It may open up the possibility that the Zodiac Killer, immediately after the murders, headed west towards Vallejo via Springs Road, as he likely did six and a half months later, after the attack at Blue Rock Springs Park on July 4th 1969. On that occasion the Zodiac Killer made a call from the payphone at the intersection of Springs and Tuolumne, and it may be entirely plausible he also made a phone call after the murders of Betty Lou Jensen and David Faraday, from the exact same payphone, just 12 minutes after the crime.
First we must take another look at the eyewitness timelines.
In the Lake Herman Road police report it was first stated that James Owen passed the turnout at 11.20 pm the night in question, but on the police sketch dated 12/20/68 it was changed to 11.14 pm. It was also noted that James Owen stated he left for work at Humble Oil in Benicia that night at 11.00 pm, but the clock he went by was found to be 6 minutes fast, therefore he left his residence at 10.54 pm.
It is easy to assume this clock discrepancy was factored in, when adjusting his passing the turnout from 11.20 pm to 11.14 pm, but this was not the case. The police report dated 12/24/68, four days after the crime detailed that "Responding officers asked Mr Owen what time he left the house Friday 12/20/68. He stated it was 11.00 pm. He checked the time on the cuckoo clock in the dining room. Responding officers had Mr Owen phone for the time to check the accuracy of the clock." But the police sketch already had him passing the turnout at 11.14 pm. This now had to be corrected, having James Owen passing the turnout at approximately 11.08 pm. It fits perfectly, deducting the 6 minutes from either end of his timeline.
This timeline has James Owen leaving his 1735 Mini Drive, Vallejo residence at 10.54 pm, arriving at the turnout at approximately 11.08 pm. The journey of 14 minutes, bearing in mind he would have encountered no traffic delays on this particular route, holds firm when we look at the nine mile journey estimated by car on Google Maps.
. She stated in the police report "she glanced at the clock in the kitchen and believes it was 11.10 pm." It was calculated by responding officers that she arrived at the turnout 4-5 minutes later. However, her clock was discovered to be one minute fast, indicating she left at 11.09 pm, and thus placed her at the turnout at around 11.14 pm.
. Here however in the police report of Officer Daniel Pitta, it clearly stated he was flagged down by Stella Medeiros at 11.25 pm and arrived at Gate #10 (the turnout) at 11.28 pm.
. This is what Gian Quasar stated on the Quester files "Stella Medeiros must have left her ranch with her mother and daughter. It would only take a few minutes to get to the crime scene. She must have been there at 11:20 p.m. The bodies are visible. No car had passed her going toward Vallejo. She races to Benicia, speeding up to 70 mph. She finds Benicia police before an Enco gas station on East 2nd. The police officers report it was 11:25 p.m."
 Mike Morford of Zodiac Killer Site forum stated "From Pitta’s report, he notes that Borges flagged him down at aprox 11:25 pm. Pitta then raced to the scene arriving there at about 11:28 pm. This is apparently how they established that Borges took 5 minutes to find and make contact with Pitta. They now think that Borges was actually at the scene at 11:20, hence the 6 minute window for zodiac to strike. The police report mentions “the distance was 3.4 miles” from where she found the cops, and the murder scene, and “possibly took her 5 minutes to drive”.
This is how the 11.20 pm timeline for Stella Medeiros passing the turnout was established. But you can see the problem. If you return to  above, it was calculated by these officers that she arrived at the turnout at 11.14 pm, not 11.20 pm.
Had she passed the turnout at 11.20 pm, she would have left the house at approximately 11.15 pm, not 11.09 pm. But the police report stated that "She rode with her mother-in-law and her daughter and drove casually over the 2.7 mile, the distance being established by the officers, and she arrived at the area four or five minutes later. She estimates between 11.14 pm and 11.15 pm. Her clock is one minute fast, as we found out during this interview. She states no cars were going in either direction while she was on the road."
There is also discrepancy to the Borges Ranch, measured by officers at 2.7 miles, but it has been discovered its distance is closer to 1.5 miles, cutting her traveling time to the turnout to 3 minutes. http://zodiackillersite.com/viewtopic. Here is a close up view of the ranch on Lake Herman Road.
