Zodiac Killer

Zodiac Killer
Composite sketch made in 1969 based on eyewitness accounts of the Presidio Heights murder
Criminal status	Unidentified
Motive	Unclear
Wanted by	Federal Bureau of Investigation
Wanted since	1968
Details
Victims	7
Span of crimes	1968–1969
Country	United States
State(s)	California
Location(s)	San Francisco Bay Area Napa Valley
Killed	5
Injured	2
Weapons	9 mm pistol, .22 caliber rifle, knife
Signature
Notes
Wikisource has original text related to this article: Zodiac Killer

The Zodiac Killer is the pseudonym of an unidentified serial killer who murdered five known victims in the San Francisco Bay Area between December 1968 and October 1969. The case has been described as "arguably the most famous unsolved murder case in American history," and has become both a fixture of popular culture and a focus for efforts by amateur detectives.

The Zodiac's known attacks took place in Benicia, Vallejo, unincorporated Napa County, and the city of San Francisco proper. He attacked three young couples and a lone male cab driver. Two of these victims survived. The Zodiac coined his name in a series of taunting messages that he mailed to regional newspapers, in which he threatened killing sprees and bombings if they were not printed. He also said that he was collecting his victims as slaves for the afterlife. He included four cryptograms or ciphers in his correspondence. Two were solved in 1969 and 2020, and two remain unsolved.

In 1974, the Zodiac claimed 37 victims in his last confirmed letter. This tally included victims in Southern California such as Cheri Jo Bates, who was murdered in Riverside in 1966. Despite many theories about the Zodiac's identity, the only suspect authorities ever named was Arthur Leigh Allen, a former elementary school teacher and convicted sex offender who died in 1992.

The unusual nature of the case led to international interest that has been sustained throughout the years. The San Francisco Police Department marked the case "inactive" in 2004 but re-opened it prior to 2007. The case also remains open in the California Department of Justice, Federal Bureau of Investigation, the city of Vallejo, as well as in Napa and Solano counties.

45km
30miles

4

3

2

1

  

Map of the Zodiac Killer attacks

1

Murder of David Faraday and Betty Lou Jensen

2

Attack on Michael Mageau and Darlene Ferrin

3

Attack on Bryan Hartnell and Cecelia Shepard

4

Murder of Paul Lee Stine

Investigators agree on four confirmed attacks by the Zodiac Killer in California. Five victims were killed during these attacks, and two survived:^[1]

1. David Arthur Faraday (17) and Betty Lou Jensen (16) were shot and killed on December 20, 1968, on Lake Herman Road in Benicia.
2. Michael Renault Mageau (19) and Darlene Elizabeth Ferrin (22) were shot around midnight between July 4 and 5, 1969, in the parking lot of Blue Rock Springs Park in Vallejo. Mageau survived the attack; Ferrin was pronounced dead at Kaiser Foundation Hospital.
3. Bryan Calvin Hartnell (20) and Cecelia Ann Shepard (22) were stabbed on September 27, 1969, at Lake Berryessa in Napa County. Hartnell survived, but Shepard died at Queen of the Valley Hospital as a result of her injuries on September 29.
4. Paul Lee Stine (29) was shot and killed on October 11, 1969, in the Presidio Heights neighborhood of San Francisco.

From 1969 to 1974, the Zodiac mailed heavily misspelled letters and ciphers to law enforcement and media outlets. Some letters began, "This is the Zodiac speaking" and were signed with a symbol resembling the crosshairs of a gunsight: .^[2] Four of the mailings had a cryptogram enclosed. Two have been solved, in 1969 and 2020.^[3] The letters were postmarked in San Francisco and Pleasanton.^[4]

The Zodiac's confirmed correspondence with date, recipient, and incipit:

1. July 31st 1969: San Francisco Chronicle, San Francisco Examiner, and Vallejo Times. One-third of "Z408 cipher" enclosed with each letter. "I am the killer of the 2 teenagers last Christmass..."
2. August 4th 1969: Examiner. "This is the Zodiac speaking."
3. October 13th 1969: Chronicle. Swatch of Paul Stine's shirt. "I am the murderer of the taxi driver..."
4. November 8th 1969: Chronicle. "Z304 cipher." The "Dripping Pen" card. "I though you would need a good laugh..."
5. November 9th 1969: Chronicle. Bomb diagram. "...I have killed 7 people".
6. December 20th 1969: Melvin Belli. Swatch of Stine's shirt. "...happy Christmass."
7. April 20th 1970: Chronicle. "Z13 cipher." "My name is..."
8. April 28th 1970: Chronicle. Greeting card. "I hope you enjoy yourselves..."
9. June 26th 1970: Chronicle. "Z32 cipher." "I have become very upset..."
10. July 24th 1970: Chronicle. "I am rather unhappy..."
11. July 26th 1970: Chronicle. "Being that you will not wear some nice ⌖ buttons..."
12. October 5th 1970: Chronicle. Thirteen-hole punch card. "You'll hate me..."
13. October 27th 1970: Paul Avery at Chronicle. Halloween card. "From your secret pal..."
14. March 13th 1971: Los Angeles Times. "...I am crack proof."
15. January 29th 1974: Chronicle. The "Exorcist" letter.

