The Zodiac Killer: Chilling Letters and Crimes

A bloodstained scrap of a cab driver’s shirt arrived at the San Francisco Chronicle inside a plain envelope. It was October 1969, and the sender called himself “the Zodiac.” He scrawled a crossed-circle symbol as his signature, and taunted police with details only a killer could know.

David Faraday was 17 years old when he promised to bring Betty Lou Jensen, his 16-year-old date, home by 11 p.m. The two teenagers were shot at close range as they sat in their parked car on a cold night in December 1968, on Lake Herman Road outside Benicia, California. Their parents would learn the news early the next morning, when police knocked on their doors. Betty Lou was found face down, just outside the passenger door, five bullet wounds in her back. David lay slumped beside the car, a single fatal bullet behind his left ear.

Darlene Ferrin, 22, worked as a waitress in nearby Vallejo. On July 4, 1969, she pulled into Blue Rock Springs Park with Michael Mageau, a 19-year-old friend. Just after midnight, another car pulled up behind them and left. Minutes later, the car returned. Its driver stepped out and fired into Darlene’s car, unloading a .9mm pistol. Darlene was killed; Michael, though wounded, survived. As he lay bleeding, he heard the killer walk away, then return to fire two more shots at each victim at close range. Later that night, a man called the Vallejo Police Department from a payphone, calmly stating, “I want to report a double murder. If you will go one mile east on Columbus Parkway, to the public park, you will find the kids in a brown car. They were shot with a 9-millimeter Luger. I also killed those kids last year.” The call was traced to a phone booth near the police station.

On August 1, 1969, three Bay Area newspapers—Vallejo Times-Herald, San Francisco Chronicle, and San Francisco Examiner—received nearly identical letters. Each included one-third of a cryptogram, a 408-symbol cipher. The author demanded the ciphers be published, threatening to kill again if ignored. The letters opened with, “Dear Editor, This is the murderer of the 2 teenagers last Christmas at Lake Herman.” The killer included details that hadn’t been made public: the type of weapon, the brand of ammunition, the positions of the bodies.

Donald Harden, a high school teacher in Salinas, California, and his wife Bettye, spent a weekend cracking the code. The decoded message began, “I like killing people because it is so much fun.” The rest rambled through fantasies and threats, ending with, “I will not give you my name.” Police and amateur cryptographers would spend decades trying to solve the other ciphers Zodiac sent; two remain unbroken.

Bryan Hartnell and Cecelia Shepard were both college students from Pacific Union College, spending the afternoon of September 27, 1969, at Lake Berryessa, Napa County. They settled on a remote shore, reading and talking. As the sun lowered, a man approached from behind a tree, wearing a black hood resembling an executioner’s mask, clip-on sunglasses over the eyeholes, and a bib-like chest piece marked with a white cross-circle. He carried a pistol and a pre-cut length of clothesline.

Speaking in a low voice, the attacker told the couple that he had escaped from prison, needed money and a car, and intended to go to Mexico. After tying both victims, he stabbed them repeatedly with a long knife—ten times into Cecelia’s back, six in Bryan’s. He then drew his symbol and the dates of his previous crimes on the door of Bryan’s car, along with the time of attack and the notation, “by knife.” Cecelia died two days later; Bryan survived by playing dead until rescuers arrived.

Two weeks later, on October 11, 1969, Paul Stine, a 29-year-old cab driver, picked up a fare in San Francisco’s Presidio Heights. He drove the man to the corner of Washington and Cherry Streets. At 9:55 p.m., Stine was shot in the head at point-blank range. The killer took Stine’s wallet, keys, and tore off a section of his shirt. Several children, and an adult, witnessed the killer calmly wiping down the cab and walking away. Less than an hour later, the San Francisco Chronicle received another letter from the Zodiac, containing a piece of Stine’s shirt as proof. He taunted police, threatening to “wipe out a school bus some morning.”

