View source for Zodiac Killer

{{Short description|Serial killer in California in the 1960s}}
{{protection padlock|small=yes}}
{{For-multi|the New York City Zodiac copycat|Heriberto Seda|}}
{{Use mdy dates|date=February 2012}}
{{Infobox criminal
| name              = Zodiac Killer
| image             = Zodiac-Killer.jpg
| image_size = 220px
| caption           = [[Composite sketch]] made in 1969 based on eyewitness accounts of the [[#Presidio Heights murder|Presidio Heights murder]]
| victims           = 7
| fatalities        = 5
| injuries          = 2
| criminal_status   = Unidentified
| country           = United States
| states            = [[California]]
| beginyear         = 1968
| endyear           = 1969
| other_names       = 
| motive            = Unclear
| wanted_since      = 1968
| locations         = {{ubl|[[San Francisco Bay Area]]|[[Napa Valley]]}}
| weapons           = {{ubl|[[9 mm caliber|9 mm pistol]] (2 different weapons)|[[.22 caliber]] pistol |[[knife]]}}
| signature         = [[File:Zodiac Killer symbol.svg|class=skin-invert|30px]]
| wanted_by         = [[Federal Bureau of Investigation]]
| footnotes         = {{Wikisource|Author:Zodiac Killer|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 [[Zodiac Killer in popular culture|fixture of popular culture]] and a focus for efforts by amateur detectives.

The Zodiac's known attacks took place in [[Benicia, California|Benicia]], [[Vallejo, California|Vallejo]], unincorporated [[Napa County]], and the [[City and County 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 [[cryptogram]]s or [[cipher]]s in his correspondence; two were decrypted in 1969 and 2020, and two are generally considered to be unsolved.<ref>{{cite news |last1=Ocenada |first1=Ryan |last2=Fagan |first2=Kevin |date=October 22, 2023 |title=Zodiac Killer: Why sleuths are still obsessed with S.F.'s most notorious serial killer |url=https://www.sfchronicle.com/sf/article/zodiac-killer-18436725.php |work=[[San Francisco Chronicle]] |access-date=December 17, 2024}}</ref>

In 1974, the Zodiac claimed 37 victims in his last confirmed letter. This tally included victims in [[Southern California]] such as [[Murder of Cheri Jo Bates|Cheri Jo Bates]], who was murdered in [[Riverside, California|Riverside]] in 1966. Despite many theories about the Zodiac's identity, the only suspect authorities ever named was [[Zodiac Killer suspects#Arthur Leigh Allen|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 County, California|Solano]] counties.

==Murders and correspondence==
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| mark-title1 = Murders of David Faraday and Betty Lou Jensen
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| mark-title2 = Attack on Michael Mageau and Darlene Ferrin
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| mark-title3 = Attack on Bryan Hartnell and Cecelia Shepard
| mark-coord4 = {{coord|37.78818611|-122.45709444}}
| mark-title4 = Murder of Paul Lee Stine
| caption = Map of the Zodiac Killer attacks
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Investigators agree on four confirmed attacks by the Zodiac Killer in [[California]]. Five victims were killed during these attacks, and two survived:<ref name=HISTORY-2023a>Butterfield, Michael. "[https://www.history.com/news/the-zodiac-killer-a-timeline The Zodiac Killer: A Timeline]", ''[[History Channel|History]]''. August 8, 2023.</ref>
# David Arthur Faraday (17) and Betty Lou Jensen (16) were shot and killed on December 20, 1968, on Lake Herman Road in [[Benicia, California|Benicia]].
# 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, California|Vallejo]]. Mageau survived the attack; Ferrin was pronounced dead at [[Kaiser Foundation Hospital]].
# Bryan Calvin Hartnell (20) and Cecelia Ann Shepard (22) were stabbed on September 27, 1969, at [[Lake Berryessa]] in [[Napa County, California|Napa County]]. Hartnell survived, but Shepard died at [[Queen of the Valley Medical Center (Napa, California)|Queen of the Valley Hospital]] as a result of her injuries on September 29.
# Paul Lee Stine (29) was shot and killed on October 11, 1969, in the [[Presidio Heights, San Francisco, California|Presidio Heights]] neighborhood of [[San Francisco]].

From 1969 to 1974, the Zodiac mailed heavily misspelled letters and [[cipher]]s to law enforcement and media outlets. Some letters began, "This is the Zodiac speaking" and were signed with a symbol resembling the [[Reticle|crosshairs]] of a [[Sight (device)|gunsight]]: [[File:Zodiac Killer symbol.svg|20px]].<ref>Jenkins, John Philip. "[https://www.britannica.com/biography/Zodiac-killer Zodiac Killer]", ''[[Encyclopædia Britannica]]''. October 23, 2024.</ref> Four of the mailings had a [[cryptogram]] enclosed. Two have been solved, in 1969 and 2020.<ref>Fagan, Kevin. "[https://www.sfchronicle.com/crime/article/zodiac-340-cypher-cracked-by-code-expert-51-years-15794943.php Zodiac '340 Cipher' cracked by code experts 51 years after it was sent to the S.F. Chronicle]". [[San Francisco Chronicle]]. March 11, 2020.</ref> The letters were postmarked in San Francisco and [[Pleasanton, California|Pleasanton]].<ref name=Read>Read, Simon. "[https://www.eastbaytimes.com/2005/03/13/zodiacs-shadow-crossed-valley/ Zodiac's shadow crossed valley]". ''[[East Bay Times]]''. March 13, 2005.</ref>

The Zodiac's confirmed correspondence with date, recipient, and [[incipit]]:
#[[s:Zodiac Killer letter, July 31st 1969|July 31st 1969]]: ''[[San Francisco Chronicle]]'', ''[[San Francisco Examiner]]'', and ''[[Vallejo Times Herald|Vallejo Times]]''. One-third of "Z408 cipher" enclosed with each letter. "I am the killer of the 2 teenagers last Christmass..."
#[[s:Zodiac Killer letter, August 4th 1969|August 4th 1969]]: ''Examiner''. "This is the Zodiac speaking."
#[[s:Zodiac Killer letter, October 13th 1969|October 13th 1969]]: ''Chronicle''. Swatch of Paul Stine's shirt. "I am the murderer of the taxi driver..."
#[[s:Zodiac Killer letter, November 8th 1969|November 8th 1969]]: ''Chronicle''. "Z340 cipher." The "Dripping Pen" card. "I though you would need a good laugh..."
#[[s:Zodiac Killer letter, November 9th 1969|November 9th 1969]]: ''Chronicle''. Bomb diagram. "...I have killed 7 people".
#[[s:Zodiac Killer letter, December 20th 1969|December 20th 1969]]: [[Melvin Belli]]. Swatch of Stine's shirt. "...happy Christmass."
#[[s:Zodiac Killer letter, April 20th 1970|April 20th 1970]]: ''Chronicle''. "Z13 cipher." "My name is..."
#[[s:Zodiac Killer letter, April 28th 1970|April 28th 1970]]: ''Chronicle''. Greeting card. "I hope you enjoy yourselves..."
#[[s:Zodiac Killer letter, June 26th 1970|June 26th 1970]]: ''Chronicle''. "Z32 cipher." "I have become very upset..."
#[[s:Zodiac Killer letter, July 24th 1970|July 24th 1970]]: ''Chronicle''. "I am rather unhappy..."
#[[s:Zodiac Killer letter, July 26th 1970|July 26th 1970]]: ''Chronicle''. "Being that you will not wear some nice ⌖ buttons..."
#[[s:Zodiac Killer letter, October 5th 1970|October 5th 1970]]: ''Chronicle''. Thirteen-hole punch card. "You'll hate me..."
#[[s:Zodiac Killer letter, October 27th 1970|October 27th 1970]]: [[Paul Avery]] at ''Chronicle''. Halloween card. "From your secret pal..."
#[[s:Zodiac Killer letter, March 13th 1971|March 13th 1971]]: ''[[Los Angeles Times]]''. "...I am crack proof."
#[[s:Zodiac Killer letter, January 29th 1974|January 29th 1974]]: ''Chronicle''. The "Exorcist" letter.

===Lake Herman Road murders===
[[File:D.A.F.B.LJ.Lake Herman Road 1968 A.jpg|thumb|David Arthur Faraday and Betty Lou Jensen]]
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 at Hogan High School. At 8:30&nbsp;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 [[Lovers' lane|lover's lane]] on Lake Herman Road, just inside [[Benicia, California|Benicia]] city limits. Between 10:15 and 10:30 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.<ref name=Ripper>Fagan, Kevin. "[https://www.sfchronicle.com/crime/article/zodiac-killer-case-50-years-later-tracing-the-13464347.php Zodiac Killer case, 50 years later: Tracing the legend of 'our Jack the Ripper']", ''[[San Francisco Chronicle]]''. October 16, 2023.</ref><ref name=KN/>{{rp|30–1}}

Between 11:05 and 11:10 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|.22-caliber]] pistol. 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.<ref name="KN">Kelleher, Michael D., and David Van Nuys. ''"This Is the Zodiac speaking": Into the Mind of a Serial Killer''. [[Greenwood Publishing Group|Praeger]], 2002.</ref>{{rp|30–1}}<ref name=Grey/>

At 11:10&nbsp;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.<ref name="KN"/>{{rp|30–2}} The murders were extensively covered by the media.<ref name="KN"/>{{rp|37–8}}