The first murders retroactively attributed to the Zodiac were the shootings of high school students Betty Lou Jensen (16) and David Arthur Faraday (17) on December 20, 1968. Faraday was a student at Vallejo High School, while Jensen was a student Hogan High School. At 8:30 p.m. Faraday picked up Jensen, and the couple visited one of Jensen's friends. Sometime after 9 p.m., they drove to the outskirts of Vallejo and parked at a lover's lane on Lake Herman Road, just inside Benicia city limits. Between 10:15–30 p.m., a passing motorist noticed the couple parked on a gravel runoff near the gate to a water pumping station. They were spotted again at 11 p.m.^{[5][6]: 30–1}

Between 11:05–10 p.m., Faraday and Jensen were attacked. Police determined that their assailant parked his vehicle about ten feet alongside the passenger side of Faraday's car. He fired several shots at Faraday's car as he walked around to the driver's side. None of the shots hit Faraday and Jensen. The couple scrambled to get out through the passenger door. Jensen succeeded. As Faraday was exiting, the killer shot him in the head with a .22-caliber rifle. The assailant chased Jensen as she fled, firing six shots at her back. Only one missed. Police theorized the whole attack took two to three minutes.^{[6]: 30–1 [7]}

At 11:10 p.m., a motorist spotted the couple's bodies and alerted police. Jensen was dead. Faraday was still breathing. He died at the hospital. There were no witnesses and no usable tire or foot prints. The only motive the police could deduce was a "madman" wanting to kill. Despite an intense investigation in the following months, no viable suspects emerged.^{[6]: 30–2} The murders were extensively covered by the media.^{[6]: 37–8}

Darlene Ferrin (22) and Michael Mageau (19) were shot shortly after midnight on July 4, 1969. Ferrin was popular in Vallejo due to her job at a local restaurant, where she met Mageau. On July 4, they went on a date despite the fact that Ferrin was married. After 11:30 p.m., Ferrin received a phone call at her house. She arrived at Mageau's house around 11:50 p.m.^{[6]: 32–5}

Immediately after leaving Mageau's house, the couple noticed they were being followed by a man in a light-colored car. Ferrin drove out of Vallejo in the direction of Lake Herman Road. Shortly before midnight, she turned her car into an empty parking lot at Blue Rock Springs Park.^[8][9] This was another lover's lane, located just two miles from Lake Herman Road. Ferrin either parked or stalled 70 feet from the lot entrance.^[10]: 26 Another vehicle parked about 80 feet to their left. The driver turned his headlights off and sat motionless. Mageau asked who the driver was. Ferrin told him not to worry. The stranger abruptly tore away from the parked couple.^[6]: 34

Five minutes later, the stranger returned, parked a few feet next to Mageau's side of the car and got out. He shone a flashlight into Ferrin's car as he approached. Assuming he was a police officer, the couple rolled down Mageau's window. Without speaking, the stranger fired a 9mm pistol into the car.^[11] One bullet hit Mageau in the right arm, and the other hit Ferrin in the neck. Mageau tried to leave the car, but his door handle was missing or removed. The assailant returned to his car, opened the door, and did something Mageau could not see. As Mageau struggled to exit the vehicle, the stranger shot him and Ferrin two more times each. The killer hurried into his car and drove off. A golf course caretaker heard the shots around 12:10 a.m.^{[6]: 34–5} The perpetrator left no clues that could be traced back to him.^[6]: 38

Three teenagers drove into the parking lot, saw the wounded couple, and got help. Police arrived at 12:20 a.m. Twenty minutes later, Ferrin was pronounced dead at the hospital. Mageau survived and described the attacker as a heavyset white man, around 5'8" tall. He estimated the assailant's weight as 195–200 pounds, with a large face and curly light brown hair. The killer wore dark clothes and no glasses. These details were not enough to develop a suspect.^{[6]: 35, 41} Moments after 12:40 a.m., the Vallejo Police Department (VPD) received a phone call from a payphone two blocks from headquarters. The man on the other end of the line said:

"I want to report a double murder. If you go one mile east on Columbus Parkway to the public park you will find kids in a brown car. They were shot with a 9-millimeter Luger. I also killed those kids last year. Goodbye."^{[6]: 35, 39}

Serial killers will commonly pause to reflect on their actions. Authors Michael Kelleher and David Van Nuys speculated that the seven months between the attacks on Lake Herman Road and at Blue Rock Springs was a "cooling off period" for the Zodiac.^{[6]: 37–8}

Many have speculated that Darlene Ferrin knew her killer. Kelleher and Nuys credit the origin of the theory to Robert Graysmith's 1986 book Zodiac. He argued extensively for a connection based on interviews with Ferrin's friends.^[10]: 39ff A definitive connection has not been proven.

Mageau gave conflicting accounts on whether Ferrin knew her killer. At the hospital, he stated he did not know the murderer. At another point, he said the assailant's name was "Richard". Ferrin's sister claimed one of Darlene's boyfriends was named Richard.^[12] Linda also reported receiving annual phone calls on the Fourth of July from someone who identified himself as the Zodiac.^[11] In the Zodiac's later correspondence, he only ever refers to Ferrin as "girl".^{[6]: 32, 35–6}

In Graysmith's telling, Ferrin and Mageau were chased. They only stopped when their car hit a log and stalled. The detective on the scene noticed that the car was still on and in low gear.^[10]: 31 Kelleher and Nuys suggest that Ferrin would not tell Mageau to ignore the mystery driver, nor would they assume he was a police officer, if they had not stopped at the spot by choice.^{[6]: 36–7}

Ferrin did know Betty Lou Jensen and David Faraday. She lived less than two blocks from Jensen and attended Hogan High School. She was also familiar with Lake Herman Road's status as a lover's lane.^{[6]: 32–3} There is a picture of Ferrin and an unknown man who closely resembles a composite sketch of the Zodiac. In a 2011 episode of America's Most Wanted, police stated they believe the photo was taken in San Francisco in either 1966 or 1967.^[13]

See: Zodiac Letters

On August 1, 1969, the Vallejo Times, San Francisco Chronicle, and San Francisco Examiner all received letters written by someone taking credit for the attacks in Vallejo. The three letters were nearly identical and began, "I am the killer of the 2 teenagers last Christmass at Lake Herman & the girl last 4th of July." The three letters were rife with misspellings and presented the first definitive link between the two separate attacks in Vallejo.^[14][15]