The Zodiac’s letters often included new ciphers. On November 8, 1969, he mailed a 340-character cipher—now known as the “Z340”—which would remain unsolved for fifty years. The following day, he sent another letter with a seven-page confession and a map of the Bay Area, marked with a cross-circle. He claimed there was a bomb buried at the location, set to detonate if police didn’t decipher the code.

On December 20, 1969, exactly a year after the first murders, the Zodiac sent a letter claiming credit for the murder of Kathleen Johns, a young woman abducted near Modesto, California, in March 1970. Kathleen, seven months pregnant, was driving with her ten-month-old daughter when a stranger flagged her down, claiming her car’s wheel was loose. He offered her a ride and drove around for over an hour, refusing to let her go. Kathleen escaped with her child by jumping from the car and hiding in a field. She later identified her abductor as the man in the Zodiac composite sketch.

On July 26, 1970, the Zodiac mailed a letter to the San Francisco Chronicle including a hand-drawn map of the San Francisco Bay Area, a 32-character cipher, and claims of a hidden bomb. He warned, “The Map coupled with this code will tell you where the bomb is set. You have until next fall to dig it up.” Police scoured the area but found nothing.

On October 27, 1970, the Chronicle’s crime reporter Paul Avery received a Halloween card. The card was signed with a “Z” and the cross-circle symbol. Scribbled on the card was the message, “Peek-a-boo, you are doomed.” Avery, already obsessed with the case, began wearing a button on his coat featuring the killer’s symbol for protection.

The Zodiac’s correspondence grew more erratic. On March 13, 1971, he mailed a letter to the Los Angeles Times, taking credit for the unsolved 1966 murder of Cheri Jo Bates in Riverside, California. This was the first time Zodiac linked himself to a crime outside the Bay Area.

The last confirmed Zodiac letter arrived at the San Francisco Chronicle on January 29, 1974. In it, the killer praised the film “The Exorcist,” calling it “the best saterical comidy that I have ever seen.” He ended with a chilling score: “Me = 37, SFPD = 0,” claiming he had killed thirty-seven people.

The investigation that followed was one of the largest in California history, involving law enforcement from at least four jurisdictions: Vallejo Police, Benicia Police, Napa County Sheriff’s Office, and San Francisco Police Department. The FBI was called in to analyze the ciphers and letters, seeking handwriting and fingerprint matches.

Detectives examined more than 2,500 suspects over decades. The primary suspect named publicly was Arthur Leigh Allen, a former elementary school teacher and convicted sex offender. Allen owned a Zodiac watch featuring the same cross-circle logo used by the killer. He lived near the sites of the first murders and was reported by acquaintances for making disturbing comments about killing people and writing ciphers. Police searched his home in 1972 and 1991, seizing typewriters, weapons, and homemade bombs. Handwriting experts compared Allen’s script to the Zodiac letters but found no match. His fingerprints and DNA did not conclusively link him to the crimes. Allen died in 1992 without ever being charged.

The ciphers themselves became a focus for professional and amateur codebreakers. The Harden couple solved the first 408-symbol cipher in just over a week. The Z340 cipher, sent in November 1969, was decoded only in December 2020 by a team of cryptologists using computer algorithms. The message contained no new clues, but repeated Zodiac’s enjoyment of killing and taunting police.

Zodiac’s letters sometimes included details that only the killer would know, such as the color and position of the victims’ cars, the wounds on their bodies, or the direction of tire tracks at the scene. He described the exact ammunition used in the Lake Herman Road murders and drew diagrams of the crime scenes.

The Lake Berryessa attack introduced a new detail: a costume. The Zodiac wore a homemade black hood, cut from a rectangular piece of cloth, with eye holes covered by clip-on sunglasses. The chest bib, made from a sheet of fabric, was stitched with a 3-inch white cross-circle, attached by safety pins and cord. This elaborate disguise was unique among serial killers of the era.

Paul Stine’s murder was distinctive for happening in a crowded city neighborhood. The police dispatcher mistakenly described the suspect as a black male, allowing the white suspect to walk past officers who were searching the area. This error may have allowed the killer to escape undetected.

