The Zodiac Killer: Inside America's Most Infamous Unsolved Serial Murder Case
Between 1968 and 1969, the Zodiac Killer murdered five people in Northern California and taunted police with coded letters. Over 50 years later, he's never been identified.
On the evening of December 20, 1968, two high school students parked on a quiet road outside Vallejo, California. Within minutes, both were shot. The boy died at the hospital. The girl was already dead when police arrived. There were no witnesses, no motive, and no suspects. Six months later, a letter arrived at three Bay Area newspapers. It opened with: "I am the killer of the 2 teenagers last Christmass." Enclosed with each letter was one-third of a 408-character cryptogram. The writer demanded the newspapers print his cipher on the front page, or he would "cruse around all weekend killing lone people in the night."
The Zodiac Killer had introduced himself. Over the next year, he would kill at least three more people, wound two others, and send over 20 letters to newspapers and police filled with threats, ciphers, and taunting details that only the killer could know. He claimed 37 victims total, a number most investigators believe was exaggerated. He was never caught. And despite over half a century of investigation, DNA analysis, and obsessive amateur detective work, the Zodiac Killer's identity remains unknown.
What You'll Learn
- •Who Were the Zodiac's Confirmed Victims?
- •What Did the Zodiac's Letters Say?
- •Have the Zodiac's Ciphers Been Solved?
- •Who Are the Main Suspects?
- •Why Hasn't DNA Solved the Case?
- •What Made the Zodiac Different From Other Serial Killers?
- •Is the Case Still Open?
- •Frequently Asked Questions
Who Were the Zodiac's Confirmed Victims?
Police and investigators agree on four attacks and seven victims between December 1968 and October 1969. All occurred in or near the San Francisco Bay Area.
December 20, 1968: Lake Herman Road, Benicia. David Faraday (17) and Betty Lou Jensen (16) were parked on a quiet road when someone pulled up alongside their car, ordered them out, and opened fire with a .22-caliber pistol. Jensen was shot five times in the back as she tried to run. Faraday was shot once in the head. Jensen died at the scene; Faraday died at the hospital.
July 4, 1969: Blue Rock Springs Park, Vallejo. Darlene Ferrin (22) and Michael Mageau (19) were parked at another lover's lane, just two miles from the first attack. A man pulled up, walked to their car, and fired multiple shots with a 9mm pistol. Ferrin died at the hospital. Mageau survived despite being shot multiple times, and later provided a description of the attacker. About 40 minutes after the shooting, someone called the Vallejo Police Department from a pay phone and claimed credit for both the Blue Rock Springs attack and the Lake Herman Road murders.
September 27, 1969: Lake Berryessa, Napa County. Bryan Hartnell (20) and Cecelia Shepard (22) were picnicking by the lake when a man approached wearing a black executioner-style hood with a crosshair symbol on the chest. He claimed to be an escaped convict who needed their car and money. He tied them up with pre-cut lengths of clothesline, then stabbed them repeatedly with a knife. Hartnell was stabbed six times and survived. Shepard was stabbed ten times and died two days later at the hospital. Before leaving, the killer wrote on the door of Hartnell's car: the dates of his previous attacks, the crosshair symbol, and the words "Vallejo 12-20-68 / 7-4-69 / Sept 27-69-6:30 / by knife."
October 11, 1969: Presidio Heights, San Francisco. Taxi driver Paul Stine (29) was shot once in the head with a 9mm pistol while driving a fare through the wealthy Presidio Heights neighborhood. The killer tore a piece of Stine's shirt, which he later mailed to the San Francisco Chronicle as proof. Three teenagers witnessed the killer from across the street and described a stocky white man, about 5'8" to 5'10", with a crew cut. Police arrived within minutes but, due to a dispatch error that described the suspect as a Black male, an officer may have actually spoken to the killer and let him walk away.
What Did the Zodiac's Letters Say?
The Zodiac's letters are what transformed a regional murder case into a national obsession. Between 1969 and 1974, he sent over 20 letters to Bay Area newspapers, primarily the San Francisco Chronicle, as well as to police, journalist Paul Avery, and attorney Melvin Belli.
The first batch of letters arrived on July 31, 1969, three weeks after the Blue Rock Springs shooting. Each of the three Bay Area papers received a nearly identical letter taking credit for the first two attacks, along with one-third of a 408-symbol cipher. The writer demanded the papers publish the ciphers or he would go on a killing spree.
The letters escalated over time. After the Stine murder, the Zodiac mailed a piece of the victim's bloody shirt to prove he was the killer. He threatened to shoot schoolchildren on a school bus. He described how he would build a bomb. He taunted investigators by name. In one letter, he wrote: "I like killing people because it is so much fun." In another, he claimed his victims would become his slaves in the afterlife.
The last confirmed Zodiac letter arrived at the Chronicle on January 29, 1974, referencing the film "The Exorcist." In it, he claimed to have killed 37 people. After that, the letters stopped. Nobody knows why.
