Zodiac Killer is the pseudonym of an unidentified serial killer who operated in Northern California from at least the late 1960s to the early 1970s. The Zodiac murdered victims in Benicia, Vallejo, Napa County, and San Francisco between December 1968 and October 1969. The killer targeted four men and three women between the ages of 16 and 29, with two of the men surviving attempted murder. The Zodiac himself claimed to have killed up to 37 victims. The killer originated the name "Zodiac" in a series of taunting letters and cards sent to the local Bay Area press. The letters included four cryptograms (or ciphers). Of the four cryptograms sent, only one has been definitively solved.
Sketch of the Zodiac Killer
|Victims||5 confirmed dead, 2 injured, possibly 20–28 total dead (claimed to have killed 37)|
Span of crimes
|State(s)||California, possibly also Nevada|
Suspects have been named by law enforcement and amateur investigators, but no conclusive evidence has surfaced. The San Francisco Police Department marked the case "inactive" in April 2004, but re-opened it at some point prior to March 2007. The case also remains open in the city of Vallejo, as well as in Napa County and Solano County. The California Department of Justice has maintained an open case file on the Zodiac murders since 1969.
- 1 Victims
- 2 Timeline
- 2.1 Lake Herman Road attack
- 2.2 Blue Rock Springs attack
- 2.3 Letters from the Zodiac
- 2.4 Lake Berryessa attack
- 2.5 Presidio Heights attack
- 2.6 Communication from the Zodiac
- 2.7 Modesto attack
- 2.8 Further Zodiac communications
- 2.9 Zodiac letter to Paul Avery
- 2.10 Riverside attack
- 2.11 Lake Tahoe disappearance
- 2.12 Santa Barbara attack
- 2.13 Final Zodiac letter
- 2.14 Later letters of suspicious authorship
- 3 Current status of investigations
- 4 Suspects
- 5 See also
- 6 Notes
- 7 References
- 8 Further reading
- 9 External links
Although the Zodiac claimed to have committed 37 murders in letters to the newspapers, investigators agree on only seven confirmed victims, two of whom survived. They are:
- David Arthur Faraday, 17, and Betty Lou Jensen, 16: shot and killed on December 20, 1968, on Lake Herman Road, within the city limits of Benicia. Coordinates:
- Michael Renault Mageau, 19, and Darlene Elizabeth Ferrin, 22: shot on July 4, 1969, in the parking lot of Blue Rock Springs Park in Vallejo. While Mageau survived the attack, Ferrin was pronounced dead on arrival at Kaiser Foundation Hospital. Coordinates:
- Bryan Calvin Hartnell, 20, and Cecelia Ann Shepard, 22: stabbed on September 27, 1969, at Lake Berryessa in Napa County. Hartnell survived eight stab wounds to the back, but Shepard died as a result of her injuries on September 29, 1969. Coordinates:
- Paul Lee Stine, 29: shot and killed on October 11, 1969, in the Presidio Heights neighborhood in San Francisco. Coordinates:
The following murder victims are suspected to be victims of Zodiac, though none have been confirmed:
- Robert Domingos, 18, and Linda Edwards, 17: shot and killed on June 4, 1963, on a beach near Gaviota. Edwards and Domingos were identified as possible Zodiac victims because of specific similarities between their attack and the Zodiac's attack at Lake Berryessa six years later. Coordinates:
- Cheri Jo Bates, 18: stabbed to death and nearly decapitated on October 30, 1966, at Riverside City College in Riverside. Bates's possible connection to the Zodiac only appeared four years after her murder when San Francisco Chronicle reporter Paul Avery received a tip regarding similarities between the Zodiac killings and the circumstances surrounding Bates's death. College coordinates:
- Donna Lass, 25: last seen September 6, 1970, in Stateline, Nevada. A postcard with an advertisement from Forest Pines condominiums (near Incline Village at Lake Tahoe) pasted on the back was received at the Chronicle on March 22, 1971, and has been interpreted as the Zodiac claiming Lass's disappearance as a victim. No evidence has been uncovered to connect Lass's disappearance with the Zodiac Killer definitively.
- The Zodiac is also a suspect in the unsolved Santa Rosa hitchhiker murders.
There is also a suspected third escapee from the Zodiac Killer:
Lake Herman Road attack
The first murders widely attributed to the Zodiac Killer were the shootings of high school students Betty Lou Jensen and David Faraday on December 20, 1968, on Lake Herman Road, just inside Benicia city limits. The couple were on their first date and planned to attend a Christmas concert at Hogan High School about three blocks from Jensen's home. The couple instead visited a friend before stopping at a local restaurant and then driving out on Lake Herman Road. At about 10:15 p.m., Faraday parked his mother's Rambler in a gravel turnout, which was a well-known lovers' lane. Shortly after 11:00 p.m., their bodies were found by Stella Borges, who lived nearby. The Solano County Sheriff's Department investigated the crime but no leads developed.
Utilizing available forensic data, Robert Graysmith postulated that another car pulled into the turnout, just prior to 11:00 pm and parked beside the couple. The killer apparently exited the second car and walked toward the Rambler, possibly ordering the couple out of the Rambler. Jensen appeared to have exited the car first, yet when Faraday was halfway out, the killer apparently shot him in the head. The killer then shot Jensen five times in the back as she fled; her body was found 28 feet from the car. The killer then drove off.
Blue Rock Springs attack
Just before midnight on July 4, 1969, Darlene Ferrin and Michael Mageau drove into the Blue Rock Springs Park in Vallejo, four miles (6.4 km) from the Lake Herman Road murder site, and parked. While the couple sat in Ferrin's car, a second car drove into the lot and parked alongside them but almost immediately drove away. Returning about 10 minutes later, this second car parked behind them. The driver of the second car then exited the vehicle, approaching the passenger side door of Ferrin's car, carrying a flashlight and a 9 mm Luger. The killer directed the flashlight into Mageau's and Ferrin's eyes before shooting at them, firing five times. Both victims were hit, and several bullets had passed through Mageau and into Ferrin. The killer walked away from the car but upon hearing Mageau's moaning, returned and shot each victim twice more before driving off.
On July 5, 1969, at 12:40 a.m., a man phoned the Vallejo Police Department to report and claim responsibility for the attack. The caller also took credit for the murders of Jensen and Faraday six-and-a-half months earlier. Police traced the call to a phone booth at a gas station at Springs Road and Tuolumne, located about three-tenths of a mile (500 m) from Ferrin's home and only a few blocks from the Vallejo Police Department. Ferrin was pronounced dead at the hospital. Mageau survived the attack despite being shot in the face, neck and chest. Mageau described his attacker as a 26-to-30-year-old, 195-to-200-pound (88 to 91 kg) or possibly even more, 5-foot-8-inch (1.73 m) white male with short, light brown curly hair.
