#1. On page 6 of the police report it read "White stated at approximately 18.55 hours 9/27/69 he was on routine patrol around the Lake Berryessa area when he received a call from Park Headquarters to proceed to the Rancho Monticello Resort where a person was reporting a possible stabbing. Ronald Fong advised him that he had seen a male and a female victim on the beach area south of Rancho Monticello Resort, hollering that they had been stabbed." link
#2. Bryan Hartnell interview: "There was a boat kept circling around out there in the lake and we started yelling at it and finally it came within about 100 yards of the shore and turned off its motor and stayed there watching us for about 15 minutes." link
#3. "I heard this screaming," said Fong, who has relocated to Washington state but was back in San Francisco last week visiting his family. "I used binoculars to see what was going on. He wanted me to go help him. But I had my 9-year-old son. ... I was close to the boathouse, so I went and told the park rangers." link
#4. "Victim stated he thought suspect had been with the couple for approximately 15 minutes from time of observing suspect until suspect departed." link
The Rancho Monticello Resort is 3.7 miles by road from the Volkswagen Karmann Ghia, 3.2 miles as the crow flies. By boat from the area of the crime scene to dock at the Rancho Monticello Resort is also approximately 3.7 miles.
We shall use these pieces of information to calculate the time of the attack, first of all using the shortest timeline.
Sergeant William White received a call from Park Headquarters regarding the attack and proceeded to the Rancho Monticello Resort at 6.55 pm. Because this time is approximated, we will take 6.55 pm as the time Ronald Fong reported the stabbing at the Rancho Monticello Resort, and assume it was transferred through fairly quickly.
The journey time of Ronald Fong at an estimated 10 mph is 22.2 minutes (22 approx). After docking his boat he traveled by foot to the Rancho Monticello Resort, and allocating little time to the delay in transferring the call to Sergeant William White, this is estimated at 6 minutes. So far, a minimum of 28 minutes has elapsed since Ronald Fong departed the crime scene.
Bryan Hartnell stated that after the attack Ronald Fong had "stayed there watching us for about 15 minutes." This time may have appeared longer than it actually was, but it will remain untouched, because Bryan Hartnell certainly wouldn't have started shouting for help immediately with the Zodiac Killer nearby. This delay in calling for help will be incorporated into the 15 minutes. Keeping these timelines as tight as possible will compensate for the speed of Ronald Fong's boat, had it traveled slightly quicker.
Adding the 15 minutes to the 28 minutes already elapsed, we have 43 minutes to deduct from 6.55 pm (18.55 pm), to tell us when the Zodiac Killer finished his attack on the young couple. This would have been 6.12 pm.
Now let us ramp up the speed of the boat to 20 mph. This would cut his journey time in half, to 11 minutes. Giving us a total time elapsed of 32 minutes, placing the end of the attack at 6.23 pm. Traveling at an unlikely 30 mph, the end of the attack would be 6.27 pm. But having kept the timeline as tight as possible, to allow the 10 mph boat speed, the end of the attack was more likely around 6.12-6.17 pm.
On page 6 of the police report it continued "Sergeant William White stated he proceeded to the Rancho Monticello Resort where a person was reporting a stabbing. Ranger Sgt White, accompanied by Archie White, Mrs Elizabeth White and Ronald Fong, proceeded to the beach area via speedboat owned by Archie White. When they arrived on the beach they observed a young female lying on the ground with what appeared to be numerous stab wounds. White stated he immediately radioed in and had Park Headquarters radio the Sheriff's Office to dispatch an ambulance and deputy."
Deputy Ray Land and Sergeant David Collins were dispatched directly to the crime scene from St Helena and Napa respectively. Sgt David Collins spoke on the documentary 'This is the Zodiac Speaking' "It took us a half hour from Napa and/or St Helena to arrive at the location. And we later found out of course that crime had occurred at least half an hour before we were notified." They were notified at approximately 7.10 pm, which by their statement above would place the crime at around 6.10 pm.
Allowing Sergeant William White 8 minutes from being radioed at 6.55 pm to entering the speedboat and 1 minute to reaching Cecelia Shepard once they arrived at the crime scene and contacting Park Headquarters, who in turn contacted the Sheriff's Office, this affords 6 minutes for the speedboat journey. Or 7 minutes if we tighten the timeline. The speedboat was therefore traveling approximately 30-37 mph. This is the reason they took Archie White's speedboat- it likely accommodated four people and could travel at a far greater speed than Ronald Fong's small fishing boat. Indicating that the 10-20 mph range of Ronald Fong's boat, and more likely the lower end estimate, is likely the correct one.
Bryan Hartnell estimated that "he thought suspect had been with the couple for approximately 15 minutes from time of observing suspect until suspect departed." Therefore, if the end of the attack was 6.12 pm, the Zodiac must have approached the couple at 5.57 pm. The distance from the Volkswagen Karmann Ghia to the crime scene was approximately 510 yards. Allowing for the terrain, and the time for the killer to hide behind the tree and don his costume, it would take approximately 7 minutes. This would have the Zodiac Killer spotting the Volkswagen Karmann Ghia at 5.50 pm, slightly earlier than the anticipated 6.00 pm in the previous article. But allowing for a little flexibility in the timeline and taking the end of the attack at 6.17 pm, would have the killer approaching the Volkswagen Karmann Ghia at 5.55 pm, only five minutes out from the previous article. Had the attack finished at 6.12-6.17 pm, then Zodiac would be writing on the car door at 6.19-6.24 pm.
Keeping a tight timeline, with Ronald Fong's boat traveling between 10-20 mph, the end of the attack on the young couple never would have exceeded 6.23 pm. His small boat was extremely unlikely to have reached anything in excess of this range, and indicates the Zodiac Killer more than likely 'signed' the car door by at least 6:30 pm, or possibly slightly earlier.
The last article theorized Zodiac's vehicle just over a mile north of this location. However, if he had parked by the Volkswagen Karmann Ghia, the Zodiac Killer could have had anywhere from 70-80 minutes for his 40-50 minute journey to the payphone in Napa, indicating he either went off route on the return journey, he stopped or was delayed somewhere, or his vehicle wasn't parked behind the Volkswagen Karmann Ghia of Bryan Hartnell.
But why did Ronald Fong, if he frequented the area regularly, travel 3.7 miles north to the Rancho Monticello Resort for help, when he could have traveled 0.7 miles south, directly to Park Headquarters.
LAKE BERRYESSA- A KILLER'S TIMELINE [PART ONE]