A cipher is a message that asks to be read by the right person and defeated by everyone else. In the five cases that follow, the records that investigators and courts had to deal with ranged from a true cipher mailed to newspapers to a single sheet of cryptic entries, a notebook in private shorthand, a set of journals partly in a code of the writer’s own, and a string of labels for what one man called his projects. Some of these were meant to be solved. Some were meant to stay private. In each, the question that mattered was the same one: what could the writing prove, and what could it only suggest?
The set is small: five well-documented cases, not a survey of the subject.
On July 31, 1969, three letters were mailed, one each to the Vallejo Times-Herald, the San Francisco Examiner and the San Francisco Chronicle. Each was handwritten, claimed the killing of a teenage couple at Christmas 1968 and the July 4 killing, and enclosed one third of a cipher made of letters and symbols. The writer demanded that the papers publish it and threatened more killings if they did not. It first appeared in print on August 1, according to the 2024 history of the ciphers written by the three men who later solved the second one.
Donald and Bettye Harden of Salinas, a schoolteacher and his wife, solved it in Salinas. They sent their solution to the Chronicle on August 8, eight days after the cipher was mailed. Donald Harden had been interested in ciphers since boyhood; Bettye, the codebreakers' history records, brought insight and persistence. Donald C. B. Marsh, a Colorado School of Mines professor and former president of the American Cryptogram Association, checked the solution independently. The cipher used a homophonic substitution, in which several symbols can stand for the same letter, and its message began, "I like killing people because it is so much fun." It gave no name. The last 18 characters have never been explained; they may be filler, or need a second step to read.
On August 4, 1969, the Examiner turned over to the Vallejo police an anonymous letter it had received, according to FBI records released in the bureau’s online Vault. It began with the line the writer would use for years: "This is the Zodiac speaking." The name, the Examiner later noted, was coined in a 1969 letter to the paper.
After the fourth incident, the killing in San Francisco in October, the letters acquired a proof of authorship beyond handwriting and phrasing. Within days a letter reached the Chronicle claiming the killing and enclosing physical proof of it; laboratory tests confirmed it, a 1969 ABC7 report recorded. The victim was Paul Stine, 29. Police said at the time that Stine was the fifth and last confirmed victim.
On October 22, 1969, a man claiming to be the Zodiac called again and again into the live morning program "A.M. San Francisco" on KGO, which that day featured the attorney Melvin Belli. "I need help. I’m sick," the caller said, according to the codebreakers' history. Belli agreed to meet him at a building in Daly City, and the caller never came. Richard Carlson wrote in the Washington Examiner in 2013 that police later traced the caller to a mental hospital in Oakland, that a survivor and two police dispatchers who had heard the real caller’s voice judged him an impostor, and that Chief of Inspectors Martin Lee said he was not the Zodiac. The broadcast produced more than a thousand leads, none of which went anywhere.
Just before Christmas the writer turned to Belli directly. A letter postmarked in San Francisco on December 20, 1969, the first anniversary of the first killings, reached Belli’s law office on December 23 and was forwarded to him in Munich. It claimed eight killings, warned of a ninth and possibly a tenth unless the writer got help soon, and enclosed another such item, the third he had mailed, the Associated Press reported. Belli said it read as a plea for help in controlling "this thing in me," and publicly offered to meet the writer on any terms.
The letters went on after the killings stopped. On April 20, 1970, the writer sent the Chronicle a note that asked whether the last cipher had been cracked and then said, "My name is," followed by a code of just 13 characters. Another letter followed, postmarked April 28. On June 26, 1970, the writer mailed a map and a 32-character cipher, claiming that its solution would show where a bomb had been placed. The 13-character and 32-character codes are too short to be solved by ordinary analysis, and neither has an accepted solution.
On October 27, 1970, a Halloween card was mailed to the Chronicle’s offices for the paper’s reporter Paul Avery. It carried the words "Peek a boo you are doomed." The FBI laboratory examined the card and could not draw from it anything that would help identify its source. An FBI memo from that month noted that the writer now claimed 13 victims. A January 1974 letter, accepted by police as authentic, raised the claimed total to 37.