Letters from the Zodiac
On August 1, 1969, three letters prepared by the killer were received at the Vallejo Times Herald, the San Francisco Chronicle, and The San Francisco Examiner. The nearly identical letters—subsequently described by a psychiatrist to have been written by "someone you would expect to be brooding and isolated"—took credit for the shootings at Lake Herman Road and Blue Rock Springs. Each letter also included one-third of a 408-symbol cryptogram which the killer claimed contained his identity. The killer demanded they be printed on each paper's front page or he would "cruse [sic] 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."
"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 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"
— The solution to Zodiac's 408-symbol cipher. The meaning, if any, of the final eighteen letters has not been determined.
The Chronicle published its third of the cryptogram on page four of the next day's edition. An article printed alongside the code quoted Vallejo Police Chief Jack E. Stiltz as saying "We're not satisfied that the letter was written by the murderer" and requested the writer send a second letter with more facts to prove his identity. The threatened murders did not happen, and all three parts were eventually published.
On August 7, 1969, another letter was received at The San Francisco Examiner with the salutation "Dear Editor This is the Zodiac speaking." This was the first time the killer had used this name for identification. The letter was a response to Chief Stiltz's request for more details that would prove he had killed Faraday, Jensen and Ferrin. In it, the Zodiac included details about the murders which had not yet been released to the public, as well as a message to the police that when they cracked his code "they will have me."
On August 8, 1969, Donald and Bettye Harden of Salinas, California, cracked the 408-symbol cryptogram. It contained a misspelled message in which the killer said he was collecting slaves for the afterlife. No name appears in the decoded text, and the killer said that he would not give away his identity because it would slow down or stop his slave collection.
Lake Berryessa attack
On September 27, 1969, Pacific Union College students Bryan Hartnell and Cecelia Shepard were picnicking at Lake Berryessa on a small island connected by a sand spit to Twin Oak Ridge. A white man, about 5 feet 11 inches (1.80 m) weighing more than a 170 pounds (77 kg) with combed greasy brown hair, approached them wearing a black executioner's-type hood with clip-on sunglasses over the eye-holes and a bib-like device on his chest that had a white three-by-three-inch (7.6 cm × 7.6 cm) cross-circle symbol on it. He approached them with a gun, which Hartnell believed to be a .45. The hooded man claimed to be an escaped convict from a jail with a two-word name, in either Colorado or Montana (a police officer later inferred he had been referring to a jail in Deer Lodge, Montana), where he had killed a guard and subsequently stolen a car, explaining that he now needed their car and money to go to Mexico, as the vehicle he had been driving was "too hot".
He had brought precut lengths of plastic clothesline and told Shepard to tie up Hartnell, before he tied her up. The killer checked, and tightened Hartnell's bonds after discovering Shepard had bound Hartnell's hands loosely. Hartnell initially believed this event to be a weird robbery, but the man drew a knife and stabbed them both repeatedly, Hartnell suffering six and Shepard ten wounds in the process. The killer then hiked 500 yards (460 m) back up to Knoxville Road, drew the cross-circle 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."
At 7:40 p.m., the killer called the Napa County Sheriff's office from a pay telephone to report this latest crime. The caller first stated to the operator that he wished to "report a murder - no, a double murder," before stating that he had been the perpetrator of the crime. The phone was found, still off the hook, minutes later at the Napa Car Wash on Main Street in Napa by KVON radio reporter Pat Stanley, only a few blocks from the sheriff's office, yet 27 miles (43 km) from the crime scene. Detectives were able to lift a still-wet palm print from the telephone but were never able to match it to any suspect.
After hearing their screams for help, a man and his son who were fishing in a nearby cove discovered the victims and summoned help by contacting park rangers. Napa County Sheriff's deputies Dave Collins and Ray Land were the first law enforcement officers to arrive at the crime scene. Cecelia Shepard was conscious when Collins arrived, providing him with a detailed description of the attacker. Hartnell and Shepard were taken to Queen of the Valley Hospital in Napa by ambulance. Shepard lapsed into a coma during transport to the hospital and never regained consciousness. She died two days later, but Hartnell survived to recount his tale to the press. Napa County Sheriff Detective Ken Narlow, who was assigned to the case from the outset, worked on solving the crime until his retirement from the department in 1987.
Presidio Heights attack
Two weeks later on October 11, 1969, a white male passenger entered the cab driven by Paul Stine at the intersection of Mason and Geary Streets (one block west from Union Square) in San Francisco requesting to be taken to Washington and Maple Streets in Presidio Heights. For reasons unknown, Stine drove one block past Maple to Cherry Street; the passenger then shot Stine once in the head with a 9mm, took Stine's wallet and car keys, and tore away a section of Stine's bloodstained shirt tail. This passenger was observed by three teenagers across the street at 9:55 p.m., who called the police while the crime was in progress. They observed a man wiping the cab down before walking away towards the Presidio, one block to the north. Two blocks from the crime scene, patrol officer Don Fouke and Eric Zelms, responding to the call, observed a white man, walking along the sidewalk east on Jackson Street, and stepping onto a stairway leading up to the front yard of one of the homes on the north side of the street; the encounter lasted only five to ten seconds.
Fouke estimated the white male pedestrian to be 35-to-45 years old, 5'10" tall and with a crew cut hair, somewhat similar but slightly older than the description of the teenagers who observed the killer in and out of Stine's cab as a 25-to-30-year-old crewcut white male at about 5-foot-8-inch (1.73 m) to 5-foot-9-inch (1.75 m) tall. The police radio dispatcher had however initially alerted officers to be on the lookout for a black suspect, so Fouke and Zelms drove past him without stopping; the mix-up in descriptions remains unexplained. A search ensued, but no suspects were found. This was the last officially confirmed kill by the Zodiac Killer.
The Stine murder was initially thought to be a routine cabbie-killing, a robbery that has escalated. However quickly, on October 13, the San Francisco Chronicle received a new letter from Zodiac containing a piece of bloody shirt and taking credit for the killing. The three teen witnesses worked with a police artist to prepare a composite sketch of Stine's killer; a few days later, this police artist returned, working with the witnesses to prepare a second composite sketch of the killer. Detectives Bill Armstrong and Dave Toschi were assigned to the case.[n 1] The San Francisco Police Department investigated an estimated 2,500 suspects over a period of years.
