If you take a look at the Blue Rock Springs parking lot in the police report, it shows the bullet casings (slag) marked to the left of the passenger door, as though the bulk of the casings ejected to the shooter's left. Seven bullet casings were retrieved from this location, with two casings discovered on the back floorboard of the Corvair. This indicates that the killer must have leaned a considerable distance into the Corvair when returning and targetting Michael Mageau for the second time. At this juncture, Darlene Ferrin had been struck three times and Michael Mageau twice, having thrust himself backwards over the rear of the front passenger seat. There is a high probability that a killer leaning into the vehicle and over the front seat to sight Michael Mageau for the final two shots, would receive blood transfer from the vehicle interior onto his short-sleeved blue shirt. If the firearm continued to eject casings laterally, the gun would likely have to be some distance inside the vehicle for two of the casings to remain in the back passenger area of the Corvair. Any blood transfer from the seating to the perpetrator would now be a problem (whether the murderer has a jacket or not). Would a killer now choose to remain in the area 30 minutes longer than necessary in a public setting, seek refuge or place as much distance between himself and the crime scene as conceivably possible?
Law enforcement would very likely have canvassed the area around the Springs and Tuolumne payphone for eyewitnesses to the call, and scoured the near vicinity for any vehicle identified by Michael Mageau. The Zodiac Killer probably used the appeal from Vallejo Police Chief Jack E. Stiltz, who requested the writer to send a further correspondence "with more facts to prove it", as an opportunity to put distance between his residence and the payphone. He sent a correspondence to the San Francisco Examiner on August 4th 1969 with some very useful information to help police. Having never mentioned any of his victims by name, or dwelled on their actual killings, before or since, he was extremely helpful in providing police with a extremely detailed and convenient eyewitness to his payphone call. Not only did this eyewitness see Zodiac make the telephone call, but he was very helpful in providing police with the color of the Zodiac Killer's vehicle. The problem is, the police don't seem to have any recollection of this "shabbily dressed negro male, about 40-45 years of age" in the police report, or in the subsequent 51 years. Despite the fact an admission of his existence and his contact with police, would place him in no jeopardy whatsoever in 2020, there has been no report or spoken word that this negro male ever existed. The over descriptive nature of this helpful eyewitness by Zodiac, seemed designed to convince the reader that Zodiac was driving around in a brown car 40 minutes after the Blue Rock Springs attack.
It is my contention that the purpose of the section of letter highlighted above was primarily designed, not to throw police a curveball about the color of his vehicle, but to sell a story that he was still driving around in his vehicle. Why would a killer still be in this vicinity only 10 minutes from the Blue Rock Springs parking lot, 40 minutes later? Especially if he hadn't distanced himself from numerous pieces of incriminating evidence. The mention of my "car was brown" wasn't designed with the color of his vehicle in mind, it was designed to indicate that an eyewitness had corroborated he was still in possession of his vehicle through the testimony of Michael Mageau. The emphasis was placed on an eyewitness "walking by" to conveniently spot Zodiac as the phone rang, which drew his "attention to me + my car". The Zodiac Killer stated in the August 4th Debut letter, that "When I hung the phone up the damn thing began to ring & that drew his attention to me + my car". The mention of his car in this sentence is not required, other than to convince the reader he was still in tandem with his vehicle and could drive anywhere after the payphone receiver had been hung up. He chose his words carefully, so not to reveal he had walked to the payphone from a residence nearby. A residence he had to travel to immediately after the attack, because of blood transfer to his person from leaning inside the Corvair of Darlene Ferrin. The cries of Michael Mageau may have been his undoing.