Gareth Penn & Michael O’Hare

One article contained this short biography of freelance writer and Zodiac theorist Gareth Penn: “Gareth Penn was trained as a surveyor by the U.S. Army. In addition to work in that field, he spent seven years as a reference librarian. In his studies at the Free University of Berlin on a Fulbright scholarship, he specialized in medieval literature and historic linguistics.” In December 1980, Penn’s interest in the Zodiac case led to a discussion with his father, who made a cryptic remark. Well, my father used to work for the attorney general’s office, and during his tenure there, he read all of the letters of which the attorney general’s office had that the Zodiac had sent during his episode in the Bay Area, and in one of these letters that had never been published, the Zodiac said that if police were to place a radian on Mt. Diablo they would find something interesting.”

Learn more about the “Radian Theory”
Penn was convinced that the radian clue provided a window into the Zodiac’s mind, methods and codes.Like many before him, Penn noticed that some of the crime scenes were near water, or had names that alluded to water – RIVERside, LAKE Herman Road, Blue Rock SPRINGS, LAKE Berryessa, and finally, the strained, WASHington and Cherry Streets in San Francisco (Penn also pointed out that a fire hydrant sits on this block). This pattern convinced Penn that the Zodiac’s name may have some connection to water. According to Penn, he believed that the giant radian angle over the Bay Area indicated that the Zodiac was an artist of some sort, and therefore he consulted biographical directories of artists in the reference section of the Napa City and County Library. In search of a name that could allude to the elemental equation for water, H20, he discovered not an artist, but the son of an artist. The man’s initials could be rearranged to meet the requirements of Penn’s water theory, and the amateur sleuth set out to learn more about his new suspect, MrO.

At the time, MrO was a lecturer at Harvard University in Boston, Massachusetts, and he had an impressive background as an early achiever in academic studies, including mathematics. MrO married in the early 1970s, and he later worked at the university, where he delivered lectures on government and public policy. He also held a position in the Commonwealth of Massachusetts at one time. He had no criminal record.

Penn decided to try the in-direct approach. “Twelve years after the last Zodiac crime was committed, I began corresponding with MrO,” Penn wrote to this author. “He received a number of anonymous cards and letters mailed from all over this continent. In NONE of them was the word ‘Zodiac’ used. I did not allude to the Zodiac. I did not allude to the Zodiac murders. I confined myself to esoteric references which I felt at the time would be familiar to the author of the Zodiac letters. Looking back on it, I think I was barking up the wrong tree.”

Penn authored an article for the California’s magazine New West, written under the pseudonym “George Oakes,” and titled, “Portrait of the Artist as a Mass Murderer.” In the story, Penn described his theory that the Zodiac used a combination of binary numbers and Morse code to disguise his identity in the text of his letters. Binary numbers are used to compress language into a code of sorts. Inside every personal computer, words, images and sounds are translated into a complex, coded series of numbers – the number 0 and the number 1. In Morse code, dots and dashes are used to form messages. Penn’s theory believed that the Zodiac combined the two methods of communication to create a third – his own language.

Penn’s article also stated that he made a series of strange phone calls to his suspect, also named in the article with a pseudonym. Penn also wrote of his belief that MrO was responsible for a massive fire in the area near his home. He hoped authorities would investigate MrO as a suspect. The FBI was more interested in Gareth Penn. In May 1981, the Bureau investigated MrO’s complaint under the classification of “VICTIM – POSSIBLE EXTORTION.”

FBI analysts examined Penn’s theories and code solutions, but agents also wanted to examine him. The memo read that an agent “contacted [Penn] telephonically and told [Penn] that if he is responsible for the correspondence to [MrO] he should immediately cease and desist, pointing out that if could jeopardize any investigation and he could possibly be subject to both civil and criminal penalties.” The agent “did not specifically elicit or ask [Penn] if he were responsible for the letter to [MrO]. [Penn] stated he is completely willing to discuss the entire matter with the FBI.”

The memo said that Penn was “very absorbed by the Zodiac case, but certainly not a ‘nut’ or in any way deranged.” On May 22, 1981, Penn met with FBI agents and “freely admitted sending material to [MrO] but stated he had no intent to extort anything from [him]. His motive was to elicit some response from [MrO] if he was, in fact, the Zodiac.” Penn told the men that he “had made considerable progress in deciphering the Zodiac’s messages and felt extremely frustrated by the lack of response or follow up by law enforcement agencies.”

FBI analysts examined Penn’s work and could not confirm his findings. One agent wrote, “The submitted materials represent speculation regarding the meaning of various components of communications sent to police and the media by Zodiac. Due to the nature of the material there is no way to confirm or refute the theories advanced.”

Penn was not discouraged, and he continued his efforts to link MrO to the Zodiac crimes. He believed that MrO was a devious criminal mastermind with a love of numbers and hidden meanings. Penn thought that his suspect selected his phone number because the digits formed his name in Penn’s Zodiac language of binary numbers and Morse code. He also believed that the text of the Zodiac letters revealed hints to the names of MrO and his parents.

Penn compiled his findings into a book titled TIMES 17. Released in April 1987 by “Foxglove Press,” the self-published work was filled with speculation, complex calculations and factual errors. Penn received moderate attention from the Bay Area media, thanks in part to the publicity surrounding Graysmith’s book. He told Chronicle writer Sandra Konte that he was not worried about possible lawsuits. “My suspect knows I’m right.”

The Zodiac’s first coded message had been assembled in lines of seventeen characters across and twenty-four lines down. Other messages were formed with lines of seventeen characters across and a varying number of lines down. Gareth Penn thought this patten was significant and was intended by the Zodiac to suggest the phrase, “times seventeen,” as in the multiplication of the numbers, seventeen times twenty-four. By using his binary/Morse method, Penn determined that the phrase translated to a number, and that this number happened to be the exact number of days that MrO had been alive on the day of the stabbing at Lake Berryessa in September 1969. Further, Penn found that the number also represented another important date – the thirty-eighth birthday of MrO’s mother; the number thirty-eight was another repeated element of Penn’s theories.