Communication from the Zodiac
On October 14, 1969, the Chronicle received another letter from the Zodiac, this time containing a swatch of Paul Stine's shirt tail as proof he was the killer; it also included a threat about killing schoolchildren on a school bus. To do this, Zodiac wrote, "just shoot out the front tire & then pick off the kiddies as they come bouncing out." At 2:00 p.m. on October 20, 1969, someone claiming to be the Zodiac called the Oakland Police Department (OPD), demanding that one of two prominent lawyers, F. Lee Bailey or Melvin Belli, appear on the local television show A.M. San Francisco, hosted by Jim Dunbar. Bailey was not available, but Belli did appear on the show. Dunbar appealed to the viewers to keep the lines open, and eventually, someone claiming to be the Zodiac called several times and said his name was "Sam". Belli agreed to meet with him in Daly City, but the suspect never showed up.
On November 8, 1969, the Zodiac mailed a card with another cryptogram consisting of 340 characters. The 340-character cipher has never been decoded. Numerous possible solutions have been suggested, but none can be claimed as definitive.
On November 9, 1969, the Zodiac mailed a seven-page letter stating that two policemen stopped and actually spoke with him three minutes after he shot Stine. Excerpts from the letter were published in the Chronicle on November 12 including the Zodiac's claim; that same day, Officer Don Fouke wrote a memo explaining what had happened the night of Stine's murder. On December 20, 1969, exactly one year after the murders of David Faraday and Betty Lou Jensen, the Zodiac mailed a letter to Belli that included another swatch of Stine's shirt; the Zodiac said he wanted Belli to help him.
On the night of March 22, 1970, Kathleen Johns was driving from San Bernardino to Petaluma to visit her mother. She was seven months pregnant and had her 10-month-old daughter beside her. While heading west on Highway 132 near Modesto, a car behind her began honking its horn and flashing its headlights. She pulled off the road and stopped. The man in the car parked behind her, approached her car, stated that he observed that her right rear wheel was wobbling, and offered to tighten the lug nuts. After finishing his work, the man drove off; yet when Johns pulled forward to re-enter the highway the wheel almost immediately came off the car. The man returned, offering to drive her to the nearest gas station for help. She and her daughter climbed into his car.
During the ride the car passed several service stations but the man did not stop. For about 90 minutes he drove back and forth around the backroads near Tracy. When Johns asked why he was not stopping, he would change the subject. When the driver finally stopped at an intersection, Johns jumped out with her daughter and hid in a field. The driver searched for her using his flashlight telling her that he would not hurt her, before eventually giving up. Unable to find her, he got back into the car and drove off. Johns hitched a ride to the police station in Patterson.
When Johns gave her statement to the sergeant on duty, she noticed the police composite sketch of Paul Stine's killer and recognized him as the man who had abducted her and her child. Fearing he might come back and kill them all, the sergeant had Johns wait, in the dark, at the nearby Mil's Restaurant. When her car was found, it had been gutted and torched.
Most accounts say he threatened to kill her and her daughter while driving them around, but at least one police report disputes that. Johns's account to Paul Avery of the Chronicle indicates her abductor left his car and searched for her in the dark with a flashlight; however, in one report she made to the police, she stated he did not leave the vehicle.
Further Zodiac communications
Zodiac continued to communicate with authorities for the remainder of 1970 via letters and greeting cards to the press. In a letter postmarked April 20, 1970, the Zodiac wrote, "My name is _____," followed by a 13-character cipher. The Zodiac went on to state that he was not responsible for the recent bombing of a police station in San Francisco (referring to the February 18, 1970, death of Sgt. Brian McDonnell two days after the bombing at Park Station in Golden Gate Park) but added "there is more glory to killing a cop than a cid [sic] because a cop can shoot back." The letter included a diagram of a bomb the Zodiac claimed he would use to blow up a school bus. At the bottom of the diagram, he wrote: " = 10, SFPD = 0."
Zodiac sent a greeting card postmarked April 28, 1970, to the Chronicle. Written on the card was, "I hope you enjoy yourselves when I have my BLAST," followed by the Zodiac's cross circle signature. On the back of the card, the Zodiac threatened to use the bus bomb soon unless the newspaper published the full details he wrote. He also wanted to start seeing people wearing "some nice Zodiac butons [sic]."
In a letter postmarked June 26, 1970, the Zodiac stated he was upset that he did not see people wearing Zodiac buttons. He wrote, "I shot a man sitting in a parked car with a .38." The Zodiac was possibly referring to the murder of Sgt. Richard Radetich, a week earlier, on June 19. At 5:25 am, Radetich was writing a parking ticket in his squad car when an assailant shot him in the head with a .38-caliber pistol. Radetich died 15 hours later. SFPD denies the Zodiac was involved in this murder; it remains unsolved.
Included with the letter was a Phillips 66 roadmap of the San Francisco Bay Area. On the image of Mount Diablo, the Zodiac had drawn a crossed-circle similar to the ones he had included in previous correspondence. At the top of the crossed circle, he placed a zero, and then a three, six, and a nine. The accompanying instructions stated that the zero was "to be set to Mag. N." The letter also included a 32-letter cipher that the killer claimed would, in conjunction with the code, lead to the location of a bomb he had buried and set to go off in the fall. The cipher was never decoded, and the alleged bomb was never located. The killer signed the note with " = 12, SFPD = 0."
In a letter to the Chronicle postmarked July 24, 1970, the Zodiac took credit for Kathleen Johns's abduction, four months after the incident. In a July 26, 1970 letter, the Zodiac paraphrased a song from The Mikado, adding his own lyrics about making a "little list" of the ways he planned to torture his "slaves" in "paradice". The letter was signed with a large, exaggerated cross circle symbol and a new score: " = 13, SFPD = 0". A final note at the bottom of the letter stated, "P.S. The Mt. Diablo code concerns Radians + # inches along the radians." In 1981, a close examination of the radian hint by Zodiac researcher Gareth Penn led to the discovery that a radian angle, when placed over the map per Zodiac's instructions, pointed to the locations of two Zodiac attacks.
On October 7, 1970, the Chronicle received a three-by-five inch card signed by the Zodiac with the and a small cross reportedly drawn with blood. The card's message was formed by pasting words and letters from an edition of the Chronicle, and thirteen holes were punched across the card. Inspectors Armstrong and Toschi agreed it was "highly probable" the card came from the Zodiac.
Zodiac letter to Paul Avery
On October 27, 1970, Chronicle reporter Paul Avery (who had been covering the Zodiac case) received a Halloween card signed with a letter 'Z' and the Zodiac's cross circle symbol. Handwritten on the card was the note "Peek-a-boo, you are doomed." The threat was taken seriously and received a front-page story on the Chronicle. Soon after receiving this letter, Avery received an anonymous letter alerting him to the similarities between the Zodiac's activities and the unsolved murder of Cheri Jo Bates, which had occurred four years earlier at the city college in Riverside in the Greater Los Angeles Area, more than 400 miles (640 km) south of San Francisco. He reported his findings in the Chronicle on November 16, 1970.
