Kim Rossmo is a Canadian criminologist who pioneered the art of geographic profiling- a technique used to compliment conventional police work in the tracking of criminals. He has used data from the Zodiac Killer case to narrow down the likely residence and possible commuter routes of the murderer, and even a suggestion of where he may have worked. When the details from the Zodiac case were placed into the Rigel crime mapping software it created significant zones of interest in Rancho Vallejo, northern Vallejo, American Canyon and Benicia. These areas have one critical commuter route relevant to all- that of California State Route 37- which the significance of regarding Zodiac's knowledge of courting couples, his base location and possible workplace will become apparent. Some of Kim Rossmo's ideas will be presented here, but to read his excellent analysis of the Zodiac case, please visit here. 
Below is a map showing all the relevant locations concerning the killer's first two crimes- the red circle at the northern end of Tuolumne Street being of significant interest, as it also brings into focus the easy access to and from the payphone after his murder and attempted murder of Darlene Ferrin and Michael Mageau at the Blue Rock Springs parking lot on July 5th 1969. The journey time to the payphone from the crime scene of less than 10 minutes, and the phone call to police nearly 40 minutes after the attack lends good weight to the premise the killer was a native Vallejoan, and possibly returned home to ditch his weapon and/or clothes before returning to place the call to police dispatcher Nancy Slover.  

What better way to have knowledge that Lake Herman Road and Blue Rock Springs were frequented regularly by courting couples, than if you routinely traveled this route to reach your place of work, not unlike eyewitness James Owen who lived at 1735 Mini Drive and would have likely used California State Route 37 at the beginning of his journey, to arrive at Humble Oil in Benicia. The same applies to an area around Mare Island Shipyard and Rancho Vallejo, where Tuolumne Street nears State Route 37. Lake Herman Road on the eastern fringes of Vallejo and Benicia, is a dark, unlit stretch of rural road infrequently used. It is, however, a logical choice for somebody living in Ranch Vallejo (north Vallejo) or American Canyon to use, if they worked in the industrial area of Benicia.
The northern side of the green line on the map above, shows that access to State Route 37 would take somebody towards the northern side of Columbus Parkway, before heading southeast along Lake Herman Road towards Benicia, and crucially encompassing both crime scenes. If the killer lived in the northern region of Vallejo and worked in Benicia, his 'compass' knowledge of specific locations would not be surprising. This was evident in his first attack when he stated in the July 31st 1969 letters, that Betty Lou Jensen "was on her right side feet to the west." Of course, he had six and a half months to work this out, but had only 36-38 minutes after the Blue Rock Springs attack, in which he was able to direct Vallejo police to the crime scene along Springs Road and Columbus Parkway with completely accurate directions when he called Nancy Slover, stating "I wish to report a double murder. If you will go one mile east...... on Columbus Parkway to the public park, you will find the kids in a brown car. They have been shot with a 9 mm Luger. I also killed those kids last year.... Good-bye." 
Knowledge such as this, could suggest complete familiarity with the public park, golf course, Lake Herman Road and the location of the police station with respect to the Springs and Tuolumne payphone. 
The killer would have one direct route, to and from his residence to the payphone at the intersection of Springs Road and Tuolumne Street. His route to work (possibly a night-shift) also giving him first hand knowledge of courting couples and where to trawl for victims at the weekend.   

Kim Rossmo, referring to Lake Herman Road and Blue Rock Springs Park, stated "In contrast, his target selection at Lake Berryessa and San Francisco did not show any evidence of local area knowledge. Also, the time lapse between the Blue Rock Springs shooting and the Zodiac’s telephone call was approximately 40 minutes, even though the distance between these two locations is only 3.5 miles (7 minutes normal driving time). What did he do for that other half hour? One possibility is that he returned home and disposed of his weapon. If so, that means he most likely lived within a five-mile radius of the crime site. The Zodiac also knew to telephone the Vallejo Police Department, even though the Blue Rock Spring Golf Course and park area was an unusual offshoot of municipal jurisdiction, totally surrounded by Solana County. The Zodiac’s comfort zone clearly includes the Vallejo area."
However, there is one thorn in our side- the testimony of Michael Mageau. He stated in the police report "as he fell out onto the ground the vehicle the subject was in backed up in a turning movement and then took off toward Springs Road in Vallejo at a very high rate of speed." The obvious route back home for the killer, had he lived somewhere by the top of Tuolumne Street, and wanted to ditch his weapon and clothes before making the call to police, would have been to head north and west along Columbus Parkway- the opposite direction that he chose for work. There may be several explanations for this.
Michael Mageau was simply mistaken, the killer's initial intention was to make the phone call immediately but changed his mind, preferring to remove his weapon and possibly bloodied clothing from the equation, or the intended payphone at the initial time of his arrival had potential eyewitnesses, forcing a hasty change of plan. This may have been his preferred choice of payphone, as it provided easy access to and from his home residence, yet allowed a reasonable 'buffer zone' of just over two miles. It had the added benefit of a voyeur killer who wanted to remain in his vehicle and watch responding officers scurry into action from the police station, along Springs Road to the crime scene. It may actually have been the primary reason he chose this particular payphone so close to the police station, despite it seemingly being an added unnecessary risk on his part.        