===Blue Rock Springs murder===
[[File:Darlene Ferrin Zodiac Killer Ventura County Star 19 October 1969.jpg|thumb|150px|Darlene Ferrin]]
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&nbsp;p.m., Ferrin received a phone call at her house. She arrived at Mageau's house around 11:50&nbsp;p.m.<ref name=KN/>{{rp|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.<ref name=Fagan/><ref name=LAMag>Gell, Aaron. "[https://lamag.com/news/zodiac-killer-paul-alfred-doerr Has The Zodiac Killer Mystery Been Solved (Again)?]", ''[[Los Angeles (magazine)|Los Angeles]]''. September 22, 2022.</ref> 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.<ref name=Grays/>{{rp|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.<ref name=KN/>{{rp|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 [[9 mm caliber|9mm pistol]] into the car.<ref name=DailyDem>Raskin-Zrihen, Rachel. "[https://www.dailydemocrat.com/2019/07/05/former-vallejo-woman-recalls-her-sister-murdered-by-the-zodiac-killer-50-years-ago-this-weekend-2/ Zodiac killer struck 50 years ago this weekend]". ''[[Daily Democrat]]''. July 5, 2019.</ref> 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&nbsp;a.m.<ref name=KN/>{{rp|34–5}} The perpetrator left no clues that could be traced back to him.<ref name=KN/>{{rp|38}}

Three teenagers drove into the parking lot, saw the wounded couple, and got help. Police arrived at 12:20&nbsp;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.<ref name=KN/>{{rp|35, 41}} Moments after 12:40&nbsp;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:<blockquote>"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 pistol|Luger]]. I also killed those kids last year. Goodbye."<ref name=KN/>{{rp|35, 39}}</blockquote>

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 Murders|Lake Herman Road]] and at Blue Rock Springs was a "cooling off period" for the Zodiac.<ref name=KN/>{{rp|37–8}}

====Ferrin—Zodiac prior relationship theory====
[[File:Ferrin and unknown man, 1960s.jpg|thumb|upright|A 1966 photo of Ferrin and a man who resembles the Zodiac composite sketch from the Stine murder.]]
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 (true crime book)|Zodiac]]''. He argued extensively for a connection based on interviews with Ferrin's friends.<ref name=Grays/>{{rp|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.<ref>Schunn, Caitlin. "[https://www.oxygen.com/crime-news/zodiac-killer-theories-in-based-on-a-true-story-explained The Zodiac Killer Theories in Based on a True Story, Explained]". [[Oxygen (TV channel)|Oxygen]]. June 8, 2023.</ref> In the Zodiac's later correspondence, he only ever refers to Ferrin as "girl".<ref name=KN/>{{rp|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.<ref name=Grays/>{{rp|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.<ref name=KN/>{{rp|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.<ref name=KN/>{{rp|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.<ref>[https://web.archive.org/web/20120509161730/http://www.amw.com/fugitives/case.cfm?id=43096 "Fugitives: Zodiac Killer, Case File"]. ''[[America's Most Wanted]]''. February 19, 2011.
:Includes [https://web.archive.org/web/20120609181004/http://zodiackiller.com/images/newdarleneamwhuge.jpg hi-res images].</ref>

===First letters from the Zodiac===
{{wikisource|Author:Zodiac Killer}}
[[File:Zodiac Killer letter, San Francisco Chronicle, July 31st 1969.pdf|left|thumb|[[s:Zodiac Killer letter, San Francisco Chronicle, July 31, 1969|Zodiac letter]] to the ''[[San Francisco Chronicle]]'', August 1, 1969.]]
On August 1, 1969, the ''[[Vallejo Times Herald|Vallejo Times]]'', ''[[San Francisco Chronicle]]'' and ''[[San Francisco Examiner]]'' all received letters written by someone taking credit for the attacks in Vallejo. [[s:Zodiac Killer letter, San Francisco Chronicle, July 31st 1969|The three letters]] were nearly identical and began, "I am the killer of the 2 teenagers last Christmass at [[#Lake Herman Road Murders|Lake Herman]] & the [[#Blue Rock Springs Murder|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.<ref>Smith, Dave. "Zodiac Kills His Fifth Victim", ''Los Angeles Times''. October 16, 1969. 1, 33.</ref><ref name=Zoellner-2000>Zoellner, Tom. "[https://www.sfgate.com/bayarea/article/Amateurs-Stir-Embers-Of-Notorious-Zodiac-Case-3303028.php Amateurs Stir Embers Of Notorious Zodiac Case/30 years after 5 slayings, killer remains unknown]". [[SFGate]]. October 2, 2000.</ref>

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 [sic]." He demanded the codes be printed on each newspaper's front page. If they were not, he threatened to "cruise 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."<ref name=Grays>Graysmith, Robert. ''Zodiac''. [[Berkley Books]]. 1986.
:Corrected and updated editions in 2007 and 2020.</ref>{{rp|49}} The ''Chronicle'' published its third of the cryptogram inside the August 2 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.<ref>"[https://web.archive.org/web/20090205124833/http://cdn.sfgate.com/chronicle/acrobat/2007/02/25/zodiac_1969_08_02_a.pdf Coded Clue in Murders]", ''[[San Francisco Chronicle]]''. August 2, 1969. 4.</ref>

On August 4, the ''Examiner'' received [[s:Zodiac Killer letter, August 4th 1969|a letter]] with the salutation, "Dear Editor This is the Zodiac speaking." This letter marked the debut of the Zodiac persona.<ref name=CB/>{{rp|161}} It was the first time the killer called himself by this nickname.<ref>Kobek, Jarett (2022). ''How to Find Zodiac''. We Heard You Like Books. 4–5.</ref>

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 4 letter also referred investigators back to the Z408 cipher. The killer wrote, "when they do crack it they will have me".<ref name=Grays/>{{rp|55–57}}

[[File:Zodiac Killer cipher deciphered by Donald and Bettye Harden.pdf|right|thumb|Part 1 of Z408 cipher and its decryption by Donald and Bettye Harden. ([https://upload.wikimedia.org/wikipedia/commons/a/ae/Zodiac_Killer_cipher_deciphered_by_Donald_and_Bettye_Harden.pdf Parts 2 & 3])]]
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 5, it was cracked by Donald and Bettye Harden, a couple in [[Salinas, California|Salinas]]. Neither was a cryptologist. Bettye deployed a [[Known-plaintext attack|crib]] by correctly guessing the word "kill" would appear in the message.<ref name=CB/>{{rp|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:
<blockquote>"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"<ref name=Grays/>{{rp|54–5}}</blockquote>

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 [[Social isolation|isolated]]". The psychiatrist speculated the killer's praise of murder over sex could be "an expression of inadequacy".<ref name=Smith>Smith, Dave. "[https://www.newspapers.com/article/the-los-angeles-times-zodiac-killer-15/106025754/ Identity in Code? Zodiac Killer—Chilling Portrait of Madness]", ''Los Angeles Times''. October 15, 1969. 1, 26–27.
:[https://news.google.com/newspapers?nid=1817&dat=19691017&id=MxwfAAAAIBAJ&pg=7420,3801832 Syndicated nationwide].</ref>

=== Lake Berryessa murder ===
[[File:Lake Berryessa, California, looking northeast from Oak Shore.jpg|thumb|left|[[Lake Berryessa]]]]
At 4:00&nbsp;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.<ref name=Dorgan>Dorgan, Marsha. "[https://web.archive.org/web/20081006215107/http://www.napavalleyregister.com/articles/2007/02/18/news/local/iq_3823497.txt Online exclusive: In the wake, of the Zodiac]". ''[[Napa Valley Register]]''. February 18, 2007.</ref> He wore a [[bib (garment)|bib]] with a white 3x3" [[File:Zodiac Killer symbol.svg|20px]] symbol on it. He brandished a gun, which Hartnell believed was a [[.45 ACP|.45]]. The Zodiac said he escaped from jail after killing a guard and needed their car and money to travel to Mexico.<ref name=Beck>Beck, Malinda. [https://www.history.com/news/could-any-of-these-men-have-been-the-zodiac-killer "Could Any of These Men Have Been the Zodiac Killer?"] ''[[History Channel|History]]''. November 6, 2017.</ref><ref name=Flaherty>Flaherty, Thomas H. (1993). ''True Crime: Unsolved Crimes''. Time Life Education.</ref>{{rp|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.<ref name=Smith/><ref>Voigt, Tom. "[https://zodiackiller.com/ShepardHartnell.html Definite Zodiac Victims Cecelia Shepard and Bryan Hartnell]", ''ZodiacKiller.com''.</ref>
[[File:Door of Bryan Hartnell's car.jpg|thumb|Photo of Bryan Hartnell's car door, where the Zodiac tallied his crimes]]
The Zodiac hiked 500 yards to Knoxville Road, leaving several footprints for investigators to study. The killer drew the [[File:Zodiac Killer symbol.svg|20px]] symbol on Hartnell's car door with a black felt-tip pen and wrote beneath it:{{poemquote|Vallejo
12-20-68
7-4-69
Sept 27–69–6:30
by knife<ref name=Napa>"[https://www.newspapers.com/article/the-napa-valley-register-zodiac-killer-b/48447758/ Zodiac killer Berryessa Manhunt]", ''[[Napa Valley Register]]'', October 2, 1969. 1, 11.</ref>}}After hearing the victims' screams, a fisherman and his son sought help. Hartnell untied Shepard's ropes with his teeth, and she freed him.<ref name=Grays/>{{rp|73}} Two [[park ranger]]s 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.<ref name=Dorgan/> Shepard was conscious and gave a detailed description of their attacker. She and Hartnell were taken to a hospital in [[Napa, California|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.<ref>Carson, L. Pierce. "[https://web.archive.org/web/20080922140432/http://www.napavalleyregister.com/articles/2007/02/18/news/local/iq_3823540.txt Zodiac victim: 'I refused to die']". ''[[Napa Valley Register]]''. February 18, 2007.</ref><ref>"[https://web.archive.org/web/20090205124846/http://cdn.sfgate.com/chronicle/acrobat/2007/02/25/zodiac_1969_09_30_1.pdf Girl Dies of Stabbing at Berryessa]". ''[[San Francisco Chronicle]]''. September 30, 1969.</ref>

