It's no big secret now that I have long suspected it was actually Armond Pelissetti, and not Donald Fouke, who stopped and spoke with Zodiac. Or to be a tad more specific, 'Called him over to them.'
Don has always adamantly denied he neither stopped a suspect that night, nor spoke with him declaring "That is an emphatic statement by me! I wouldn't make the denial" and went on to state quite passionately "We DID NOT stop the Zodiac! We didn't stop anyone! I wish Eric Zelms were alive today to tell you so." Armond Pelissetti has claimed that Don told him that He had stopped someone that night, but not on the night itself but rather, 'In subsequent conversations with him.'
Don consistently denies speaking to a suspect, or in fact, anyone in the vicinity at all that night. Armond, on the other hand, freely and openly admits that it was he who encountered a White Guy saying "I asked that Gentleman had he seen anybody in the area and he told me 'No.' Well hold on, wasn't that kinda the same question that Zodiac wrote a cop had asked him that night, too? "This cop car pulled up and one of them called me over and asked had I seen anyone acting suspicious or strange.?"
Fouke doesn't respond to the initial radio broadcast that Armond does, Fouke responds to a broadcast that can only have been issued AFTER Armond has arrived and assessed the scene because Armond, as previously stated, responds to 'Cab Driver being robbed and/or possibly assaulted" whereas Don Fouke states He responded after "A call came in of a shooting at Washington and Cherry Streets." There is absolutely no way anybody can know, bar Zodiac himself, that Paul had been shot in the cab, not until Armond arrives on scene and inspects the scene and body.
This would also explain the need for the cop to 'Call me over' as Zodiac proclaimed. If it's Don encountering and speaking with the Suspect, both Don and 'The Suspect' are on the North side of the street. All he has to do is roll up right next to him. If your coming down the hill in a vehicle, your now on the other side of the street to the 'White Guy' and would need to stop and, as Zodiac said, Call him over to them.