There may be another reason why the Zodiac Killer chose the 'wrong way' after leaving the Blue Rock Springs parking lot. A reason that involved near eyewitnesses to the murder in the parking lot..
Three young kids, Debbie, Jerry and Roger were the first to find Michael Mageau just after he had extracted himself from the brown Corvair and was lying adjacent to it.
They must have arrived extremely close to the time of the attack- possibly as little as a minute or two after the brutal shooting. The time of the attack can be calculated with a fair degree of confidence to 12.02 am on July 5th 1969. See here. 
Police dispatcher Nancy Slover received a phone call from Jerry's house at  938 Catlewood Drive, Vallejo from Debbie at 12.10 am. The drive to 938 Castlewood Drive from Blue Rock Springs is approximately 6 minutes, indicating they would have had to leave the parking lot by about 12.04 am to make this phone call in time.
​Yet, this isn't the time they arrived at the parking lot, which must have been around a minute earlier at 12.03 am- just after the attack at 12.02 am. The Zodiac Killer may literally have been leaving the Blue Rock Springs parking lot as they were approaching it. This may have influenced the direction Zodiac exited from the crime scene.
Debbie, Jerry and Roger stated in the police report that "they had been downtown to see the festivities for the 4th of July. After this was over, at about 11 pm, they decided to look for this girl that Roger knows. They drove around town and did not see her and decided to go to Blue Rock Springs Park to look for her. They went out the freeway to Columbus Parkway and came into the park the back way. While they were driving in toward the park neither boy recalls seeing any vehicle coming out, none parked along the road, nor did they pass any vehicle."  They must have been almost on top of Zodiac as they approached from the north side of Columbus Parkway. Had Zodiac intended to travel home before making the phone call, his obvious route north and then west along Columbus Parkway, was now not so obvious if he didn't want himself or his vehicle spotted by the three kids. They obviously didn't see him, but he may have spotted their vehicle approaching in the distance. This may have forced a change of plan and coerced Zodiac south toward Springs Road.
The journey time heading in this direction to somewhere close to the green circle at the top of Tuolumne Street, would take approximately 11-12 minutes. The Zodiac Killer would arrive home at about 12.14 am- leaving him approximately 20 minutes at his residence before driving back to the Springs and Tuolumne payphone to make the call. Once doing so, his escape home is a mere 4 minutes.  
Calfornia State Route 37 and Highway 101 may have played a decisive factor when selecting a quick and easy separation from San Francisco after the murder of taxicab driver Paul Stine on October 11th 1969. Whether or not the murderer had entered the Presidio Park is a moot point today, but in 1969 the Zodiac Killer would certainly have wanted to escape from the area in as little time as possible. A vehicle parked somewhere along West Pacific Avenue or to the east of the park in Cow Hollow, would provide immediate access to Highway 101 across the Golden Gate Bridge, and in a handful of minutes out of San Francisco. The killer can then head north and eventually east just before Novato, taking California State Route 37 right onto his doorstep.  

The selection of a taxicab driver to take him to a predetermined destination so close to an exit route from San Francisco, one could argue was the perfect choice for a resident of Vallejo. The killer has a nearby park in case things don't go to plan, along with an immediate escape and separation from the crime scene via Highway 101 and the Golden Gate Bridge. Even Inspector Dave Toschi thought this a viable proposition: "The detectives heard from neighbors that a stocky figure was seen dashing across Julius Khan playground and into the dense undergrowth of the Presidio. The dog patrol units, seven of the best search dogs in the country, gathered at the front entrance of the Presidio and were deployed one at a time in various directions. Armstrong and Toschi considered the possibilities. Had the killer gone quickly through the dark woods and emerged from the Presidio at Richardson Avenue, and taken Highway 101 past Fort Point onto the Golden Gate Bridge and vanished into Marin County."
Kim Rossmo made an extremely salient point regarding the murder of Paul Stine.
He 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."  Control your location and you control your escape route.
The Lake Berryessa attack on September 27th 1969 speaks for itself. The killer headed to downtown Napa and the payphone at 1231 Main Street. He may have been only 12 miles from California State Route 37 and home, had he continued the trajectory he had set for himself. Was the Zodiac Killer's apparent knowledge of a road on the fringes of Vallejo more indicative of his recreational habits or a route he traveled daily..... particularly when the sun went down. 

If the Zodiac Killer touched the stamp or envelope inner while sealing either, even if he didn't lick the glue, there remains a reasonable probability of securing a full DNA profile of the Bay Area murderer in the coming weeks, so long as the evidence has been stored correctly in a controlled temperature and humidity. However, this may not be the case with the July 31st 1969 letters, which were apparently kept in the private files of a "retired police source." 
If the numerous Zodiac letters have been treated in a similar manner to other cases around the world, then just a few cells would be needed.
​The amount of cells required can be as small as a millionth the size of a grain of salt. This DNA can be harbored from skin cells stuck to the back of the envelope or stamp, or from the pasted newspaper cuttings from the '13 Hole' postcard, the 'Pines' card or the 'Halloween'.card  This has been achieved before in cold cases.
Low Copy Number (LCN) was developed in 1999 by the UK Forensic Science Service, but has not been adopted by all countries due to the risk of contamination in the sample.
The amount of material or DNA required is so microscopically small the results achieved are effectively non-reproducible, but with so many Zodiac letters available, the possibility of a match between letters could produce corroborative proof.
This technique has led to the successful apprehension of numerous individuals in the UK.
One such case was the conviction of Paul Hutchinson in 2010, who raped and strangled Colette Aram (16) in Nottingham, England in 1983, despite the case being cold for 27 years. "After the murder, Hutchinson, a psychology graduate who had also been a youth worker, returned to the village to watch the police investigation unfold and later sent a letter taunting officers that he was still free."No one knows what I look like. That is why you have not got me," he wrote, also claiming he was wearing a Halloween mask. "You will never get me." The Guardian. 
A DNA profile was generated using 'Low Copy Number' taken from the letter and matched in the nationwide database to one of his relatives, ultimately leading to his arrest and conviction. Remarkably a fingerprint from the letter was also matched to Hutchinson.
​This extremely small sample size offers hope in the Zodiac case. Even if the results are questioned due to the risk of contamination- once a suspect has been identified, further comparisons could be then implemented using the bloodied fingerprint from the taxicab of Paul Stine or the palm print from the 'Exorcist' letter, as two simple examples. This would then be followed up by looking at all aspects of the subject identified, in order to validate or refute the credibility of the DNA results.  

In 2017, Osmond Bell was eventually convicted 36 years after the murder of Nova Welsh in Birmingham, England in 1981 by saliva retrieved from chewing gum he had used to seal the door of a cupboard he had hidden her body in.
"The 60-year-old killer also left traces of DNA on the envelope of a letter he sent after the killing in an attempt to frame an innocent man for the crime.
Jurors acquitted the pensioner of murder, opting instead to convict him of manslaughter by an 11-1 majority verdict following a six-week trial at Birmingham Crown Court on Wednesday." The Sun.
DNA retrieval after 27 and 36 years was successful in both cases, resulting in conviction. This gives us the hope that correctly preserved evidence can without doubt generate a full DNA profile in the Zodiac case, whether through saliva or skin cells in the smallest of samples.

