Detective Terry Poyser of the Vallejo Police told The Bee that DNA from saliva may be recovered from the envelopes. If that happens, and “we get a good profile, then you start tracking back,” Poyser said. “It really comes down to DNA. Without it, you have nothing. It’s a 50-years-old case". Results from the DNA analysis are expected back in the coming weeks.

Unfortunately, the "coming weeks" has now extended to 2 1/2 years with limited hope of a resolution - but all is not lost. Searching for a killer in a pool of potentially millions of people, is like finding a needle in a field of haystacks. Identifying a person of interest and lego-building a case around them in the fashion displayed on the internet has spawned a growing list of suspects, cobbled together with weak circumstantial evidence and viewed through rose-tinted glasses by their promoter. Any inconvenient observation regarding that suspect, which pours huge doubt on their guilt, will be routinely dismissed - an essential prerequisite for anybody with a long-standing fixation or unfaltering conviction in their suspect as the Zodiac Killer. The healthy interest in a person as a likely candidate for the Bay Area murders often metamorphosizes into an unhealthy obsession, in which the author ends up creating something akin to Mary Shelley's Frankenstein - a hideously manufactured humanlike creature that ultimately bears no resemblance to the Zodiac Killer or the facts of the case. The fact we have hundreds of Zodiac suspects in 2020, is testimony to how easy it is to manipulate the communications and crimes to fit our desired choice.

In a case stretching back 50 years, we have to play the odds and drain the ever-growing ocean of suspects by reducing the search field. We can do this by employing the useful tool of geographic profiling and creating a mental map of the killer. This is not a replacement for good old fashioned police work and forensics, but can prioritize where we begin our search, before extending outwards. Dr IPIP (Investigative Psychology for Investigative Practitioners) was created by Dr Susanne Knabe-Nicol, an investigative psychologist. She has created an excellent video playlist of investigative tools on Youtube, including a 53 minute interview with Kim Rossmo, a Canadian criminologist specializing in geographic profiling. This interview should give you an insight into all aspects of geographic profiling and its uses in a criminal investigation such as the Zodiac Killer. Dr Susanne Knabe-Nicol (Dr IPIP) can also be accessed via her website here.

On December 25th 1954 at approximately 8:40 pm, 39-year-old taxicab driver Conrad John Favreau of 1312 Hazel Street, Inglewood, picked up a fare at 7th Street and Union Avenue, Los Angeles for the short trip to Bonnie Brae. Five minutes later at 8:45 pm he was discovered lying in the street alongside his taxicab, shot once in the back of the head with a 25-caliber pistol. Blood spatter was evident on the right rear of the Yellow Cab near to the taillight, shown here in a crime scene photograph. It appeared that he had been subject to a violent assault just prior to the murder, with a tooth discovered on the front seat of the taxicab. Homicide Officer Joe La-Monica stated that his pockets had been gone through, but his watch remained on his wrist. Near to the body investigators found a single 25-caliber cartridge casing. 

An earwithness, Fred Perez of 557 N Bonnie Brae Street, described hearing "a sharp crack like a 22" rifle at about 8:45 pm and seeing the Yellow Cab parked on the street. A short time later the body of Conrad John Favreau lying face up was found by a passing motorist, David Lindsay (17) of 2941-A Los Flores Boulevard. The final entry on the trip sheet was detailed as 7th Street and Union Avenue to Bonnie Brae. An all-points bulletin was issued for "a man wearing white trousers and black shoes and possibly armed with a 25-caliber pistol".

Not nearly as relevant to the Zodiac case as the 2017 discovery by Kristi Hawthorne, who unearthed a possible link to the Bay Area murders while searching through some old newspaper articles. Taxicab driver Ray Davis (29) on April 11th 1962 was discovered in an alley behind 1926 South Pacific Street in Oceanside, having been shot twice in his taxicab. The vehicle was later discovered parked at the 400 block of South Pacific Street. The perpetrator had killed Ray Davis, dumped his body and driven the taxicab away from the crime scene. However, the interesting part of the story is a telephone call to police two days before the murder in which the anonymous male stated “I am going to pull something here in Oceanside and you will never be able to figure it out".  On April 16th 1962, it appears the same man rang the Oceanside Police Department once again, stating “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". Youtube.

The reason for this case being highlighted isn't just because of its location near a lake and the reference to a pumping station, or its proximity to several golf courses, but the striking appearance of both victims. Judy Gifford was of Asian descent, while Deana Hooper and Tonna Albright had been adopted at a young age from an orphanage in Hong Kong by their foster father. Some killers target a particular victim type, so the circumstances in both cases was noteworthy having been separated by just two years.  

Nikki Alexandra Benedict (14) had left her friend Kathie Gomski's house in Halper Road, Poway on May 1st 1967 shortly after 6:00 pm, to walk the 2 1/2 mile journey to her home at 13530 Olive Tree Lane, when approximately 25 minutes into her journey her life was cruelly snatched away. She was just passing the intersection of 12784 Poway and Carriage Road, traveling along a dirt pathway that straddled the Poway Road, when a man laying in wait leapt from a grassy depression and viciously attacked the young teenage girl with a short-bladed knife. She had a knife wound to her neck and bruises on her elbows and knees, but the fatal injuries were two stab wounds that penetrated her heart. The young girl did not succumb to her injuries immediately, with a trail of blood extending 200 yards to the west side of Carriage Road as she desperately sought help near a local shopping center. At approximately 6:30 pm, an 11-year-old boy, Ronald Fisk, discovered the critically injured girl and raced away on his bicycle to seek help from his father, who worked at a nearby market store. Unfortunately, despite the best efforts of responding personnel, Nikki Benedict would be pronounced dead upon her arrival at Palomar Hospital.

Nikki Benedict would usually travel the 2.3 mile journey home from Meadowbrook Junior High School on the school bus, however, on this Monday she visited her friend Kathie in Halper Road to discuss an art project. Kathie was planning to escort Nikki along the initial part of her journey home, but was unable to accompany her friend because she had to stay home for her dinner. Nikki Benedict would have traveled south, before heading east alongside the Poway Road toward home, or traveled southeast from Halper Road to the intersection of Poway and Carriage Road, near to where her body was discovered. Whether she had been trailed by her attacker or had walked into his path has yet to be fully determined, but the attack was swift and deadly, with no robbery or sexual interference apparent. One eyewitness recalled a white man fleeing the scene, although no solid suspects have subsequently emerged from this sighting and the case has remained relatively trapped in time for just over 52 years.

Links have been forged to the Riverside murder of Cheri Jo Bates on October 30th 1966, some six months earlier. She too was savagely attacked with a short-bladed knife, with the Zodiac Killer belatedly laying claim to her murder on March 13th 1971 when he wrote to the Los Angeles Times, stating "I do have to give them credit for stumbling across my riverside activity, but they are only finding the easy ones, there are a hell of a lot more down there". Poway, San Diego is 83 miles south of Terracina Drive in Riverside, where Cheri Jo Bates body was ultimately discovered on Halloween morning by Riverside City College caretaker, Cleophus Martin.

I always find it helpful to provide a map regarding any crime scenes, so below I have identified the relevant locations in the murder of Nikki Benedict, despite the fact the topography has changed over the last half-century.  

On the map I have highlighted a second attack - that of Patricia Lee Kuzara (7), who was murdered while walking home on Saturday, September 28th 1974, with her badly beaten body discovered the following morning in a field just off Midland and Hilleary Road, Poway, just alongside the First Baptist Church. She was just a few blocks from her home in Putney Road when the attacker struck, inflicting numerous blows to her head with a blunt instrument. She had been staying with family friends/babysitters approximately 2 1/2 miles away and had left shortly before dusk (6:30 pm) according to the friends. Why on earth a babysitter would allow a seven-year-old girl to walk this distance unaccompanied I have no idea? Four days after her body was discovered, a 40-inch long angle iron with pieces of wood attached was found on Hilleary Road. It was believed to have been innocently moved from its original location in the field. 

Sergeant Doug Clements was of the opinion that the killer probably lived nearby, creating understandable apprehension in the local community. The killing of Patty Lee Kuzara was only a mile from the murder site of Nikki Benedict, and both were attacked alongside the Poway Road in a grassy area. Both young girls lived only 660 meters from one another. Investigators in a press release stated that the Patty Lee Kuzara murder appeared sexually motivated, so whether any connection exists to the murder of Nikki Benedict is sheer speculation. Had the murderer of Nikki Benedict failed to complete his objective that day because of the vigorous defence she displayed in countering his attack, and therefore had chosen easier prey in his subsequent attacks? (if any). Of course, the two may be totally unrelated.