Enclosed in all three letters was a different cryptogram. They combined to form a 408-symbol cipher (Z408). The writer claimed, "In this cipher is my idenity." He demanded the codes be printed on each newspaper's front page. If they were not, he threatened to "cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend."^[10]: 49 The Chronicle published its third of the cryptogram inside the August 2nd edition. In the accompanying article, Vallejo Police Chief Jack E. Stiltz said, "We're not satisfied that the letter was written by the murderer". He requested the killer send more facts to prove his identity.^[16]

On August 4, the Examiner received a letter with the salutation, "Dear Editor This is the Zodiac speaking." This letter marked the debut of the Zodiac persona.^[17]: 161 It was the first time the killer called himself by this nickname.^[18]

In this second letter to the media, the killer wrote at much greater length. He happily obliged Chief Stiltz's request for more information about both murders. He provided minute details about how he shot Michael Mageau. He described the golf course caretaker. Regarding the Lake Herman Road attack, he revealed that he had taped a flashlight to his gun in order to aim easily in the dark. The August 4th letter also referred investigators back to the Z408 cipher. The killer wrote, "when they do crack it they will have me".^{[10]: 55–57}

The decoded message did not reveal the Zodiac's identity. Both the Federal Bureau of Investigation (FBI) and Central Intelligence Agency (CIA) attempted to decrypt the Z408 cipher. On August 5th, it was cracked by Donald and Bettye Harden, a couple in Salinas. Neither was a cryptologist. Bettye deployed a crib by correctly guessing the word "kill" would appear in the message.^{[17]: 162ff}

The message was rife with misspellings and referred to Richard Connell's 1924 short story "The Most Dangerous Game". The Zodiac explained killing was a way of collecting slaves for his afterlife. The full text of the decoded Z408 cipher reads:

"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 to kill something gives me the most thrilling experence it is even better than getting your rocks off with a girl the best part of it is thae when I die I will be reborn in paradice and all the I have killed will become my slaves I will not give you my name because you will try to sloi down or atop my collectiog of slaves for my afterlife ebeorietemethhpiti"^{[10]: 54–5}

VPD asked a psychiatrist at the California Medical Facility in Vacaville to analyze the Zodiac's message. The doctor concluded the writer felt omnipotent based on his fantasy about collecting spiritual slaves. The analysis described the Zodiac as "someone you would expect to be brooding and isolated". The psychiatrist speculated the killer's praise of murder over sex could be "an expression of inadequacy".^[19]

At 4:00 p.m. on September 27, 1969, Pacific Union College students Bryan Hartnell (20) and Cecelia Shepard (22) were picnicking at Lake Berryessa on a small island connected by a sand spit to Twin Oak Ridge. Sometime later, Shepard noticed a man watching them. When he emerged from behind a tree, he put on a black executioner's hood with clip-on sunglasses.^[20] He wore a bib with a white 3x3" symbol on it. He brandished a gun, which Hartnell believed was a .45. The Zodiac said he escaped from jail after killing a guard and needed their car and money to travel to Mexico.^{[21][22]: 20}

Before tying up Shepard, the Zodiac made Shepard bind Hartnell with precut lengths of plastic clothesline. He tightened Hartnell's bonds because Shepard's knots were too loose. Hartnell still believed they were being robbed when the Zodiac drew a knife and stabbed them. Hartnell suffered six wounds and Shepard ten.^[19][23]

The Zodiac hiked 500 yards to Knoxville Road, leaving several footprints for investigators to study. The killer drew the symbol on Hartnell's car door with a black felt-tip pen and wrote beneath it:

Vallejo
12-20-68
7-4-69
Sept 27–69–6:30
by knife^[24]

After hearing the victims' screams, a fisherman and his son sought help. Hartnell untied Shepard's ropes with his teeth, and she freed him.^[10]: 73 Two park rangers arrived and tended to the stricken couple until the ambulance arrived. Napa County deputies Dave Collins and Ray Land responded to the report of the attack.^[20] Shepard was conscious and gave a detailed description of their attacker. She and Hartnell were taken to a hospital in Napa. Shepard lapsed into a coma during transport; she never regained consciousness and died two days later. Hartnell survived to recount his tale to the press.^[25][26]

Earlier that day, a suspicious man had been seen around Lake Berryessa by several people. A dentist and his son saw a heavyset man looking at them from a distance before he hurried off. Around 2:50 p.m., three women noticed a strange man as they stopped on their way to Lake Berryessa. After they had arrived to sunbathe, they noticed the man again.^[10]: 63f Since they had potentially seen the Zodiac without his hood, the women worked with Napa Valley Register photographer Robert McKenzie to create a composite sketch using an Identi-Kit. Police showed the image to other potential witnesses.

The suspect was described as being roughly 6' tall and weighing 200 pounds, which matched the descriptions by Shepard and Hartnell.^{[24][10]: 78} Graysmith also drew a sketch of the Zodiac's costume after Hartnell described it to him.^[27] Napa County detective Ken Narlow was assigned to the case from the outset and worked on solving the crime until his retirement in 1987.^[28]

The Zodiac drove 27 miles from the crime scene to a car wash in downtown Napa. He used a payphone to call the Napa County Sheriff's Department at 7:40 p.m. He told the dispatcher he wished to "report a murder – no, a double murder" and confessed to the crime.^[24] He did not hang up the phone.^[22]: 21 KVON radio reporter Pat Stanley found the phone off the hook a few minutes later. The payphone was located a few blocks from the sheriff's office. Detectives lifted a wet palm print from the phone but were never able to match it to any suspect.^[29]

The last confirmed Zodiac murder took place two weeks after the Lake Berryessa attacks. Around 9:40 p.m. on October 11 in downtown San Francisco, the Zodiac hailed a cab which was driven by a doctoral student named Paul Stine. The killer gave a destination in Presidio Heights. When the taxi arrived at Washington and Maple streets, the killer asked to be driven another block. At Washington and Cherry around 9:55 p.m., the Zodiac shot Stine in the head with a handgun and took his wallet and car keys.^[15]

