His identification has been challenged, as possibly being a different subject, based on differences in weight, hair color and age compared the the description given by the teenagers. However, there are also similarities in the description. The timeline of a subject leaving the taxicab at a normal walking speed of 3.1 mph, traveling north on Cherry St and east on Jackson St, matches perfectly with the sighting of Donald Fouke's timeline from when he received the first police broadcast. In addition, Zodiac specifically highlighted in his 'Bus Bomb' correspondence on November 9th 1969 that he ran into two cops who "pulled a goof." The movement of the patrol car occupied by Donald Fouke and Eric Zelms was never disclosed in the newspapers, but was known to the letter writer, and the timeline fits perfectly.
Although people point to discrepancies in the eyewitness identification, what we do know is that the initial sketch of the suspect was given by the three teenagers recollection - and at no time to my knowledge did Donald Fouke view this sketch and state that this wasn't the man he observed. The facial features in the second sketch were virtually identical to the original, only marginally older. If Donald Fouke had spotted a totally different subject, he would surely have said so.
Donald Fouke, in his original statement, stated he saw the subject turn into the northern section of Maple Street, however, there is no direct access from here into the park without negotiating bushes and a retaining wall, which at night may have appeared a dead end to the murderer. This drives to the heart of the killer's knowledge of the area. He may well have known the area fairly well - but to anybody other than the occupants of the residence at the top of Maple Street - why should the responsible be aware of a possible route through, when to all intense and purpose, the area looks like a blind alley. The Zodiac may simply have turned into Maple as a ruse to get out of sight, before continuing on down Jackson Street.
If the Zodiac disappeared into the park one and a half blocks from his 'meeting' with Donald Fouke, he would then arrive at Spruce Street at approximately 10.01 pm. For Zodiac, the journey eastwards to Spruce Street from just past the intersection of Jackson and Maple Street is 180 meters (0.112 miles), so if we assume he picked up his walking speed to 4 mph after giving Donald Fouke and Eric Zelms the runaround, he would arrive somewhere in the vicinity of the Jackson and Spruce intersection in 1 minute 45 seconds. The time would be approaching 10.01 pm. This is where the October 12th 1969 San Francisco Chronicle article makes perfect sense from the standpoint of our third set of eyewitnesses. They describe a man with traits very similar to the characteristics described by Donald Fouke - a man about 40 years, with a blond crew-cut, wearing glasses, with dark clothing. It was 10.01 pm at night, with curtains likely drawn, so how did it come about that 'neighbors' described by Robert Graysmith in his book, noticed the suspect man and were able to give a fairly detailed description? We probably have Donald Fouke to thank for that.
If we go on memory, then what Donald Fouke stated in the 1989 'Crime of the Century' documentary is likely more accurate than his differing claims in the 2007 Zodiac documentary. In the 1989 documentary, he said after passing the subject on Jackson St: "We proceeded on Jackson Street towards Arguello continuing our search, as we arrived at Arguello Street the description of the suspect was changed to a white male adult, believing this suspect was possibly the one involved in the shooting we entered the Presidio of San Francisco and conducted a search on West Pacific Avenue, the opposite side of the wall and the last direction we observed the suspect going, we did not find the suspect."
This tends to give credence to Zodiac's claims that he spoke to and directed the police - bearing in mind Donald Fouke was traveling towards Arguello Boulevard and away from a crime scene he should have been approaching. When he received the update to a white male, he naturally may have realized the man he had just encountered may have been the killer. Having last seen the subject enter the top part of Maple, it is understandable that he would have believed the man may have entered the Presidio park over the retaining wall. After passing Zodiac, the journey westwards for Donald Fouke to Arguello Boulevard and eastwards along West Pacific Avenue to Julius Khan playground is 810 meters (1/2 mile), taking approximately 1 minute traveling at 30 mph. However, he is obviously scouring the roadway and dense undergrowth bordering West Pacific Avenue, so his journey time to Julius Khan Playground likely took nearer to 90 seconds. This places Donald Fouke's patrol car, red light and siren, reaching the area adjacent to Spruce Street at 10.00:30 pm - just slightly before Zodiac also arrives at Spruce Street. At this point Donald Fouke finds nothing, but his patrol car has ultimately alerted the neighbors, who understandably have looked out of their windows in the area of Spruce Street. Donald Fouke begins to turn his vehicle around as Zodiac approaches (who obviously remains out of sight until Donald Fouke departs back up West Pacific Avenue). Zodiac then makes haste into the park to gain some cover from the upcoming police search. What he doesn't realize though, is that the neighbors are still looking out of their windows and notice Zodiac as he makes haste into the park. Their description is the one given in the October 12th 1969 San Francisco Chronicle article.
Richardson Avenue is situated right by Highway 101, and provides easy access to the Golden Gate Bridge back to the Vallejo area, forming an immediate separation from San Francisco within minutes of the crime.
However, Zodiac is still by Julius Khan playground, therefore his next move eastwards is telling. He describes this in the November 9th 1969 'Bus Bomb' letter, stating "I enjoy needling the blue pigs. Hey blue pig I was in the park -- you were useing fire trucks to mask the sound of your cruzeing prowl cars. The dogs never came with in 2 blocks of me, they were to the west". This suggests the Zodiac was likely just over two blocks east of Julius Khan playground. We know this because the sniffer dogs had assembled at this location, as well as Arguello Boulevard, to sweep across the park in dragnet style. The Zodiac Killer had only one option to avoid capture - head east. Fortunately for him, he had already taken this option. The journey time by road to the mid-section of Laurel and Walnut Street (just over 2 blocks) is approximately 5 minutes, likely nearer 6 minutes via the park. His next point of cover is shown by the map here, situated by dense undergrowth. The time is now 10.07 pm, and the motorcycles and police cars are circling the park. He may at this point have been intending to ride it out until the coast was clear, but he likely hadn't banked on the sniffer dogs being deployed at around 10.10 pm, as detailed in the police report. Faced with reducing options the Zodiac Killer continued eastwards through the undergrowth towards Presidio Boulevard, shown here on the map.
The Zodiac Killer made this apparent only two days after the crime, on October 13th 1969, when he mailed the first Stine letter: "The S.F. Police could have caught me last night if they had searched the park properly instead of holding road races with their motorcicles seeing who could make the most noise. The car drivers should have just parked their cars and sat there quietly waiting for me to come out of cover". That cover was probably on the south-eastern corner of the park. The Zodiac Killer waited for his opportunity until the coast was clear and made good his escape shortly after 10.15 pm. If his vehicle is parked somewhere near to Highway 101 in Cow Hollow, then he is across the Golden Gate Bridge in as little as 8 minutes. His escape is complete.