On October 30, 1966, 18-year-old Cheri Jo Bates, a student of Riverside Community College, spent the evening at the campus library annex until it closed at 9:00 p.m. Neighbors reported hearing a scream around 10:30 p.m. Bates was found dead the next morning, a short distance from the library, between two abandoned houses slated to be demolished for campus renovations. The wires in her Volkswagen's distributor cap had been pulled out. She was brutally beaten and stabbed to death. A man's Timex watch with a torn wristband was found nearby. The watch had stopped at 12:24, but police believe the attack occurred much earlier.
A month later, on November 29, 1966, nearly identical typewritten letters were mailed to the 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." In December 1966, a poem was discovered carved into the bottom side of a desktop in the Riverside City College 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 the initials rh. During the 1970 investigation, Sherwood Morrill, California's top "Questioned Documents" examiner, expressed his opinion that the poem was written by the Zodiac.
On April 30, 1967, exactly six months after the Bates murder, Bates' father Joseph, the Press-Enterprise, and the Riverside police all received nearly identical letters: in a handwritten scrawl the Press-Enterprise and police copies read "Bates had to die there will be more", with a small scribble at the bottom that resembled the letter Z. Joseph Bates' copy read "She had to die there will be more", this time without the Z signature.
On March 13, 1971, five months after Avery's article linking the Zodiac to the Riverside 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."
The connection between Cheri Jo Bates, Riverside and the Zodiac remains uncertain. Paul Avery and the Riverside Police Department maintain that the Bates homicide was not committed by the Zodiac, but did concede some of the Bates letters may have been his work to claim credit falsely.
Lake Tahoe disappearance
On March 22, 1971, a postcard to the Chronicle, addressed to "Paul Averly" and believed to be from the Zodiac, appeared to claim responsibility for the disappearance of Donna Lass on September 6, 1970. Made from a collage of advertisements and magazine lettering, it featured a scene from an advertisement for Forest Pines condominiums and the text "Sierra Club", "Sought Victim 12", "peek through the pines", "pass Lake Tahoe areas", and "around in the snow". Zodiac's cross circle symbol was in both the place of the usual return address and the lower right section of the front face of the postcard.
Lass was a nurse at the Sahara Tahoe hotel and casino. She worked until about 2:00 a.m. on September 6, 1970, treating her last patient at 1:40 a.m. Later that same day, both Lass's employer and her landlord received phone calls from an unknown male falsely claiming Lass had left town due to a family emergency. Lass was never found. What appeared to be a grave site was discovered near the Clair Tappaan Lodge in Norden, California, on Sierra Club property, but an excavation yielded only a pair of sunglasses. No evidence has been uncovered to connect the Lass disappearance with the Zodiac Killer definitively.
Santa Barbara attack
In a Vallejo Times-Herald story appearing on November 13, 1972, Bill Baker of the Santa Barbara County Sheriff's Office postulated that the murders of a young couple in northern Santa Barbara County might have been the work of the Zodiac Killer. On June 4, 1963, high school senior Robert Domingos and fiancée Linda Edwards were shot dead on a beach near Lompoc, having skipped school that day for "Senior Ditch Day". Police believed that the assailant attempted to bind the victims, but when they freed themselves and attempted to flee, the killer shot them repeatedly in the back and chest with a .22-caliber weapon. The killer then placed their bodies in a small shack and then tried, unsuccessfully, to burn the structure to the ground.
Final Zodiac letter
After the "Pines" card, the Zodiac remained silent for nearly three years. The Chronicle then received a letter from the Zodiac, postmarked January 29, 1974, praising The Exorcist as "the best saterical comidy [sic] that I have ever seen". The letter included a snippet of verse from The Mikado and an unusual symbol at the bottom that has remained unexplained by researchers. Zodiac concluded the letter with a new score, "Me = 37, SFPD = 0".
Of further communications sent by the public to members of the news media, some contained similar characteristics of previous Zodiac writings. The Chronicle received a letter postmarked February 14, 1974, informing the editor that the initials for the Symbionese Liberation Army spelled out an Old Norse word meaning "kill". However, the handwriting was not authenticated as the Zodiac's.
A letter to the Chronicle, postmarked May 8, 1974, featured a complaint that the movie Badlands was "murder-glorification" and asked the paper to cut its advertisements. Signed only "A citizen", the handwriting, tone, and surface irony were all similar to earlier Zodiac communications. The Chronicle subsequently received an anonymous letter postmarked July 8, 1974, complaining of their publishing the writings of the antifeminist columnist Marco Spinelli. The letter was signed "the Red Phantom (red with rage)". The Zodiac's authorship of this letter is debated.
A letter, dated April 24, 1978, was initially deemed authentic, but was declared a hoax less than three months later by three experts. Dave Toschi, the SFPD homicide detective who had worked the case since the Stine murder, was thought to have forged the letter, because author Armistead Maupin believed the letter to be similar to "fan mail" he received in 1976 which he believed was authored by Toschi. While he admitted to writing the fan mail, Toschi denied forging the Zodiac letter and was eventually cleared of any charges. The authenticity of this letter remains unverified.
On March 3, 2007, an American Greetings Christmas card sent to the Chronicle, postmarked 1990 in Eureka had recently been discovered in their photo files by editorial assistant Daniel King. Inside the envelope, with the card, was a photocopy of two U.S. Postal keys on a magnet keychain. The handwriting on the envelope resembles Zodiac's print, but was declared inauthentic by forensic document examiner Lloyd Cunningham. However, not all Zodiac experts agree with Cunningham's analysis. There is no return address on the envelope nor is his crossed-circle signature to be found. The card itself is unmarked. The Chronicle turned over all the material to the Vallejo Police Department for further analysis.
Current status of investigations
In April 2004, the SFPD marked the case "inactive", citing caseload pressure and resource demands, effectively closing the case. However, they re-opened their case sometime before March 2007.
In May 2018, the Vallejo Police Department announced their intention to attempt to collect the Zodiac Killer's DNA from the back of stamps he used during his correspondence. The analysis, by a private laboratory, is expected to utilize an advanced new technique that is able to separate DNA from the glue present on the back of stamps. It is hoped the Zodiac Killer may be caught in a similar fashion to the Golden State Killer. In May 2018, a Vallejo police detective said that results were expected in several weeks. However as of December 2019 no results have been reported.