The letters contained details about the crimes that hadn't been released to the public, confirming they came from the actual killer. They also contained misspellings and unusual phrasing that may have been deliberate misdirection or genuine quirks of the writer.
Have the Zodiac's Ciphers Been Solved?
The Zodiac sent four cryptograms. Their status:
Z408 (solved in 1969): The first cipher, split into three parts and mailed to three newspapers, was cracked within a week by Donald and Bettye Harden, a schoolteacher couple from Salinas, California. The decoded message read in part: "I like killing people because it is so much fun. It is more fun than killing wild game in the forrest because man is the most dangeroue anamal of all." It also described killing as a way to collect "slaves" for the afterlife. Notably, the cipher did NOT contain the killer's name, despite his implication that it would.
Z340 (solved in 2020): This 340-character cipher arrived with the November 8, 1969 letter and went unsolved for 51 years. In December 2020, a team of three codebreakers, David Oranchak, Sam Blake, and Jarl Van Eycke, cracked it using a combination of computational techniques and manual analysis. The decoded message read: "I hope you are having lots of fun in trying to catch me... I am not afraid of the gas chamber because it will send me to paradice all the sooner because I now have enough slaves to work for me." Again, no name. Their solution was later published in a 2024 academic paper.
Z13 (unsolved): A 13-character cipher sent on April 20, 1970, accompanied by the message "My name is." The cipher is by some interpretations too short to be solved definitively; there are too many possible solutions for so few characters.
Z32 (unsolved): A 32-character cipher from June 26, 1970, paired with a map and instructions for finding a bomb. This remains unsolved, though its brevity makes a unique solution unlikely.
The cracking of Z340 in 2020 was a breakthrough, but it also confirmed what many feared: the ciphers didn't contain the Zodiac's identity. If his name is hidden anywhere in his communications, it's in the two shorter unsolved ciphers, which may never yield definitive answers.
Who Are the Main Suspects?
Over 2,500 people have been named as potential Zodiac suspects over the decades. The most prominent:
Arthur Leigh Allen is the only suspect ever publicly named by police. A former schoolteacher and convicted sex offender from Vallejo, Allen was investigated extensively throughout the 1970s and 1980s. The circumstantial evidence was significant: a friend said Allen had spoken of wanting to kill people and call himself "Zodiac" before the murders began; he owned the same type of watch (a Zodiac brand) that bore a crosshair symbol similar to the killer's signature; he lived near the first two crime scenes; and he couldn't account for his whereabouts during several attacks.
However, Allen's fingerprints didn't match prints recovered from the Zodiac's letters and taxi cab. His handwriting didn't match the letters. And DNA extracted from the stamps on the Zodiac's envelopes didn't match Allen (though the DNA sample's quality and provenance are debated). Allen died of a heart attack in 1992, and the case against him remains circumstantial.
Gary Francis Poste was named in 2021 by a group called the Case Breakers, led by a former Army counterintelligence agent. They claimed Poste's forehead scars matched the Zodiac composite sketch, and that dark room photos contained hidden messages. Law enforcement agencies did not confirm these claims, and the FBI stated the case remained open.
Other suspects over the years have included Lawrence Kane, Rick Marshall, Ross Sullivan, Earl Van Best Jr., and dozens of others proposed by amateur investigators. None has been confirmed.
Why Hasn't DNA Solved the Case?
This is the question that frustrates everyone, especially given that forensic genetic genealogy has solved other famous cold cases like the Golden State Killer in 2018.
The challenge is the DNA evidence itself. Investigators have attempted to extract DNA from the stamps and envelope flaps of the Zodiac's letters, assuming the killer licked them to seal them. However:
- •The letters are over 50 years old, and DNA degrades over time.
- •Multiple people may have handled the letters, contaminating any genetic material.
- •It's possible the Zodiac didn't lick the stamps or envelopes himself; he may have used a sponge or had someone else seal them.
- •The existing DNA samples are partial profiles, not full enough for a definitive match or genealogical search.
As of 2025, investigators have been re-examining evidence from the letters and crime scenes using more advanced extraction techniques. No definitive DNA match has been publicly announced, but officials have said they remain optimistic that forensic genetic genealogy could eventually crack the case, similar to how it identified the Golden State Killer through distant relatives in public DNA databases.
The stamps on the original letters represent the best remaining hope. If a consistent DNA profile can be extracted from the adhesive, it could potentially be run through genealogy databases to identify the killer or his family line, even if the Zodiac himself is long dead.
What Made the Zodiac Different From Other Serial Killers?
Several things set the Zodiac apart and explain why the case has endured in public consciousness:
The communication. Most serial killers avoid contact with police and media. The Zodiac craved it. He created a persona, gave himself a name, designed a symbol, and essentially conducted a public performance of serial murder. The letters weren't just confessions; they were entertainment for him.