Much expectation has surrounded the capture of 72-year-old Joseph James DeAngelo on suspicion of 50 rapes and 12 murders between 1976 and 1986 in California, with respect to the possible future identification of the Zodiac Killer through the use of genealogy websites and familial DNA testing. The Sacramento Bee newspaper stated "Vallejo police Detective Terry Poyser, who has worked the Zodiac case for four years, said his agency has submitted two envelopes 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. Referring to testing done in 2002 "Poyser said that DNA sample was hampered because technology didn't exist at the time to separate the glue used on the stamps and envelopes from the genetic material. However, science now has advanced to allow a clean grab of the DNA."

Peter Sutcliffe, known as the Yorkshire Ripper, was convicted of thirteen counts of murder and seven counts of attempted murder in England between 1969 and 1980. The case was severely hampered by poor detective work and the intervention of a hoaxer dubbed 'Wearside Jack,' who falsely claimed to be the murderer, sending detectives three letters and a cassette recording between 1978 and 1979.
One letter read  "Dear Sir
I am sorry I cannot give my name for obvious reasons. I am the Ripper. I've been dubbed a maniac by the Press but not by you, you call me clever and I am. You and your mates haven't a clue that photo in the paper gave me fits and that bit about killing myself, no chance. I've got things to do. My purpose to rid the streets of them sluts. My one regret is that young lassie McDonald, did not know cause changed routine that night. Up to number 8 now you say 7 but remember Preston '75. get about you know. You were right I travel a bit. You probably look for me in Sunderland, don't bother, I am not daft, just posted letter there on one of my trips. Not a bad place compared with Chapeltown and Manningham and other places. Warn whores to keep off streets cause I feel it coming on again. Sorry about young lassie.
Yours respectfully
Jack the Ripper
Might write again later I not sure last one really deserved it. Whores getting younger each time. Old slut next time I hope. Huddersfield never again, too small close call last one."

In 2005, only three years after the Zodiac documentary with Cydne Holt, in which the programme claimed only a partial DNA sample was acquired, police made a major breakthrough in the 'Wearside Jack' investigation. "Senior officers from West Yorkshire Police's Homicide and Major Inquiry Team, headed by Det Chief Supt Chris Gregg, decided to review the case. A small piece of the gummed seal from one of the envelopes was located in a forensic laboratory and following publicity about the cold case review the hoax tape was retrieved from a retired scientist who had worked on the original investigation. As a result of this cold case review, DNA from envelopes sent by Humble as part of the hoax were matched in the United Kingdom National DNA Database with samples police had obtained from Humble in an unrelated incident in 2000, when he had been arrested and cautioned for being drunk and disorderly. By this time Humble had become an alcoholic loner." Wikipedia.  John Samuel Humble was arrested and sentenced to eight years in jail. After 26 years, the gum on the 1979 envelope required only a few cells to generate a profile from the DNA database. It would seem the technology did exist in 2005 for a "clean grab" of DNA from the glue- and other cases exist.
Yet here we are, thirteen years later, waiting in expectation once again, despite having a possible 21 letters at our disposal and numerous double postage stamps available for testing. Whether or not the Zodiac envelopes and stamps were licked by the killer and contain enough traces of saliva, if at all, should not be an argument in 2018.
The Golden State Killer case may have jolted the investigation into the Zodiac Killer into life, with the use of familial DNA testing- but this scientific advancement is nothing new, having been available through current DNA databases for years. The use of familial DNA testing in the USA has been bedeviled with privacy issues, currently adopted by very few states in America, including California. ​

The implementation or otherwise of familial DNA testing through databases such as CODIS, searching for near matches of blood relatives, could be the difference between apprehending a serial killer such as the Zodiac or Golden State Killer, or not.
There is a possibility that besides the July 31st 1969 letters and others, the items recovered from Lake Berryessa may contain the Zodiac Killer's blood. Often during bladed attacks, the assailant will cut themselves, depositing blood at the crime scene. By all accounts Bryan Hartnell played dead to avoid further repeated stabbing, but seemingly Cecelia Shepard did not adopt this strategy and hence sustained greater knife injuries to her back and abdomen.
If the Zodiac had knowingly left while under the impression one person was still alive, then had he cut himself during the latter part of the attack as the knife became sodden with blood, not dissimilar to the murder of Cheri Jo Bates in Riverside on October 30th 1966. 
If so, this may provide investigators with the possibility of testing for DNA on the clothing and blanket recovered from Lake Berryessa on September 27th 1969. 


On June 9th 1984, Melanie Road, 17, was stabbed to death in Bath, Somerset, England. She had been brutally stabbed 26 times. "A trail of blood matching Hampton's blood group, and later his DNA, was found leading from nearby St Stephen's Road in the direction of his home half a mile away."  Independent.  It was entered into the UK database.
Thirty years later his daughter, then aged 41, was arrested for a domestic incident, leading to a familial DNA match to the genetic fingerprint stored in the database. Christopher Hampton was jailed for 22 years in 2015.
Privacy issues have been argued over the recent Golden State Killer case and aggressively pursued in many American states regarding the use of familial DNA to trace offenders. The same issues have arisen over the use of CCTV trailing our every move. One can ask yourself the question- if the killer of your mother was captured on CCTV or through familial DNA testing, would you argue against its use when it helps you, or only argue against it when it helps somebody else.
If you think the DNA in the Zodiac case is too old and degraded, then think again. Detectives in the 'Little Red Riding Hood' murder of 12-year-old Muriel Drinkwater from Swansea in 1946, extracted DNA from a semen stain on her coat in 2008.
This has been touted as "possibly the oldest one in the world to be successfully extracted in a murder investigation.
In 2008, a team of retired detectives investigating cold cases found Drinkwater's clothes in storage. Her blue coat, her underwear and school uniform had been wrapped in a paper bag and stored. On the back of the coat, a no-longer visible semen stain was circled with yellow crayon. Scientists successfully retrieved a DNA profile from the stain on the coat. A familial DNA profile was extracted using a technique called Y-STR, but no match was found in the national DNA database. Hubert Hoyles, who saw her after buying eggs at her parent's farm, was cleared by the DNA evidence. He stated he had long been suspected by some locals as the murderer and was happy to clear his name."
Wikipedia.
It seems rather odd to now claim with renewed optimism, the possibility of generating a full and complete DNA fingerprint of the Zodiac Killer, when this possibility has been there for years. The recent likely capture of the Golden State Killer has given a much needed 'kick up the backside' to the Zodiac investigation. But it shouldn't have been required.