[[File:Lake Berryessa Sketch of the Zodiac Killer as described by 3 coeds sunbathing that day.jpg|thumb|Witness sketch of man seen at Lake Berryessa shortly before the murder|259x259px]]
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&nbsp;p.m., three women noticed a strange man as they stopped on their way to Lake Berryessa. After they had arrived to [[sunbathing|sunbathe]], they noticed the man again.<ref name=Grays/>{{rp|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 [[Facial composite|facial compositing]] device. 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.<ref name=Napa/><ref name=Grays/>{{rp|78}} Graysmith also drew a sketch of the Zodiac's costume after Hartnell described it to him.<ref>Fagan, Kevin. "[https://datebook.sfchronicle.com/books/robert-graysmith-writes-about-shooting-zodiac-with-dozens-more-books-on-many-subjects-ready-to-roll Robert Graysmith wrote the definitive Zodiac Killer book]", ''Datebook: San Francisco Chronicle''. September 20, 2021.</ref> Napa County detective Ken Narlow was assigned to the case from the outset and worked on solving the crime until his retirement in 1987.<ref>Dorgan, Marsha. "[https://web.archive.org/web/20090903100345/http://www.napavalleyregister.com/articles/2007/02/18/news/local/iq_3821597.txt Tracking the mark of the Zodiac for decades]". ''[[Napa Valley Register]]''. February 18, 2007.</ref>

The Zodiac drove 27 miles from the crime scene to a car wash in downtown [[Napa, California|Napa]]. He used a payphone to call the [[Napa County, California|Napa County]] Sheriff's Department at 7:40&nbsp;p.m. He told the [[Police dispatcher|dispatcher]] he wished to "report a murder – no, a double murder" and confessed to the crime.<ref name=Napa/> He did not hang up the phone.<ref name=Flaherty/>{{rp|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.<ref name=Stanley>Stanley, Pat. "[https://web.archive.org/web/20090115214124/http://www.napavalleyregister.com/articles/2007/02/18/news/local/iq_3812957.txt Zodiac on the line...]", ''[[Napa Valley Register]]''. February 18, 2007.</ref>

===Presidio Heights murder===
[[File:Zodiac Paul Stine Washington and Cherry Presidio Heights October 11 1969.jpg|thumb|left|Crime scene image at Washington and Cherry Street, October 11, 1969]]
The last confirmed Zodiac murder took place two weeks after the Lake Berryessa attacks. Around 9:40&nbsp;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 [[Neighborhoods in San Francisco, California#Presidio Heights|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&nbsp;p.m., the Zodiac shot Stine in the head with a handgun and took his wallet and car keys.<ref name=Zoellner-2000/>

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.<ref name=Dowd>Dowd, Katie. "[https://www.sfgate.com/sfhistory/article/why-has-Zodiac-Killer-never-been-caught-15847923.php Why has the Zodiac Killer never been caught?]". SFGate. January 6, 2021.</ref> The teenagers watched as the Zodiac wiped down the vehicle and rifled through Stine's clothes. He left behind two partial [[fingerprint]]s 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 [[Police dispatcher|dispatcher]] mistakenly alerted SFPD that the suspect was [[Black people|Black]].<ref name=KN/>{{rp|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 of San Francisco|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.<ref name=KN/>{{rp|77–8}}

[[File:Oct 1969 Zodiac wanted poster.png|thumb|upright=1.1|October 1969 SFPD poster featuring initial sketch made from the teenagers' description (''left''), and one based on the officers' description of the man they encountered (''right'').<ref name=Dowd/>]]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.<ref name=Flaherty/>{{rp|27}} He enclosed it in [[s:Zodiac Killer letter, October 13th 1969|a letter]] where he boasted about the murder and claimed to have clandestinely watched SFPD search for him. The Zodiac also threatened to shoot a tire on a [[school bus]] and kill children as they exited.<ref name=Zoellner-2000/>

The teenage witnesses helped a police artist make a [[Facial composite|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.<ref name=Dowd/><ref name=KN/>{{rp|78}}

SFPD detectives Bill Armstrong and [[Dave Toschi]] were assigned to the case.<ref name=KN/>{{rp|78}} Toschi ended up working on the case by himself and filled eight filing cabinets with potential suspects.<ref>"Zodiac", ''New York Times''. July 3, 1977. 23.</ref> 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."<ref name=Toschi76>[[Associated Press]] (AP). "[https://web.archive.org/web/20210619194215/https://news.google.com/newspapers?nid=1906&dat=19760915&id=M90fAAAAIBAJ&pg=1279,960140 Lone Officer Continues Search for Zodiac]". ''[[Fort Scott Tribune]]''. September 15, 1976. 7.</ref>

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 [[Pawnbroker|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.<ref>Genzlinger, Neil. "[https://archive.today/20180116153532/https://www.nytimes.com/2018/01/12/obituaries/david-toschi-86-detective-who-pursued-the-zodiac-killer-dies.html David Toschi, 86, Detective Who Pursued the Zodiac Killer, Dies]". ''The New York Times''. January 12, 2018. A25.</ref><ref>[[Associated Press|AP]]. "Police Officials on Coast Deny Inspector Forged Zodiac Letters". ''The New York Times''. July 16, 1978. 12.</ref>

=== ''A.M. San Francisco'' interview ===
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 television. 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.<ref>{{cite web |url=https://www.zodiacciphers.com/call-to-chat-show.html |title=Call to Chat Show |access-date=September 21, 2023 |archive-date=June 4, 2023 |archive-url=https://web.archive.org/web/20230604012621/https://www.zodiacciphers.com/call-to-chat-show.html |url-status=live }}</ref><ref name=Flaherty/>{{rp|32}}

===November & December 1969 correspondence===
[[File:4abc - San Francisco Chronicle Dripping Pen Card November 8 1969 340 Cipher COLOR.jpg|left|thumb|The Zodiac's Z340 cypher, November 8, 1969]]On November 8, the Zodiac mailed [[s:Zodiac Killer letter, November 8th 1969|a card with a 340-character cryptogram]] ('''Z340''') to the ''Chronicle''. He asked for his code to be printed on the front page. It remained unsolved for 51 years. One cryptologist ranked Zodiac's unsolved ciphers second only to the [[Voynich manuscript]].<ref>Schmeh, Klaus. "[https://scienceblogs.de/klausis-krypto-kolumne/the-top-50-unsolved-encrypted-messages/ The Top 50 unsolved encrypted messages]", ''[https://scienceblogs.de/klausis-krypto-kolumne/2020/01/11/the-top-50-unsolved-encrypted-messages-2-the-zodiac-killer/ Cipherbrain]''. January 11, 2020.</ref> Zodiac ciphers were [[crowdsourcing|crowdsourced]] through a variety of websites, which led to gradual breakthroughs.<ref name=JG>Gathen, Joachim von zur. 2023. “Unicity Distance of the Zodiac-340 Cipher.” ''[[Cryptologia]]'' 47 (5): 474–88.</ref><ref name=340z>McCarthy, Chris. "[https://web.archive.org/web/20080206131017/http://www.dtm.ciw.edu/chris/z/340explain.html Alphabet of the 340 Character Zodiac Cypher]". Archived February 6, 2008.</ref>

Z340 was deciphered by an international team of private citizens on December 5, 2020. The cryptology group included American [[Software engineering|software engineer]] David Oranchak, Australian [[mathematician]] Sam Blake and Belgian programmer Jarl Van Eycke.<ref name=Canon/><ref name=Ong/> 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 [[Key (cryptography)|encryption key]].<ref name=NYT21>Méheut, Constant. "[https://ghostarchive.org/archive/20211228/https://www.nytimes.com/2021/06/22/world/europe/france-zodiac-killer-cipher.html I've Cracked Zodiac, a French Engineer Says. Online Sleuths Are Skeptical]". ''The New York Times''. June 22, 2021.</ref><ref>Claburn, Thomas. "[https://www.theregister.com/2024/04/04/zodiac_killer_code/ Sleuths who Cracked Zodiac Killer's Cipher Thank the Crowd]". ''[[The Register]]''. April 4, 2024.</ref>

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.<ref name=Canon>Canon, Gabrielle. "[https://www.theguardian.com/us-news/2020/dec/11/zodiac-killer-cipher-cracked-california Zodiac: cipher from California serial killer solved after 51 years]". ''[[The Guardian]]''. December 11, 2020.</ref><ref name=Ong>Ong, Danielle. "[https://web.archive.org/web/20210117124857/https://sftimes.com/identity-of-zodiac-killer-that-terrorized-san-francisco-remains-a-mystery/ Identity of 'Zodiac Killer' That Terrorized San Francisco Remains a Mystery]". The San Francisco Times. December 19, 2020.</ref><ref name=SFChron3.16.21>Fagan, Kevin. "[https://web.archive.org/web/20201211183549/https://www.sfchronicle.com/crime/article/Zodiac-340-cypher-cracked-by-code-expert-51-years-15794943.php Zodiac '340 Cipher' cracked by code experts 51 years after it was sent to the S.F. Chronicle]". ''San Francisco Chronicle''. December 11, 2020.</ref> Subsequent analysis confirmed the Z340 decryption using [[unicity distance]] as a measure.<ref name=JG/>

The decoded Z340 cipher included the usual Zodiac respellings:<blockquote>"I hope you are having lots of fan in trying to catch me that wasn't 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"<ref name=SFChron3.16.21/><ref>Oranchak, David. "[https://www.youtube.com/watch?v=-1oQLPRE21o Let's Crack Zodiac - Episode 5 - The 340 Is Solved!]". ''[[YouTube]]''. December 11, 2020.</ref></blockquote>
[[File:Normal 5a - San Francisco Chronicle letter November 9 1969 Page 1.jpg|thumb|The first page of the letter sent on November 9, 1969]]
On November 9, the Zodiac mailed [[s:Zodiac Killer letter, November 9th 1969|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".<ref name=Zoellner-2000/> The ''Chronicle'' excerpted the letter on November 12.<ref>Avery, Paul. "[https://web.archive.org/web/20120326202024/http://cdn.sfgate.com/chronicle/acrobat/2007/02/25/zodiac_1969_11_12_1.pdf 'I've Killed Seven', the Zodiac Claims]", ''San Francisco Chronicle''. November 12, 1969. 1, [https://web.archive.org/web/20120308211232/http://cdn.sfgate.com/chronicle/acrobat/2007/02/25/zodiac_1969_11_12_jump_1.pdf 22].</ref>

