted to the Butte Division to contact mental and correctional institutions in Montana to determine if suspects matching the Zodiac composite had recently been released or escaped.
• Yosemite National Park Lead: Law enforcement rangers suggested a similarity between an employee and the Zodiac sketch. Identifying data (FBI Number for an arrest for a Penal Code violation) and employment signatures were submitted for analysis ($November 14, 1969$).
• Military Record Reviews:   - Requested review of military records in St. Louis for an individual in Missoula to check for instability or coding expertise ($November 21, 1969$).   - Coordination with the Office of the Provost Marshal, $1^{st}$ Marine Division, regarding a "Communicating a Threat" case ($95-157496$) to see if there was a connection to Zodiac; handwriting comparisons established no connection ($November 24, 1969$).

Questions & Discussion

• Inquiry from Iva, South Carolina ($November 13, 1969$):   - Question: A citizen contacted J. Edgar Hoover noting that a local paper mentioned the Zodiac signature was "Des." She mentioned "Des" is a German word and wondered if it could be a clue.   - Response: Director Hoover sent a formal acknowledgement on $November 19, 1969$, thanking the individual for the information.
• Inquiry from San Jose PD ($November 21, 1969$):   - Question: San Jose PD requested immediate decryption of a letter stating "you're next / The Zodiac" postmarked from Montclair, California. They feared a specific person was in danger.   - Response: The FBI Laboratory's Cryptogram Section attempted to decipher the message, but the results were ultimately negative or inconclusive.