The question for most Zodiac sleuths, is whether any credence can be placed in his Los Angeles Letter of March 13th 1971, of "a hell of a lot more down there". The Zodiac Killer certainly claimed or insinuated many more murders than the canonical five attributed to him, so whether his exploits took him to Poway on May 1st 1967 is wholly dependent on which side of the fence you sit. The timeline bridges the gap between Riverside and Lake Herman Road - and the April 30th 1967 Bates' letters were mailed only one day before the murder of  Nikki Benedict - and did promise "there will be more".

Here is a complimentary video venerating the memory Nikki Benedict. Zodiac Killer Insights.

A serial killer exhibiting the traits of a marauder will operate using a buffer zone from their residence but radiate from this base when committing their murders, whereas a commuter will operate outside their normal activity spaces, thereby shifting the focus of the investigation away from the offenders anchor point. A serial killer living in Vallejo and operating as a commuter, would in the examples below, travel to San Francisco or Pleasanton to commit their murders and so shift the focus of the investigation away from their home base or residence. Canter and Larkin (1993) proposed the Circle Theory of Environmental Range that suggested a circle drawn around the two furthest offences from each other, would likely reveal the offender's home base, at or near the circle center (as shown by the Zodiac map on the right of the illustration below). This is just a rough example, as the circle could be shifted slightly to the left. Regardless, the center point falls in the approximate area of Vallejo or American Canyon. The problem arises when we draw a circle around a commuter's known offences, in that it would reveal a home location for the killer completely unrelated to his true residence. Therefore, it is critical that we identify whether the Zodiac Killer was a marauder or commuter.

There have been several studies done that suggest the vast majority of serial killers are marauders, who venture out from their anchor point, with the distance chosen from their residence based upon a buffer zone, the least effort principle, distance decay and a mental map of the area. A serial killer will often commit his earlier crimes closer to home because of uncertainty and inexperience, but venture further afield as their confidence grows. From the perspective of a killer working Monday to Friday, one might expect their Friday crimes to be situated closer to their home location, governed by the least effort principle and time constraints. Whereas their Saturday crimes, free from time constraints and tiredness, would unburden their unwillingness to travel further afield. If the Zodiac Killer lived in Vallejo, then the Canter and Larkin model looks like a good fit. Once the Zodiac Killer had committed his first two attacks close to his residence, the natural inclination on a Saturday would be to shift the emphasis away from the Vallejo and Benicia areas. The third attack at Lake Berryessa swung the focus approximately 42 miles north, while the Presidio Heights murder veered the investigation 35 miles south, into a fourth jurisdiction. It could be argued that the Zodiac Killer was deliberately attempting to redirect investigators away from where he lived. 

Canter and Young noted from a geographical standpoint that a commuter's crimes will generally be grouped closer together, whereas a marauder's crimes will be more spread. If the Zodiac Killer was a commuter living in Vallejo, one could expect him to commit multiple attacks at a secondary location such as San Francisco, in an attempt to focus the investigation far from home. Grouping the attacks within San Francisco would achieve this objective, but spreading the attacks would effectively nullify this tactic. A killer living in Vallejo may attempt to spread his attacks in all directions with each subsequent attack, designed in such a fashion to confuse investigators trying to pinpoint the murderer's anchor point, but may in essence have the reverse effect to the one desired. However, there is one important dichotomy to unpick when we consider the Zodiac Killer compared to most serial murderers - and that is the copious communications he mailed primarily from San Francisco.        

The Zodiac Killer's attacks spread out as time went by, but apart from his Vallejo Times-Herald communication on July 31st 1969, his focus for letter writing centered squarely on San Francisco. The least effort principle argues that when an offender is presented with two or more options to commit a crime, with equal availability and outcome, they will usually opt for the one that takes the least effort to achieve the same objective. The Zodiac Killer only committed four attacks, but likely mailed in excess of 20 letters. Therefore, is he more likely to go out of his way to deceive investigators by shifting his murders around the map in two or three instances, or mail his letters from an array of different locations to achieve a similar objective? He could have mailed his letters from anywhere, but primarily focused on San Francisco. When you are applying the least effort principle to his letter writing, it is easy to understand why he would choose the path of least resistance. If he had lived in Vallejo and mailed them at various locations on his route to work in San Francisco, then investigators (in his mind) may have been able to piece together his route taken and thereby identify an approximate home location. But by mailing virtually everything in San Francisco it could be interpreted by investigators that he lived in San Francisco - which is something the Zodiac Killer probably realized early on when his communications to the Vallejo Times-Herald went no further.  

His attacks took on the appearance of a marauder, while his letter writing took on the appearance of a commuter - which is exactly what he would have been, had he worked in San Francisco and lived in Vallejo. When your letter writing count outweighs your murder sites five to one, it is far easier to use this in order to focus investigators into a belief that you live in San Francisco, when it requires no more effort than traveling to work each day. The final confirmed murder at Presidio Heights could have been a deliberate choice by a killer determined to divert the investigation down a path far from home, but by reverse psychology, may have achieved the complete opposite to the one intended. 

The Zodiac Killer showed his ability to be unconstrained by a method of operation or modus operandi, with the 'couple killings' more a result of circumstance than choice. Had a third person been present in either vehicle at Lake Herman Road and Blue Rock Springs Park, does anybody believe that the Zodiac Killer would have turned around and gone home? The same could be said for a single person. This was evident when the Zodiac Killer mailed his trinity of letters on July 31st 1969, stating "I will cruse around and pick of all stray people or coupples that are alone, then move on to kill some more untill I have killed over a dozen people". His other two letters made no mention of couples. The idea that this was a sexually frustrated hater of courting couples is not warranted by the limited number of attacks in the sample size, and the idea that he would have just skulked off home, disappointed that he didn't see any couple's making out, is a hard argument to sell. However, the notion of earlier attacks carrying less risk and distance in respect to a home residence, has statistically been proven in previous studies of serial killers, whether or not it is true in this instance.    

This is an extension to the Washington Street Sketch article, further examining the age of the Zodiac Killer in 1969. Many people have argued that the Zodiac Killer, through four attacks, wasn't one individual because of the varying age estimations, differing from 26-30 by Michael Mageau, 20-30 by Bryan Hartnell (voice concept) and 25-30 by the three teenagers at Presidio Heights, up to 35-45 by Officer Donald Fouke and about 40 by the Julius Khan playground eyewitnesses. However, this really isn't the case when we consider that Michael Mageau's testimony cannot be relied upon, bearing in mind he was blinded by the light from the assailant's vehicle and flashlight, while being shot in the head. His recollection of the events are unclear, with probably less than a second to make a visual on the suspect's face. In the following attack at Lake Berryessa, Bryan Hartnell never saw the suspect's face at all, so we only have a recollection of "voice concept", which in essence means very little. The only attack where the Zodiac Killer's face was seen for any reasonable length of time was on October 11th 1969. At Presidio Heights there were three sets of eyewitnesses who saw the Zodiac Killer from the taxicab to the park - and all gave the same age. The three teenagers described a man in his early forties, Officer Donald Fouke described the man as 35-45 (therefore a median age of 40) and the Julius Khan playground eyewitnesses described the man running into the park as about 40. Three sets of eyewitnesses pinpointing the Zodiac Killer as 40 years of age or slightly above, within a five minute window.

We can of course throw away or disregard the last sighting of a man running into the park and matching the other two descriptions, if our theory revolves around the Zodiac Killer never entering the park or getting into a vehicle along Jackson Street, but this again relies on cherry-picking the evidence to suit our theory, rather than let the evidence or eyewitness testimony become the driver.

The three teenagers never described the suspect as 25-30 years - only the October 13th 1969 police sketch did. Their account was comprehensively detailed in the police report countersigned by Officer Armond Pelissetti on October 12th 1969. Their viewing of the suspect "last seen walking north on Cherry Street, from Washington Street" was the only eyewitness testimony in the police report, and therefore the suspect description on page 2 could only have been derived from them. It stated the man was in his early forties. It couldn't have been from the other two sets of eyewitnesses because the police report clearly states that the suspect was "last seen walking north on Cherry Street, from Washington Street". The other eyewitnesses viewed the suspect after Cherry Street.