One year after the Lake Herman Road murders on December 20, the Zodiac mailed [[s:Zodiac Killer letter, December 20th 1969|a letter to Melvin 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."<ref name=Flaherty/>{{rp|35}}

===April 1970 letter and card===
For the remainder of 1970, the Zodiac continued to communicate with authorities and the press by mail. In a [[s:Zodiac Killer letter, April 20th 1970|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.<ref name=Bauer2>Bauer, Craig P. "[https://www.history.com/news/the-zodiac-ciphers-what-we-know The Zodiac Ciphers: What Cryptologists Know]". ''[[History Channel|History]]''. September 12, 2023.</ref>

The Z13 cipher:
[[File:My Name Is....Zodiac Cipher (cropped).jpg|center|frameless|400x400px]]
The cryptologist Craig P. Bauer proposed the solution "[[Alfred E. Neuman]]", the mascot of humor magazine [[Mad (magazine)|''Mad'']].<ref name=CB>Bauer, Craig P. ''[http://assets.press.princeton.edu/chapters/s10949.pdf Unsolved!: The History and Mystery of the World's Greatest Ciphers from Ancient Egypt to Online Secret Societies]''. [[Princeton University Press]], 2017. 182.</ref> Ryan Garlick, a [[University of North Texas]] computer science and engineering professor, used the key to the Z340 to get the solution "Dr. Eat a Torpedo". Garlick believes that this is an insult directed at D. C. B. Marsh, then president of the [[American Cryptogram Association]], who had publicly challenged Zodiac to reveal his full name in a cipher.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=tqwVEU5hapk |title=Let's Crack Zodiac #23 - Dr Garlick's solution |date=2025-04-08 |last=David Oranchak |access-date=2025-04-09 |via=[[YouTube]]}}</ref><!-- From WP:SELFPUB: "Self-published expert sources may be considered reliable when produced by an established subject-matter expert, whose work in the relevant field has previously been published by reliable, independent publications." The proposed solution was published on the YouTube channel of David Oranchak, one of the three solvers of the Z340. -->{{Multiple images
| image1            = Zodiac-Bomb.gif
| caption1          = [[s:Zodiac Killer letter, April 20th 1970|Bomb diagram]], April 20, 1970
| image2            = Zodiac Killer Dragon Card.pdf
| caption2          = [[s:Zodiac Killer letter, April 28th 1970|Dragon Card]], postmarked April 28, 1970
| total_width       = 300
| align             = right}}

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."<ref name=Zamora/> He also included a diagram of another school bus bomb. At the bottom of the diagram, he wrote: "[[File:Zodiac Killer symbol.svg|20px]] = 10, SFPD = 0."

On April 28, 1970, the Zodiac mailed a [[s:Zodiac Killer letter, April 28th 1970|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"<ref>"[https://web.archive.org/web/20100130054938/http://www.zodiackiller.com/DragonCard.html  Dragon card letter]", ''ZodiacKiller.com''. Archived January 30, 2010.</ref>

===June 1970 letter and map===
[[File:June 26 1970 Zodiac letter.jpg|thumb|The [[s:Zodiac Killer letter, June 26th 1970|Z32 cipher letter]] with its map of the Bay Area, June 26, 1970]]In a [[s:Zodiac Killer letter, June 26th 1970|letter to the ''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.<ref>"[https://www.odmp.org/officer/10956-officer-richard-radetich Officer Officer Richard Radetich]". ''Officer Down Memorial Page''. January 1, 1996.</ref> Radetich's murder is unsolved, but the SFPD denies that Zodiac is a suspect in the case.<ref name=Zamora/>

A [[Phillips 66]] roadmap of the San Francisco Bay Area was enclosed with the letter. At [[Mount Diablo]], the Zodiac drew a modified [[File:Zodiac Killer symbol.svg|20px]] symbol as a [[compass rose]]. The [[Cardinal direction|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'''):
[[File:Zodiac-Colour-SFC-Cipher-Black-Clean.png|center|frameless|400x400px]]
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 ever located.<ref name=NYT21/><ref name=Bauer2/> In [[#July 1970 letters|another letter]], the Zodiac explained, "The Mt. Diablo code concerns Radians + # inches along the radians."<ref>Voigt, Tom. "Zodiac Mikado letter". ''Zodiackiller.com''.
:Pages [https://www.zodiackiller.com/Mikado1.html  1], [https://www.zodiackiller.com/Mikado2.html 2], [https://www.zodiackiller.com/Mikado3.html 3], [https://www.zodiackiller.com/Mikado4.html 4], [https://www.zodiackiller.com/Mikado5.html 5].</ref> 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]].<ref name=GP>Penn, Gareth. ''[http://zodiackillerciphers.com/images/times-17-full.pdf Times 17: the amazing story of the Zodiac murders in California and Massachusetts, 1966–1981]'', Foxglove Press. 1987.</ref>{{rp|3–4}} On one arm of the radian lay the [[#Blue Rock Springs murder|Blue Rock Springs]] and [[#Lake Herman Road murders|Lake Herman Road]] murders. The other arm of the radian centered on Mount Diablo extended to the site of [[#Presidio Heights murder|Paul Stine's murder]].<ref name=CB/>{{rp|190}}

Hundreds of solutions to the Z13 and Z32 have been proposed and, according to Oranchak, “it is practically impossible to determine if any of them are correct” due to how short the ciphers are.<ref>{{Cite news |last=Méheut |first=Constant |date=2021-06-22 |title=I've Cracked Zodiac, a French Engineer Says. Online Sleuths Are Skeptical. |url=https://www.nytimes.com/2021/06/22/world/europe/france-zodiac-killer-cipher.html |access-date=2025-04-09 |work=[[The New York Times]] |language=en-US |issn=0362-4331}}</ref>

===July 1970 letters===
In a [[s:Zodiac Killer letter, July 24th 1970|letter postmarked July 24, 1970]] to the ''Chronicle'', the Zodiac again complained about no one wearing Zodiac-themed buttons. He claimed to have "a little list" of victims which included the woman and her baby he drove around for several hours. The details match [[#Kathleen Johns|Kathleen Johns']] description of her abduction on March 22, four months earlier.

Two days later on July 26, the Zodiac mailed [[s:Zodiac Killer letter, July 26th 1970|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: "[[File:Zodiac Killer symbol.svg|20px]] = 13, SFPD = 0". The letter's postscript explained the Mount Diablo code from his previous letter.

===October 1970 cards===
{{Multiple images
| image1            = Zodiac-Postcard.jpg
| caption1          = '''[[s:Zodiac Killer letter, October 5th 1970|The "13 Hole Punch Card"]]''', October 7, 1970
| image2            = Zodiac-back.pdf
| caption2          = '''[[s:Zodiac Killer letter, October 27th 1970|The "Halloween Card"]]''', October 27, 1970
| total_width       = 400
}}

On October 7, 1970, the ''Chronicle'' received a [[s:Zodiac Killer letter, October 5th 1970|three-by-five-inch card]] (nicknamed the "13 [[Hole punch|Hole Punch]] Card") signed by Zodiac with the [[File:Zodiac Killer symbol.svg|20px]] symbol and a small cross reportedly drawn in blood.<ref>Rozak, Bill. "[https://www.theunion.com/news/crime/yet-to-be-published-memoir-possibly-ids-zodiac-killer-says-he-killed-tahoe-woman-hung/article_5d109985-e643-55c6-9cd0-9271c36a4cf2.html Yet to be published memoir possibly IDs Zodiac killer: Says he killed Tahoe woman, hung remains in tree]". ''[[The Union (newspaper)|The Union]]''. October 8, 2021.</ref> 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.<ref name=Avery70>Avery, Paul. "[https://web.archive.org/web/20070306090854/http://cdn.sfgate.com/chronicle/acrobat/2007/02/25/zodiac_1970_10_12_1.pdf Gilbert and Sullivan Clue to Zodiac]", ''[[San Francisco Chronicle]]''. October 12, 1970. 5.</ref>

On October 27, 1970, Paul Avery received a [[s:Zodiac Killer letter, October 27th 1970|Halloween card]] signed by "Z" alongside the [[File:Zodiac Killer symbol.svg|20px]] symbol.<ref name=Avery70/> A handwritten note read, "Peek-a-boo, you are doomed." The ''Chronicle'' covered this threat on its front page.<ref name=Grays/>{{rp|160}} The card's postmark was from a San Francisco mailbox that afternoon.<ref>[[United Press International]] (UPI). "'Zodiac killer' threatens to take reporter's life". ''[[Windsor Star]]''. October 31, 1970. 1.</ref> The implication of a fourteenth Zodiac victim was speculated based on the phrase "4-teen" found in the card.<ref name=Grays/>{{rp|178}} Avery refused police protection and started carrying a pistol.<ref>"[https://www.newspapers.com/article/the-san-francisco-examiner-zodiac-killer/26884828/ Zodiac Killer sends Halloween Card to Paul Avery]". ''[[San Francisco Examiner]]''. October 31, 1970. 7.</ref> His colleagues wore "I Am Not Avery" buttons.<ref name=Fagan2020>Fagan, Kevin. "[https://www.sfchronicle.com/nation/article/zodiac-killer-case-how-the-san-francisco-13464935.php Zodiac Killer case: How the San Francisco Chronicle was involved]", ''San Francisco Chronicle''. December 11, 2020.</ref> Shortly after the "Halloween Card", Avery also received an anonymous letter about the parallels between the 1966 murder of [[Murder of Cheri Jo Bates|Cheri Jo Bates]] and the Zodiac.<ref name=Grays/>{{rp|161–2}}