As with many aspects of the Zodiac Killer case nothing is quite as simple as it should be, but the fact "she glanced at the clock in the kitchen and believes it was 11.10 pm," coupled with the less than clear measurements detailed by the officers, I am inclined to go with backtracking from her meeting with Officer Daniel Pitta, placing her at the turnout at 11.20 pm. This would open up the very narrow window of 6 minutes Zodiac had to commit the crime to 12 minutes. James Owen passes the turnout at 11.08 pm and Stella Medeiros passes the turnout at 11.20 pm. Indicating she likely left her residence 1.5 miles east on Lake Herman Road at approximately 11.17 pm for the three minute journey.
James Owen viewed two vehicles side by side in the turnout, stating that approximately one quarter of a mile past the turnout
(30 seconds), he thought he heard a shot. Since James Owen passed the turnout at 11.08 pm, this may suggest the beginning of the attack on Betty Lou Jensen and David Faraday at 11.08:30 pm, with the Zodiac killer exiting the crime scene by 11.09 pm or 11.10 pm. The murderer exits the turnout and now could conceivably head off in the direction of Vallejo. The Zodiac Killer would comfortably have passed the Borges Ranch before Stella Medeiros exited her driveway at 11.17 pm, confirming her statement to police that she never passed any vehicles that night.
Initially, they were told a woman was lying outside a car; they thought they were being sent to a crash. Police at first speculated it might have been a crank call, but the officers headed back north. But when they arrived, Bidou realized it was no crank call and no car accident. Instead, it was a sinister crime scene."
When Stella Medeiros observed the crime scene at 11.20 pm, she raced off to seek help in Benicia, eventually locating Officer Daniel Pitta at the Enco Gas Station on East 2nd Street. This is 3.4 miles from the turnout, an estimated journey time of 5 minutes on Google Maps. She is obviously driving faster than normal and flags down Daniel Pitta probably slightly shy of 11.25 pm, allowing her to give her account and for Officer Daniel Pitta to head to the crime scene by 11.28 pm. In the course of this, the information would have been relayed to Benicia Police Department.
So where did the supposition of a crank call or a car accident originate from. The description given by Stella Medeiros may have been interpreted as a car crash originally and relayed this way, but why would a radio message from an officer of the law be interpreted as a crank call. Betty Lou Jensen and David Faraday are lying prostrate in the turnout, whether a crash or not, why would Pierre Bidou be under any illusion of a crank call, unless a payphone call had come in slightly earlier than the radio message from Daniel Pitta. The Zodiac Killer made phone calls after both his subsequent attacks, why not this one. The only difference being, he called it in as a car accident, unwilling to show his hand as the murderer.
Had the Zodiac Killer left the turnout and headed to Vallejo via Springs Road, his journey time to the payphone at the intersection of Springs and Tuolumne would be approximately 12 minutes, placing the call at 11.22 pm, just prior to Stella Borges' meeting with Officer Daniel Pitta at 11.25 pm, and his radio message, possibly leading to the uncertainty experienced by Pierre Bidou. The Zodiac Killer could equally have placed a call from Benicia.
In 1986 a letter arrived at the San Francisco Chronicle, believed by some to be a hoax Zodiac letter. The crime it details is eerily similar to the first two Zodiac attacks.
Koy Ien Saechao and Choy Fow Salee were shot in their car by the side of a Sacramento freeway on April 22nd 1986. The Laotian couple were shot multiple times from close range. Both front side windows were blown out, with 15 shell casings strewn around the vehicle.
Minutes after the crime, a hitchhiker flagged down a patrolman and directed him to the crime scene, as Zodiac had done via payphone subsequent to Blue Rock Springs Park and Lake Berryessa, however on this occasion the hitchhiker directed them to what he called a "road accident." The hitchhiker was never traced. Could the Zodiac Killer have done exactly the same at Lake Herman Road, directing police to what he described as a "road accident," explaining why police were under the illusion it was a car crash and had "first suspected it was a crank call," having not arrived through official police channels.
The Zodiac Killer laid claim to his crimes after 40 minutes, 70 minutes and 2 days. At Lake Herman Road it took 6 1/2 months, in which he belatedly claimed the murders of Betty Lou Jensen and David Faraday. Or did it take just 12 minutes, but nobody recognized his 'game'.
In a case where official lines of investigation have effectively ground to a halt, the search for a game changer in finding the Zodiac Killer's identity, has become an almost impossible task. If, and it's a big if, that the Zodiac Killer headed to the same payphone twice, bearing in mind the forty unexplained minutes after Blue Rock Springs attack, and his directional movements after Lake Berryessa, it may be wise to concentrate the search back to the heart of Vallejo once again.