This correspondence dated December 15th 1971 was mailed from Scottsville, New York and addressed to Mr J Edgar Hoover, first Director of the Federal Bureau of Investigation.
​In respect to the Zodiac timeline, it was sent 15 months after the disappearance of Donna Lass from Stateline, Nevada on September 6th 1970.
The communication claims to have evidence that with proper investigation would disclose the name and identity of the infamous 'Zodiac Killer of California.' 
The author of this letter would receive a reply dated December 23rd 1971, informing him that the matter was not within the investigative jurisdiction of the FBI and he should advise the San Francisco, California Police Department of any information which pertains to the Zodiac Killer. Signed by Director, John Edgar Hoover. 
The identity or signature of this individual is redacted, with a return address of some description- therefore determining its sincerity or otherwise is difficult to determine. One would like to think this was an extremely concerned citizen or somebody from an official agency, frustrated enough to mail a letter to the FBI offices (handwritten letter below). 

Tracers wrote this on the Zodiac Killer Tapatalk forum: "I did find this old reference to a letter: In a letter from J.Edgar Hoover dated 11/30/70 to Senator Karl E. Mundt concerning his interest in finding Donna A. Lass, he says, "In an effort to be of assistance, a search of our Identification Division files was conducted but I regret to tell you no indication of the whereabouts was disclosed. A missing person notice was previously placed in file in behalf of Senator George McGovern. In view of your interest I am having a notification added to the effect that any information we may receive will also be forwarded to you. We do not, of course, have the authority to conduct an active investigation in the absence of a violation of a federal statute within our jurisdiction."
​
Senator George Stanley McGovern was a U.S. Representative and U.S. Senator born in Avon, South Dakota, approximately 100 miles from Sioux Falls, South Dakota, which may reflect his interest in the case. 
 
Another communication in the form of a Christmas card was mailed to the sister of Donna Lass, Mary Pilker, in Sioux Falls, South Dakota on December 27th 1974. The Christmas card read 'Holiday Greetings and Best Wishes for a Happy New Year', followed by the handwriting "Best Wishes, St Donna & Guardian of the Pines." 
It is unknown whether this card had sinister connotations in respect to where Donna Lass may be buried (somewhere in between the pines), or whether it is just misguided support. There are, however, some similarities in the handwriting of the John Edgar Hoover letter and the Christmas card mailed to Mary Pilker (shown below).
Handwriting comparisons in the Zodiac case are the topic of much debate, as they are extremely subjective, and should always be used in conjunction with other evidence. 

John Edgar Hoover (January 1, 1895 – May 2, 1972) was an American detective and the first Director of the Federal Bureau of Investigation (FBI) of the United States. He was appointed as the director of the Bureau of Investigation — the FBI's predecessor — in 1924 and was instrumental in founding the FBI in 1935, where he remained director until his death in 1972 at the age of 77. Hoover has been credited with building the FBI into a larger crime-fighting agency than it was at its inception and with instituting a number of modernizations to police technology, such as a centralized fingerprint file and forensic laboratories.
Wikipedia.

Michael Morford wrote an excellent article on the June 8th 1967 murders of Enedine Molina (35) and boyfriend Fermin Rodriguez (36) near Pleasanton, California. This was covered on this site and discussed on Zodiac Killer Site forum.
​Below I shall detail this double murder using a visual from Google Maps and only the newspaper reports that covered the story, to sequence the order of events that night. Here is a layout of where the victims were found in relation to the March 22nd 1970 abduction of Kathleen Johns on Highway 132, west of Modesto, and the city of Pleasanton, where Zodiac mailed the 'Los Angeles' letter on March 13th 1971.    

"According to detectives Regional Park Naturalist Richard Angel called the Santa Rita sheriff's substation last night (Thursday June 8th 1967) and reported hearing two shots in the park area at 10.05 pm. The woman's body was discovered about 11.00 pm just outside the remote Sunol Regional Park. The body was found by Deputy George Robinson, the first man to arrive at the park. Mrs Molina had been shot in the back (and possibly left wrist). It appeared she had been running when she was shot, deputies reported.
On his way back to the substation about 2.30 am (Deputy George Robinson) spotted a station wagon parked along Vallecitos Road about six miles from the park, stopped to check it and found Rodriguez's body. He had been shot in the left breast and shoulder bone. The bullets entered his body from the front deputies said. The murder weapon was believed to be a .22 caliber revolver. No gun was found."  Detectives ordered weekend roadblocks to canvass individuals.
"The weekend roadblocks were in the areas of Geary Road and Calaveras Road. Captain Tom Houchins said officers questioned persons between 10.00 pm and midnight, believed to be the timespan when the two were killed. Houchins said there is the possibility that another car was involved.
A Mountain View man, Joe Martinez of 1819 Birch Street (ex-husband of Enedine Molina), turned himself in at the Sunnyvale Police Station this morning after hearing he was wanted for questioning. He was later released by Sunnyvale Police and Alameda County sheriff's officers. Captain Tom Houchins, in charge of the investigation said "as of now we have no suspects." 
Detectives investigated suspicious events in the run-up to the double murder:
"Investigation of the two June 8 murders in Sunol has disclosed that each of the victims had been followed several times by an unidentified driver. Each also received mysterious phone calls over a period of many months, according to reports from Alameda County Sheriff's deputies." The daughter of Molina "told detectives the family had been receiving disturbing telephone calls at her mother's residence since July. She said that whoever called didn't speak and that all that could be heard over the phone was heavy breathing (reminiscent of the 0.1.30 am calls on July 5th 1969, after the BRS attack). The daughter said the calls usually were made between 10 and 11 am, or between 7 and 8 pm, and that her mother was usually not home when they were received. Detectives also reported that the daughter told them she had overheard her mother say that a car followed her when she was out. Substantially, the same story was given detectives by Mrs Lydia Rodriguez, widow of Fermin Rodriguez, who was found murdered in his car parked along Vallecitos Road. Mrs Rodriguez said her husband had also complained about a car following him. On another occasion, she said, her husband had told her he had seen the strange car parked in front of his house, but could not describe the driver."  