The three teenagers sat down with a sketch artist who interpreted their description of the man - and it's extremely likely that because the sketch was interpreted and drawn looking younger, the police attributed the age range of 25-30 years to it - likely believing this was the correct course of action based on the appearance of the sketch. In other words, the contradiction of the three teenagers early forties description in the police report to the appearance of the sketch, likely played a part in the revision of the age range placed on the wanted poster. However, it is apparent that the three teenagers were not happy with the first sketch, forcing the police to create an amended sketch more in line with their original early forties description. The police then released the amended sketch on October 18th 1969 with a compromise age range of 35-45 years, which allowed for any slight error either way.      

If we factor in Officer Donald Fouke's description of a man "older and heavier" with a "lumbering gait", possibly "graying in the rear" with a "widows peak", we could be looking at a much more mature Zodiac Killer. A killer who described David Faraday (17), Betty Lou Jensen (16), Michael Mageau (19) and Darlene Ferrin (22) as boy, girl and kids in his initial correspondence. Our suspect is unlikely to be a young man aged between 25-30 years, addressing a 19 and 22-year-old as a boy, girl or kid. The way the Zodiac Killer addressed the couple at Blue Rock Springs Park suggests more of a generational divide.

Here is an excerpt by Donn Devine: "But just how long is a generation? Don’t we all know as a matter of common knowledge that it generally averages about 25 years from the birth of a parent to the birth of a child, even though it varies case by case? And wasn’t it closer to 20 years in earlier times when humans mated younger and life expectancies were shorter? Where did those numbers come from? Several recent studies by a sociologist-demographer and groups of population geneticists and biological anthropologists show that male-line generations, from father to son, are always longer on average than female-line generations, from mother to daughter. They show, too, that both are longer than the 25-year interval that conventional wisdom has assigned to a generation. The male generation is at least a third longer, the female generation is longer by perhaps half that amount".

Most people affix around 20-25 years to a generation, so if we took the average of the four victim's ages from the first two attacks, we would arrive at 19 years. Add the generational divide of 20-25 years and we have a suspect between 39-44 years of age - a man in his early forties or about 40. We know the attack at Presidio Heights was a Zodiac crime because of the blooded piece of taxicab driver Paul Stine's shirt being mailed to the San Francisco Chronicle, therefore these three sets of eyewitnesses, in a time window of just five minutes, all describing a man about 40 years of age should carry great value. But does this argument have any sway with the long-held convictions of people regarding suspects in the Zodiac case, or will no amount of eyewitness testimony cloud the lens through which they view the Zodiac case?

In 1969, the ages of the most widely touted suspects were: Theodore Kaczynski (27), Bruce Davis (27), Gareth Penn (28), Ross Sullivan (28), Richard Gaikowski (33), Arthur Leigh Allen (35), Richard Marshall (41), Lawrence Kane (45) and Kjell Qvale (50). Based on the eyewitness testimony at Presidio Heights, only two candidates fit the age description of the Zodiac Killer and these are poor suspects at best. The farther we travel to either end of the suspect age-scale spectrum, the weaker the argument becomes for these men to be the infamous Zodiac Killer. People often defy their years, but the argument still stands.
We have multiple eyewitnesses at Presidio Heights, all of whom were able to give fairly detailed descriptions of a killer emerging from the taxicab, heading up Cherry Street, turning into Jackson Street, before seeking refuge in the Presidio Park just after 10:00 pm. The question is, what faith do you have in three corroborating sets of eyewitnesses?   

Geographic profiling ia an invaluable tool for mapping the probable location where an offender most likely lives. This offender, like all of us, has areas of familiarity with respect to their profession and personal life that governs one's comfort zone, and therefore the commuter routes they opt for. These are factored into their way of thinking when considering any crimes that are to be committed or the areas where an offender may conceal a body. There is a delicate balance to be struck between the least effort principle (expenditure of the least amount of effort to accomplish a task) and the buffer zone (where an offender will avoid committing crimes too close to their home). In other words, they don't want to focus the attention around the place they live, but may equally not want to expend the effort in traveling a great distance, thereby creating a mental map of a target zone - usually somewhere with which they have a familiarity. Of course, factors such as their working week will affect the distance they are prepared to travel on any given day.

​This mental map was considered in the article Seventy One Days of Terror from October 11th 1969 to December 20th 1969, analyzing confirmed and unconfirmed letters, phone calls, murders and proposed murders during this time period. It became apparent that the locations targeted during this period, that included Sacramento, Fairfield, Vallejo, Oakland, San Francisco, Palo Alto and San Jose, all have Interstate 80 and U.S. Route 101 running directly through them. This may give us a clue to the areas where the Zodiac Killer was most comfortable. If he frequented these areas regularly in his profession, then this could very well influence the newspapers he read and the stories he became interested in. The case of murder victim Reet Jurvetson in a previous article, another example of a crime conforming to the above criteria. He may not have murdered this young woman, but was familiar with the area in which she was murdered, which ultimately governed his decision to choose her as victim number eight - allied to his new found fascination of knife crime. She too was brutally stabbed 157 times and unceremoniously dumped down a ravine off Mulholland Drive in Los Angeles. Her body was discovered just 2 miles from U.S. Route 101.           

When the Zodiac Killer failed to acquire the "front page coverage" he craved, he may have drew inspiration from the murders of Debra Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found brutally stabbed and murdered on August 3rd 1969 in the Bay Area of San Jose. They each had suffered in excess of 100 knife wounds that can only be described as savagery. In less than two months he would arrive on the shores of Lake Berryessa armed with a 12-inch bayonet. The killer wrote on the car door of victim Bryan Hartnell "by knife". On November 8th 1969, he claimed his involvement in the Snoozy-Furlong murders by the addition of "Aug" on the 'Dripping Pen' greeting card, followed by the November 21st 1969 San Jose letter possibly suggesting that Reet Jurvetson was another one of his knife victims. Then came the "Bleeding Knife of Zodiac" mailed from Fairfield on December 16th 1969, followed by the 'Melvin Belli' letter on December 20th 1969, stating he was losing control and looking for victims nine and ten.  

On April 20th 1970 he was claiming a victim count of ten - so if we are to determine the murder victims or proclaimed murder victims of the Zodiac Killer, then we must take all of the above into account. Based on three of the four attacks to date, victims nine and ten may have been a couple. They would have been murdered between December 20th 1969 and April 20th 1970, in a non-sexual attack that involved numerous knife wounds. It is also critical (whether the Zodiac Killer was responsible or claiming to be the responsible) that they would would be found close to Interstate 80 or U.S. Route 101.
​
On February 22nd 1970, John Franklin Hood (24), who had served decorated time in Vietnam in the 64th Armoured Division and Sandra Garcia (20), who worked in the California Department of Motor Vehicles, were discovered brutally stabbed on a beach close to Santa Barbara Cemetery and East Cabrillo Boulevard. This crime in some ways mirrored the stabbings at Lake Berryessa on September 27th 1969, with Sandra Garcia receiving the brunt of the vicious attack. The beach where their bodies were found, lies only 500 meters from U.S. Route 101. The mental map of the Zodiac Killer is starting to take shape.

The Zodiac Killer may have been inspired to switch from gun to knife after the extensive front page coverage given to the murders of Debra Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found murdered on August 3rd 1969 in the Bay Area of San Jose. They were savagely attacked with a penknife. The chief medical examiner described the ferocity of the attack: "Dr. Hauser, so shaken by the brutality of the crime he could scarcely find words, said the Snoozy youngster had 150 wounds on her back, 50 on the front and a "storm" of punctures on her neck. Deborah's body had about 100 wounds on her back and upper front and a dozen on her neck". Disillusioned by his lack of front page coverage, the Zodiac Killer struck in Lake Berryessa on September 27th 1969 inflicting 16 knife wounds on the defenseless Bryan Hartnell and Cecelia Shepard. He would write on the card door of Bryan Hartnell's vehicle minutes after the attack, stating Vallejo 12-20-68, 7-4-69, Sept 27-69 -6:30 by knife. On November 8th 1969 he would not only claim the murder of Cecelia Shepard, but the murders of Debra Furlong and Kathy Snoozy in the August of 1969, writing Des, July, Aug, Sept, Oct = 7 on the greeting card. 