In 2018 Vallejo police submitted evidence in the case for DNA comparison, as the Benicia Herald and ABC30 reported. The 340-character cipher went undeciphered for 51 years. In December 2020 three amateur codebreakers, among them the Australian mathematician Sam Blake, solved it, as CBS News, ABC7 in San Francisco, Global News and ABC News in Australia reported. The three men published their method in a 2024 paper, and a separate paper in the HistoCrypt proceedings examined the cipher’s unicity distance. The solved message did not contain a name. Time has listed the Zodiac among the country’s top unsolved crimes, and as of October 20, 2026, no charge or official identification has been reported.
His mathematics was not a sideline. In the fall of 1962 he began graduate work at the University of Michigan. Apart from a failed physics course, his lowest grade was a B minus, The Michigan Daily reported in 2006. The mathematician George Piranian recalled describing a problem he believed was unsolved, and finding Kaczynski’s solution on his desk weeks later. His dissertation, "Boundary Functions," written under Allen Shields, earned him a Ph.D. in 1967 and the Sumner Myers prize for the best thesis of the year. Berkeley hired him from July 1, 1967. He resigned in 1969, "quite out of the blue," the department chairman John Addison wrote, telling colleagues he was leaving mathematics and did not know what he would do next.
The bomber’s communications were a different kind of record from the Zodiac’s. They did not present a cipher to be solved. They left marks of another kind. Some of the early devices were marked with the letters FC, and a letter that preceded one of them was signed with an invented name, "Enoch W. Fisher." The FBI-led task force formed in 1979 grew to more than 150 investigators and analysts, and it had no name to work with until 1996.
In 1995 the bomber offered to stop killing if a major newspaper printed his long essay against industrial society. It was printed in September 1995. Kaczynski’s brother, David, and David’s wife, Linda Patrik, read it, compared it with letters he had written to the family, and brought their suspicion to the FBI through a lawyer. The Bureau’s own summary is that its linguistic analysis concluded that the author of David’s documents and the author of the essay were almost certainly the same person, and that this, combined with what investigators knew of the bombings and of Ted Kaczynski’s life, supported a search warrant. Kaczynski became suspect number 2,416.
Agents arrested him at his cabin on April 3, 1996. Inside they recovered what the task force had never had: what investigators believed was the original typed copy of the essay, and about 40,000 handwritten journal pages describing bomb experiments and the crimes, some in a code of his own. A manila envelope held detailed admissions to all 16 bombings, Terry Turchie of the FBI said in a Bureau podcast. Kaczynski was first held in Helena on a federal complaint for possessing bomb components, a charge meant to keep him in custody while the larger case was built. The government said his journals described the bombs, and he acknowledged responsibility for all 16 as part of his plea.
A federal grand jury in Sacramento indicted him on June 18, 1996, on ten counts covering four bombings, and a New Jersey indictment followed on October 1, 1996. On January 22, 1998, he pleaded guilty in federal court in Sacramento to charges covering all three deaths and two of the injuries, and he admitted the rest. On May 4, 1998, he received four consecutive life sentences plus 30 years and was ordered to pay $15,026,000 in restitution. He spent the rest of his life in federal prison. He died on June 10, 2023, aged 81, at the Federal Medical Center in Butner, North Carolina; he died by suicide, according to the Associated Press and CNN.
For most of the years covered by the charges, these deaths were investigated one at a time by different departments. Some were not treated as homicides at first. When the death of Michael Ray Schlicht came to light in 1974, it was recorded as accidental, the Orange County Sheriff’s Department said in 2023. In November 2023 the department identified him, after 49 years, as a presumed early victim of Kraft.
The sheet is the reason the press called him the Scorecard Killer. The entries were short phrases in Kraft’s handwriting, and prosecutors read them as reminders of particular young men. They linked 13 entries to the charged murders. "EDM" stood, in their reading, for the initials of one victim; "Airplane Hill" was matched to the unidentified man in Huntington Beach; "Parking Lot," "New Years Eve" and "Jail Out" were each matched to a separate count; "Hike Out LB Boots" and "MC HB Tattoo" were matched to two more; and "2 in 1 Beach" to two victims together. No entry was linked to two of the 16 charged victims. Prosecutors linked eight more entries to the Oregon and Michigan deaths, among them six beginning with the word "Portland" and one reading "GR 2." They linked 21 others to young men whose deaths were never charged, and they could not match the rest to anyone. The total figure of 67 victims that appears in news reports and in sheriff’s releases since then comes from this reading of the list, not from any court finding.