This was a couple attacked while parked up in their vehicle, not dissimilar to the Lake Herman Road and Blue Rock Springs attack. The obvious connection is apparent with respect to the abduction of Kathleen Johns just 28 miles east of where the vehicle of Molina and Rodriguez was discovered. These murders were one and a half years prior to the double murder of David Faraday and Betty Lou Jensen, who were also killed using .22 small caliber ammunition. Then there is the menacing silent phone calls to the 1300 Virginia Street residence of Darlene Ferrin. Yet, these murders also have the trait of jealousy, in the form of a previous partner or husband unable to move forward. What evidence was given to discount Joe Martinez, or fail to implicate him we may never know.
​Detectives stated that "officers questioned persons between 10.00 pm and midnight, believed to be the timespan when the two were killed." They also believed "another vehicle was involved."
The indications from the newspaper reports seem to suggest the murder occurred at approximately 10.05 pm, when Enedine Molina was attempting to flee from her assailant, after leaving his vehicle. Fermin Rodriguez had likely already been murdered at this point in time, when the killer approached in his vehicle, murdered him and abducted the woman. His body was discovered in his vehicle 6 miles north on Vallecitos Road. The time of his murder was likely 10 minutes earlier at 9.55 pm, if the two murders were one continuous sequence of events. 
One alternative could be, the killer approached the couple on foot as they were in their vehicle on a dirt turn off, just alongside Calaveras Road (by Geary Road), shot the woman, and then forced the male victim to drive north to Vallecitos Road, before murdering him and fleeting on foot. However, this seems the less likely of the two. 
Whether these murders have any connection to Zodiac is likely never to be proved or disproved half a century on, but being only 38 miles south of Vallejo (as the crow flies) it is worthy of consideration. 
Thanks to Michael Morford.   

The following will be explaining in more detail the subconscious wording of the Zodiac Killer in his first three communications with the Bay Area newspapers, putting forward a compelling argument that the confirmed murderer of five was a resident of the Vallejo area. The Zodiac Killer would never willingly have given us his name or the locality of his residence, however, one could argue that had he revealed his home location without realizing it, then it is likely true. To do this, we have to examine closely the wording he chose on his July 31st 1969 letters using the present and past tense. Here is what the Zodiac stated on each communication:
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."
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." 
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." 

You will notice the two San Francisco newspapers are being addressed in the present tense regarding the other two mailings, using the word ARE. While the Vallejo Times-Herald newspaper is being addressed in the past tense regarding the other two mailings, using the word HAVE. There is every indication that this has been written subconsciously by the Zodiac Killer and therefore he has inadvertently given us his home location of Vallejo. The word "are" immediately precedes Vallejo Times on both occasions. 

If the Zodiac Killer lived in Vallejo when he composed these three communications, he would associate Vallejo with the present (everything that is happening in or around him). If the Zodiac Killer had traveled to San Francisco for a day out and then had returned to Vallejo, he would be referring to San Francisco in the past tense: "I have been to San Francisco and have mailed three letters." In the Vallejo Times-Herald communication text above, he is doing just that, when referring to his mailing of letters to the Chronicle and Examiner, which are approximately 40 miles away: "the other 2 parts have been mailed to the S.F. Examiner + the S.F. Chronicle."  Because now he is back home. ​  

When he is at home in Vallejo writing these communications, his mind is actually projecting forward to their future postings in San Francisco, which is where they were ultimately mailed. 
In two of the communications to the Chronicle and Examiner in San Francisco, he is referring back to his hometown Vallejo in conjunction with another mailing. Therefore he uses the plural form of the present tense, in the word "are". That is because at this moment in time (the time of writing), he is present here in Vallejo, so is effectively forced to abandon the past tense of "have". The Zodiac Killer cannot refer to Vallejo in the past tense in this instance, because the Vallejo Times-Herald office is in his locality, and therefore he is referring to it in the present of "are". 
Anything in the Zodiac Killer's locality is the 'here and now.'  Anyplace one has to travel and return, whether in the mind or reality, will be referred to in the past tense. Traveling to San Francisco physically and returning to Vallejo will now be referred to as "I have mailed", because of the distance you associate with the offices of the San Francisco Chronicle and San Francisco Examiner from Vallejo. Even if you do it in your mind.
But the Vallejo Times-Herald office is effectively on your doorstep and will therefore be seen as in the "here and now" to somebody living in Vallejo, without any real distance associated with it. Therefore it doesn't need to be referred to in the past tense, which is exactly what Zodiac does in two of his communications regarding the mailing to Vallejo- he uses the word "are". 

The Zodiac Killer is associating the Vallejo Times-Herald as his home location, so let us use this analogy with a fictitious friend.
Zodiac is in his house opposite the Vallejo Times-Herald office and he has just finished preparing his three July 31st 1969 letters for delivery. He bids farewell to his housemate and travels to San Francisco to post his letters. Upon his return two hours later he says to his friend "I have posted two letters to the San Francisco newspapers".  Looking out of his window and pointing he states "One letter is being posted to the Vallejo Times-Herald." He would be using the present tense regarding something in the "here and now". But because he is referring to the Vallejo Times-Herald mailing in two communications he uses the present tense "are". It clearly indicates that on a subconscious level the Zodiac Killer is referring to Vallejo in the present tense, because that is where he was when he penned the three July 31st 1969 letters.