=== March 1971 letter ===
In a March 13, 1971, [[s:Zodiac Killer letter, March 13th 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".<ref name=Read/>

=== January 1974 letter ===
Zodiac remained silent for nearly three years. The ''Chronicle'' received a [[s:Zodiac Killer letter, January 29th 1974|letter from the Zodiac]], postmarked January 29, 1974 from [[San Mateo County, California|San Mateo County]]. It complained that columnist Count Marco needed to "feel superior to everyone" and praised ''[[The Exorcist (film)|The Exorcist]]'' (1973) as "the best [[Satire|saterical]] comidy [sic] 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."<ref name=Zoellner-2000/><ref name=Bee74>"[https://www.newspapers.com/article/the-sacramento-bee-zodiac-killer-exorcis/48295902/ Zodiac Killer Exorcist Letter]". ''[[The Sacramento Bee]]''. January 31, 1974. 62.</ref>

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.<ref name=Taylor>Taylor, Michael. "[https://www.sfgate.com/news/article/UNDYING-LEGEND-OF-A-KILLER-MYSTERY-He-taunted-2645447.php Undying Legend of a Killer / Mystery: He Taunted Police, Terrified Children, Kept the Bay Area on Edge -- Then Went Silent]". SFGate. March 1, 2007.</ref>

==Letters of suspicious authorship==
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 (state)|New York]]. The return address was the [[File:Zodiac Killer symbol.svg|20px]] 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 [[Cryptanalysis|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.<ref name=HISTORY-2023a/>

The ''Chronicle'' received a [[s:Zodiac Killer letter, Feb 14th 1974|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]].<ref name=HISTORY-2023a/><ref>[[Associated Press|AP]]. "[https://web.archive.org/web/20110724162841/http://cdn.sfgate.com/chronicle/acrobat/2007/02/25/zodiac_1976_08_26_1.pdf Tips Still Pursue Multiple Slayer]", ''San Francisco Chronicle''. August 26, 1976. 3.</ref> The handwriting was not authenticated as the Zodiac's.<ref>Oswell, Douglas Evander. ''[https://www.google.com/books/edition/The_Unabomber_and_the_Zodiac/maiGcstEdAwC?hl=en&gbpv=1&pg=PA231&printsec=frontcover The Unabomber and the Zodiac]''. Douglas Oswell, 2007. 231.</ref>

A [[s:Zodiac Killer letter, May 8th 1974|letter to the ''Chronicle'']] postmarked May 8, 1974, opined that ''[[Badlands (film)|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 [[s:Zodiac Killer letter, July 8th 1974|anonymous letter postmarked July 8, 1974]], complaining about [[Antifeminism|antifeminist]] columnist Marco Spinelli. The letter was signed, "the Red Phantom (red with rage)".<ref name=Flaherty/>{{rp|44}}

In 2007, an [[American Greetings]] [[Christmas card]] was discovered in the ''Chronicle's'' photo files. Its postmark was from 1990 in [[Eureka, California|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.<ref>Williams, Lance. [http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/03/03/MNG37OETI71.DTL&hw=zodiac+christmas+card&sn=001&sc=1000 "Zodiac's written clues fascinate document expert"], ''[[San Francisco Chronicle]]''. March 3, 2007.</ref><ref>Freedman, Rich. "[https://web.archive.org/web/20230125171929/https://www.timesheraldonline.com/2007/03/04/zodiac-did-killer-send-card-in-1990/  Zodiac: Did killer send card in 1990?]". ''Vallejo Times Herald''. March 3, 2007.</ref><ref name=Harris-2007>Harris, Paul. "[https://www.theguardian.com/film/2007/apr/15/usa.world So who was the Zodiac killer?]". ''[[The Observer]]''. April 15, 2007.</ref>

== Suspected victims ==
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 [[Box score|boxscore]] of 37".<ref name=Toschi76/> Robert Graysmith estimated 49 Zodiac victims.<ref name=Grays/>{{rp|308–11}} Many high-profile murders and attacks in the 1960s and 1970s were seen as possible Zodiac crimes, but none have been confirmed.

=== Raymond Davis ===
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&nbsp;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.<ref name=Harrison>Harrison, Ken. "[https://www.sandiegoreader.com/news/2020/sep/14/stringers-oceanside-zodiac-murder/ The Oceanside Zodiac murder]". ''[[San Diego Reader]]''. September 14, 2020.</ref><ref>Lothspeich, Jennifer. "[https://www.cbs8.com/article/news/crime/police-looking-into-claims-by-historian-that-zodiac-killer-may-be-responsible-for-1962-oceanside-murder/509-06453d97-3244-478f-9160-3cd499ce2ec0 Police looking into claims by historian that Zodiac Killer may be responsible for 1962 Oceanside murder]", CBS8. February 3, 2020.</ref> 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.<ref name=KGTV>Staahl, Derek. "[https://www.10news.com/news/local-news/did-the-zodiac-kill-in-oceanside-police-re-test-evidence-in-cold-case Did the Zodiac kill in Oceanside? Police re-test evidence in cold case]". [[KGTV]]. February 3, 2020.</ref>

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 [[#Presidio Heights murder|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.<ref name=Lombardo>Lombardo, Delinda. "[https://www.sandiegoreader.com/news/2020/mar/18/city-lights-was-zodiac-killer-san-diego/ Was the Zodiac killer in San Diego?]". ''[[San Diego Reader]]''. March 18, 2020.</ref><ref name=Harrison/><ref>Hawthorne, Kristi. "[https://historiesandmysteries.blog/2020/01/07/the-murder-of-ray-davis/ 62 Year Old Cold Case Remains Unsolved – The Murder of Ray Davis]", ''Histories and Mysteries''. January 7, 2020.</ref> Hawthorne presented her findings to the Oceanside Police Department, which began an inquiry.<ref name=KGTV/>

===Robert Domingos and Linda Edwards===
On June 2, 1963, on the beach at [[Tajiguas, California|Tajiguas]] in [[Santa Barbara County, California|Santa Barbara County]], California, an unidentified [[sniper]] fired two shots from a .22 caliber gun at a group of teenagers. None of them were hit.<ref name=Lompoc>"[https://interactive.cbs8.com/pdf/Zodiac_1963gaviotabeachsniper.pdf Sniper Said at Scene of Murders]", ''[[Lompoc Record]]''. June 19, 1963. 1f.</ref> On June 4, on a beach within [[Gaviota State Park]], just west of Tajiguas, Robert George Domingos (18) and his fiancée Linda Faye Edwards (17) were shot dead by an unidentified person. They were at the beach while skipping school at [[Lompoc High School]] for [[Senior Skip Day|Senior Ditch Day]].<ref name="Grey">Grey, Jeremy. "[https://www.al.com/news/2020/10/did-the-zodiac-killer-murder-an-alabama-couple-in-1964.html Did the Zodiac killer murder an Alabama couple in 1964?]", AL.com. October 22, 2020.</ref><ref name="BB">Brantingham, Barney. "[https://www.independent.com/2011/06/02/murdered-but-not-forgotten/ Murdered but Not Forgotten]". ''[[Santa Barbara Independent]]''. June 2, 2011.</ref> On June 5, when the couple had not returned home, their parents called the police. During a police search, several of the couple's belongings, like Edwards' purse, were inside Domingos' car.<ref name="Oakland">[[Associated Press|AP]]. "[https://www.newspapers.com/article/oakland-tribune-domingos-murder/27128148/ Manhunt for Killer of Boy, Girl]", ''[[Oakland Tribune]]''. June 7, 1963. 5.</ref><ref name="LAT63">"[https://www.newspapers.com/image/381571889/?clipping_id=26842906 High School Sweethearts: COUPLE FOUND SLAIN ON SECLUDED BEACH Mystery Deaths Cast Gloom Over Lompoc Commencement Rites]." ''Los Angeles Times''. June 07, 1963. 1, 13.</ref>

Police believed that the assailant attempted to bind the couple with pre-cut rope. This was the same ''[[modus operandi]]'' as the [[#Lake Berryessa murder|Lake Berryessa attacks]].<ref name="Grey" /> Likely, when the victims got loose and tried to flee, the killer shot them repeatedly in the back and chest. Domingos was shot 11 times and Edwards 8 times.<ref name="Oakland" /> The killer placed their bodies in a small shack nearby, and tried to burn it to the ground.<ref name="BB" /> The firearm was probably a .22 caliber [[semi-automatic firearm|semi-automatic rifle]], like the Tajiguas and [[#Lake Herman Road murders|Lake Herman Road]] incidents.<ref name="Minsky" /><ref name="BB" /> The [[Winchester Repeating Arms Company|Winchester]] Western Super X copper-coated bullets also matched the Zodiac's.<ref name="BB" /> The [[lot number]] of the .22 ammunition was traced to an April purchase from a store in [[Santa Barbara, California|Santa Barbara]]. The only other place that lot number turned up was at [[Vandenberg Space Force Base|Vandenberg Air Force Base]] near [[Lompoc, California|Lompoc]]. Investigators looked into purchases of the ammunition at both locations.<ref name="Lompoc" />

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 murders,<ref>[[Associated Press|AP]]. "Did Zodiac Murder Two Students?", ''[[Santa Cruz Sentinel]]''. November 14, 1972. 22.</ref> and "although the anticipated response to this statement would be one of skepticism, let me say that we do not make this assertion frivolously."<ref>"[http://www.crimeandinvestigation.co.uk/crime-files/zodiac-killer/crime The Zodiac Killer Crime Files]", ''[[Crime & Investigation (European TV channel)|Crime+Investigation UK]]''. January 31, 2013.</ref><ref name="Minsky">Minsky, David. "[https://www.santamariasun.com/news/nefarious-crimes-cold-cases-santa-barbara-county-is-linked-to-some-of-the-countrys-notorious-and-unsolved-murders-14795067 Nefarious crimes, cold cases: Santa Barbara County is linked to some of the country's notorious, and unsolved, murders]". ''[[Santa Maria Sun]]''. October 27, 2016.</ref> When SFPD detectives Bill Armstrong and Dave Toschi investigated the murders in 1972, Toschi said a connection is possible.<ref>"[https://www.newspapers.com/article/the-san-francisco-examiner-toschi-commen/26885249/ Toschi Comments on Zodiac Possibility of murdering Domingos and Edwards]". ''[[San Francisco Examiner]]''. November 14, 1972. 19.</ref> A classmate of Domingos and Edwards, who later became a [[Clinical psychology|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."<ref name="BB" /> 