The trial judge admitted only the 13 entries tied to the charged counts. On their own, the judge said, the entries "meant nothing," but in context the prosecution’s reading was a reasonable one. On appeal, the California Supreme Court held that the list was relevant, admissible as Kraft’s own statement, and not unfairly prejudicial. The court summed up the prosecution’s case in one sentence: "Physical evidence linked defendant to eight of the murders." For the others, prosecutors relied on how much the killings resembled one another and on the list.
Kraft has always given a different explanation. He told the Bay Area Reporter in 2016 that the sheet was a coded guest list for a housewarming party he planned for his partner, Jeff Seelig, with one column of people he wanted to invite and another of possible guests. He said he had written it in code so that Seelig would not recognize it. The Long Beach Post reported that he had also described the names as friends and lovers.
The court rejected each of Kraft’s main claims. It held that the trial court had not abused its discretion in refusing to sever the counts. It upheld the admission of the 13 list entries. It upheld the searches: the magistrate had good reason to issue the warrant for the car, the warrant’s breadth was "commensurate with the scope of the investigation," and officers were entitled to search the binder in the trunk, because a plan for a murder might have been written down in advance.
The automatic appeal is followed in capital cases by habeas corpus proceedings, in which a prisoner can raise claims outside the trial record. A June 1, 2026, list kept by the state’s Habeas Corpus Resource Center shows that state habeas counsel had been appointed for Kraft and that no habeas petition was then pending before the California Supreme Court. His federal habeas case began in 2001, Orange Coast reported, and a federal ruling in 2009 rejected many of his claims as without merit but allowed some to go forward. Kraft has repeatedly tried to change lawyers. He went to the U.S. Court of Appeals for the Ninth Circuit himself in 2009, in a death penalty habeas appeal against Robert K. Wong (No. 09-55806), and in 2014 he filed a petition in that court against the federal district court in Los Angeles (No. 14-72292). The Bay Area Reporter reported in 2016 that appellate courts had rejected his claim that he should have been tried only for one death.
Kraft spent decades on San Quentin’s condemned row. Orange Coast reported in 2013 that he was inmate E38700 and lived in a small, windowless cell, where he listened to Nat King Cole, Jimmy Buffett and Brooks and Dunn and had signed up with a pen pal service. Vice reported the next year that he spent his days with music, cards and legal briefs. In 2016, at 71, he spoke to the Bay Area Reporter. Apart from a 1983 newspaper interview, the paper said, he had until then spoken publicly only through court filings. "I didn’t get a fair trial," he said. "The government turned it into a serial killer trial." He told the paper he expected to die in prison. "I am getting older. I am going to die here," he said, calling his situation "death penalty by attrition."
In May 2025 the Associated Press reported that Oregon State Police said Kraft was the only person under investigation in the 1980 death of Larry Eugene Parks in Oregon. The Woodburn Independent reported the identification of the man that month. Kraft’s name appears seven times, once for each of seven offense dates, on the Department of Corrections and Rehabilitation’s condemned inmate list updated October 2, 2026. The list gives his age as 81, his trial county as Orange, his sentence date as November 29, 1989, and his date of reception as November 30, 1989. California has had a moratorium on executions since March 13, 2019.
His record of swindling predated the war by decades. According to France Bleu, Landru built a prototype motorized bicycle in 1899, and archivists at the French patent office located a patent in his name from that year. He could not get the machine into production, and used the prototype instead to attract investors, and then defrauded them. The historian Bruno Fuligni, speaking on RTBF in 2021, described the same pattern: classified advertisements seeking money for the invention, followed by his departure with the money under an assumed name.
Inspector Jules Belin of the mobile brigades arrested him in Paris on April 12, 1919, and seized a small notebook. Herodote says it listed the names of eleven victims. RTBF describes notebooks that became the main evidence at trial: they recorded dates and times that matched the dates the prosecution set out for each woman, together with ordinary expenses, among them metal-cutting saws and the train tickets to Gambais. Infosyvelines calls the coded notebook the decisive piece of evidence, recording meetings, expenses and the nicknames he used for the women. RTBF and Infosyvelines both note the entries that later carried great weight in court: a return ticket for Landru, and a single ticket for the woman travelling with him.