The old Vallejo Times-Herald office was at 440 Curtola Parkway, just 0.96 miles (as the crow flies) from the Springs and Tuolumne payphone.

The Zodiac Killer's first three attacks were on couples, before switching to the murder of Paul Stine in Presidio Heights, San Francisco on October 11th 1969. It was considered that he may have 'changed his way of collecting slaves' in the fourth attack, due to the newspaper coverage, insinuating or suggesting he targeted the females primarily and likely feared the males, or the crimes themselves had a sexual component. However, an attack on a lone person in San Francisco was probably cemented in his mind, at least as early as July 31st 1969. Two of the three letters postmarked July 31st were mailed to the San Francisco Chronicle and San Francisco Examiner, and both failed to mention couples: The Chronicle letter stated "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 Examiner letter stated "I will cruse around killing people who are alone at night untill Sun Night or un till I kill a dozen people." The Vallejo Times-Herald letter was the only letter that mentioned couples: "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." This tends to indicate the Zodiac Killer was well aware of his locations of opportunity and the 'availability' of courting couples in Vallejo as opposed to San Francisco. 
The following observation may be reading a little too much into the Zodiac's wording, but the Vallejo Times-Herald communication is the only one of the three letters he used the past tense regarding his mailing of the letters. He used the phrase "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,"  whereas the San Francisco communications used the present tense: "The other 2 parts are being mailed to the Vallejo Times + S.F. Chronicle" and "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." If he was a resident of Vallejo, and was going to post all three communications somewhere in or near the Richmond District of San Francisco, which he did, then subconsciously on his future return to his residence in Vallejo, he would have posted the other two communications (to the Examiner and Chronicle). That is because he is associating the Vallejo Times-Herald with his home location. The letter he is sending to the Vallejo Times-Herald is close to his residence, so he labels the two San Francisco communications containing the word Vallejo, as are being mailed, because he is projecting further ahead. This subconscious use of words may very early on have told us exactly where the Zodiac Killer lived- somewhere he knew that couples were readily available over the weekend, before he returned to work in San Francisco on Monday morning.    

One always has to question why the killer after the Blue Rock Springs attack on Darlene Ferrin and Michael Mageau, who apparently lived in San Francisco, wouldn't just make the phone call somewhere equidistant between Vallejo and San Francisco, rather than from a payphone relatively close to the crime scene and extremely close to the police station. Why was he apparently constrained in choosing a payphone 10 minutes from the crime scene, yet 40 minutes after the double shooting, if it wasn't for the fact he lived in the Vallejo area, or extremely close to the payphone. 
If the killer lived in Vallejo and traveled to San Francisco weekly for his occupation, where did he work?. There are plenty of reasons to believe the Zodiac Killer knew the Presidio Heights area fairly well. If you are going to murder a taxicab driver in an affluent, built-up area, in the heart of San Francisco, it would have been advisable to know everything about the area and your likely escape route in advance.
There are two ways to enter San Francisco by vehicle from Vallejo- either by the Golden Gate Bridge or Oakland Bay Bridge. Either journey from Vallejo to the Richmond District is approximately the same distance. But if you entered via the Golden Gate Bridge every day, you would certainly have every opportunity to become accustomed to the roadways in and around the Presidio Park area. This is the area the Zodiac Killer may have left his vehicle- somewhere on the fringes of the park, by West Pacific Avenue or Lyon Street- towards the east. 
A man fitting the description of Zodiac was seen running into the Julius Khan playground minutes after the murder of Paul Stine- a description that virtually matched that of the three teenagers and Officer Donald Fouke. If we contend this wasn't the killer, then we have to conveniently dismiss this independent eyewitness testimony as erroneous. Even Dave Toschi believed this was a viable sighting, as search dogs and police vehicles were stationed alongside the Julius Khan playground. 
A passage in Robert Graysmith's book Zodiac appears to corroborate the premise that eyewitnesses at, or near Spruce Street, observed a man running into Julius Khan playground, and tallies with the October 12th 1969 San Francisco Chronicle article. Here is the excerpt: "The detectives heard from neighbors that a stocky figure was seen dashing across Julius Khan playground and into the dense undergrowth of the Presidio. The dog patrol units, seven of the best search dogs in the country, gathered at the front entrance of the Presidio and were deployed one at a time in various directions. Armstrong and Toschi considered the possibilities. Had the killer gone quickly through the dark woods and emerged from the Presidio at Richardson Avenue, and taken Highway 101 past Fort Point onto the Golden Gate Bridge and vanished into Marin County." Richardson Avenue leads onto Highway 101 and the Golden Gate Bridge- a route the killer would be completely familiar with, had he traveled this way to and from work each day. Even if he didn't travel this exact route, if he worked in the Richmond District area, he would surely be familiar with the surrounding area and his best escape route from the intersection of Washington and Cherry.  

The website (now not available online) crackproof.com examined the Zodiac communications and their associated postmarks. This indicated that the July 31st 1969 '408' letters were franked in the Central Richmond District, and the Paul Stine letter, mailed two days after the murder, was franked in the Inner Richmond District. This doesn't mean they were necessarily posted here, but processed at this location (these letters were franked 1A and 1B). However, they were very likely posted by the killer somewhere in the northwest region of San Francisco, with Richmond being a strong possibility.
This area and vicinity is an extremely significant area when it comes to the exploits of the Zodiac Killer in San Francisco. This can be seen in the Google map diagram below.     