=== Johnny Ray Swindle and Joyce Ann Swindle ===
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, San Diego|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 Group USA|Timex]] watch—the same brand watch found at the Cheri Jo Bates crime scene, and assumed to belong to Bates' killer.<ref name=Grey/><ref name=Lombardo/>

Johnny's mother said she could not think of him having any enemies.<ref>Castanien, Pliny. "[https://interactive.cbs8.com/pdf/Zodiac_honeymoonmurders1964SDUnion.pdf Psychopathic Sniper Hunted in 2 Slayings]". ''[[The San Diego Union-Tribune|The San Diego Union]]''. February 7, 1964. a-17.</ref> His sister theorized the Zodiac may have been the culprit. Police investigated a 51-year-old man living in a nearby beach shack, a teenager alleged by a priest to be violent, and a 19-year-old [[United States Marine Corps|Marine]] from San Diego who killed his parents and sister in Illinois. Police speculated that the Swindles were victims of a "[[Thrill killing|thrill killer]]", and they also saw a parallel with the Domingos and Edwards murders.<ref name=Grey/> In both the Santa Barbara and Ocean Beach killings, the victims were shot from a distance, then again at close range.<ref>Korsgaard, Soren Roest. ''America's Jack The Ripper: The Crimes and Psychology of the Zodiac Killer''. [[Lulu.com]], 2017. 264ff.</ref> 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 [[Cartridge (firearms)|cartridges]] found at the two scenes. The San Diego Reader noted that the murders at Lake Berryessa, Santa Barbara, and Ocean Beach were all near bodies of water.<ref name=Lombardo/>

=== Cheri Jo Bates ===
{{Main|Murder of Cheri Jo Bates}}
[[File:Cheri Jo Bates Crime Scene Terracina Drive October 31 1966.jpg|thumb|Officers from the [[Riverside Police Department]] examining the Bates crime scene at Terracina Drive, Riverside, in 1966. Bates' body lies at the right of the gravel path.]]
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&nbsp;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&nbsp;a.m.<ref name=Grey/> 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.<ref>Voigt, Tom. "[https://www.zodiackiller.com/BatesWatch2.html Photo of watch found near Bates' body]" ZodiacKiller.com.</ref><ref name=Grays/>{{rp|165–6}}

One month later, on November 29, nearly identical [[Typewriter|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."<ref name=Grays/>{{rp|168–9}}

{{Multiple images
| direction         = horizontal
| total_width       = 390
| image1            = Zodiac-confession.jpg
| caption1          = The typewritten confession received by the Riverside Police Department and ''[[The Press-Enterprise]]'' on November 29, 1966
| image2            = ZodiacsPoem.jpg
| caption2          = The inscription upon the [[Riverside City College]] library desk, discovered in 1967
| align             = right
}}

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.<ref name=Grays/>{{rp|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."<ref>Rogers, Kate. ''The Zodiac Killer: Terror in California''. Greenhaven Publishing LLC, 2017. 40.</ref> The connection between Bates and the Zodiac remains uncertain.

===Enedine Molina and Fermin Rodriguez===
On June 8, 1967, Enedine Molina (35) and Fermin Rodriguez (36) were parked on Vallecitos Road in [[Alameda County, California|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, California|Pleasanton]]. The March 1971 [[s:Zodiac Killer letter, March 13th 1971|Zodiac letter]] to the ''[[Los Angeles Times]]'' was postmarked in Pleasanton.<ref>Morford, Mike. "[https://zodiacrevisited.com/the-zodiac-killers-forgotten-victims/ The Zodiac Killer's Forgotten Victims?]", ''Zodiac Revisited''. April 16, 2013.</ref>

===John Franklin Hood and Sandra Garcia===
[[File:East Beach (3391461890).jpg|thumb|Santa Barbara's [[East Beach (Santa Barbara)|East Beach]]]]
On February 21, 1970, John Franklin Hood (24) and his fiancée, Sandra Garcia (20), visited [[East Beach (Santa Barbara)|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 murder|Lake Berryessa attack]].<ref name=BB/><ref>"[https://www.newspapers.com/article/the-napa-valley-register/116997516/ Local Officials Checking if Zodiac Involved in Santa Barbara Stabbings]", ''[[Napa Valley Register]]''. February 24, 1970. 1.</ref>

=== Kathleen Johns ===
On the night of March 22, 1970, Kathleen Johns (22) was driving to [[Petaluma, California|Petaluma]] with her 10-month-old daughter. Johns was also seven months pregnant.<ref>Smith, Dave. "Evidence Links Zodiac Killer to '66 Death of Riverside Coed". ''Los Angeles Times''. November 16, 1970.</ref> She left [[San Bernardino, California|San Bernardino]] at 4:30&nbsp;p.m. At 11:30&nbsp;p.m. on [[California State Route 132|Highway 132]] near [[Patterson, California|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.<ref name=Avery11.70>Avery, Paul. "New Evidence in Zodiac Killings: A Link to Murder in Riverside", ''San Francisco Chronicle''. November 16, 1970. 1, 4.</ref><ref>[[United Press International|UPI]]. "Death of coed in 1966: Zodiac killer traced back to Riverside". ''[[Redlands Daily Facts]]''. November 16, 1970. 4.</ref><ref name=SFExaminer70>"[https://www.newspapers.com/article/the-san-francisco-examiner-kathleen-john/26884769/ Rode With Zodiac, Woman Claims]". San Francisco Examiner. March 23, 1970.</ref>

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 [[#Presidio Heights murder|Paul Stine's murder]], she exclaimed, "Oh my god...that's him".<ref name=Avery11.70/><ref name=Adams>Adams, Charles F. (2004). ''Murder by the Bay: Historic Homicide in and about the City of San Francisco''. Quill Driver Books.</ref>{{rp|268}} Johns car was found in flames on Highway 132.<ref name=SFExaminer70/> [[#July 1970 letters|A few months later]], the Zodiac referenced this kidnapping in a [[s:Zodiac Killer letter, July 24th 1970|letter to the ''Chronicle'']].<ref>Voigt, Tom. "[https://www.zodiackiller.com/JohnsLetter.html Kathleen Johns Letter]", ZodiacKiller.com.</ref>

=== Richard Radetich ===
Around 5:25&nbsp;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. [[#June 1970 letter and map|A week later]], the [[s:Zodiac Killer letter, June 26th 1970|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.<ref name=Zamora>Zamora, Jim Herron. "[https://www.sfgate.com/news/article/1967-71-a-bloody-period-for-S-F-police-2654263.php 1967-71 -- a bloody period for S.F. police]". ''[[SFGate]]''. January 7, 2007.</ref><ref>"[https://www.odmp.org/officer/10956-officer-richard-radetich Officer Richard Radetich]". Officer Down Memorial Page.</ref>

===Donna Lass===
[[File:Sahara Tahoe postcard.png|thumb|The [[Sahara Tahoe]] casino in [[Stateline, Nevada]], in 1965]]
[[File:Lake Tahoe card with message from Zodiac killer.jpg|thumb|[[s:Zodiac Killer letter, March 22th 1971|Lake Tahoe postcard]] sent to Paul Avery,  March 22, 1971]]
[[Registered nurse]] Donna Lass (25) was last seen on September 6, 1970, in [[Stateline, Nevada|Stateline]], [[Nevada]]. She worked at the [[Horizon Casino Resort|Sahara Tahoe]] [[casino]] until 2:00&nbsp;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.<ref name=Grays/>{{rp|178}} Her car was parked near her apartment, which was undisturbed.<ref name=Crofton>Crofton, Gregory. "[https://www.tahoedailytribune.com/news/zodiac-killers-trail-leads-to-tahoe/ Zodiac killer's trail leads to Tahoe]". ''[[Swift Communications#California|Tahoe Daily Tribune]]''. December 19, 2001.</ref>

Paul Avery received [[s:Zodiac Killer letter, March 22th 1971|a Lake Tahoe postcard]] several months later with potential connections to Lass' disappearance.<ref name=Fagan-3>Fagan, Kevin. "[https://www.sfchronicle.com/sf/article/zodiac-killer-identity-sierra-rock-formation-18138246.php Alleged clue to Zodiac Killer shrugged off]", ''San Francisco Chronicle''. June 11, 2023. A1, A18.</ref><ref name=Avery70/><ref name=Adams/>{{rp|274}} Like the "[[#October 1970 cards|13-Hole Punch Card]]", placed over the original image is a [[collage]] of phrases like "Peek through the pines...around in the snow". It also said, "Sought Victim 12" and included the [[File:Zodiac Killer symbol.svg|20px]] symbol.<ref name=Fagan-2>Fagan, Kevin. "[https://www.sfchronicle.com/california/article/id-sierra-skull-helps-prove-zodiac-killed-her-18586424.php Is skull from High Sierra tied to the Zodiac Killer?]". San Francisco Chronicle. January 5, 2024. A1, A11.</ref><ref>"[https://news.google.com/newspapers?nid=1243&dat=19710327&id=6-lPAAAAIBAJ&pg=5837,2680403 Search Called Off for Zodiac Victim in Mountain Area]". ''[[The Bulletin (Bend)|The Bulletin]]''. March 27, 1971. 9.</ref><ref name=Flaherty/>{{rp|43}}