Just thirteen days after the mailing of the 'Dripping Pen' greeting card, the Zodiac Killer would write another cryptic message on November 21st 1969 - this time to the San Jose Police Department (the city of the Snoozy and Furlong murders), bumping up his running victim total to November = 8 and beginning the message with "There's no doubt I will do my Thing!". Bearing in mind the Zodiac Killer had switched to a knife at Lake Berryessa to achieve "front page coverage", and claimed the savage knife murders of two teenage girls, who had both been stabbed in excess of 100 times, the Zodiac Killer's claimed 8th victim should mirror these attacks. If he was going to keep up the terror in the minds of the American people, the 8th victim would likely have been murdered in California just prior to the mailing of the November 21st 1969 letter - and stabbed multiple times. 

Although unidentified until 2016 and known only as Jane Doe 59, Reet Jurvetson (19) was discovered on November 16th 1969 by Trevor Santochi, who was hiking on Mulholland Drive in Los Angeles. Reet Jurvetson had been viciously stabbed in excess of 150 times by a common penknife in the neck, chest and torso, similar to the attack on the two teenage girls from San Jose. Close to her body in the ravine next to the road, a pair of black prescription glasses (Liberty brand frames) were discovered. Detectives have concluded they are likely connected to her death. The Zodiac Killer was extremely unlikely to have been responsible for her murder, but just like the vague clue of "Aug" on November 8th 1969 insinuating his involvement in the penknife attack on Snoozy and Furlong, was he similarly giving us the vague clue of November = 8 to suggest his involvement in another senseless penknife attack just five days earlier? Had he read about the discovery of Reet Jurvetson's murder in the newspapers - the similarities between the two crimes of which would not have gone unnoticed.   

On October 20th 1969, nine days after the murder of Paul Stine in Presidio Heights, somebody made a threatening phone call to the Palo Alto Times newspaper saying he intended "to pick the kids off as they get on the school bus". The San Bernardino County Sun reported on the threat, stating "Patrol cars convoyed school buses around Palo Alto yesterday after a telephoned murder threat by a man claiming to be the Zodiac Killer of five persons. The weird slayer who signs himself "The Zodiac" made a similar threat in a letter to the San Francisco Chronicle last week after the Oct 11 shooting of a taxi driver. The district transportation supervisor said an armed guard might ride with each of the system's 25 buses. Officers in Napa and Vallejo, areas of the first three murderous attacks, some 45 miles north of Palo Alto, have been convoying police officers. Palo Alto Police Chief William Hydie called the new threat "extremely serious," but warned against over reaction to what might be a crank call".

On November 8th 1969, the Zodiac Killer mailed the 'Dripping Pen' card and 340 cipher to the San Francisco Chronicle claiming the "Aug" murders of Debra Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found brutally stabbed on August 3rd 1969 in the Bay Area of San Jose.

On November 21st 1969, somebody claiming to be the Zodiac Killer wrote to the San Jose Police Department​ threatening the life of a widow, accompanied by the words "There's no doubt I will do my Thing". The brief text in the letter clearly contained enough information for police to identify the woman and implement 24-hour surveillance on her residence.

On December 7th 1969, a letter was mailed from Fairfield stating "I just need help. I will kill again, so expect it any time the will be a cop".

On December 16th 1969, another letter arrived from Fairfield threatening to kill "government life" and "cops" in Sacramento, Fairfield, Napa, Vallejo, Oakland, San Francisco and San Jose. A future geographic profiling technique was applied to the locations in which he 'threatened murder' (as detailed in the Fairfield letter), and noted that "Interstate 80 begins at an interchange with U.S. Route 101 (US 101) in San Francisco, and then crosses the San Francisco–Oakland Bay Bridge into Oakland. It then heads northeast through Vallejo, Fairfield, Sacramento, and the Sierra Nevada mountains before crossing into Nevada". The idea was to identify the areas the Zodiac Killer was prepared to target, based on their accessibility to him using a main commuter route he regularly traveled. If he regularly used the I-80 for his profession, then six of these seven destinations are directly passed by the I-80, with Napa only a few miles off route.

On December 19th 1969, somebody claiming to be the Zodiac Killer again threatened cops, making a phone call to Sergeant Robert Rengsdorff of the San Jose Highway Patrol (see article above), stating "I am going to kill five of you officers and a family of five between now and Monday". This threat towards San Jose police and a family of five was issued on a Friday, exactly as was the November 21st 1969 letter, mailed to San Jose police threatening harm on a widow. After the threat on the widow was thwarted by 24-hour police surveillance on her residence, was this the response, to once again instigate fear in the San Jose community? Were the widow and 'family of five' of the same residence? We know he was threatening the lives of numerous police officers, but the threat on five members of a family appears rather specific.           

On December 20th 1969, the Zodiac Killer mailed the 'Melvin Belli' letter containing a piece of murdered Paul Stine's shirt, effectively proving the author was the murderer of the taxicab driver on October 11th 1969. This letter mimicked the December 7th 1969 Fairfield letter by stating "please help me", which in some way helps to authenticate both Fairfield letters not released to the newspapers.

​The purpose of this article is to show the targeted areas of the Zodiac Killer (if responsible for these letters and phone calls) from the standpoint of geographic profiling. These events spanned from the October 11th 1969 murder of Paul Stine, to the mailing of the 'Melvin Belli' letter on December 20th 1969 (71 days). The areas shown in red above, highlight the locations the Zodiac Killer targeted by murder, proposed murder, as well as by his threatening phone calls and letters - and they are all connected by one direct route of travel.

During these 71 days in October, November and December the Zodiac Killer focused his attention on Sacramento, Fairfield, Vallejo, Oakland, San Francisco, Palo Alto and San Jose. Interstate 80 and U.S. Route 101 provide one seamless journey from Sacramento to San Jose. Was the Zodiac Killer a traveling salesman which took him through each of these locations - and therefore he had a familiarity with? Do these commuter route tell you anything about his home residence during this time period? 
When you commit, or intend to commit these acts, accessibility to and from a main commuter route could be invaluable.

Equidistant (as the crow flies) to Sacramento and San Jose is the waterfront city of Vallejo, believed by many to be the home residence of the Zodiac Killer. It is 53 miles from Sacramento and 57 miles from San Jose. The Springs and Tuolumne payphone, where Zodiac placed a call to police dispatcher Nancy Slover on the morning of July 5th 1969, sits 728 metres from Interstate 80.

Most, if not all Zodiac forums and websites classify the January 29th 1974 Exorcist letter as confirmed Zodiac correspondence. It is widely touted by law enforcement, newspapers and documentaries as the last confirmed Zodiac communication, and in a poll conducted on this site, 86% of visitors believe it to be genuine Zodiac material. This mailing was listed in the 2000 San Francisco 'Suspected Zodiac Correspondence' DNA Report as one of the communications processed for DNA. The subsequent 1974 letters were not processed for DNA, otherwise the report would have stated this. Since the Exorcist letter was widely considered to be the last confirmed Zodiac communication, it would therefore make perfect sense that this took priority over the Citizen Card and Red Phantom letter to be the only 1974 correspondence tested.

Mike Rodelli wrote in his book, 'The Hunt for Zodiac:The Inconceivable Double Life of a Notorious Serial Killer', that Alan Keel, Criminalist at the San Francisco Police Department, San Francisco, California from 1996 to 1999 "revealed that there were two letters in possession of the department that, in contrast to the "true" Zodiac letters, had abundant saliva and DNA-containing oral epithelial cells on them, that DNA was easily extracted from these two letters, and that the DNA extracted from these two letters matched between them. These two letters were considered forgeries, since the "true" Zodiac verifiable letters had not been licked by the sender." Mike Rodelli added that "In contrast (to earlier communications), Keel analyzed two other letters, one of which is the 1978 forgery, and finds that this letter and one of the 1974 letters are loaded with saliva and cells. He then easily extracts DNA from both of these letters using the more primitive DNA technology of that time and finds that the DNA matches between those two letters, thus proving that one person sent both."  

For two letters to have a definitive match of DNA they must have a complete profile. A partial DNA profile from one letter compared to a full DNA profile of the other could only be used to exclude them as having been licked by the same person, not conclusively tie them together as having a single contributor. Since the Exorcist letter appeared to be the only 1974 letter processed for DNA, it can be argued from Alan Keel's statement that the two letters that matched in DNA were the 1978 letter and Exorcist letter. If the San Francisco DNA report concluded that the 1978 letter was "not an authentic Zodiac letter", then there is a strong possibility that neither was the Exorcist letter.