Two of the four cryptograms Zodiac sent have never been solved. The 32-character cipher sent with the Bay Area map and the cipher sent to the San Francisco Chronicle in 1970 both remain mysteries. Experts debate whether they are genuine codes or simply gibberish.

The Zodiac claimed credit for crimes far beyond the five confirmed murders. He wrote that he killed 37 people, but law enforcement was only able to conclusively link him to seven attacks, resulting in five deaths and two survivors. No clear evidence ever supported his higher claims, but unsolved murders in the region continue to be re-examined for possible links.

Kathleen Johns’ abduction was unlike the other attacks. She survived, but the Zodiac’s letter claimed responsibility and included details of her ordeal. She described her abductor as heavyset, with dark-rimmed glasses and a distinctive voice, matching the composite sketch made after Paul Stine’s killing.

The Zodiac’s communication with the media was unprecedented. He sent at least 18 letters, ciphers, and postcards from 1969 to 1974. His demands for publication forced newspapers to cooperate with police, balancing public safety with the risk of encouraging further violence. He threatened to attack school buses, claiming he would “pick off the kiddies as they come bouncing out.”

The Halloween card sent to Paul Avery was covered in images of skeletons and included the taunt, “I feel it in my bones, you ache to know my name. And so I’ll clue you in…” The card contained a puzzle, but no solution was found.

The Riverside murder of Cheri Jo Bates, which the Zodiac later claimed, occurred in 1966—two years before his first known attack. Bates was a college student in Riverside, found stabbed to death beside her car. Typed letters, signed “the Confession,” were sent to police and media, describing her murder. Handwriting experts found similarities to Zodiac’s later letters, but no definitive connection.

The case’s biggest break came when the Stine murder was linked to the other attacks by the piece of shirt received by the Chronicle. Forensic testing confirmed the blood type matched Stine’s. Zodiac continued to include shirt fragments in later letters as proof of authenticity.

Law enforcement agencies developed a behavioral profile of the killer. He was believed to be white, aged 25 to 35 at the time of the first murders, well-educated, with knowledge of ciphers, firearms, and forensic procedures. He demonstrated careful planning and left few physical traces at crime scenes.

Several suspects were investigated, including Arthur Leigh Allen, but none were conclusively linked to all the murders. DNA testing of the stamps and envelopes used in the Zodiac letters failed to match Allen or any other suspect. Partial fingerprints were found on some letters, but these were smudged and could not be used to identify the sender.

The Zodiac case exposed limitations in information sharing between police departments. The murders occurred in multiple counties, each with its own procedures and evidence storage. Investigators sometimes missed connections or failed to share tips in a timely manner.

The Zodiac’s cryptograms inspired generations of amateur sleuths. The first cipher, solved by Donald and Bettye Harden, revealed the killer’s mentality but no clues to his name or motive. The unsolved ciphers keep curiosity alive, drawing cryptologists from around the world.

For decades, the Zodiac Killer case has remained open in multiple jurisdictions. The San Francisco Police Department, Vallejo Police Department, and Napa County Sheriff’s Office all keep cold case files on Zodiac. The FBI continues to maintain a case file and appeals for public tips.

The Zodiac’s impact on American culture is hard to overstate. True crime books, films, and documentaries have kept the story alive. T-shirts and buttons with his coded symbol have appeared at protests and in pop culture. The case led to the creation of new protocols for sharing information between law enforcement agencies, as well as new methods for analyzing cryptograms and anonymous threats.

The last confirmed Zodiac communication, sent in January 1974, contained a cryptic reference to “the Exorcist,” as well as a “score” of “Me = 37, SFPD = 0.” This was the final taunt—an explicit claim of victory over the police and a reminder that the killer had never been caught.

On September 27, 1969, at Lake Berryessa, the Zodiac killer wrote the dates of his previous murders and the words “by knife” on Bryan Hartnell’s car door using a black marker, immediately after stabbing Hartnell and Cecelia Shepard.