The final shocker of Penn’s analysis was the revelation that the Zodiac had stabbed victims Bryan Hartnell and Cecelia Shepard a total of seventeen times. In Penn’s theory, MrO had stabbed the young couple a specific number of times on a specific day in order to symbolize his age and the birthday of his mother. “Coincidence can hardly explain the fact that the number of times a knife entered human flesh is not only repeated again and again, with precision and variety, in the Zodiac literature,” Penn wrote for the Mensa Bulletin, “or that it actually describes both a woman’s 38th birthday and her son’s exact age on the day of the killing.” Penn’s claim might have been compelling if he was correct about the number of stab wounds. According to the report of the autopsy of Cecelia Shepard and the statements of Ken Narlow, Shepard was stabbed a total of ten times. Bryan Hartnell himself said that he had been stabbed a total of six times, a total of sixteen stab wounds between the two victims. Penn’s analysis of the Riverside writings also proved flawed. He added the number of characters in the typed Riverside “Confession” letter and determined that the sum could be translated to represent the name of MrO. Inspection of the letter in question revealed that Penn was wrong about the total number of characters, and therefore wrong about its meaning. Like most amateur sleuths with theories and suspects, Penn seemed to see only what he wished to observe.

Penn claimed that MrO had been in California during the Zodiac years as part of his assignment with the Boise Cascade Corporation to work on a condominium project in Lake Tahoe. One of the Zodiac’s postcards featured an illustration of the Incline Village condominium project in Lake Tahoe by the Boise Cascade Corporation. [In a conversation with this author, MrO denied that he worked on this or any other project in Lake Tahoe, at that or any other time. A check of the records at the South Tahoe Regional Planning Office proved that MrO’s name was not in the documents and files pertaining to the project in question.]

MrO knew that a lawsuit would only give Penn more attention. Zodiac survivor and attorney Bryan Hartnell agreed. “He’d be playing right into his hands.” Penn’s accusations were unsettling but had not interfered with MrO’s life or career. “I didn’t have the sense that it needs any refutation and it’s never been believed by anyone who’s important to me in the whole world.” MrO had escaped the jaws of the Zodiac machine until circumstances changed on May 28, 1987. “I was entrapped on a talk show.”

California radio personality Anthony Hilder learned of Penn’s book and planned a sensational show in which Penn and MrO would finally confront one another on the air. The host apparently thought MrO would refuse to appear if he knew the subject of the program. Hilder called MrO at his home in Massachusetts and asked the suspect to be a guest for a discussion on public policy. Hilder’s interest and request seemed odd, but MrO agreed and the show was scheduled for later that evening.

At the start of the show, Hilder introduced Penn and told his audience of the plan to lure to MrO as a guest. After a commercial break, the host welcomed MrO, identified him by name, and mentioned that he was employed as a lecturer at Harvard University. MrO described his experience. “He engaged me in twenty minutes of almost completely unfocused and pointless conversation about my past and some tangential reference to the city government question with which he had induced me to appear on the program, and abruptly launched into a discussion of the Penn book.”

HILDER: The facts and figures are just enormous. There’s this enormous information flow now. We’re just bogged down that. I’ve got stacks of it –

MrO: And you haven’t got time to read it all.

HILDER: No, if I read all day long I couldn’t read it all. So one has to be selective in what they read.

MrO: Right.

HILDER: One particular book that came across my desk in the past couple of days was one called TIMES 17, by a gentlemen out of San Francisco named Gareth Penn. Have you heard of him?

MrO: Have I heard of Gareth Penn? Well, Gareth Penn has been a minor bane of my existence for, gee, I guess, seven or eight years now. In fact, when you called, and I recalled, when my wife described the peculiar, paranoid manner in which you approached the conversation I suspected I was likely to have a conversation about that, I don’t know why you’ve decorated it with this stuff about at-large representation.

HILDER: Well, I’m curious about this particular book, of course, Gareth Penn is making claims, that you are, according to Gareth Penn, the Zodiac killer.

MrO: Well, you’ve put me in an odd position, especially in an interview of this kind. But I’ll give you a couple of words about it. There’s a series of, there’s a series of unsolved murders, and the victims have relatives and mourners, and they haven’t got justice. Mr. Penn started out, it seems to me, with a fairly courageous enterprise when he thought he was onto something, but he’s wrong.


Penn / O’Hare Radio Show
Part 1: Introduction w/ Gareth Penn
Part 2: O’Hare on Public Policy
Part 3: Ambushing the Suspect
Part 4: Penn –  Part 5: Penn –  Part 6: Penn –  Part 7: Penn

GARETH PENN: The Radian Theory – In this isolated clip from The Anthony J. Hilder Show, Penn describes his radian discovery and theories. (Penn’s entire “Radian Theory” was debunked in the article GARETH PENN, MT. DIABLO and The RADIAN THEORY.)

Gareth Penn had accused MrO for almost two decades, based on little more than his dubious deciphering of the Zodiac’s letters and codes. “It will remain mysterious to me forever,” said MrO. The suspect offered these final words in his defense. “Here’s a statement: I had nothing to do with the Zodiac murders or any other homicides or any felony, in California or any other place. This is intended to be the most complete, inclusive, unqualified denial I can phrase. I’ve never initiated any contact with Gareth Penn and as far as I know I’ve never met him or had anything to do with him. I think his hobby is not only abusive of me but more importantly a cruel deception of the victims’ families and survivors.”