Arthur Leigh Allen
Robert Graysmith's book Zodiac advanced Arthur Leigh Allen as a potential suspect based on circumstantial evidence. Allen had been interviewed by police from the early days of the Zodiac investigations and was the subject of several search warrants over a 20-year period. In 2007 Graysmith noted that several police detectives described Allen as the most likely suspect. However, in 2010, Toschi stated that all the evidence against Allen ultimately "turned out to be negative."
On October 6, 1969, Allen was interviewed by detective John Lynch of the Vallejo Police Department. Allen had been reported in the vicinity of the Lake Berryessa attack against Hartnell and Shepard on September 27, 1969; he described himself scuba diving at Salt Point on the day of the attacks. Allen again came to police attention in 1971 when his friend Donald Cheney reported to police in Manhattan Beach, California, that Allen had spoken of his desire to kill people, use the name Zodiac, and secure a flashlight to a firearm for visibility at night. According to Cheney, this conversation occurred no later than January 1, 1969.
Jack Mulanax of the Vallejo Police Department subsequently wrote Allen had received an other than honorable discharge from the US Navy in 1958, and had been fired from his job as an elementary school teacher in March 1968 after allegations of sexual misconduct with students. He was generally well-regarded by those who knew him, but he was also described as fixated on young children and angry at women. He apparently never had a girlfriend or wife.
In September 1972, San Francisco police obtained a search warrant for Allen's residence. In 1974 Allen was arrested for committing lewd sex acts upon a 12-year-old boy; he pleaded guilty and served two years imprisonment.
Vallejo police served another search warrant at Allen's residence in February 1991. Two days after Allen's death in 1992, Vallejo police served another warrant and seized property from Allen's residence.
Other evidence existed against Allen, albeit entirely circumstantial. A letter sent to the Riverside Police Department from Bates's killer was typed with a Royal typewriter with an Elite type, the same brand found during the February 1991 search of Allen's residence. He owned and wore a Zodiac brand wristwatch. He lived in Vallejo and worked minutes away from where one of the Zodiac victims (Ferrin) lived and from where one of the killings took place.
In 2002, SFPD developed a partial DNA profile from the saliva on stamps and envelopes of Zodiac's letters. SFPD compared this partial DNA to the DNA of Arthur Leigh Allen. A DNA comparison was also made with the DNA of Don Cheney, who was Allen's former close friend and the first person to suggest Allen may be the Zodiac Killer. Since neither test result indicated a match, Allen and Cheney were excluded as the contributors of the DNA, though it cannot be stated definitively that it is DNA from the Zodiac on the envelopes. However, as of March 2018[update], it was announced that the 2002 DNA sample was collected from outside the stamp rather than behind it, or from the envelope seal, meaning Allen could still be a suspect.
Retired police handwriting expert Lloyd Cunningham, who worked on the Zodiac case for decades, added "they gave me banana boxes full of Allen's writing, and none of his writing even came close to the Zodiac. Nor did DNA extracted from the envelopes (on the Zodiac letters) come close to Arthur Leigh Allen." While police often use document examiners during investigations, court rulings on the scientific validity of handwriting analysis have been mixed to negative.
Public suspicions and speculation
In 2007, a man named Dennis Kaufman claimed that his stepfather Jack Tarrance was the Zodiac. Kaufman turned several items over to the FBI including a hood similar to the one worn by the Zodiac. According to news sources, DNA analysis conducted by the FBI on the items was deemed inconclusive in 2010.
In 2009, a former lawyer named Robert Tarbox (who, in August 1975, was disbarred by the California Supreme Court for failure to pay some clients) said that in the early 1970s a merchant mariner walked into his office and confessed to him that he was the Zodiac Killer. The seemingly lucid seaman (whose name Tarbox would not reveal due to confidentiality) described his crimes briefly but persuasively enough to convince Tarbox. The man said he was trying to stop himself from his "opportunistic" murder spree but never returned to see Tarbox again. Tarbox took out a full-page ad in the Vallejo Times-Herald that he claimed would clear the name of Arthur Leigh Allen as a killer, his only reason for revealing the story 30 years after the fact. Robert Graysmith, the author of several books on Zodiac, said Tarbox's story was "entirely plausible".
In 2009, an episode of the History Channel television series MysteryQuest looked at newspaper editor Richard Gaikowski (1936–2004). During the time of the murders, Gaikowski worked for Good Times, a San Francisco counterculture newspaper. His appearance resembles the composite sketch, and Nancy Slover, the Vallejo police dispatcher who was contacted by the Zodiac shortly after the Blue Rock Springs Attack, has identified a recording of Gaikowski's voice as being the same as the Zodiac's.
Retired police detective Steve Hodel argues in his book The Black Dahlia Avenger that his father, George Hodel (1907–1999), was the Black Dahlia killer, whose victims include Elizabeth Short. The book led to the release of previously suppressed files and wire recordings by the Los Angeles district attorney's office of his father, which showed that the elder Hodel had indeed been a prime suspect in Short's murder. District Attorney Steve Kaye subsequently wrote a letter which is published in the revised edition stating that if George Hodel were still alive he would be prosecuted for the crimes. In a follow-up book, Hodel argued a circumstantial case that his father was also the Zodiac Killer based upon a police sketch, the similarity of the style of the Zodiac letters to the Black Dahlia Avenger letters and questioned document examination.
On February 19, 2011, America's Most Wanted featured a story about the Zodiac Killer. In 2010, a picture surfaced of known Zodiac victim Darlene Ferrin and a man who closely resembles the composite sketch, formed based on eyewitnesses' descriptions, of the Zodiac Killer. Police believe the photo was taken in San Francisco in the middle of 1966 or 1967.
Former California Highway Patrol officer Lyndon Lafferty said the Zodiac killer was a 91-year-old Solano County, California man whom he called by the pseudonym "George Russell Tucker". Using a group of retired law enforcement officers called the Mandamus Seven, Lafferty discovered "Tucker" and outlined an alleged cover-up for why he was not pursued. "Tucker" died in February 2012 and was not named because he was not considered a suspect by police.
In February 2014, it was reported that a man named Louis Joseph Myers had confessed to a friend in 2001 that he was the Zodiac Killer, after learning that he was dying from cirrhosis of the liver. He requested that his friend, Randy Kenney, go to the police upon his death. Myers died in 2002, but Kenney allegedly had difficulties getting officers to cooperate and take the claims seriously. There are several potential connections between Myers and the Zodiac case. Myers attended the same high schools as victims David Farraday and Betty Lou Jensen, and allegedly worked in the same restaurant as victim Darlene Ferrin. Myers also had access to the same sort of military boot whose print was found at the Lake Berryessa crime scene. Furthermore, during the 1971–1973 period when no Zodiac letters were received, Myers was stationed overseas with the military. Kenney says that Myers confessed he targeted couples because he had had a bad breakup with a girlfriend. While officers associated with the case are skeptical, they believe the story is credible enough to investigate.