The prosecution’s case, as RTBF and Infosyvelines describe it, rested on the notebook, whose dates and ticket purchases matched, and on the women’s property in Landru’s hands. Actu-Juridique reports that searches turned up that property. RTBF mentions furniture in the Henri II style from a shed at Clichy, which was later shown in court.
The historian Richard Tomlinson, in Samantha David’s summary for Connexion, argues that the notebook was not a full record. Landru did not buy it to record his crimes, he says, and the names in it were a selection; the police later acknowledged that Landru did not keep a detailed record in it. Tomlinson also points to police records listing 72 women in contact with Landru who were never traced, and stresses that this does not show that he killed them. No court ever considered that number, and the figure of eleven rests on the notebook, the property and the testimony.
The trial ran at Versailles from November 7 to 30, 1921, before the assize court of Seine-et-Oise. Landru defended himself point by point. According to Herodote, he admitted the thefts and frauds but denied the murders. RTBF describes him repeatedly daring his accusers to prove his guilt. The courtroom held the evidence: RTBF lists wigs belonging to the women and the Henri II furniture from Clichy, guarded by two gendarmes. The novelist Colette covered the trial for Le Matin. Actu-Juridique, which examined her reports in 2025, records that on first sight she wrote "Voici Landru!" and judged him neither brilliant nor deformed. What struck her was his eye, "un œil qui n’est point humain," an eye that was not human, with the stare of a caged big cat. She watched him fold his handkerchief with great care and remarked on how tidy he was.
The court sentenced him to death on November 30, 1921, and he was executed at dawn on February 25, 1922, outside the prison at Versailles. The case file survives. The Archives départementales des Yvelines hold the records of the Seine-et-Oise assize court from 1811 to 1940, and Actu-Juridique reported in January 2025 that the Landru file is open to consultation as part of a project to digitize those records.
The correspondence began three decades earlier. By the autumn of 1974 three men had confessed to the Otero killings, including a man held in a psychiatric ward, and police had announced an arrest. All three confessions were later discounted. In October a caller telephoned Don Granger, who ran The Wichita Eagle’s secret witness tip line, and told him where to find a letter hidden in a mechanical engineering textbook at the Wichita Public Library. Granger passed the tip to police, who recovered it.
"Those three dude(s) you have in custody are just talking to get publicity for the Otero murders," the letter said. "I did it by myself and no ones help." It described details the police had not released, and was signed with initials the writer had chosen for himself. Police kept the letter from the public for fear of panic. Nearly 30 psychologists studied it. On October 24 police ran a classified advertisement inviting the writer to call. Nobody did. In December a Sunday magazine published excerpts and the police chief confirmed the letter was real.
On January 31, 1978, an index card with a rubber-stamped poem arrived at the Eagle. Staff took it for an advertisement and sent it to the classified department. On February 10 a two-page letter reached KAKE-TV. "How many people do I have to kill before I get my name in the paper or some national attention?" it asked. It claimed seven lives and blamed an urge it called "factor X." "There is no help, no cure except death or being caught and put away," the writer said. Another passage, quoted by the Associated Press in later years, read: "How about some name for me, its time: 7 down and many more to go." The police chief, Richard LaMunyon, announced that evening that a serial killer was at large in Wichita. He said police had kept the first letter quiet in the hope of preventing further killings, but that the strategy had failed and public safety came first.
Police assigned 15 detectives and 8 laboratory investigators. A New York specialist enhanced a 1977 dispatcher tape, and when it was broadcast on August 15, 1979, police received more than 100 tips on the first day. None led to the caller. The writer did not write again for 25 years.
The investigation never closed. In 1984 the Wichita police set up a secret unit at City Hall, known as the Ghostbusters, which spent about three years on the case using computers, DNA testing, database searches and psychological profiles. Detectives traced one of the poems to a nursery rhyme and a folklore textbook, and a copy of a letter to a photocopier in the Wichita State University library. They narrowed a list of local men to 225; five refused to give DNA samples and seven remained possible suspects. The unit was disbanded in 1987 with about a dozen names still unresolved. In 1988, after a triple killing in Wichita, the widow received a letter from someone claiming to be the Wichita letter writer. The letter did not claim the killings, and experts disagreed about whether the same writer had written it. No charge against Rader has ever been brought in those deaths.