For those who resolutely argue that the Exorcist letter is a genuine Zodiac communication, may have to accept the authenticity of the 1978 letter too. According to all the above observations, these two communications are inextricably linked by one sender. In early 2018 Vallejo police Detective Terry Poyser, who has worked the Zodiac case for four years, said his agency has submitted two envelopes (in late 2017) that contained letters from the Zodiac Killer for a type of advanced DNA analysis that previously had not been available in the case. Poyser declined to identify the lab, but said it would attempt to obtain a full DNA profile from saliva on the envelope flap and stamps. He said he expected to have results back from the lab as soon as in the next few weeks, and almost certainly by summer. Sacramento Bee.

Why are they attempting to find a full DNA profile, when presumably they have already achieved a full DNA profile, according to Alan Keel and the San Francisco Police Department DNA report? They cannot claim the 1978 letter as "not an authentic Zodiac letter" in a DNA report, unless a full profile exists. Furthermore, how did they ascertain the 1978 letter was not Zodiac, unless they knew who licked the envelope and stamp seal - and knew that person wasn't Zodiac. They couldn't ascertain the 1978 letter wasn't Zodiac by comparing it authenticated early Zodiac material, because seemingly these had not yielded a full DNA profile as we stand today. They clearly seem to have little faith in the Exorcist letter either, because if this has generated a full DNA profile in the past, but they are still "attempting to obtain a full DNA profile from saliva" today, then I presume this invalidates their confidence in its authenticity.  

Tom Voigt recently began a forum thread on the Zodiac Killer message board entitled Vallejo Police Department DNA Update, stating "The lab work has turned into more lab work. VPD is still at it. The hunt continues..." Why are they still hunting for viable DNA when apparently a full profile has been secured previously? Even if law enforcement have little confidence in the Exorcist and 1978 letter, these would have provided the best options to run through a genealogy website 18 months ago and the results would have been in by now had anything fruitful been generated. Unless of course, you already know who forged both of these letters. I see no benefit in not seeking profiles from these two letters (generated from the 1978 letter and another, if different to suggested) to enter into a familial DNA program. If the familial search threw out a notable family tree, or the lineage of a recognized Zodiac suspect, then it would add credence to the previously doubted Zodiac communication. 

For the 60% of people who voted on this site, believing the 1978 letter to be from the hand of the Zodiac Killer, the question you should be asking is, why did the the 2000 San Francisco DNA  Report determine the 1978 correspondence to be "not an authentic Zodiac letter" if they hadn't already obtained a full DNA profile to make such an authoritative and conclusive judgement? The only other reasonable conclusion, is that they already know who the author is.    ​

Bringing together several articles to paint the entire picture, I would like to tell you a little story about San Jose and the major impact it had on the actions of the Zodiac Killer spanning just over two years. The attack on Bryan Hartnell and Cecelia Shepard at Lake Berryessa on September 27th 1969, inextricably linked to Debra Gaye Furlong (14) and Kathy Ann Snoozy (15), two young girls who were found murdered on August 3rd 1969 in the Bay Area of San Jose. The man ultimately convicted for these two murders in 1971, Karl Francis Werner, was the trigger behind the attack at Lake Berryessa. 

The Zodiac Killer had successfully murdered three and seriously injured one person by the time he mailed his trinity of July 31st 1969 letters to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald. He then presented codebreakers with the extremely unusual challenge of deciphering three parts of one cipher from the hand of a serial killer, demanding that he receive front page coverage for his efforts. The three communications and three murders, in his mind, warranted the full attention of the American public when he wrote "Here is part of a cipher the other 2 parts of this cipher are being mailed to the editors of the Vallejo Times and SF Examiner. I want you to print this cipher on the front page of your paper. In this cipher is my idenity. If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend".  

The two major news publications, the San Francisco Chronicle and Examiner, dismissed his demands by only publishing his offerings on page four and nine respectively. The Zodiac Killer's disdain was immediate, when on August 4th 1969 he presented us with his sinister pseudonym "This is the Zodiac Speaking" in a follow-up letter, that concluded with "I was not happy to see that I did not get front page coverage". But imagine his horror, when two days later the San Francisco Chronicle (August 6th 1969) ran a comprehensive front page article about the murders of Debra Gaye Furlong and Kathy Ann Snoozy in San Jose. Here is an excerpt:

The two young girls, found dead Sunday on a sun-parched San Jose hillside, appear to have been victims of a sexual psychopath, whose blood frenzy led him to "overkill". Dr. John E. Hauser, Santa Clara county's chief medical examiner and coroner, said yesterday that the girls, Deborah Gay Furlong, 14, and Kathy Snoozy, 15, died in a "frenzied flurry of knife-wounds" inflicted so swiftly that neither gave any evidence of having struggled against the attack. Dr. Hauser, so shaken by the brutality of the crime he could scarcely find words, said the Snoozy youngster had 150 wounds on her back, 50 on the front and a "storm" of punctures on her neck. Deborah's body had about 100 wounds on her back and upper front and a dozen on her neck. Dr. Hauser said he was "puzzled" by many aspects of the brutal slaying. He said neither girl had been sexually molested; neither had suffered any wounds below her waist, neither gave evidence of having struggled to escape. Only the Snoozy girl, he said, had one small mark on her hand, suggesting she may have tried vainly to deflect the plunging knife. The coroner said both girls must have died very quickly and he is investigating the possibility they may have been drugged before the stabbing began. Blood and skin samples as well as stomach contents have been sent for further examination to area laboratories, he said. The results should be known in a few days. It is Dr. Hauser's opinion that the multiple puncture wounds were inflicted by one or two small knives, the largest wound the size of a pocket knife with a half-inch blade. "I've never seen a case with this many stab wounds," Dr. Hauser said. "You know, I've been in this profession a long time and sometimes I think I'm rather callous, but when I saw these girls, believe me it was terrifying. "The Nazi sex mutilations during World War II were nothing compared to what was done to these young girls.     

The Zodiac Killer must have been incensed that despite his brutal murder of three people during the holiday season, followed by his cryptic correspondences, he failed to achieve front page coverage from the Chronicle or the Examiner, despite threatening another dozen victims over the weekend. The only difference, he must have surmised, was the method of attack and the horror that such an intimate attack with a bladed instrument on two young girls had engendered in the psyche of the newspapers and public at large. The Zodiac Killer knew at this moment he had to ratchet up his attacks and get up close and personal with the use of a knife. But this wouldn't be any ordinary attack - he would dress up in an executioner's costume and hunt for young girls armed with a 12-inch knife - not "a pocket knife with a half-inch blade". Although Karl Francis Werner's capture was two years in the making, he was the absent agent behind the attack on Bryan Hartnell and murder of Cecelia Shepard just seven weeks later. Without the murders of Debra Gaye Furlong and Kathy Ann Snoozy on August 3rd 1969, it can be argued the attack at Lake Berryessa would never have taken place.

No surprise then, that the Zodiac Killer wanted to outdo the August 3rd 1969 murders, by setting his sights on three young girls from Pacific Union College as they sunbathed on the shores of Lake Berryessa on September 27th 1969. Three murders with a 12-inch bladed knife would definitely have done the trick. But something clearly thwarted this attack and two hours later he focused in on Bryan Hartnell and Cecelia Shepard, determined not to be denied and secure his front page coverage. After the sixteen strikes into the young couple, he retreated and traveled back up the hill to lay claim to this attack as the Zodiac Killer. After writing the dates of his previous two attacks and this one on the car door of Bryan Hartnell, he emphasized the words "by knife" at the foot of the message. The Zodiac Killer was effectively saying "do I get front page coverage now". The brutal knife attack, he hoped, would get the recognition akin to the murders of Kathy Snoozy and Deborah Furlong. Not only did he get the recognition, but it had an added benefit of the newspapers considering the possibility of his involvement in the Kathy Snoozy and Deborah Furlong murders. This certainly didn't escape his attention.    

Six weeks later he duly obliged by slipping in "Aug" into his confirmed murder count when mailing the 'Dripping Pen card on November 8th 1969, bumping up his total to seven victims. The Lake Berryessa attack "by knife" had effectively secured him two more victims by association. But to cement his perceived involvement in the San Jose murders, he had to strike while the iron was hot.