In 1986, the [[Placer County, California|Placer County]] Sheriff's Office located a skull near [[Emigrant Gap]] along [[California State Route 20]] in the [[Sierra Nevada]]. The [[South Lake Tahoe, California|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.<ref name=Fagan-2/><ref name=Dowd-2023>Dowd, Katie. "[https://www.sfgate.com/bayarea/article/missing-tahoe-casino-nurse-zodiac-link-identified-18577174.php  Missing Tahoe casino nurse Donna Lass finally identified]". [[SFGate]]. December 28, 2023.</ref>

===Potentially related serial murders===
====Astrological murders====
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 [[jurisdiction]]s made a tentative connection between a single culprit and at least a dozen unsolved homicides that occurred between the late 1960s and early 1970s. 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 [[astrology|astrological]] events, such as the [[winter solstice]], [[equinox]] and [[Friday the 13th]].<ref name=Grays/>{{rp|309, 311}}

====Santa Rosa hitchhiker murders====
{{Main|Santa Rosa hitchhiker murders}}

The Zodiac was also suspected of being the perpetrator behind the "[[Santa Rosa Hitchhiker Murders|Santa Rosa hitchhiker murders]]". Between 1972 and 1973, at least seven female hitchhikers were murdered in [[Sonoma County, California|Sonoma County]] and [[Santa Rosa, California|Santa Rosa]].<ref name=Grays2>Graysmith, Robert. ''Zodiac Unmasked: The Identity of America's Most Elusive Serial Killer Revealed''. [[Berkley Books]], 2002.</ref>{{rp|163}} In the Zodiac's January 29, 1974 "Exorcist letter" to the ''Chronicle'', he [[#Final Zodiac letter|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 [[s:Zodiac Killer letter, November 9th 1969|a previous letter]], "when I comitt [''[[sic]]''] my murders, they shall look like routine robberies, [[Crime of passion|killings of anger]], + a few fake accidents, etc."<ref name=SFGateZL2>"[https://web.archive.org/web/20130925202130/http://www.sfgate.com/news/slideshow/Zodiac-Killer-The-Letters-37941/photo-2044019.php Zodiac Killer: The Letters]". [[SFGate]]. December 2, 2008.</ref>

One of the main Zodiac suspects, [[Zodiac Killer suspects#Arthur Leigh Allen|Arthur Leigh Allen]], was also suspected of being the Santa Rosa killer.<ref>Weiss, Mike. "[https://www.sfgate.com/crime/article/dna-seems-to-clear-only-zodiac-suspect-2784268.php DNA seems to clear only Zodiac suspect / new-found evidence may allow genetic profile of '60s killer]". SFGate. October 15, 2002.</ref>

==21st-century developments==
In April 2004, the SFPD cited caseload pressure and marked the Zodiac case "inactive."<ref>Goodyear, Charlie. [http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2004/04/07/MNG8N61MGI1.DTL "Files shut on Zodiac's deadly trail"], ''[[SFGate]]''. April 7, 2004.</ref> By March 2007, they reactivated the case.<ref>Russo, Charles. "Zodiac: The killer who will not die". ''[[San Francisco (magazine)|San Francisco]]''. March 2007.</ref> The case remains open in Riverside and Napa County.<ref>Osier, Valerie. "[https://www.pressenterprise.com/2013/11/30/riverside-co-ed8217s-1966-slaying-still-a-mystery/#:~:text=FOUND%20ON%20CAMPUS,houses%20on%20the%20RCC%20campus. Riverside: Co-ed's 1966 slaying still a mystery]". ''[[The Press-Enterprise]]''. November 30, 2013.</ref><ref>Moyer, Justin. "And the Zodiac Killer is ..." ''[[The Washington Post]]'', ''[[Press Enterprise (Pennsylvania)|Press Enterprise]]''. May 14, 2014.</ref> 

In 2018, the Vallejo Police Department attempted to use [[GEDmatch]] to catch the Zodiac.<ref>Chabria, Anita. "[https://web.archive.org/web/20190627152354/https://www.sacbee.com/latest-news/article210320689.html Vallejo police have sent Zodiac Killer DNA to a lab. Results could come in weeks]". The Sacramento Bee. May 2, 2018.</ref> They did not receive definitive results.<ref>Kettler, Sara. "[https://web.archive.org/web/20211102165106/https://www.biography.com/news/zodiac-killer-murder-identity Why the Zodiac Killer Has Never Been Identified]." [[Biography (TV program)|Biography]]. December 12, 2019.</ref> The FBI's investigation was still ongoing as of 2020.<ref name=Stuti>Mishra, Stuti. "[https://ca.news.yahoo.com/zodiac-killer-copycat-sends-threatening-084719134.html New Zodiac killer copycat sends threatening letters to New York media outlets]", ''[[The Independent]]''. December 13, 2021.</ref>

== Suspects ==
{{Main|Zodiac Killer suspects}}
[[File:Allen Suspect 1991.jpg|thumb|Arthur Leigh Allen in 1991]]
In 2009, ''[[The Guardian]]'' reported that the SFPD had investigated an estimated 2,500 Zodiac suspects, and only a half-dozen of them were seen as credible by the department.<ref name=Tunzelmann>Tunzelmann, Alex von. "[https://www.theguardian.com/film/2012/feb/23/zodiac-signs-historical-accuracy Zodiac shows all the vital signs of historical accuracy]". [[The Guardian]]. February 23, 2012</ref><ref name=amw.com>"[https://web.archive.org/web/20101101205432/http://www.amw.com/features/feature_story_detail.cfm?id=1543 Zodiac Killer: Meet the Prime Suspects]", America's Most Wanted. September 2, 2008.</ref> Richard Grinell, who runs the website Zodiac Ciphers, stated in 2022 that "there are probably 50 or 100 suspects named every year."<ref name=LAMag/>

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.<ref name=Ripper/><ref name=SFCCaseBreakers>Fagan, Kevin. "[https://web.archive.org/web/20211011095228/https://www.sfchronicle.com/bayarea/article/Zodiac-Killer-case-solved-Case-Breakers-16514228.php Zodiac Killer case solved? Case Breakers group makes an ID, but police say it doesn't hold up]". San Francisco Chronicle. October 6, 2021.</ref> Allen denied being the Zodiac.<ref>Dornin, Rusty. "[https://www.cnn.com/2002/US/West/10/22/zodiac.killer/ Zodiac killer terrorized, then stopped]", [[CNN]]. October 22, 2002.</ref> He was interviewed by police from the early days of the investigation, and was subject to several related [[search warrant]]s over a twenty-year period. In 2007, Graysmith said that several detectives described Allen as the most likely suspect.<ref>Graysmith, Robert. "[https://web.archive.org/web/20170803170007/http://www.washingtonpost.com/wp-dyn/content/discussion/2007/03/09/DI2007030900522.html Transcript: The 'Zodiac' Writer]". ''[[The Washington Post]]''. March 9, 2007.</ref> In 2010, Toschi stated that all the evidence against Allen ultimately "turned out to be negative."<ref>Williams, Lance. "[https://californiawatch.org/dailyreport/thank-you-note-zodiac-suspect-7071 A thank-you note from a Zodiac suspect]". [[California Watch]]. November 30, 2010.</ref> Other suspects widely seen as viable by professional or amateur investigators include Earl Van Best Jr., Gary Francis Poste, Giuseppe Bevilacqua, Lawrence Kane, Paul Doerr, Richard Gaikowski, and Richard Marshall.<ref>Jujjavarapu, Apoorva. "[https://www.yahoo.com/entertainment/zodiac-killer-suspects-were-names-151705590.html Zodiac Killer Suspects: What Were Their Names & Did They Face Any Charges?]". Yahoo Entertainment. December 27, 2023.</ref><ref>Beck, Melinda. "[https://www.history.com/news/could-any-of-these-men-have-been-the-zodiac-killer Could Any of These Men Have Been the Zodiac Killer?]". [[History Channel|History]]. August 22, 2023.</ref><ref name="LAMag" />

==Legacy==
{{Quote box
| quote = This is the case that won't go away. The killer's catch-me-if-you-can taunting of police, the mind-puzzlers he sent to the press, the way he dropped off the face of the Earth in the early 1970s combined to give the Zodiac case a legendary status that in some ways outstripped the magnitude of the murders. – Michael Taylor<ref name=Taylor/>
| align = right
| width = 300px
}}
In 2020, the ''Chronicle'' called the Zodiac case "the most famous unsolved murder case in American history."<ref name=SFChron3.16.21/> The unusual nature of the spree has sustained international interest for years.<ref name=SFCAnother>Williams, Lance. "[https://www.sfgate.com/bayarea/article/Another-possible-Zodiac-suspect-put-forth-3225232.php Another possible Zodiac suspect put forth]", [[SFGate]]. July 19, 2009.</ref> A cottage industry of "Zodiologists" sprung up in the wake of the killings.<ref>Raskin-Zrihen, Rachel. "[https://www.timesheraldonline.com/2018/10/02/local-authors-theory-included-in-zodiac-special-airing-wednesday/ Local author's theory included in Zodiac special airing Wednesday]". ''[[Vallejo Times Herald]]''. October 3, 2018.</ref> They try to solve the case and have informal annual meetings.<ref>Banes, Lanz Christian. "[https://www.eastbaytimes.com/2009/07/06/zodiac-killer-buffs-gather-in-vallejo-to-mark-grisly-anniversary/ Zodiac Killer buffs gather in Vallejo to mark grisly anniversary]". ''[[East Bay Times]]''. July 6, 2009.</ref><ref>Raskin-Zrihen, Rachel. "[https://www.timesheraldonline.com/2016/12/21/zodiologists-gather-at-lake-herman-road-to-mark-grisly-anniversary/ 'Zodiologists' gather at Lake Herman Road to mark grisly anniversary]". ''[[Vallejo Times Herald]]''. August 29, 2018.</ref> Several websites collect information about the crimes and ciphers.<ref>Newman, Judith. "[https://www.nytimes.com/2022/04/26/books/review/the-puzzler-aj-jacobs.html What's a Six-Letter Word for Fanatical Devotion to Solving Things?]". ''The New York Times''. April 26, 2022.</ref>