Three teenagers witnessed the crime from a house directly across the street from Stine's cab. The Zodiac's face was clearly visible by streetlight.^[30] The teenagers watched as the Zodiac wiped down the vehicle and rifled through Stine's clothes. He left behind two partial fingerprints from his right hand. While the Zodiac was tending to the cab, the kids called the San Francisco Police Department (SFPD). They described the criminal as a "husky" white man in a "dark or black jacket". The dispatcher mistakenly alerted SFPD that the suspect was Black.^{[6]: 76–7}

Just two minutes after the call to SFPD, two nearby patrol officers responded to the radio dispatch. They encountered a white man in dark clothes walking north towards the Presidio army base. They pulled alongside the man and asked if he had seen anything suspicious. The man confirmed he had seen someone waving a gun and heading east. The officers hurried away. The Zodiac later claimed he was the witness that spoke to the two officers. When police arrived at the scene, Stine was declared dead. SFPD canvassed the area, including the Presidio. The Zodiac had probably fled the area in a car by then.^{[6]: 77–8}

Police assumed the murder was a result of the robbery. However, the Zodiac mailed a bloody piece of Paul Stine's shirt to the San Francisco Chronicle on October 13.^[22]: 27 He enclosed it in a letter where he boasted about the murder and claimed to have clandestinely watched the SFPD search for him. The Zodiac also threatened to shoot a tire on a school bus and kill children as they exited.^[15]

The teenage witnesses helped a police artist make a composite sketch of the man they saw at Stine's cab. The two patrol officers who questioned the witness near the scene realized it may have been the Zodiac. They also helped develop a sketch of the suspect.^{[30][6]: 78}

SFPD detectives Bill Armstrong and Dave Toschi were assigned to the case.^[6]: 78 Toschi ended up working on the case by himself and filled eight filing cabinets with potential suspects.^[31] In 1976 he told the Associated Press that Zodiac's letters were an "ego game". He believed the killer lived in the San Francisco Bay Area, "He's a weekend killer. Why can't he get away Monday through Thursday? Does his job keep him close to home? I would speculate he maybe has a menial job, is well thought of and blends into the crowd...I think he's quite intelligent and better educated than someone who misspells words as frequently as he does in his letters."^[32]

After working on the Zodiac case for seven years, Toschi started writing anonymous letters praising his own investigative work to Chronicle columnist Armistead Maupin. Two years later in 1978, Toschi was removed from the case and demoted to pawn shop detail. He expressed regret for the hoax. That same year, Maupin also received a purported Zodiac letter. SFPD investigated whether Toschi wrote it as well and concluded he did not.^[33][34]

On October 22, 1969, mental patient Eric Weill duped attorney Melvin Belli into a conversation on KGO-TV's A.M. San Francisco. Investigators concluded Weill was not the Zodiac. He called the Oakland Police Department and demanded to speak to Belli or F. Lee Bailey on TV. During the show, Weill told Belli he would not reveal his identity for fear of being executed. He arranged a rendezvous with Belli on Mission Street in Daly City and did not show.^{[35][22]: 32}

On November 8, the Zodiac mailed a card with a 340-character cryptogram (Z340) to the San Francisco Chronicle. He asked for his code to printed on the front page. It remained unsolved for 51 years. One cryptologist ranked Zodiac's unsolved ciphers second only to the Voynich manuscript.^[36] Zodiac ciphers were crowdsourced through a variety of websites, which led to gradual breakthroughs.^[37][38]

Z340 was deciphered by an international team of private citizens on December 5, 2020. The cryptology group included American software engineer David Oranchak, Australian mathematician Sam Blake and Belgian programmer Jarl Van Eycke.^[39][40] Using a program made by Van Eycke called AZdecrypt, the team ran 650,000 possible solutions for the cipher until the program came up with the best possible encryption key.^[41][42]

In the decrypted message, the Zodiac denied being the "Sam" who spoke on A.M. San Francisco and explained he was not afraid of the gas chamber "because it will send me to paradice all the sooner." The team submitted their findings to the FBI's Cryptographic and Racketeering Records Unit, which verified the decryption and concluded the decoded message gave no further clues to the Zodiac's identity.^[39][40][43] Subsequent analysis confirmed the Z340 decryption using unicity distance as a measure.^[37]

The decoded Z340 cipher included the usual Zodiac respellings:

"I hope you are having lots of fan in trying to catch me that wasnt me on the tv show which bringo up a point about me I am not afraid of the gas chamber becaase it will send me to paradlce all the sooher because e now have enough slaves to worv for me where every one else has nothing when they reach paradice so they are afraid of death I am not afraid because i vnow that my new life is life will be an easy one in paradice death"^[43][44]

On November 9, the Zodiac mailed a seven-page letter to the Chronicle. In his postscript, he claimed he was stopped and questioned by two policemen three minutes after he shot Stine. He threatened to blow up a school bus and included a diagram of the bomb. The Zodiac boasted police would never catch him because "I have been to clever for them".^[15] The Chronicle excerpted the letter on November 12.^[45]

One year after the Lake Herman Road murders on December 20, the Zodiac mailed a letter to Marvin Belli. He enclosed another swatch of Paul Stine's shirt. He pleaded, "Please help me I am drownding...I can not remain in control for much longer."^[22]: 35

For the remainder of 1970, the Zodiac continued to communicate with authorities and the press by mail. In a letter to the San Francisco Chronicle postmarked April 20, he wrote, "My name is—". It was followed by a 13-character cipher (Z13) which has not been definitively solved.^[46]

The Z13 cipher:

One cryptologist solved Z13 as "Alfred E. Neuman".^[17]

Bomb diagram, April 20, 1970

Dragon Card, postmarked April 28, 1970

In the same letter, the Zodiac denied responsibility for the fatal bombing of an SFPD police station in Golden Gate Park. He added, "there is more glory to killing a cop than a cid because a cop can shoot back."^[47] He also included a diagram of another school bus bomb. At the bottom of the diagram, he wrote: " = 10, SFPD = 0."