Robert Ivan Nichols aka Joseph Newton Chandler III was a formerly unidentified identity thief who committed suicide in Eastlake, Ohio, in July 2002. After his death, investigators were unable to locate his family and discovered that he had stolen the identity of an eight-year-old boy who was killed in a car crash in Texas in 1945. The lengths to which Nichols went to hide his identity led to speculation that he was a violent fugitive. In late 2016, U.S. Marshals Service-Cleveland, Ohio announced that forensic genealogist Dr. Colleen Fitzpatrick of Identifinders International had compared the then-unidentified man's Y-STR profile to public genetic genealogy Y-STR databases to determine his possible last name was "Nicholas". In 2017 Fitzpatrick, along with Dr. Margaret Press, formed the non-profit DNA Doe Project, which revisited the case by analyzing the man's autosomal DNA using the same methodology they used in identifying Debra Jackson and Lyle Stevik. In March 2018 the DNA Doe Project identified the man as Robert Ivan Nichols. The U.S. Marshals Service announced the identification at a press conference in Cleveland on June 21, 2018. Authorities had believed that he was a fugitive of some kind. There were many theories as to what he may have been running from, none of which were confirmed. Some Internet sleuths suggested that he might have been the Zodiac killer as he resembled police sketches of the Zodiac and had lived in California, where the Zodiac operated. Another theory was that he was Steven Campbell, an engineer from Cheyenne, Wyoming, wanted for attempted murder. Authorities also considered that he could have been a German soldier or Nazi official from World War II who had escaped to the United States.
Ross Sullivan and Lawrence Kane are suspected of being the zodiac killer.
- In 1976, Toschi would opine his belief to a reporter from the Fort Scott Tribune that the Zodiac killer lived in the San Francisco Bay area, and that the letters he had sent had been an "ego game" for him, adding: "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."
- "Zodiac Letters". Zodiackiller.com. Archived from the original on June 27, 2017. Retrieved August 9, 2011.
- SFPD News Release, March 2007
- Russo, Charles (March 2007). "Zodiac: The killer who will not die". San Francisco. San Francisco, California: Modern Luxury. Archived from the original on August 24, 2011.
- Napa PD Website, Vallejo PD Website and "Tipline," Solano County Sheriff's Office
- California Department of Justice Website
- Graysmith, p. 160.
- Adams, p. 274
- Graysmith, Robert (January 1, 2007). Zodiac Unmasked: The Identity of America's Most Elusive Serial Killer Revealed. ISBN 9780425212738.
- "Zodiac Killer: The Letters". SFGate. December 2, 2008.
- Graysmith, Robert (2007). Zodiac. p. 252. ISBN 9780425212189.
- "Police report". Zodiackiller.com. Archived from the original on February 16, 2012. Retrieved May 30, 2010.
- "Dec. 20, 1968 – Lake Herman Road". Archived from the original on March 4, 2007. Retrieved June 16, 2008.
- Graysmith, Robert (1976). Zodiac. Berkley. pp. 4–7. ISBN 978-0-425-09808-0.
- Graysmith, pp. 26–28.
- Graysmith, pp. 32–33.
- Graysmith, p. 29.
- "The Tuscaloosa News: Zodiac the Killer". The Tuscaloosa News. October 27, 1969. Retrieved January 18, 2018.
- Graysmith, p. 49.
- Graysmith, pp. 54–55.
- "Coded Clues in Murders". San Francisco Chronicle, August 2, 1969. Archived from the original on February 5, 2009.
- Graysmith, pp. 55–57.
- True Crime: Unsolved Crimes ISBN 0-7835-0012-2 p. 20
- "Zodiac the Killer". The Tuscaloosa News. October 27, 1969. Retrieved January 20, 2018.
- "Definite Zodiac Victims Cecelia Shepard and Bryan Hartnell".
- Graysmith, pp. 62–77
- "Message written on Hartnell's car door". Zodiackiller.com. Archived from the original on April 21, 2010. Retrieved May 30, 2010.
- True Crime: Unsolved Crimes ISBN 0-7835-0012-2 p. 21
- Stanley, Pat (February 18, 2007). "Zodiac on the line ..." Napa Valley Register. Retrieved September 16, 2008.
- Dorgan, Marsha (February 18, 2007). "Online exclusive: In the wake, of the Zodiac". Napa Valley Register. Archived from the original on October 6, 2008. Retrieved September 16, 2008.
- Carson, L. Pierce (February 18, 2007). "Zodiac victim: 'I refused to die'". Napa Valley Register. Archived from the original on September 22, 2008. Retrieved September 16, 2008.
- "Girl Dies of Stabbing at Berryessa" (PDF). San Francisco Chronicle. September 30, 1969. Archived from the original (PDF) on September 10, 2008. Retrieved September 16, 2008.
- Dorgan, Marsha (February 18, 2007). "Tracking the mark of the Zodiac for decades". Napa Valley Register. Retrieved December 16, 2014.
- "Definite Zodiac Victim Paul Stine". Zodiackiller.com. Archived from the original on January 26, 2010. Retrieved January 2, 2010.
- Rodelli, Mike (2005). "4th Interview with Don Fouke – Thoughts on the Zodiac Killer". Mike Rodelli. Archived from the original on May 1, 2006. Retrieved October 23, 2017.
- "Lone Officer Continues Search for Zodiac". The Fort Scott Tribune. September 15, 1976. Retrieved January 20, 2018.
- "Zodiac Killer: Meet The Prime Suspects". America's Most Wanted. September 2, 2008. Archived from the original on September 1, 2011.
- McCarthy, Chris. "Alphabet of the 340 Character Zodiac Cypher". Archived from the original on February 6, 2008.
- "I've Killed Seven" The Zodiac Claims Archived March 26, 2012, at the Wayback Machine. San Francisco Chronicle,m November 12, 1969.
- New Letters From Zodiac – Boast of More Killings Archived March 8, 2012, at the Wayback Machine. San Francisco Chronicle, November 12, 1969.
- Foreman, Laura, ed. (1993). True Crime: Unsolved Crimes. New York City: Time Life Books. p. 35. ISBN 978-0-7835-0012-6.
- Smith, Dave (November 16, 1970). "Evidence Links Zodiac Killer to '66 Death of Riverside Coed". Los Angeles Times.