Dozens of books and documentaries have focused on the Zodiac.<ref name=Fagan>Ocenada, Ryan and Kevin Fagan. "[https://www.sfchronicle.com/sf/article/zodiac-killer-18436725.php Zodiac Killer: Why sleuths are still obsessed with S.F.'s most notorious serial killer]". ''[[San Francisco Chronicle]]''. October 22, 2023.</ref><ref name=Anguiano-2022>Anguiano, Dani. "[https://www.theguardian.com/us-news/2022/sep/30/zodiac-killer-jarett-kobek-california 'It's not an unsolvable case': has the Zodiac killer finally been found?]". ''[[The Guardian]]''. October 1, 2022</ref><ref>Riley, Brendan. "[https://www.timesheraldonline.com/2022/06/17/brendan-rileys-solano-chronicles-zodiac-murders-mystery-still-unsolved/ Brendan Riley's Solano Chronicles: Zodiac murders — mystery still unsolved]". ''[[Vallejo Times Herald]]''. June 17, 2022.</ref> 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.<ref name=CB/>{{rp|193}} John Bowman published the book ''The Allen Files'', containing Arthur Leigh Allen's military records.<ref>{{cite web |last1=Bowman |first1=John |title=The Allen Files |website=Amazon |url=https://www.amazon.com/Allen-Files-John-Bowman/dp/B0CZ11PK9F/}}</ref> That was followed with, ''Zodiac Killer - Fact Vs. Fiction''.<ref>{{cite web |last1=Bowman |first1=John |title=Zodiac Killer - Fact Vs. Fiction |website=Amazon |url=https://www.amazon.com/Zodiac-Killer-Fact-vs-Fiction/dp/B0DXKHT9N1/}}</ref>

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''.<ref>Wallace, Bill. "The murder mystery that wouldn't die Graysmith's second book on the Zodiac reveals the killer's identity -- but that's not really news." ''[[San Francisco Chronicle]]'', Sunday Review. May 12, 2002. 6.</ref> Attributing victims to the Zodiac is also a popular pastime. One Zodiologist has persistently claimed to also be a target of the killer.<ref>Hernandez, Jodi. "[https://www.nbcbayarea.com/news/local/organizers-cancel-50th-anniversary-zodiac-killer-tour-due-to-repeated-threats/200973/ Organizers Cancel 50th Anniversary Zodiac Killer Tour Due to Repeated Threats]". NBC Bay Area. December 11, 2018.</ref> Since 2013, accusing [[United States Senator]] [[Ted Cruz]] of being the Zodiac has been a [[Ted Cruz–Zodiac Killer meme|popular Internet meme]].<ref>[[Matthew Yglesias|Yglesias, Matthew]]. "[https://www.vox.com/2016/3/8/11179492/ted-cruz-zodiac-killer Ted Cruz and the Zodiac Killer, explained]". Vox. March 8, 2016.</ref>

The Zodiac inspired [[copycat killer]]s like [[Heriberto Seda]] in New York City and [[Kobe child murders|Shinichiro Azuma]] in Japan, both of whom called themselves "the Zodiac".<ref>Wudunn, Sheryl. "[https://www.nytimes.com/1997/07/02/world/could-that-murderous-child-be-one-of-mine.html Could That Murderous Child Be One of Mine?]". ''The New York Times''. July 2, 1997.</ref><ref>Toy, Vivian. "[https://www.nytimes.com/1998/05/26/nyregion/reporter-s-notebook-in-the-box-with-the-zodiac-suspect.html Reporter's Notebook; In the Box With the Zodiac Suspect]". ''The New York Times''. May 26, 1998.</ref> In 2021, an anonymous author sent letters to media outlets in [[Albany, New York|Albany]] using a "Chinese Zodiac Killer" [[sobriquet]].<ref name=Stuti/>

===Popular culture===
{{Further|Zodiac Killer in popular culture}}
[[File:2017 Golden Gate Theatre.jpg|thumb|The [[Golden Gate Theater]] in San Francisco]]
The first film about the Zodiac Killer was produced two years after his last confirmed murder during his letter-writing campaign. [[Tom Hanson (American actor)|Tom Hanson's]] [[The Zodiac Killer (film)|''The Zodiac Killer'']] was made as a scheme to capture the culprit. The film premiered on April 19, 1971, at the [[Golden Gate Theatre|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 motorcycles|Kawasaki]] motorcycle.<ref>Meline, Gabe. "[https://www.kqed.org/arts/13833330/a-bizarre-plot-to-catch-the-real-life-zodiac-killer A Bizarre Plot to Catch the Real-Life Zodiac Killer]", [[KQED Inc.|KQED]]. May 23, 2018.</ref> The audience surveys were secretly compared to the Zodiac's handwriting. Hanson hoped the killer's supposed [[egotism]] would lure him to the movie, and deployed volunteers to detain anyone whose handwriting matched the Zodiac's.<ref>Sonoras, Steven. "[https://pulp.aadl.org/node/366726 'The Zodiac Killer" comes alive in 4K at the Michigan Theater]", Pulp, [[Ann Arbor District Library]]. September 20, 2017.</ref> The scheme lasted for several screenings, and in one, the volunteers actually confronted one potential suspect and held the suspect before releasing him due to lack of evidence.<ref>Symchuk, Adam. "[https://movieweb.com/the-zodiac-killer-catch-real-life-killer/ This Horror Movie Almost Succeeded in Catching The Zodiac Killer]". MovieWeb. September 21, 2024.</ref>

The Zodiac has inspired villains in multiple movies, including Scorpio in ''[[Dirty Harry]]'' (1971), the Gemini Killer in ''[[The Exorcist III]]'' (1990), John Doe in [[Seven (1995 film)|''Seven'']] (1995), and the [[Riddler]] in [[The Batman (film)|''The Batman'']] (2022).<ref>Kaye, Don. "[https://www.denofgeek.com/movies/zodiac-movies-inspired-by-real-serial-killer/ This Is the Zodiac Speaking: Movies Inspired by the Real Serial Killer]". [[Den of Geek]]. March 2, 2022.</ref> The Zodiac case is also the subject of the film ''[[Zodiac (film)|Zodiac]]'' (2007), directed by [[David Fincher]], who also directed ''Seven''. Fincher grew up in the Bay Area during the Zodiac killings. The film was an adaptation of Robert Graysmith's books,<ref>Dargis, Manohla. "[https://www.nytimes.com/2007/03/02/movies/02zodi.html Hunting a Killer as the Age of Aquarius Dies]", ''The New York Times''. March 2, 2007.</ref> focusing on Graysmith and Paul Avery's investigation over 23 years.<ref>Zilko, Christian (March 2, 2022). "[https://www.indiewire.com/feature/zodiac-david-fincher-behind-the-scenes-trivia-1234702993/ 'Zodiac' Turns 15: Behind-the-Scenes Facts You Didn't Know About the David Fincher Movie]". IndieWire.</ref><ref name=Tunzelmann/> The filmmakers extensively researched the case, conducting interviews with people involved in the case. The film posits Arthur Leigh Allen's culpability and led to more public interest in the Zodiac.<ref name=Minsky/><ref name=Harris-2007/>

== See also ==
* [[List of serial killers in the United States]]
* [[List of fugitives from justice who disappeared]]

==References==
{{reflist}}

==Further reading==
===True Crime===
{{refbegin|30em}}
* {{citation |author=Brenda Haugen |title=The Zodiac Killer: Terror and Mystery |url=https://books.google.com/books?id=p2bS3thnD5YC&pg=PP1 |year=2010 |publisher=Capstone Press |isbn=978-0-7565-4357-0}}
* {{citation |author=William T. Rasmussen |title=Corroborating Evidence II |url=https://books.google.com/books?id=G8v-moyT8w0C&pg=PP1 |date=2006 |publisher=Sunstone Press |isbn=978-0-86534-536-2}}
* 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, NY: [[Prometheus Books]], pp.&nbsp;113–128. {{ISBN|978-1-63388-532-5}}
{{refend}}

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

===FBI File===
[[Wikimedia Commons]] copies of FBI file #9-HQ-49911 on the Zodiac Killer: [[:File:FBIZodiacFile1.pdf|Sections 1]], [[:File:FBIZodiacFile2.pdf|2]], [[:File:FBIZodiacFile3.pdf|3]], [[:File:FBIZodiacFile4.pdf|4]], [[:File:FBIZodiacFile5.pdf|5]]

==External links==
* {{Commons category-inline}}
* {{wikisource-inline}}
* [https://maps.google.com/maps/ms?ie=UTF8&hl=en&om=1&msid=110578061651284892934.00000111d3cf57de2c360&msa=0&ll=38.201497,-122.203674&spn=1.651111,2.271423&z=9 "Zodiac Murder Map"] – Google Map plotting definite and possible Zodiac attacks (with details).

{{Zodiac killer}}
{{Portal bar|San Francisco Bay Area|Law}}

{{Authority control}}

[[Category:Zodiac Killer| ]]
[[Category:20th-century American letter writers]]
[[Category:20th-century pseudonymous writers]]
[[Category:20th-century American murderers]]
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[[Category:American murderers of children]]
[[Category:American robbers]]
[[Category:Crimes adapted into films]]
[[Category:History of Napa County, California]]
[[Category:Modern cryptographers]]
[[Category:Murder in Riverside County, California]]
[[Category:Murder in the San Francisco Bay Area]]
[[Category:Nicknames in crime]]
[[Category:Possibly living people]]
[[Category:Serial killer epithets]]
[[Category:Serial killers from the San Francisco Bay Area]]
[[Category:Undeciphered historical codes and ciphers]]
[[Category:Unidentified American serial killers]]
[[Category:Unsolved murders in California]]
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[[Category:Year of birth unknown]]