The court record added one more layer of code. Captain Sam Houston of the Sedgwick County Sheriff’s Office told the court in 2005 that Rader gave code names to what he called "projects," and that one of them, from April 1985, was "Project Dogside." Rader told police he had become "lazy" in his last years. "This is not really good serial killer business, this is right at my back door," he said. After Dolores Davis in January 1991 there were no more killings attributed to him.
Rader was sentenced on August 18, 2005, by District Judge Gregory Waller to 10 consecutive life terms, with a minimum of 175 years before parole eligibility; the Davis count carried a "hard 40." The earliest possible release date was reported in December 2005 as February 26, 2180. The death penalty was not available: Kansas had none in force for crimes committed between 1972 and 1994. He has been held at El Dorado Correctional Facility since August 19, 2005, and KCTV5 reported him there in August 2025. In 2023 the Osage County, Oklahoma, sheriff’s office named him the prime suspect in the 1976 case of Cynthia Dawn Kinney; the district attorney said in September 2023 the evidence was insufficient to charge him. In March 2024 the McDonald County, Missouri, sheriff closed a separate case, named another man and said Rader was not linked.
In none of the five cases did a court rely on a code alone. The first Zodiac cipher took a schoolteacher and his wife eight days; the second took 51 years; the 13-character and 32-character codes have no accepted solution. Kraft says his list is a guest list. A code is a private language, and the courts in the cases that reached them treated it as a record usable only where something outside it, a date, a ticket, a typed essay, a disk, agreed with it.
• 1869, April 12: Henri Désiré Landru born in Paris.
• 1899: Landru builds a prototype motorized bicycle and obtains a patent.
• 1915 to January 1919: the Vernouillet and Gambais deaths for which Landru is later convicted.
• 1919, April 12: Landru arrested in Paris; his notebook is seized.
• 1921, November 7 to 30: Landru tried at Versailles; sentenced to death November 30.
• 1922, February 25: Landru executed at Versailles.
• 1942, May 22: Theodore Kaczynski born in Chicago.
• 1962: Kaczynski begins graduate work at the University of Michigan. 1967: Ph.D. and Berkeley appointment.
• 1968, December 20, to 1969, October 11: the incidents attributed to the Zodiac.
• 1969: Kaczynski resigns from Berkeley.
• 1969, July 31: three letters with a three-part cipher mailed; printed August 1; solved August 8 by Donald and Bettye Harden.
• 1969, October 22: a caller on KGO claims to be the Zodiac. November 8: a 340-character cipher mailed to the Chronicle.
• 1969, December 18: FBI cryptanalysts report no decryption. December 20: letter postmarked for Belli.
• 1970, April 20 and June 26: the 13-character and 32-character codes. October 27: Halloween card to Paul Avery.
• 1971: Kaczynski moves to a cabin near Lincoln, Montana.
• 1972 to 1983: the deaths for which Randy Kraft is later convicted.
• 1974, January: a letter attributed to the Zodiac claims 37 victims. January 15: the first of Rader’s killings. October: a signed letter is recovered from a library textbook.
• 1978, January 31 and February 10: Rader’s poem reaches the Eagle; a letter reaches KAKE-TV claiming seven lives. May: the first UNABOM bomb.
• 1979, August 15: dispatcher tape broadcast; the writer silent for 25 years.
• 1983, May 14: Kraft arrested in southern Orange County; the list is recovered.
• 1989, November 29: Kraft’s judgment and death sentence.
• 1995, September: Kaczynski’s essay printed.
• 1996, April 3: Kaczynski arrested near Lincoln, Montana. June 18: Sacramento indictment. October 1: New Jersey indictment.
• 1998, January 22: Kaczynski pleads guilty. May 4: sentenced.
• 2000, August 10: California Supreme Court affirms Kraft’s judgment.
• 2004, March: Rader writes again to The Wichita Eagle.
• 2005, February 25: Rader arrested. June 27: pleads guilty. August 18: sentenced.
• 2018: Vallejo police submit evidence in the Zodiac case for DNA comparison.
• 2019, March 13: California moratorium on executions.
• 2020, December: the Zodiac 340-character cipher is solved.
• 2023, June 10: Kaczynski dies at Butner, North Carolina. November: the Orange County Sheriff’s Department identifies a presumed early victim of Kraft.
• 2025, May: Oregon State Police say Kraft is the only person under investigation in the 1980 death of Larry Eugene Parks.