The caller from the payphone issued his declaration "I want to report a murder, no, a double murder. They are two miles north of Park Headquarters. They were in a white Volkswagen Karmann Ghia" and after a brief pause uttered the words "I'm the one that did it".
Strikingly similar in composition to the Blue Rock Springs phone call nearly three months earlier, where the murderer issued the words "I wish to report a double murder. If you will go one mile east on Columbus Parkway to a public park, you will find the kids in a brown car. They have been shot by a 9 mm Luger. I also killed those kids last year.... Good-bye." It has been suggested in certain quarters that the caller in the aftermath of Lake Berryessa may have been a hoaxer, having scanned police frequencies and delivered the message, yet it wasn't the actual killer. However at 7.40 pm when the call was phoned in, the police were at this point unaware it was a Zodiac crime, having not yet examined the footprints and Karmann Ghia door. They were still by the shoreline tending to the victims, after all this was their main priority at this point. The question therefore, is how could the killer and the caller be separate people, without first hand knowledge of the crime as a Zodiac crime, suggested by the near identically structured message. The fact of the matter, is that the caller would be implying a Zodiac crime, even though nobody else has yet discovered it is. This suggests strongly that the killer and payphone caller are one and the same person, especially considering the time of the attack, the distance to downtown Napa and the time of the call, not to mention his direction of travel appears southwards toward Vallejo. This similar to his direction of travel from Blue Rock Springs Park to the Springs and Tuolumne intersection, in a westerly direction toward Vallejo once again.
The roadway observations occurred after 8.00 pm, once the ambulance had departed the scene, making any Zodiac styled payphone message at 7.40 pm, to be incontrovertibly linked back to the crime scene, and one perpetrator of the crime and call.