On April 28, 1970, the Zodiac mailed a greeting card to the Chronicle. He wrote, "I hope you enjoy yourselves when I have my BLAST." On the back of the card, the Zodiac threatened to use his bus bomb unless two things happened: the Chronicle should write about his bomb, and people should wear "some nice Zodiac butons"^[48]

In a letter to the San Francisco Chronicle postmarked June 26, 1970, the killer was upset no one was wearing Zodiac buttons. He claimed, "...I punished them in another way. I shot a man sitting in a parked car with a .38." This may have been a reference to the murder of SFPD Sergeant Richard Radetich. He was shot through the window of his squad car by an unidentified gunman during a routine traffic stop.^[49] Radetich's murder is unsolved, but the SFPD denies that Zodiac is a suspect in the case.^[47]

A Phillips 66 roadmap of the San Francisco Bay Area was enclosed with the letter. At Mount Diablo, the Zodiac drew a modified symbol as a compass rose. The cardinal points were labeled 0, 3, 6, 9 clockwise from the top. The Zodiac confirmed that 0 "to be set to Mag. N."

The letter concluded with a 32-character cipher (Z32):

The Zodiac claimed that the map and the cipher would reveal where he had buried his bomb. Z32 has never been definitively decoded and no bomb was never located.^[41][46] In another letter, the Zodiac explained, "The Mt. Diablo code concerns Radians + # inches along the radians."^[50] In 1981, Gareth Penn deduced that when the map was divided as per the Zodiac's hint, three of his attacks aligned along one radian.^{[51]: 3–4} On one arm of the radian lay the Blue Rock Springs and Lake Herman Road murders. The other arm of the radian centered on Mount Diablo extended to the site of Paul Stine's murder.^[17]: 190

In a letter postmarked July 24, 1970 to the San Francisco Chronicle, the Zodiac again complained about no one wearing buttons. He claimed to have "a little list" which included the woman and her baby he drove around for several hours. The details match Kathleen Johns' description of her abduction on March 22, four months earlier.

Two days later on July 26, the Zodiac mailed another letter to the Chronicle. He again parodied "As Some Day It May Happen (I Have a Little List)" from The Mikado, adding his own lyrics about his potential victims. The letter was signed with a large Zodiac symbol and a new score: " = 13, SFPD = 0". The letter's postscript explained the Mount Diablo code from his previous letter.

The "13 Hole Punch Card", October 7, 1970

The "Halloween Card", October 27, 1970

On October 7, 1970, the San Francisco Chronicle received a three-by-five-inch card (nicknamed the "13 Hole Punch Card") signed by Zodiac with the symbol and a small cross reportedly drawn in blood.^[52] Thirteen holes were punched across the card, and its message was formed by pasting type from the Chronicle. Bill Armstrong and Dave Toschi agreed it was "highly probable" that Zodiac sent the card.^[53]

On October 27, 1970, Paul Avery received a Halloween card signed by "Z" alongside the symbol.^[53] A handwritten note read, "Peek-a-boo, you are doomed." The Chronicle covered this threat on its front page.^[10]: 160 The card's postmark was from a San Francisco mailbox that afternoon.^[54] The implication of a fourteenth Zodiac victim was speculated based on the phrase "4-teen" found in the card.^[10]: 178 Avery refused police protection and started carrying a pistol.^[55] His colleagues wore "I Am Not Avery" buttons.^[56] Shortly after the "Halloween Card", Avery also received an anonymous letter about the parallels between the 1966 murder of Cheri Jo Bates and the Zodiac.^{[10]: 161–2}

In a March 13, 1971, letter to the Los Angeles Times, the Zodiac taunted police and claimed 17 victims. Zodiac expert Tom Voigt theorized that the letter's postmark was a joke about an unpleasant letter coming from a town called "Pleasanton".^[4]

Zodiac remained silent for nearly three years. The Chronicle received a letter from the Zodiac, postmarked January 29, 1974 from San Mateo County. It complained that columnist Count Marco needed to "feel superior to everyone" and praised The Exorcist (1973) as "the best saterical comidy that I have ever seen." The letter included part of a verse from "Tit-willow Song" in The Mikado and an unusual symbol at the bottom that has remained unexplained. Zodiac concluded the letter with a new score, "Me = 37, SFPD = 0."^[15][57]

Psychiatrist David Van Nuys theorized Zodiac stopped killing because he had multiple personality disorder. It may have lessened over time as it often can, which would also explain the reduced intensity of Zodiac's letters.^[58]

Many more unconfirmed Zodiac letters were sent to the media. On August 1, 1973, a letter was mailed to the Albany Times Union in New York. The return address was the symbol. The writer promised to kill again on August 10. A three-line code in the letter was supposed to reveal the name and location of the victim. FBI cryptanalysts deciphered the code as "[redacted by the FBI] Albany Medical Center. This is only the beginning." No murder matched the details in the letter, and the handwriting was not a definitive match for Zodiac's.^[1]

The San Francisco Chronicle received a letter postmarked February 14, 1974, explaining that the Symbionese Liberation Army's initials spelled out an Old Norse word meaning "kill". The SLA had recently kidnapped newspaper heiress Patricia Hearst.^[1][59] The handwriting was not authenticated as the Zodiac's.^[60]

A letter to the Chronicle postmarked May 8, 1974, opined that Badlands (1973) was "murder-glorification" and asked the paper to remove its advertisements. Signed by "A citizen", the handwriting, tone, and sarcasm were similar to Zodiac's letters. The Chronicle also received an anonymous letter postmarked July 8, 1974 , complaining about antifeminist columnist Marco Spinelli. The letter was signed, "the Red Phantom (red with rage)".^[22]: 44

