Frank Gasser, Robert Connelly and the Your's never reported passing this vehicle on their way to Benicia, after leaving the Marshall Ranch. The only way they could avoid passing this car (if James Owen passed the turnout at 11.14 pm), is if Gasser, Connelly and the Your's had left the Marshall Ranch at approx 11.05 pm at the earliest, to avoid passing this vehicle as it entered Lake Herman Road at 11.07 pm. This vehicle would have reached the Marshall Ranch approx 1 minute 30 seconds after entering Lake Herman Road, putting it passing the Marshall Ranch at 11.08 pm and 30 seconds. So conversely Gasser, Connelly and the Your's would have had to have left after approx 11.09 pm to avoid passing it on the road. Therefore they all had to leave the Marshall Ranch at 11.05 pm or earlier or after 11.09 pm. However I do not recollect any other eyewitnesses other than James Owen mentioning this vehicle and nobody recollects this mystery vehicle driving by the entrance to the Marshall Ranch at just past 11.08 pm, meaning there was nobody present at the Marshall Ranch at this time or they failed to notice it. If this is correct Frank Gasser, Robert Connelly and the Your's must have left the Marshall Ranch at 11.05 pm or earlier, to avoid ever seeing or hearing this unknown vehicle.
The raccoon hunters Robert Connelly and Frank Gasser drove out in their red Ford pick up to Marshall Ranch, located just beyond gate #10 of the Lake Herman pumping station. The pair spent most of the evening near the pump house, approximately 25 feet into the ranch land. The Your's drove to the Marshall Ranch gate, before turning around and heading back to Benicia. Neither party ever mentioned this vehicle.
We know from Officer Daniel Pitta's police report that Stella Borges, who discovered the victims in the turnout, flagged him down about 11.25 pm in Benicia, so calculated the five minute journey back to the crime scene, meant she must have passed the turnout at 11.20 pm. Since James Owen claimed in his statement he saw two cars side by side in the turnout and no bodies, common sense tells us he must have passed the turnout slightly earlier or at the very least several minutes earlier to allow enough time for the Zodiac to have committed the double murder and escaped before the arrival of Stella Borges. This window of opportunity was calculated at six minutes or less. More importantly it would rule out the mystery car and driver as our killer, or would it.
Peggy Your stated "As they were driving west on Lake Herman Road at the turn off to the Benicia Water Pumping Station, she observed a Rambler station wagon parked with front end heading east, there were two Caucasians in the front seat, male and female, when the lights from the car came upon the station wagon, the male sat up in the seat. Mrs Your said it was a cold night and she noticed no frost on the station wagon". A very detailed description. She also stated " the girl was resting her head against his shoulder. When the lights of the car flashed on the Rambler, the subject in the car put his hands on the wheel". However despite James Owen describing the murder victims car as a "1955 or 1956 station wagon, boxy type, neutral color", he could not describe the other car at all, not even the color, even though he purported it was only 3-4 feet away in his second statement. What if these were not the only things James Owen failed to notice. He furthermore told the police "He definitely saw two cars, a station wagon and another vehicle". But how definite was he. For all we know he may well have already passed the Zodiac Killer by the Borges Ranch, heading towards Vallejo.
The unknown driver of this car never came forward as a material witness to the crime, one has to ask why.
Lake Herman Road turnout to Borges Ranch on Google Maps.