The ciphers. The cryptographic element turned the case into a puzzle that anyone could try to solve. It engaged mathematicians, codebreakers, and amateur detectives worldwide, creating a participatory mystery that's lasted decades.
The taunting. The Zodiac didn't just describe his crimes; he mocked the people trying to catch him. He criticized police incompetence, threatened more violence, and played mind games with specific journalists and investigators.
The abrupt stop. The Zodiac's confirmed killing spree lasted less than a year (December 1968 to October 1969), and his letters stopped in 1974. Did he die? Go to prison for something else? Move away? Simply stop? The unanswered ending is as unsettling as the crimes themselves.
For other famous unsolved cases, see our articles on Jack the Ripper, the Voynich Manuscript (another famous unsolved cipher), and D.B. Cooper. The Hinterkaifeck Murders in Bavaria offer another chilling unsolved case from a different era.
Is the Case Still Open?
Yes. The San Francisco Police Department marked the case "inactive" in 2004 but reopened it in 2006. The FBI, the California Department of Justice, the city of Vallejo, and the Napa and Solano county sheriff's offices all maintain it as an open case.
In practical terms, the investigation has shifted from traditional detective work to forensic science. The hope is that advances in DNA technology will eventually produce a usable genetic profile that can be matched through genealogical databases. Every year, cold case units across the country solve cases that seemed impossible using these techniques.
The Zodiac community online remains enormous and active. Reddit's r/ZodiacKiller has tens of thousands of members analyzing every detail of the case. New books, documentaries, and theories appear regularly. The case was dramatized in David Fincher's 2007 film "Zodiac," which introduced it to a new generation.
Whether the Zodiac will ever be definitively identified depends largely on what science can extract from those aging letters and envelopes. The clock is ticking, but it hasn't run out yet.
Timeline of Key Events
| Year | Event |
|---|---|
| Dec 20, 1968 | David Faraday and Betty Lou Jensen shot on Lake Herman Road |
| Jul 4, 1969 | Darlene Ferrin killed, Michael Mageau wounded at Blue Rock Springs |
| Jul 31, 1969 | First Zodiac letters arrive at three newspapers with Z408 cipher |
| Aug 8, 1969 | Donald and Bettye Harden crack Z408 cipher |
| Sep 27, 1969 | Bryan Hartnell and Cecelia Shepard attacked at Lake Berryessa |
| Oct 11, 1969 | Taxi driver Paul Stine murdered in Presidio Heights |
| Nov 8, 1969 | Z340 cipher mailed to Chronicle (unsolved for 51 years) |
| Jan 29, 1974 | Last confirmed Zodiac letter received |
| 1992 | Prime suspect Arthur Leigh Allen dies |
| 2004 | SFPD marks case "inactive" |
| 2006 | Case reopened |
| 2007 | David Fincher's "Zodiac" film released |
| Dec 2020 | Z340 cipher finally cracked by Oranchak, Blake, and Van Eycke |
| 2021 | Case Breakers name Gary Francis Poste as suspect (unconfirmed) |
| 2025 | DNA re-examination efforts continue; case remains open |
Frequently Asked Questions
How many people did the Zodiac Killer actually kill?
Five confirmed victims: Betty Lou Jensen, David Faraday, Darlene Ferrin, Cecelia Shepard, and Paul Stine. Two additional victims (Michael Mageau and Bryan Hartnell) survived their attacks. The Zodiac claimed 37 victims in his final letter, but there's no evidence to support that number. Some investigators have suggested he may have been responsible for additional unsolved murders in the region, but none have been confirmed.
Was the Zodiac Killer ever caught?
No. Despite being the subject of one of the largest investigations in California history, the Zodiac Killer was never identified or arrested. The case remains open with multiple law enforcement agencies. Advances in DNA technology represent the most promising avenue for eventually identifying the killer.
What did the solved Zodiac ciphers reveal?
The Z408 (solved in 1969) described the killer's stated motivation: killing for "fun" and collecting "slaves" for the afterlife. The Z340 (solved in 2020) contained similar themes, taunting police and referencing the gas chamber. Neither cipher contained the Zodiac's real name, despite his implications that they would.
Why is Arthur Leigh Allen the main suspect?
Allen accumulated the most circumstantial evidence of any suspect: prior statements about wanting to call himself "Zodiac," proximity to crime scenes, ownership of a Zodiac-brand watch, and inability to account for his whereabouts during attacks. However, his fingerprints, handwriting, and DNA (from available samples) didn't match the evidence. He was never charged and died in 1992.
Could the Zodiac Killer still be alive?
It's possible but increasingly unlikely. Based on witness descriptions from 1969, the Zodiac appeared to be in his late 20s to early 40s, which would make him roughly 80 to 100 years old today. If he's deceased, forensic genetic genealogy could still identify him through living relatives, similar to how the Golden State Killer was identified in 2018.
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