In 2007, an American Greetings Christmas card was discovered in the Chronicle's photo files. Its postmark was from 1990 in Eureka. The card was handed over to the Vallejo police. A photocopy of two United States Post Office keys on a magnet keychain was enclosed. The handwriting on the envelope resembled Zodiac's. A forensic document examiner deemed it inauthentic. The discovery electrified Zodiac researchers. It suggested the killing spree may not have been stopped by death or imprisonment and that the Zodiac might still be alive.^[61][62][63]

There is no consensus regarding the number of victims the Zodiac Killer actually killed or the length of his criminal spree. In 1976, SFPD detective Dave Toschi said, "We know for sure he killed at least six", and the Zodiac had "a personal boxscore of 37".^[32] Robert Graysmith estimated forty-nine Zodiac victims.^{[10]: 308–11} Many high-profile murders and attacks in the 60s and 70s were seen as possible Zodiac crimes, but none have been confirmed.

On April 9, 1962, a man called the police in Oceanside, California and said, "I am going to pull something here in Oceanside and you'll never be able to figure it out." At 11:10 p.m. on April 10, cab driver Raymond Davis (29) told his dispatcher he was taking a fare to South Oceanside. The next day, his body was found near the mayor's house in St. Malo, a gated community in Oceanside.^[64][65] Days later, the suspected killer called the police again, “Do you remember me calling you last week and telling you that I was going to pull a real baffling crime? I killed the cab driver and I am going to get me a bus driver next.” The police placed armed guards on buses.^[66]

In 2019, the unsolved murder was connected to the Zodiac when Kristi Hawthorne, the Director of the Oceanside Historical Society, was researching St. Malo for another project. She stumbled upon a story about Davis' murder and further research dug up several parallels to the Zodiac killings. Davis' murder prefigured Paul Stine's by 7 years. Both cabbie murders involved wealthy neighborhoods. The ammunition was .22 caliber, which matches the Lake Herman Road attack. The taunting of police and the threat against buses also foreshadowed the Zodiac.^[67][64][68] Hawthorne presented her findings to the Oceanside Police Department, which began an inquiry.^[66]

On June 2, 1963, a sniper fired two shots at a group of teenagers at Tajiguas, California. None of them were hit, and the weapon was identified as .22 caliber.^[69]

Two days later on June 4, Robert George Domingos (18) and his fiancée Linda Faye Edwards (17) were shot dead on a beach in Gaviota State Park, just west of Tajiguas. They skipped school at Lompoc High School for Senior Ditch Day.^[7][70] On June 5, their parents called the police when the teenagers did not return home. Several of their belongings, like Edwards' purse, were inside Domingos' car.^[71][72]

Police believed that the assailant attempted to bind the victims with pre-cut rope. This was the same modus operandi as the Lake Berryessa attacks.^[7] When the victims got loose and attempted to flee, the killer shot them repeatedly in the back and chest. Domingos was shot 11 times and Edwards 8 times.^[71] The killer placed their bodies in a small shack and tried to burn it to the ground.^[70]

The firearm was probably a .22 caliber semi-automatic rifle, the same type used in the Lake Herman Road murders.^[73][70] The Winchester Western Super X copper-coated bullets also matched the Zodiac's.^[70] The lot number of the .22 ammunition was traced to an April purchase from a store in Santa Barbara. The only other place that same lot number turned up was at Vandenberg Air Force Base. Investigators looked into purchasers of the ammunition at both locations.^[69]

In a 1972 press conference, Santa Barbara County Sheriff John Carpenter stated "there now appears to be a high degree of probability" that the Zodiac committed the 1963 murders.^[74] He continued, "Although the anticipated response to this statement would be one of skepticism, let me say that we do not make this assertion frivolously."^[75][73] A classmate of the slain teenagers who grew up to be a clinical psychologist and police officer said in 2011, "I believe the murders were the work of the Zodiac killer, but I can’t prove it."^[70] SFPD detectives Bill Armstrong and Dave Toschi investigated the murders in 1972. Toschi said a connection is possible.^[76]

On February 5, 1964, Johnny Ray Swindle and Joyce Ann Swindle (both 19), a newlywed couple from Alabama on their honeymoon, were shot while walking along Ocean Beach in San Diego. A sniper with a .22 caliber long rifle shot them five times from a nearby cliff. The killer then shot each of them once in the head at close range. Similar to the Zodiac murders, Johnny was shot behind the ear. Despite multiple bullet wounds, he remained alive for hours and died at the hospital. Joyce died almost instantly from shots to her back, left arm, and head. The killer took Joyce's necklace as well as Johnny's wallet and Timex.^[7] The same brand watch was found at the Cheri Jo Bates crime scene and assumed to be the killer's.^[67]

Johnny's mother said she could not think of him having any enemies.^[77] His sister theorized the murders might have been the work of the Zodiac. Police investigated a 51-year-old man living in a beach shack, a teenager alleged by a priest to be violent, and a 19-year-old Marine from San Diego who killed his parents and sister in Illinois. Police speculated that the Swindles were victims of a "thrill killer", and they also saw a parallel with the Domingos and Edwards murders.^[7] In both the Santa Barbara and Ocean Beach killings, the victims were shot from a distance, then again at close range.^[78] Both the Ocean Beach and Lake Herman Road murders used a .22 Remington Arms Model 550-1 rifle, but the ballistics did not match between the cartridges found at the two scenes. The murders at Lake Berryessa, Santa Barbara, and Ocean Beach were all near water.^[67]

On October 30, 1966, Cheri Jo Bates, an 18-year-old student at Riverside City College (RCC), spent the evening at the campus library annex until it closed at 9:00 p.m. Neighbors reported hearing a scream around 10:30. Her father reported her missing, and she was found dead the next morning at 6:30 a.m.^[7] She was found a short distance from the library, between two abandoned houses slated to be demolished for campus renovations. She had been brutally beaten and stabbed to death. The wires in her Volkswagen's distributor cap had been pulled out. A man's paint-spattered Timex watch with a torn wristband was found nearby. The watch stopped at 12:24, but police believe that the attack had occurred much earlier.^{[79][10]: 165–6}