The only claimed Zodiac victim outside of the canonical five and Bay Area, known to have once lived in San Francisco was Donna Lass, who disappeared on September 6th 1970 from South Lake Tahoe. She worked at the Letterman General Hospital in the Presido and resided at 4122 Balboa Street in the Outer Richmond District. Did she ever cross paths with the Zodiac Killer while she worked here?
On April 20th 1970 the '13 Symbol' cipher arrived at the San Francisco Chronicle stating "I am mildly cerous as to how much money you have on my head now.  I hope you do not think that I was the one who wiped out that blue meannie with a bomb at the cop station.  Even though I talked about killing school children with one. It just wouldn't doo to move in on someone else's teritory.  But there is more glory in killing a cop than a cid because a cop can shoot back.  I have killed ten people to date. It would have been a lot more except that my bus bomb was a dud.  I was swamped out by the rain we had a while back." In the letter the Zodiac Killer was referring to the murder of San Francisco police officer Brian McDonnell on February 16th 1970, two months earlier, when a bomb packed with fence staples exploded on an outside ledge of the 1899 Waller Street, Park Police Station in the Upper Haight neighborhood. This location, bordering Golden Gate Park  and the Richmond District areas, is only 1.45 miles south of the Paul Stine crime scene.  

The next Zodiac communication was the 'Dragon' card mailed on April 28th 1970, depicting what appears to be characters from a novel by Miguel de Cervantes Saavedra, in which Don Quixote, on his horse Rocinante, and Sancho Panza his squire, perched on a donkey called El rucio, embark on a mission to restore chivalry. The Zodiac Killer wrote on the face of the card "I hope you enjoy yourselves when I have my Blast." Was this a case of Zodiac rubbing salt into the wounds of the San Francisco Police Department, choosing this card for a specific reason. The 1899 Waller Street Police Station is situated on the boundary of the San Francisco Golden Gate Park, in which the memorial statue of Miguel de Cervantes, featuring Don Quixote and Sancho Panza sits. So was this card really just a random choice, or was Zodiac simply 'needling the blue pigs'.
In the following correspondence, the 'Button' letter, on June 26th 1970, the Zodiac Killer suggested he may have been responsible for the murder of Sgt Richard Radetich a week earlier. Officer Radetich was gunned down by three shots from a .38 caliber revolver at point blank range through the driver side window of his vehicle, while in the process of serving a parking ticket. He was sat in his police car near 643 Waller Street, San Francisco, in the Lower Haight District, where he sustained life threatening injuries and subsequently died 15 hours later.
643 Waller Street is only just over a mile from the Golden Gate Park and the Richmond District of San Francisco. One can see the clustering of these Zodiac 'events' within the northwest corner of San Francisco, and around the Richmond District area. Even the 'Dripping Pen' card mailed on November 8th 1969 was supposedly mailed just south of this area.
Nobody can definitively pin down the likely profession of the Zodiac Killer, but did it reside somewhere in this region- somewhere he could mail his communications to and from work. The question is always asked: Why would the Zodiac Killer mail a noticeable amount of his correspondence from the vicinity of where he worked?- that would be stupid. The answer probably lies within the geographical profiling term 'the least effort principle.' That, when a human can exert the least effort in accomplishing a given task (with little risk), they probably will. Obviously, he realized that the ability to trace a letter or card back to a particular mailing point is practically impossible. Only to the area the letter was franked. 
The final observation on the map above, is the locality and proximity of the three golf courses to the Richmond District- bearing in mind the golf course adjacent to the Blue Rock Springs parking lot. Could the Zodiac Killer have worked at one of these locations, or did he play golf on a regular basis, taking his scorecard from the clubhouse into the very communications he mailed.  

Having reached a bit of an impasse in the Zodiac case recently, I thought I would take a trip down memory lane and put together my favorite 10 articles from the 6 years this site has been in existence. They may not be the choice of everybody, but I thought I would place them together for reference purposes. Cheers for all your support down the years- your valued feedback is greatly received. 

SACRAMENTO COLD CASE-CONTACT​
Linking the 1986 'Zodiac' letter to the April 22nd 1986 double murder of Koy Ien Saechao and Choy Fow Salee in Sacramento. The Laotian couple were brutally gunned down through the front side window of their vehicle while parked up alongside a Sacramento freeway.
This double murder exhibited all the hallmarks of the attack on Michael Mageau and Darlene Ferrin at Blue Rock Springs Park on July 4th 1969.
The letter may or may not have been authored by the Zodiac Killer, but it was almost certainly referencing this crime.  

CHERI JO BATES-THE ANATOMY OF A CRIME 
Examining the brutal stabbing of Cheri Jo Bates in Riverside on October 30th 1966 from the standpoint of the autopsy findings. 
Could the order of events that evening/night be unfolded by studying the wounds inflicted upon the young woman in the Riverside alleyway. 
The killer or killers of Cheri Jo Bates were never caught, yet by closely scrutinizing the findings of pathologist Rene Modglin, we can formulate a possible scenario that ended the life of a beautiful and amiable young woman.   

I WANT TO TELL YOU A STORY 
Where did the Zodiac Killer go after the murder and attempted murder of Darlene Ferrin and Michael Mageau on July 4th 1969.
Using a liberal sprinkling of geographic profiling, the timeline of the payphone call, and the 'Debut of Zodiac' letter received on August 4th 1969, we presented a case for the murderer living but a short walking distance from the payphone at the intersection of Springs Road and Tuolumne Street. ​

ONE MILE EAST ON COLUMBUS PARKWAY 
Attempting, but probably failing in an attempt to convince, that the Zodiac phone call directions forty minutes after the Blue Rock Springs Park attack were in fact correct from a directional standpoint.
It has long been perceived that police dispatcher Nancy Slover, while attempting to talk over the killer, actually heard and recollected the entire message verbatim, with not one single error. The contrary is perceived of the Zodiac Killer- his message was error strewn from the standpoint of directing police from the station to the crime scene. This doesn't have to be the case.
In the aftermath of the Presidio Heights shooting, observers seem unsure where the negro male description error seemed to have originated from. At Blue Rock Springs many are totally convinced- it was Zodiac.    

PRESIDIO HEIGHTS-MINUTE BY MINUTE 
Following the movements of the Zodiac Killer, and police officers Armond Pelissetti and Donald Fouke in the aftermath of the Paul Stine murder in Presidio Heights on October 11th 1969.
Attempting to weave the conflicting stories into one coherent timeline, to unearth the movements of the Zodiac Killer once he headed north on Cherry Street and towards the Presidio Park.
This was the last of the Zodiac Killer's canonical five, yet he continued his sustained assault on the newspapers of the day for many years to come.  