- Montaldo, Charles. "The Zodiac Killer Continued – The Zodiac Letters". About.com. Archived from the original on December 20, 2008.
- Adams, p. 268.
- Graysmith, p. 139.
- "My Name Is" letter Archived February 6, 2016, at the Wayback Machine. Retrieved March 8, 2007.
- Zamorra, Jim Herron. 1967–71 – a bloody period for S.F. police Archived September 16, 2011, at the Wayback Machine. San Francisco Chronicle; January 27, 2007. Retrieved March 7, 2007.
- "Dragon card letter". Zodiackiller.com. April 28, 1970. Archived from the original on January 30, 2010. Retrieved May 30, 2010.
- "Button letter". Zodiackiller.com. June 26, 1970. Archived from the original on January 30, 2010. Retrieved May 30, 2010.
- "Zodiac map letter". Zodiackiller.com. June 26, 1970. Archived from the original on January 27, 2010. Retrieved May 30, 2010.
- "Zodiac Johns letter". Zodiackiller.com. July 24, 1970. Archived from the original on January 25, 2010. Retrieved May 30, 2010.
- "Zodiac Mikado letter". Zodiackiller.com. July 26, 1970. Archived from the original on January 26, 2010. Retrieved May 30, 2010.
- "Zodiac Mikado letter, cont". Zodiackiller.com. Archived from the original on September 20, 2010. Retrieved May 30, 2010.
- New West, Volume 6 (1981), Issues 10–12 p. 112
- "Gilbert and Sullivan Clue to Zodiac" (PDF). San Francisco Chronicle. October 12, 1970. Archived from the original (PDF) on March 6, 2007.
- Graysmith, pp. 161–162.
- Graysmith, pp. 165–166.
- Photo of watch found near Bates' body. Archived February 25, 2016, at the Wayback Machine. Retrieved July 21, 2007.
- Graysmith, pp. 168–169.
- Graysmith, pp. 170–172.
- True Crime: Unsolved Crimes ISBN 0-7835-0012-2 pp. 6–7
- Wark, Jake M. "Paul Avery and the Riverside Connection". AOL. Archived from the original on November 10, 2006.
- Zimmerman, Janet. New movie 'Zodiac' includes Redlands resident's attack Archived February 7, 2009, at the Wayback Machine Riverside Press-Enterprise, March 1, 2007. Retrieved March 13, 2007.
- "Spearch for Zodiac Victim in Mountain Area". The Bulletin. March 27, 1971. Retrieved March 11, 2017.
- True Crime: Unsolved Crimes ISBN 0-7835-0012-2 p. 43
- Graysmith, p. 178.
- "The Zodiac Killer: The Crimes". crimeandinvestigation.co.uk. January 31, 2013. Archived from the original on March 6, 2017. Retrieved March 6, 2017.
- "Murdered but Not Forgotten: Were They Victims of Zodiac Killer?". Santa Barbara Independent. June 2, 2011. Archived from the original on March 12, 2017. Retrieved March 11, 2017.
- "Zodiac Exorcist letter". Zodiackiller.com. January 29, 1974. Archived from the original on January 24, 2010. Retrieved May 30, 2010.
- "Tips Still Pursue Multiple Slayer" (PDF). San Francisco Chronicle. August 26, 1976. p. 3. Archived from the original (PDF) on July 24, 2011. Retrieved January 15, 2018.
- The Unabomber and the Zodiac Douglas Oswell ISBN 978-0-6151-4569-3 p. 231
- True Crime: Unsolved Crimes ISBN 0-7835-0012-2 p. 44
- Williams, Lance. "Zodiac's written clues fascinate document expert", Archived September 16, 2011, at the Wayback Machine San Francisco Chronicle, March 3, 2007. Retrieved March 15, 2007.
- Freedman, Rich. Zodiac: Did killer send card in 1990?; The Vallejo Times Herald, March 3, 2007. Retrieved March 16, 2007. Archived March 27, 2007, at the Wayback Machine
- Goodyear, Charlie (April 7, 2004). "Files shut on Zodiac's deadly trail" Archived May 24, 2007, at the Wayback Machine. San Francisco Chronicle. Retrieved September 18, 2008.
- Cosgrove-Mather, Bootie (April 8, 2004). "Unsolved Zodiac Killer Case Closed" Archived April 9, 2016, at the Wayback Machine. CBS News.
- "Los Angeles Man Claims to Have Met Zodiac Killer" Archived April 4, 2016, at the Wayback Machine. NBC Bay Area. January 23, 2015.
- Moyer, Justin (May 14, 2014). "And the Zodiac Killer is …" Archived April 15, 2016, at the Wayback Machine. The Washington Post.
- Osier, Valerie (November 30, 2013). "RIVERSIDE: Co-ed's 1966 slaying still a mystery" Archived April 6, 2016, at the Wayback Machine. Press Enterprise (Bloomsburg, Pennsylvania).
- Chabria, Anita (May 2, 2018). "Vallejo police have sent Zodiac Killer DNA to a lab. Results could come in weeks". The Sacramento Bee.
- "Police hope to use new DNA testing to catch Zodiac Killer".
- "Zodiac Killer: Can genealogy help crack the 50-year-old case?".
- "Police Hope to Use DNA to Catch the Zodiac Killer". May 8, 2018.
- "I am satisfied that Dave Toschi, Bawart, Capt. Conway and Lt. Jim Husted of Vallejo PD were right and that the Zodiac was Arthur Leigh Allen." Robert Graysmith, "The 'Zodiac' Writer Archived August 3, 2017, at the Wayback Machine", The Washington Post, March 9, 2007, accessed 11 June 2017
- Lance Williams (2010) A thank-you note from a Zodiac suspect, CaliforniaWatch.org November 30, 2010; accessed June 11, 2017
- "Allen's Debut As A Zodiac Suspect". www.ZodiacKiller.com. Archived from the original on August 25, 2017. Retrieved November 6, 2017.
- ""He said he would call himself the Zodiac", Page 1". www.ZodiacKiller.com. Archived from the original on August 24, 2017. Retrieved November 6, 2017.
- Jack Mulanax report 8-12-1971 (page 1 of 14) Archived June 23, 2017, at the Wayback Machine, accessed 11 June 2017
- "1972 Search Warrant, Page 1". www.ZodiacKiller.com. Archived from the original on August 25, 2017. Retrieved November 6, 2017.
- "1974 Sonoma County Sheriff's Department Report, Page 1". www.ZodiacKiller.com. Archived from the original on August 23, 2017. Retrieved November 6, 2017.
- "1991 Search Results, Page 1". www.ZodiacKiller.com. Archived from the original on July 14, 2017. Retrieved November 6, 2017.
