The crime was committed nearly half a century ago, so their movements on December 20th 1968 is wholly reliant on eyewitness testimony. Without knowing the mindset of the individuals involved, I will not discredit any of the reported sightings of the couple that evening, but will err on the side of statements, police reports, newspaper or magazine articles that corroborate the same narrative.
The police report stated that 'Betty Lou brought David home to her parents at 8.00 pm on the 20th. There he met her parents and they left with their permission to go to Hogan High School and then to a party afterwards. They were to be home sometime around 11.00 pm.' A magazine article, whether accurate or not added a little more 'At the Jensen house Betty Lou invited David in to meet her parents. The four of them chatted for about 20 minutes, then David nervously looked at his watch and announced that they would miss the 8.30 pm concert if they did not leave soon.'
David Faraday and Betty Lou Jensen were clearly not in a rush to get to the concert by 8.30 pm, as they had gone to Sharon's. But where did they go after leaving 926 Brentwood Avenue at 9.00 pm.
It is here we will go with the preponderance of evidence, as opposed to the Robert Graysmith account in his first Zodiac book. In it he described the couple 'having a Coke at Mr Ed's, a local drive-in,' before immediately heading off towards the Lake Herman Road turnout. In 'Zodiac Unmasked' Robert Graysmith wrote 'Betty Lou and David had stopped at Mr Ed's too (referring to Mageau/Ferrin) just before being shot. The teenagers had visited their friend Sharon on Brentwood Avenue at 8.20 pm, and remained until 9.00 pm. At 10.30 pm their Christmas concert was over and they went from there to Mr Ed's, then Lake Herman Road.' Well, if they had left the concert at 10.30 pm, traveled to Mr Ed's, bought a couple of drinks, then traveled to the Lake Herman Road turnout, which took approximately 15 minutes, the couple couldn't have been spotted by Helen Axe and her boyfriend in the turnout at 10.15 pm. In Robert Graysmith's original book he contradicts himself saying 'just before 10.15 pm, David pulled off the road to the right, and parked 15 feet off it, facing south, in the graveled area outside gate #10. At 10.15 pm a woman and her boyfriend, a sailor, drove by. When they reached the end of the road and came back past fifteen minutes later, the car (Faraday Rambler) was still there.'
You cannot have it both ways. Robert Graysmith additionally inferred it was a coincidence that Mageau and Ferrin had stopped at Mr Ed's also, which they didn't.
Unfortunately there is no corroborating evidence from any reports or eyewitnesses that place the couple at Mr Ed's diner that evening, however there are many other alleged sightings and reports that place them at the Hogan High School concert. One such sighting would indicate that they left Hogan High School and traveled directly to Lake Herman Road, a journey that took approximately 15 minutes by car.
#1 'During his many hours of investigation (Les Lunblad), the graying veteran detective sergeant learned the terrible murders on Lake Herman were the tragic end of a first date for the young couple. They had attended a pre-Christmas concert and chorale at Vallejo's Hogan High School, where pretty Betty Lou had been a student. The couple had left the school auditorium at 10.00 pm, bidding goodnight to their school chums.' The next sighting of the couple was approximately 10.15 pm by Helen Axe and her boyfriend in the Lake Herman Road turnout, which is a 13-15 minute car drive from Hogan High. The time given when they left the auditorium indicates their decision to head straight to the lovers lane turnout. This being the case, they couldn't have left Mr Ed's and headed straight to the turnout, as stated in Robert Graysmith's book.
#2 'At the concert, classmates of Betty Lou noticed the couple sitting side by side in the gymnasium bleachers (retractable seats), holding hands. Nobody remembers seeing them after they left the concert.'
#3 Les Lunblad in the December 22nd 1968 Sunday Examiner and Chronicle: 'Detective Sgt Les Lunblad, the graying, husky officer in charge of the investigation said there was a distinct possibility the young couple had been trailed to the murder scene from the pre-Christmas concert in Vallejo.'
#4 Sunday Times Herald: 'Authorities said the couple, David Faraday (17) and Miss Betty Lou Jensen (16), had driven to the reservoir after attending a Friday night concert at Hogan High School here, where Miss Jensen was a junior.'
It is therefore extremely likely that Les Lunblad would have checked on their whereabouts prior to the murder, discovering they had attended the concert that evening, and somewhere the couple had expressly said they were going to, while at Betty Lou's parents house.
In the police report we have William Crow in and around the Lake Herman Road turnout between 9.30 pm and 10.00 pm and no mention of the Faraday Rambler, but by 10.15 pm it is spotted by Helen Axe and boyfriend. This ties in perfectly with David Faraday and Betty Lou Jensen leaving the school auditorium at 10.00 pm in pursuit of a romantic trip to the scenic Lake Herman Road setting.
He had therefore spent 70 cents from 7.30 pm to 10.15 pm. This is important to consider when we postulate his movements during the relevant time. Did he buy any food or drink at Mr Ed's or Hogan High School, or en route to either. There are two viable alternatives.
This was David Faraday's first date with Betty Lou Jensen and no doubt was keen to impress. He had borrowed his parents vehicle, so he may have filled up with gas out of courtesy or instruction, or he may have popped into a local store to make a purchase prior to his meeting with Betty Lou. The police report on page 2 details that a bottle of Binaca breath drops were found on David Faraday. Something you may buy especially for such an occasion. A cursory search of 1968/69 advertisements shows Binaca breath drops came in varying sizes, with the price in general varying from 60 cents to 1 dollar.
These two options may account for the 'missing' 70 cents, as opposed to a trip to Mr Ed's diner, for which we have no corroborating eyewitness testimony.
However, it is extremely likely through several eyewitnesses of 'classmates of Betty Lou noticing the couple sitting side by side in the gymnasium bleachers' and 'leaving the school auditorium at 10.00 pm', that indeed the couple had attended the concert and had driven directly to the Lake Herman Road turnout, where they were spotted by Helen Axe at 10.15 pm. But being trailed there, as Les Lunblad had initially conjectured remains unlikely, as the murders were still an hour in the making.
In the aftermath of the second Zodiac attack Michael Mageau stated in the police report 'they drove west on Springs Road and as they were driving down Springs Road to go get something to eat, Dea stated to him that she wanted to talk to him about something. Michael stated that approximately at the location of Mr Ed's on Springs Road they turned around and headed east at his suggestion to go to Blue Rock Springs Park.'
It appears that neither couple, on December 20th 1968 or July 4th 1969, went to Mr Ed's. Had they done so, things may have turned out very differently, but we will never know.