On November 21st 1969 he mailed a threatening letter to the San Jose Police Department beginning with the words "There's no doubt I will do my Thing!". The letter initiated this response: 'For the information of the Bureau and Sacramento, after a cursory analysis, officers of the San Jose, California PD, believe widow in message may be Mrs (redacted), San Jose, California. San Jose PD instituting 24 hour surveillance on Mrs (redacted).' It is clear that this woman had some connection to the Snoozy and Furlong murders, and by the Zodiac Killer interjecting himself into the San Jose investigation, he was attempting to solidify the notion of his involvement in them. Bearing in mind this letter was mailed to the San Jose Police Department and their response to secure the woman's safety, it isn't too surprising that the Zodiac Killer would threaten to murder a San Jose policeman in the Fairfield letter mailed a month later, on December 16th 1969. The Zodiac Killer thought he had now successfully cemented his claim to the Snoozy and Furlong murders. His choice of switching from gun to knife had paid dividends. My guess, is he was banking on these murders never being solved.

Imagine the Zodiac Killer's dismay in late April of 1971, when his plans lay in tatters, upon the arrest of Karl Francis Werner for the April 11th 1971 murder of Kathy Bilek at Villa Montalvo in Saratoga, as well as the murders of Kathy Snoozy and Deborah Furlong in San Jose two years earlier, on August 3rd 1969. The Zodiac Killer would eventually be exposed as a fraud - caught in the act of claiming somebody else's victims at last. He reacted forthwith, by mailing two communications to the San Francisco Chronicle in the middle of 1971. 

In the first, he was trying vainly to convince us that he was in fact the murderer of all three girls (Snoozy, Furlong and Bilek) by claiming that Karl Francis Werner was the fraud or phony. Paul Avery, arch nemesis of Zodiac, wrote an article on April 30th 1971 detailing the capture of Werner. The newspaper article stated "He (Werner) was immediately advised of his rights concerning any statements he may make and legal representation to which he is entitled, the detectives said. Werner was then taken to the scenes of the crimes. Late yesterday he was undergoing questioning. The detectives would not reveal what statements, if any, he had made concerning the killings of the three girls". 

The Zodiac Killer responded sometime after he read this article (around May, June or July of 1971), mailing a 148 character cipher stating "Tis the Zodiac Speacking. Why can't you stop me. I can't stop killing. Stop listening t(o) phonys. If this is not on your front page in a week I will skin 3 little kids and make a suit from the skin". In this correspondence he claimed his victim count was 21, by writing "I done it 21 times". This, in accordance with his claimed victim count of 17+ in the March 13th 1971 'Los Angeles' letter. We can ascertain that this communication was mailed around the middle of 1971, because he fired off a second correspondence at about the same time. The correspondence about to be discussed was withheld from newspaper publication (as was the 148 character cipher), so the fact that both contained a victim count of 21 and mailed in close proximity to one another, should be enough to consider both being mailed by the Zodiac Killer. The second communication we will show, is not only trying to claim the murder of Kathy Bilek - again attempting to show that Karl Francis Werner was a phony - but is also linking itself to the murders of Snoozy and Furlong.    

On July 13th 1971 a pasted card was mailed to the San Francisco Chronicle with the words "Near Monticello Shought Victims 21 ...... In The Woods Dies April". Many have speculated on the location mentioned in the card as "Monticello" in Napa County, California, because of the Lake Berryessa attack on Bryan Hartnell and Cecelia Shepard on September 27th 1969. It has been further speculated on whether "April" was a woman's name or the month of the alleged murder. After a comprehensive review of all the information, I believe the woman's identity, labelled as victim number 21, can finally be revealed, along with the exact location of Monticello. 

On Sunday, April 11th 1971, Kathy Bilek (18) visited Villa Montalvo in Saratoga, having planned to read a paperback book (The Gabriel Hounds) and engage in a spot of bird watching​ in the seclusion of a remote, wooded portion of the park, near a small stream. Her body was found the next day by her father, Charles, while Santa Clara County Sheriff's deputies searched nearby. She had been stabbed 17 times in the back and 32 times in her chest and stomach, although her killer had taken care to avoid stabbing her breasts. Her murder was also attributed to Karl Francis Werner. Wikipedia. The brutal murder of Kathy Bilek would again be claimed by 'Zodiac', not only in the Monticello card, but in another alleged Zodiac letter, also mailed to the San Francisco Chronicle at about the same time as the Monticello card. Kathy Bilek was murdered in "April", exactly as mentioned in the Monticello card, and "in the woods" at Villa Montalvo (a wooded section of the park). Saratoga is a city in Santa Clara County, California, United States. It is located on the west side of the Santa Clara Valley, directly west of San Jose, The appearance of San Jose once again. ​ ​

It was easy to get sidelined into believing Monticello was referring to Napa County, because the town was completely covered by Lake Berryessa, the site of Zodiac's third attack. However, the "Monticello" the author is referring to in the pasted card, is again in San Jose. Monticello is a neighborhood in San Jose, California, just over 9 miles east of Villa Montalvo, the site of Kathy Bilek's murder. ​In other words, the author of the card was saying "I killed Kathy Bilek near Monticello, in the Villa Montalvo woods in April". ​To view the proximity of Monticello to Villa Montalvo click here.

The Monticello card stated "Shought victims 21", referring to the Kathy Bilek murder, whereas, in the 148 character cipher, the author was claiming he had already "done it 21 times." The Monticello card was never released to the newspapers or public, so bearing in mind these two communications were both likely mailed at approximately the same time, there is a high probability they were mailed by the Zodiac Killer.

"I killed Kathy Bilek near Monticello, in the Villa Montalvo woods in April".
"Near Monticello Shought Victims 21 ...... In The Woods Dies April".

The ​November 8th 1969 'Dripping Pen' card would not be the only communication insinuating his involvement in the murder of Deborah Gaye Furlong and Kathy Ann Snoozy, when the Monticello card arrived just over 20 months later, on July 13th 1971. The San Francisco Police Department had reason enough to place the Monticello card in 'suspected Zodiac correspondence' when searching for traces of DNA on potential Zodiac communications, indicating the high regard it was held in.

It is with little doubt that Karl Francis Werner was responsible for the murder of Deborah Furlong, Kathy Snoozy and Kathy Bilek in 1969 and 1971, but the overarching question is, why did the Zodiac Killer describe the location of Kathy Bilek's body as "near Monticello"? The neighborhood of Monticello is 9 miles east of Villa Montalvo. Why did the Zodiac Killer choose to pinpoint this particular location, rather than any other neighborhood in between Monticello and Villa Montalvo? He could have pasted "near Willow Glen", "near Oster", "near Carlton", or any other location closer than Monticello. It is arguable that he chose this particular location for a specific reason.   ​

Tom Voigt, creator of the hugely successful Zodiackiller.com website has sought a potential Zodiac letter, described as the DMV letter. On his message board he stated "While I don't yet have as many details as I would like, at some point the Zodiac wrote a letter to the chairman of the Department of Motor Vehicles (DMV) in California. The letter was authenticated, apparently via handwriting, and was kept quiet for reasons unknown". None of the following can be definitively proven, but I will attempt to expand on this elusive correspondence based on the limited information we have, and use the propensity of the Zodiac Killer to respond to newspaper and magazine articles against him. We know he closely followed anything that was written about him and often replied in kind. With that said, it is possible the DMV letter was mailed to the chairman of the Department of Motor Vehicles because he read an article referencing this department. If the letter was addressed to the chairman, it is very likely the letter was addressed to the headquarters of the DMV in Sacramento. What we now have to do, is tie the Sacramento DMV to a Zodiac crime, or a crime claimed by Zodiac, written in a publication that the Zodiac Killer had reason to read - who subsequently got upset because it portrayed him as a liar and a fraud. It therefore follows, that it is highly unlikely to be a polite correspondence from the Bay Area killer. Based on the above, I believe the DMV letter was mailed in the October or November of 1971.

As early as November 8th 1969 the Zodiac Killer was claiming the murders Deborah Gaye Furlong (14) and Kathy Ann Snoozy (15), who were found murdered on August 3rd 1969 in the Bay Area of San Jose. This was his "Aug" on the 'Dripping Pen' card. He would later insinuate his involvement in the murder of Kathy Bilek (18), murdered in the woods of Villa Montalvo in Saratoga, due west of San Jose. On July 13th 1971, a potential Zodiac communication arrived in the form of a pasted card. It read "Near Monticello Shought Victims 21 ...... In The Woods Dies April". The author of the card was detailing the murder of Kathy Bilek in the woods of Villa Montalvo on April 11th 1971, just 9 miles from the neighborhood of Monticello in San Jose. He chose this neighborhood because it sat adjacent to Oak Hill Memorial Park at 300 Curtner Avenue. The cemetery where the body of Kathy Ann Snoozy lay - and chosen to hint at the forename "Kathy", pertaining to Kathy Bilek.