- "1992 Search Warrant Property Report". www.ZodiacKiller.com. Archived from the original on August 16, 2017. Retrieved November 6, 2017.
- "Zodiac Killer: Meet The Prime Suspects". America's Most Wanted. Archived from the original on September 1, 2011. Retrieved January 18, 2009.
- Gafni, Matthias (February 22, 2007). "Zodiac revisited: Vallejo police send three letters for DNA testing". Vallejo Times Herald. Archived from the original on February 25, 2007. Retrieved March 1, 2007.
- "CNN Interview With Kelly Carroll". CNN. October 27, 2002. Archived from the original on March 28, 2007. Retrieved March 1, 2007.
- Weiss, Mike (October 15, 2002). "DNA seems to clear only Zodiac suspect". San Francisco Chronicle. Archived from the original on December 27, 2007. Retrieved February 28, 2007.
- Calhoun, Bob (March 21, 2018). "The Zodiac Killer DNA Profile That Never Was". SFWeekly.
- Williams, Lance (July 19, 2009), "Another possible Zodiac suspect put forth", San Francisco Chronicle, archived from the original on July 27, 2010
- E.g., "Even more troubling is an apparent lack of double blind studies demonstrating the ability of certified experts to distinguish between individual's handwriting or identify forgeries to any reliable degree of certainty. This lack of testing has serious repercussions on a practical level: because the entire premise of interpersonal individuality and intrapersonal variations of handwriting remains untested in reliable, double blind studies, the task of distinguishing a minor intrapersonal variation from a significant interpersonal difference—which is necessary for making an identification or exclusion—cannot be said to rest on scientifically valid principles." United States. vs. Johnsted, 30 F.Supp.3d 814, 817 (W.D. Wis. 2013)
- "Zodiac Killer: Meet The Prime Suspects". Amw.com. Archived from the original on September 1, 2011. Retrieved August 9, 2011.
- Pickel, Kris (February 10, 2010), "FBI: Test Results Back For Zodiac Killer Suspect", CBS Sacramento, archived from the original on February 13, 2010, retrieved May 31, 2010
- "Robert Earl Tarbox – #25339". Attorney Search. State Bar of California. Archived from the original on April 19, 2014. Retrieved July 28, 2014.
- Harrell, Ashley (July 21, 2009). "How Many Disbarred Lawyers Does It Take To Solve the Zodiac Murders?". SF Weekly. Archived from the original on December 7, 2014. Retrieved July 28, 2014.
- "This is the Zodiac speaking: Will the Zodiac murder cases ever be solved?". Martinez News-Gazette. Martinez, California. May 6, 2010. Archived from the original on September 3, 2012. Retrieved August 10, 2011.
- Hodel, Steve (2006). Black Dahlia Avenger: The True Story. New York City: Harper Paperbacks. ISBN 978-0-06-113961-1.
- Lopez, Steve (April 11, 2003). "A Startling Take on Black Dahlia Case". Los Angeles Times. Archived from the original on March 25, 2016.
- Hodel, Steve (2009). Most Evil: Avenger, Zodiac, and the Further Serial Murders of Dr. George Hill Hodel. New York City: Dutton Adult. ISBN 978-0-525-95132-2.
- America's Most Wanted, "Fugitive Cases: Zodiac Killer". Television airing February 19, 2011. Link to hi-res photograph Archived June 9, 2012, at the Wayback Machine
- Lafferty, Lyndon E. (2005). The Zodiac Killer cover-up : AKA the silenced badge. Vallejo, California: Mandamus Publishing. ISBN 9780982936306. OCLC 794978951.
- Fagan, Kevin. "Ex-gumshoe's Zodiac book fingers Solano County man". The San Francisco Chronicle. Archived from the original on July 17, 2012. Retrieved July 18, 2012.
- Fagan, Kevin; Bulwa, Demian (May 18, 2012). "Retired CHP gumshoe's Zodiac suspect is dead". San Francisco Chronicle. San Francisco, California. Archived from the original on May 20, 2012. Retrieved May 21, 2012.
- Noyes, Dan (February 24, 2014). "I-Team: Friend confesses to being Zodiac Killer". ABC 7 (KJO-TV) News. Archived from the original on August 10, 2014. Retrieved July 28, 2014.
- JJinPhila. "Who Was Joseph Newton Chandler?". centredaily.
- "Archived copy". Archived from the original on August 9, 2016. Retrieved February 9, 2019.CS1 maint: archived copy as title (link)
- "454UMOH". www.doenetwork.org.
- Fagan, Kevin; Wallace, Bill (May 14, 1996). "Kaczynski, Zodiac Killer – the Same Guy?". San Francisco Chronicle. Archived from the original on April 29, 2011. Retrieved December 5, 2009.
- "Il Mostro di Firenze è Zodiac. L'"impronta digitale" del serial killer Usa nei delitti in Toscana degli anni 80". May 23, 2018.
- Amicone, Francesco (June 13, 2018). "Il Mostro di Firenze è Zodiac. Ecco la decifrazione dei codici".
|Wikisource has original text related to this article:|
- Charles F. Adams (October 1, 2004), Murder by the Bay: historic homicide in and about the city of San Francisco, Quill Driver Books, ISBN 978-1-884995-46-0
- Brenda Haugen (August 1, 2010), The Zodiac Killer: Terror and Mystery, Capstone Press, ISBN 978-0-7565-4357-0
- Robert Graysmith (January 2, 2007), Zodiac, Berkley Books, ISBN 978-0-425-21218-9
- Michael D. Kelleher; David Van Nuys (2002), "This is the Zodiac speaking": into the mind of a serial killer, Praeger, ISBN 978-0-275-97338-4
- Gareth Penn (1987), Times 17: the amazing story of the Zodiac murders in California and Massachusetts, 1966–1981, Foxglove Press
- William T. Rasmussen (August 2006), Corroborating Evidence II, Sunstone Press, ISBN 978-0-86534-536-2
- Gary L. Stewart and Susan Mustafa (2014), The Most Dangerous Animal: Searching for My Father—and Finding the Zodiac Killer, New York: Harper, ISBN 978-0-06-231316-4.
- Ronald J. Dayton (2018), Zodiac 340 Cipher, Inner Rapport Publishing ISBN 978-0-244-43599-8.
- Michael H. Stone, M.D. & Gary Brucato, Ph.D., The New Evil: Understanding the Emergence of Modern Violent Crime (Amherst, N.Y.: Prometheus Books), pp. 113–128. ISBN 978-1-63388-532-5.
|Wikimedia Commons has media related to Zodiac Killer.|