One month later, on November 29, nearly identical typewritten letters were mailed to Riverside police and the Riverside Press-Enterprise, titled "The Confession." The author claimed responsibility for the Bates murder, providing details of the crime that were not released to the public. The author warned that Bates "is not the first and she will not be the last."^{[10]: 168–9}

The typewritten confession received by the Riverside Police Department and The Press-Enterprise on November 29, 1966

The inscription upon the Riverside City College library desk, discovered in 1967

In December 1966, a macabre poem was discovered carved into the bottom side of a desktop in the RCC library. Titled "Sick of living/unwilling to die," the poem's language and handwriting resembled that of the Zodiac's letters. It was signed with what were assumed to be a set of lowercase initials (r h) inscribed below. During the 1970 investigation, Sherwood Morrill, California's top "questioned documents" examiner, expressed his opinion that the poem was written by the Zodiac.^{[10]: 170–2}

On March 13, 1971, five months after Avery's article linking the Zodiac to the Bates murder, the Zodiac mailed a letter to the Los Angeles Times. In the letter, he credited the police, instead of Avery, for discovering his "Riverside activity, but they are only finding the easy ones, there are a hell of a lot more down there."^[80] The connection between Bates and the Zodiac remains uncertain.

On June 8, 1967, Enedine Molina (35) and Fermin Rodriguez (36) were parked on Vallecitos Road in Alameda County. A stranger approached and told them to get out of the car. Rodriguez was fatally shot and Molina was abducted. The killer stopped near Sunol Regional Wilderness. Molina tried to escape and was killed. Rape and robbery were ruled out as motives. The murders occurred near Pleasanton. The March 1971 Zodiac letter to the Los Angeles Times was postmarked in Pleasanton.^[81]

On February 21, 1970, John Franklin Hood (24) and his fiancée, Sandra Garcia (20), visited East Beach in Santa Barbara. The couple left their Santa Barbara home at 6 p.m. Early the following day, their fully-clothed bodies were discovered under their blanket. Hood was stabbed eleven times, mainly in the face and back. Garcia received the brunt of the vicious attack, leaving her almost unrecognizable. The bone-handled 4" fish knife used in their murder was partially buried in the sand beneath the blanket. There appeared to be no sexual interference, and robbery was ruled out. The double-murder was similar to the 1963 killing of Domingos and Edwards, thirty miles west. It also paralleled the 1969 Lake Berryessa attack.^[70][82]

On the night of March 22, 1970, Kathleen Johns (22) was driving to Petaluma with her 10-month-old daughter. Johns was also seven months pregnant.^[83] She left San Bernardino at 4:30 p.m. At 11:30 p.m. on Highway 132 near Patterson, a vehicle behind her blinked its lights. A man pulled alongside and convinced her to pull over because her left rear wheel was loose. He fixed it, but when she pulled away it immediately fell off. Johns told Paul Avery that the man offered to drive her to a gas station that was in sight just up the road.^[84][85][86]

Johns asked the man if he always helped strangers this way. He replied, "By the time I get through with them, they won't need my help." He drove past the gas station and kept Johns captive for two hours. He told her repeatedly, "you know I'm going to kill you". When he abruptly stopped, Johns jumped out of the car with her infant and hid in an irrigation ditch. The man searched for her with a flashlight before leaving. A passing farmer drove Johns to a police station in Patterson. When she saw the Wanted poster from Paul Stine's murder, she exclaimed, "Oh my god...that's him".^{[84][87]: 268} Johns car was found in flames on Highway 132.^[86] A few months later, the Zodiac referenced this kidnapping in a letter to the Chronicle.^[88]

Around 5:25 a.m. on June 19, 1970, SFPD Sergeant Richard Phillip "Rich" Radetich (25) was shot three times by a .38 caliber revolver. He was serving a parking ticket in Haight Ashbury when he was shot through the driver's window of his squad car. The SFPD started assigning two officers to every patrol car. A week later, the Zodiac claimed to have shot a man "in a parked car with a .38". Police never found direct evidence that Zodiac killed Radetich. In 2004, the SFPD reopened the Radetich investigation.^[47][89]

Registered nurse Donna Lass (25) was last seen on September 6, 1970, in Stateline, Nevada. She worked at the Sahara Tahoe casino until 2:00 a.m. that morning. Her boss and landlord both received phone calls from an anonymous man who claimed Lass had an illness in her family and would not be returning.^[10]: 178 Her car was parked near her apartment, which was undisturbed.^[90]

Paul Avery received a Lake Tahoe postcard several months later with superficial connections to Lass' disappearance.^{[91][53][87]: 274} Like the "13-Hole Punch Card", the text was a collage of phrases like "Peek through the pines...around in the snow". It also said, "Sought Victim 12" and included the symbol.^{[92][93][22]: 43}

In 1986, the Placer County Sheriff's Office located a skull near Emigrant Gap along California State Route 20 in the Sierra Nevada. The South Lake Tahoe Police Department began investigating a connection to the Zodiac killing spree in 2001. DNA profiling determined it was Donna Lass' skull in 2023.^[92][94]

The "Astrological Murders" were committed by a suspected serial killer who was also active in the same region of California and around the same time as the Zodiac. Police across multiple jurisdictions made a tentative connection between a single culprit and at least a dozen unsolved homicides that occurred between the late 1960s and early '70s. All of the victims were female and were killed in a variety of ways, including strangulation, drowning, throat-cutting, and bludgeoning, occasionally after being drugged. The killings were linked because victims were dumped in ravines and killed in conjunction with astrological events, such as the winter solstice, equinox, and Friday the 13th.^{[10]: 309, 311}