​Assuming these communications were mailed by the Bay Area murderer, it would be fairly obvious that the Zodiac Killer was following the San Jose murders closely from August 3rd 1969, through his 'Dripping Pen' card of November 8th, to the eventual murder of Kathy Bilek, and up to his correspondences in the middle of 1971. Therefore, it would be no great surprise if he continued to monitor any newspaper or magazine articles regarding the murders of the three young females. ​

In October 1971, a magazine publication entitled 'True Detective' comprehensively featured the murders of Kathy Snoozy, Deborah Furlong and Kathy Bilek, and the subsequent arrest of Karl Francis Werner. There is every chance the Zodiac Killer read this magazine article, compelling him to continue his contact with authorities regarding these murders.

One particular section about Kathy Bilek caught my eye - that may have been the reason why the Zodiac Killer wrote a letter to the chairman of the DMV in Sacramento. It stated "At about the same moment, Park Ranger Ken Williamson was informing a member of the investigative team that he, too, had noticed a tall, bespectacled young man who had been a frequent visitor at Villa Montalvo. He was a loner and had impressed the Villa's ranger staff with his almost furtive conduct, said Williamson. The ranger had jotted down the license number of the strange youth's auto.
The license number was forwarded to the California Department of Motor Vehicles headquarters in Sacramento, the state's capital 150 miles to the north of San Jose. The information teletyped back from the registration bureau was that the auto was the property of a Karl Francis Werner, living at an address on Shawnee Lane in San Jose." 

The Zodiac Killer, having previously mailed two communications (Monticello card and 148 character cipher) referencing the murder of Kathy Bilek and the victim total of 21, it wouldn't be at all surprising if he fired off a third communication, this time to the Department of Motor Vehicles in Sacramento, after reading these two paragraphs. As this magazine article was published in October of 1971, the DMV letter may have been postmarked with the latter months of that year - possibly October, November or December. The compunction of the Zodiac Killer in claiming, or interjecting himself into the middle of these murders, may have been the driver behind his contact with the chairman of the DMV. The content of this communication is unknown, but I guess he is continuing the menacing theme of his previous two correspondences, suggesting the identification of the vehicle belonging to Karl Francis Werner is somehow another red herring and threatening more murder and mayhem.

In a previous article we explored the concept of geographic profiling with respect to the Zodiac Killer, using search cost percentages to highlight the possible home location of the Bay Area murderer. Therefore, I thought it appropriate to look at the geographic profiling prediction applied to an already convicted serial killer, that of Dennis Rader (BTK). Some people have actually touted Dennis Rader as the infamous Zodiac Killer because of their propensity for writing poems, making phone calls and mailing letters to the newspapers and radio stations. So this geographic profile is more pertinent to the advocates of Dennis Rader as the cryptic killer.

Dennis Rader was responsible for 10 murders and 7 attacks from 1974 to 1991, that included in chronological order the Otero family, Kathryn Bright, Shirley Vian, Nancy Fox, Marine Hedge, Vicki Wegerle and Dolores E. Davis. He was eventually arrested near his home in Park City, Wichita on February 25th 2005. Below I have placed his murders on a map of Wichita and highlighted his home residence and the Christ Lutheran Church where he was president of the church council. The distances on the map show that he never ventured more than 9 miles from his home residence, and for the most part (except for two of his last three murders) gave himself a buffer zone of at least 6.27 miles for five of his attacks. The murders of Marine Hedge and Dolores E. Davis much closer to his home residence. The hot zone, represented by a search cost of 0% is shown by the large red dot on the map. This hot zone, predicted as where Dennis Rader most likely lived, was in the College Hill District of Wichita, exactly 7.50 miles from his home residence at 6220 Independence Street, Park City (subsequently bulldozed). His residence had a search cost of about 15% on a scale of 0 to 100%. So this would be described as a fairly warm zone.

Suspects are ranked based on their search cost—the percentage of the map searched before reaching the suspect’s anchor point. The search is conducted from the highest point of probability to the lowest; therefore, the lower the search cost, the more viable the suspect. If the geographic profile is accurate, the offender will have a low search cost. In the case of search cost, “map” refers to only the portion of the profile containing the crime scenes. As a result, suspects can have a search cost greater than 100%, which means a space larger than the area containing the crime scenes would have to be searched before reaching their anchor point. link. Here is a link to the Dennis Rader geoprofile using the Kim Rossmo model. geographicprofile.com. 

It has been stated that a serial killer will often commit his first murders in his comfort zone, implementing a buffer zone between the sites of his attacks and his home residence. In the case of Dennis Rader, his first two attacks were that of the Otero family and Kathryn Bright, 7.43 miles and 6.27 miles from his home residence. All but two of Dennis Rader's murders were perpetrated on a weekday. The Otero family were murdered on a Tuesday and Kathryn Bright was murdered on a Thursday - which is extremely relevant to the Zodiac Killer's first two attacks at Lake Herman Road and Blue Rock Springs Park, both perpetrated on a Friday. If Dennis Rader and the Zodiac Killer had worked that day, you have to consider the time constraints and expect the murders to be closer to their residence compared to a weekend, when they have greater freedom to travel.

So, if the Zodiac lived in one of the hot zones just east of American Canyon, let us compare the distances Zodiac would have traveled to his first two attack sites. As the crow flies, Lake Herman Road is 8.00 miles from American Canyon, wheres Blue Rock Springs Park is 4.77 miles. Compare this to the 7.43 miles and 6.27 miles traveled by Dennis Rader for his first two attacks. In total (both attacks) Dennis Rader traveled 13.70 miles. If the Zodiac Killer lived in American Canyon, he would have traveled a total of 12.77 miles (a difference of just 0.93 miles). The Zodiac Killer and Dennis Rader both sought the attention of the newspapers and media, but can both be compared using the Rigel software system of geographic profiling?       

The Bay Area murderer mailed three communications in total to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald on July 31st 1969, demanding that his ciphers be printed on the front page of the respective newspapers by Friday afternoon (August 1st). This is what he wrote to each newspaper after stating several facts about his crimes.

Vallejo Times-Herald - Here is a cyipher or that is part of one. the other 2 parts have been mailed to the S.F. Examiner + the S.F. Chronicle I want you to print this cipher on your frunt page by Fry Afternoon Aug 1-69, If you do not do this I will go on a kill ram page Fry night that will last the whole week end. I will cruse around and pick of all stray people or coupples that are alone then move on to kill some more untill I have killed over a dozen people.

San Francisco Examiner - Here is a cipher or that is part of one. The other 2 parts are being mailed to the Vallejo Times + S.F. Chronicle I want you to print this cipher on the frunt page by Fry afternoon Aug 1-69. If you do not print this cipher, I will go on a kill rampage Fry night. This will last the whole weekend, I will cruse around killing people who are alone at night untill Sun Night or un till I kill a dozen people.

San Francisco Chronicle - Here is part of a cipher the other 2 parts of this cipher are being mailed to the editors of the Vallejo Times and SF Examiner. I want you to print this cipher on the frunt page of your paper. In this cipher is my idenity. If you do not print this cipher by the afternoon of Fry.1st of Aug 69, I will go on a kill ram-Page Fry. night. I will cruse around all weekend killing lone people in the night then move on to kill again, until I end up with a dozen people over the weekend. 

In a previous article we examined the present and past tense usage in the three letters, along with the stamps applied to the envelope, to make the case for the Zodiac Killer being a Vallejo resident. The following will be nothing groundbreaking, but examines the phrases and grammar used by the author to paint a picture of the subject when considering his identity. The Zodiac Killer threatened chaos over the weekend if his codes were not published on the front page of the papers. Unfortunately for him, the main two publications refused to bow to his threats. On August 2nd 1969, the San Francisco Chronicle under the title Coded Clue in Murders placed one-third of his cipher on page 4, while the San Francisco Examiner under the banner Vallejo Mass Murder Threat Fails (despite publishing the entire cipher) relegated it to page 9 on August 3rd 1969. This lowly showing in the San Francisco Examiner clearly upset the Zodiac Killer the most, when he hurriedly delivered by hand the August 4th 1969 'Debut of Zodiac' letter to the Examiner, stating "I was not happy to see that I did not get front page coverage". Putting aside the December 16th 1969 'Fairfield' letter (which many dispute), he never wrote to the San Francisco Examiner again.  