CHERI JO BATES-REEVALUATING THE CRIME SCENE 
Placing Cheri Jo Bates' Volkswagen Beetle back in its rightful position just yards from the library annex.
This positioning was eventually reinforced by police in the December 2017 History Channel docudrama 'The Hunt for the Zodiac Killer.'  
Robert Graysmith, author of Zodiac, had placed Cheri Jo Bates' vehicle 75 yards west of the alleyway, which would dramatically have altered the sequence of events that night. This has hopefully corrected that premise. 
Part Two.

On November 21st 1969 a suspected Zodiac letter was received.
The FBI file read: 'Re Butte tel to Bureau 11/21/69.
Enclosed herewith for the FBI laboratory are two copies of the letter received by (redacted) San Jose PD, San Jose, California on this date.
As noted, the message reads (redacted). 
The laboratory is requested to have the Cryptogram Section attempt to immediately decipher the message and furnish the results to the San Francisco Office.
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).'
A further page read:
11/24/69 - 'Copy of handprinted note beginning "There's no doubt I will do my Thing!" and ending with the symbol (drawn crosshairs). Results of examination:
The ciphertext portion of Qc33 is not readable using previously recovered key. Its brevity precludes further cryptanalytic examination at this time. The furnished interpretation of  "- + 62 + -" as representing "1620" can be neither proved nor disproved analytically. The = between "November" and "8" could represent the number "2". Such interpretation would be based on inferences drawn from the date of the postmark, not from cryptanalytic examination.'  (see below for FBI files).​ 

The FBI files ponder the idea of "November" and "8" being bridged by the number 2, possibly giving us November 28th, and therefore tying in with a presumed threat on a widow from San Jose. Here are some thoughts on Zodiac Killer Site forum. 
However, there may be a much simpler explanation, bearing in mind the Zodiac Killer's last two communications on November 8th and 9th of 1969- in particular the 'Dripping Pen' card.

That "November = 8" means exactly what it states- that the author or Zodiac is threatening, or has already claimed victim number 8 sometime in November.
​Bearing in mind the 'Bus Bomb' letter mailed on November 9th 1969 claiming 7 kills, then had an 8th victim already been claimed (presumably a male victim, if the mention of a widow was relevant), we would be looking for a victim between November 9th and November 21st. A future victim in November would likely have been murdered between November 21st and November 30th (the claimed target possibly being the woman in San Jose).
The phrase "There's no doubt I will do my Thing!" seemed to suggest an impending threat- hence the urgency of 24 hour surveillance on the woman. Thereby, the use of the term "widow" in the FBI file may likely not carry a sinister connotation of a prior murder.  
The Zodiac Killer was certainly looking for a ninth and tenth victim on December 20th 1969, when he mailed a further correspondence to Melvin Belli's residence.
​The reference to "- + 62 + -" appears to represent six characters rather than four, so is open to interpretation. 
Here is an aerial view of 2162 Ringwood Avenue, San Jose, Ca.  A code such as 2162SJ, coupled with a specific name would be enough. This is just a crude example, so any suggestions would be welcome.   

On the left is the Fairfield letter mailed on December 16th 1969. 
Nine days prior to this communication another Fairfield letter was received, dated December 7th 1969 (see below). It is highly likely, based on the handwriting and tone of each correspondence, that they were penned by the same hand. Many have questioned these two letters as being genuine Zodiac material, however, there is every reason to consider them as being true Zodiac correspondence based on several factors.
Without knowledge of these 'dubious' letters existence or having seen them in any newspapers, it would be uncanny how the Zodiac Killer would continue the theme of these two letters into the 'Melvin Belli' letter on December 20th 1969, the 'My Name is..' letter on April 20th 1970 and the 'Button' letter mailed on June 26th 1970. In other words, three of his next four communications. Here is the theme running consecutively, starting with the December 7th 1969 letter: 
"I just need help. I will kill again so expect it any time now. The will be a cop. Then I will turn myself in OK. I will kill in SF 3 times (including cops). The one thing I ask of you is this, please help me. Please help me I cannot remain in control for much longer. But there is more glory in killing a cop than a cid because a cop can shoot back. I shot a man sitting in a parked car with a .38".
It is clear from the December 7th and 16th communications the author is threatening 'government life'- most likely the police. In the December 7th 1969 communication the author has supplied a code containing 38 characters, followed by the December 16th 1969 letter threatening another 38 kills including cops, and curiously in his June 26th 1970 'Button' letter, the claim of shooting "a man with a .38." Most likely coincidence, but you never know. 
Here is a forum thread on Zodiac Killer Site with some of the same salient observations, particularly by AK Wilks.
The 38 character December 7th 1969 Fairfield letter (below) has been cleaned up and darkened to make the letter more readable. Not all the code is very clear, so has been interpreted from what we know of the Zodiac Killer's other codes and ciphers (The final line could hold a 'boxy style' C, but has been interpreted as a square. The B on the second line is also questionable).   
"I just need help. I will kill again so expect it any time now. The will be a cop. Then I will Turn myself in    OK."

Was this code a crude attempt at pushing us in the right direction regarding his infamous 340 character cipher mailed just one month earlier. The obvious similarities are there, particularly the first four characters of this code mimicking the opening four characters of the 340 cipher, and the last five characters of each code in both instances. It certainly isn't difficult to spot an inference to 'Zodiac' once again, possibly indicating its importance within the 340 cipher. 
A hoaxer could easily have copied elements of the 340 cipher and incorporated them into, what many believe, a poor imitation of a Zodiac correspondence. But if the Zodiac Killer hadn't seen either of the two Fairfield letters, do we attribute the continuing theme through three of the next four genuine Zodiac correspondences as just sheer luck, referring to "needing help" and his suggestion of "killing a cop."  Additionally, from the 'double event' November 8th/9th 1969 contact, we have effectively been given four ciphers or codes (whether crude or not) in five correspondences. 
These observations may lend more credence to the Fairfield communications, and their rightful place as having been penned by the hand of the Zodiac Killer. 
​THE MESSAGE WITHIN THE FAIRFIELD LETTER