The Zodiac was also suspected of being the perpetrator behind the "Santa Rosa hitchhiker murders". Between 1972–3, at least seven female hitchhikers were murdered in Sonoma County and Santa Rosa.^[95]: 163 In the Zodiac's January 29, 1974 "Exorcist letter" to the Chronicle, he claims thirty-seven victims. A symbol in that letter matched Chinese characters on a soy barrel carried by one of the Santa Rosa victims. The Zodiac had warned he would vary his modus operandi in a previous letter, "when I comitt my murders, they shall look like routine robberies, killings of anger, + a few fake accidents, etc."^[96]

One of the main Zodiac suspects, Arthur Leigh Allen, was also suspected of being the Santa Rosa killer.^[97]

In April 2004, the SFPD cited caseload pressure and marked the Zodiac case "inactive."^[98] By March 2007, they reactivated the case.^[99] The case remains open in Riverside and Napa County.^[100][101]

In 2018, the Vallejo Police Department attempted to use GEDmatch to catch the Zodiac.^[102] They did not receive definitive results.^[103] The FBI's investigation was still ongoing as of 2020.^[104]

The SFPD had investigated an estimated 2,500 Zodiac suspects by 2009, a half-dozen of whom are seen as credible.^[105][106] Richard Grinell, who runs the website Zodiac Ciphers, stated in 2022 that "there are probably 50 or 100 suspects named every year."^[9]

The only man ever named by the police as a suspect is Arthur Leigh Allen, a former elementary school teacher and convicted sex offender who died in 1992.^[5][107] Allen denied being the Zodiac.^[108] Allen had been interviewed by police from the early days of the original investigation and was the subject of several search warrants over a twenty-year period. In 2007, Graysmith noted that several detectives described Allen as the most likely suspect.^[109] In 2010, Toschi stated that all the evidence against Allen ultimately "turned out to be negative."^[110]

Other suspects seen as viable include Earl Van Best Jr., Gary Francis Poste, Giuseppe Bevilacqua, Lawrence Kane, Paul Doerr, Richard Gaikowski, and Richard Marshall.^{[111][112][9]}

The Zodiac case has been called "the most famous unsolved murder case in American history."^[43] The weirdness of the spree has sustained international interest for years.^[113] The decoding of cipher Z408 by the Hardens prefigured the role amateurs would play in the life of the case. A cottage industry of "Zodiologists" sprung up in the wake of the killings.^[114] They try to solve the case and have informal annual meetings.^[115][116] Several websites collect information about the crimes and ciphers.^[117]

Dozens of books and documentaries have focused on the Zodiac, nearly all produced by amateurs.^{[8][118][119]} The original and most influential amateur book was Robert Graysmith's Zodiac (1986). He was working at the San Francisco Chronicle as a cartoonist while the Zodiac was corresponding with the paper. Graysmith compiled his research into an authoritative investigation that remains a touchstone for other researchers. Most of the books published about the Zodiac do not rise above fan fiction.^[17]: 193

Theories about the Zodiac's identity are rampant. In Zodiac, Graysmith refers to Arthur Leigh Allen as "Robert Hall Starr" to protect his identity and avoid litigation. In 2002, Graysmith wrote directly about Allen in Zodiac Unmasked.^[120] Attributing victims to the Zodiac is also a popular pastime. One Zodiologist has persistently claimed to also be a target of the killer.^[121] Since 2013, accusing United States Senator Ted Cruz of being the Zodiac has been a popular Internet meme.^[122]

The Zodiac also spawned copycat killers like Heriberto Seda in New York City and Shinichiro Azuma in Japan.^[123] Seda actually called himself "the Zodiac".^[124] In 2021, an anonymous author sent letters to media outlets in Albany using a "Chinese Zodiac Killer" sobriquet.^[104]

The first film about the Zodiac Killer was produced two years after his last confirmed murder during his letter-writing campaign. Tom Hanson's The Zodiac Killer was actually a cockamamie scheme to capture the culprit. The film premiered on April 19, 1971, at the Golden Gate Theater in San Francisco. The audience were given a survey with the prompt, "I think the Zodiac kills because..." They were asked to complete the sentence and promised the best response would be rewarded with a Kawasaki motorcycle.^[125]

The audience surveys were secretly compared to the Zodiac's handwriting. Hanson hoped the killer's egotism would lure him to the movie, and he actually deployed volunteers to detain anyone whose handwriting matched the Zodiac's.^[126] The scheme lasted for several screenings, and the volunteers actually confronted one potential suspect.^[127]

At the end of 1971, Dirty Harry was released. It featured a thinly disguised version of the Zodiac Killer named Scorpio. Other movie villains are seen as inspired by the Zodiac, such as the Gemini Killer in The Exorcist III (1990), John Doe in David Fincher's Seven (1995), and Riddler in Matt Reeves' The Batman (2022).^[128]

In 2007, Fincher returned to the subject of serial killers with Zodiac. He grew up in the Bay Area during the height of Zodiac's mayhem. The film was an adaptation of Robert Graysmith's books.^[129] The film focuses on Graysmith and Paul Avery's investigation over a period of twenty-three years.^[130][105] The filmmakers conducted extensive research, including interviews with people involved with the case. The film posits Arthur Leigh Allen's culpability and led to more public interest in the Zodiac.^[73][63]

• List of serial killers in the United States
• List of fugitives from justice who disappeared

• Schmeh, Klaus. Nicht Zu Knacken: Von Ungelösten Enigma-Codes Zu Den Briefen Des Zodiac-Killers. Hanser, 2012.

Wikimedia Commons copies of FBI file #9-HQ-49911 on the Zodiac Killer: Sections 1, 2, 3, 4, 5

• Media related to Zodiac killer at Wikimedia Commons
• Works related to Zodiac Killer at Wikisource
• "Zodiac Murder Map" – Google Map plotting definite and possible Zodiac attacks (with details).