In a recent article we discussed the topic of geographic profiling to narrow the search field for an offender's home residence. Equally, the wording used by the Zodiac Killer in his communications may also help pinpoint a location, or at the very least give us an insight into his comfort zone or movements. Target or Victim Backcloth is the model by which a murderer may select his victims. The Zodiac Killer (wherever he lived) would have selected his victims dependent upon availability and location, along with the constraints of time and the day of the week. For a serial killer committing his crimes in Vallejo, his knowledge of the Target Backcloth may govern the types of individual he chooses. This seemed evident in his choice of couples parked up in lonely areas on December 20th and July 4th.

His communications to the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald exemplified this knowledge of a Target Backcloth perfectly, when he only threatened to kill couples in his address to the Vallejo Times-Herald (or stray people). He knew exactly where to find them, despite the fact it was highly unlikely he would continue to kill in the same area again. The Zodiac Killer never used the word couples in his address to the San Francisco Chronicle and Examiner, suggesting that his knowledge of the Target Backcloth was less comprehensive and more uncertain in this city- and why at San Francisco he would target a lone taxicab driver rather than target the location, as he did at Lake Herman Road and Blue Rock Springs. As Kim Rossmo stated  "The San Francisco murder differs significantly from the Zodiac's other crimes. Up to this point he was hunting in locations that had a good probability of containing his desired victims. Target selection was a function of area, not of an individual. However, it is unlikely the Zodiac was successful in all his searches; serial killers typically engage in extensive hunting activities, and for every attack there are many unsuccessful search attempts. In San Francisco, however, the Zodiac controlled the situation through his selection of victim type. The need for such control could be indicative of the distance the Zodiac had to travel to the crime site. Criminals who travel longer distances to offend are less likely to use uncertain target selection techniques".  

The Zodiac Killer wrote of ​"killing lone people in the night" or "killing people who are alone at night" to the Chronicle and Examiner, which is exactly what he did just over two months later on October 11th 1969, when Paul Stine was brutally gunned down inside his taxicab at Presidio Heights. The target selection began with the individual not the location. He then directed Paul Stine to an area to facilitate his best chance of escape. A Target Backcloth requires knowledge of an area and will govern to some extent the victims chosen, as displayed by some serial killers who target sex workers.   

It was considered that if the Zodiac Killer lived in Vallejo, he likely had a 9-5, Monday to Friday profession, based upon the fact, that when constrained by time he murdered close to home on a Friday, but unconstrained (on his day off), he was able to venture further afield to San Francisco and Lake Berryessa. He admitted as much in all the July 31st 1969 communications.

"I will go on a kill ram-Page Fry. night. I will cruse around all weekend" and "I will cruse around killing people who are alone at night untill Sun Night". The Zodiac Killer may potentially be limited in searching for courting couples on weekdays, but certainly not for lone victims in San Francisco, Vallejo or elsewhere Yet he has specifically tied himself to murder within the parameters of Friday night to Sunday night in these letters, and therefore highly suggestive he is employed on a weekday basis. 

The Brentingham model of geographic profiling details an activity space where an individual lives, works and plays. The Zodiac Killer targeted the San Francisco Chronicle, San Francisco Examiner and Vallejo Times-Herald in his first communications to the newspapers, indicating that Vallejo and San Francisco were his primary sites of travel. He most likely lived and worked in both. The newspapers he chose and the location he lived, part of his mental map, exhibited to its fullest extent when he subconsciously used the present and past tense in his three July 31st 1969 letters 

The Zodiac Killer - A Vallejo Resident [Part 2]​   

With the search for the infamous Zodiac Killer through DNA looking ever more threadbare, one very much overlooked tool in locating our offender is the 'science' of geographic profiling pioneered by Canadian criminologist Kim Rossmo, who utilizes the software geo-profiling tool Rigel to analyze the likely home residence of the Zodiac Killer. Rigel uses an algorithm called criminal geographic targeting (CGT) to identify hot and cold zones on a map and give the areas that our killer may (or may not) likely reside. In the case of the Zodiac Killer, it would take into account such things as the murder sites, phone calls, commuter routes, and geographic profiling models such as buffer zone, comfort zone, least effort principle, mental map, target backcloth and distance decay function. As Kim Rossmo points out, this is an accompaniment to law enforcement to narrow the pool of suspects, but takes a back seat to powerful forensic evidence. However, with limited forensic evidence available from the Zodiac crimes, this appears our best bet to narrow down the home location of our killer before venturing outwards. Searching for suspects the length and breadth of California is a thankless task, with many researchers identifying a potential suspect and ultimately layering weak circumstantial evidence upon weak circumstantial evidence, until they become convinced the totality of the evidence should now be reclassified as powerful and irrefutable proof of their suspect's guilt. There is a tendency to fit the suspect around the evidence, rather than let the evidence be the driver. 

Kim Rossmo stated: ​​"The San Francisco murder differs significantly from the Zodiac's other crimes. Up to this point he was hunting in locations that had a good probability of containing his desired victims. Target selection was a function of area, not of an individual. However, it is unlikely the Zodiac was successful in all his searches; serial killers typically engage in extensive hunting activities, and for every attack there are many unsuccessful search attempts. In San Francisco, however, the Zodiac controlled the situation through his selection of victim type. The need for such control could be indicative of the distance the Zodiac had to travel to the crime site. Criminals who travel longer distances to offend are less likely to use uncertain target selection techniques. In respect to the killer's home residence, he continued "There's a number of possibilities. But remember, Rancho Vallejo was possibly 26,000 people at that time, of which only 13,000 will be male, and only a certain proportion of those are of the correct age, and a certain portion of those are only going to be white. Then we start looking at the neighborhoods involved, we have a pretty small subset. Then we start combining that with some of the personal and behavioral descriptors, and then we work in the vehicle information. If this case was active today, it would not be too difficult to find this person." 

There is an excellent interactive online tool that has generated geo-profiling heat maps for killers such as Jack the Ripper, Dennis Rader (BTK), Atlanta Child Murders, Golden State Killer, Night Stalker, Yorkshire Ripper, Long Island Serial Killer and more. It can be found here at geographicprofiler.com. The Kim Rossmo heat map for the Zodiac Killer is located here. 
You can toggle the geoprofile using the sidebar to remove the heat map and identify the locations underneath the color. The red color is the most likely residence of the Zodiac Killer, with a graded scale to the least likely areas of purple and beyond. This is classified as a percentage search cost (link) - Suspects are ranked based on their search cost—the percentage of the map searched before reaching the suspect’s anchor point. The search is conducted from the highest point of probability to the lowest; therefore, the lower the search cost, the more viable the suspect. If the geographic profile is accurate, the offender will have a low search cost. In the case of search cost, “map” refers to only the portion of the profile containing the crime scenes. As a result, suspects can have a search cost greater than 100%, which means a space larger than the area containing the crime scenes would have to be searched before reaching their anchor point.

One can see that the search cost is lowest for the area just east of the Napa Junction, the area of Ridgeview Park, Mare Island Naval Shipyard and across the Carquinez Strait Bridge to the area of Crockett Hills (just east of Rodeo). The area I favor, around the Springs and Tuolumne payphone, is afforded a 4% search cost. Despite the majority of the Zodiac mailings originating from San Francisco, this area features low on the geo-profiling heat map, and backed up by the statements of Kim Rossmo above. He states that "geographic profiling can't solve a crime; there are only three ways to do that - eyewitness, confession or physical evidence - the role of geographical profiling is to allow a detective to get to that stage, where he or she can apply one of those techniques sooner, faster, more effectively and more efficiently". 

This means we target the red hot zones first, before extending outwards to orange, yellow, green, blue etc.The hot zones will inevitably sometimes fall over an unpopulated area, so the areas around them become the focus of our search. The technique of geographic profiling is a supportive tool to narrow the suspect pool and search parameters, especially in a case over 50 years old with limited physical evidence - narrowing the search field in order to prioritize our efforts. The possible candidates for the Zodiac Killer can be massively whittled down, as shown in the case of Rancho Vallejo, highlighted by Kim Rossmo above. After all, he did state "If this case was active today, it would not be too difficult to find this person."