#1. Robert Graysmith on the Presidio Heights shooting "The front passenger side of the cab opened, and eventually the heavyset man got out. He came around the cab, taking with him some sort of rag or towel, and began wiping down the driver's side door, the handle, around the outside mirror and the left passenger side. At one point he opened the driver's side door and leaned forward to wipe off the area of the dashboard again. To steady himself, he leaned his right hand on the rail separating the front and rear windows. Then he closed the door and walked away."

#2.The teenagers who viewed the crime across the street "The suspect then appeared to be wiping on the interior of the cab, leaning over the victim to the driver's compartment. The suspect then exited the cab by the passenger side front door, also wiping with a white rag, possibly a handkerchief. The suspect then walked around the cab to the driver's side and proceeded to wipe the exterior of the left door area. The suspect then fled north on Cherry Street."

#3. The teenagers interviewed at a later date "At this time, Lindsey went downstairs to get a better look at what was happening, while one of the kids upstairs called the police. Downstairs, the lights were off, so Lindsey knew he could not be seen from the outside. He got close to the window and watched his actions. He was shortly joined by Rebecca. They both watched and observed in silence as Zodiac pushed the driver to an upright position behind the steering wheel, exited the car and walked around the rear of the car and opened the drivers door. Stine had fallen over onto the seat and Zodiac pulled him back up into the seated position and had some difficulty keeping him upright. Once upright, he was seen to have a rag, or something like a handkerchief and began to wipe down the door area and leaning over the driver, part of the dashboard. When he was finished, Zodiac calmly walked to Cherry St. and walked north."  Extract from this thread http://www.zodiackillersite.com/viewtopic.php?f=30&t=402​

One thing universal to all three accounts, portray a killer wiping down the area of the driver side compartment.
We have a killer that supposedly murdered Paul Stine at Washington and Cherry from the rear of the taxicab, exited the right rear passenger door, entered the right front passenger door, removed a section of Paul Stine's shirt and left the scene. With this scenario there is absolutely no need for the killer to wipe down the driver side compartment, he would never have come into contact with it. The same applies to a front seat shooting.

Had the murder unfolded as our minds perceive it, then clearly the actions of the killer make little sense. If we use simple supposition, we could conclude the Zodiac wiped the driver area to remove fingerprints, therefore at some time in the night's proceedings he was located in close proximity to the driver side seat and compartment area. The interior view of a Ford Galaxie 500 taxicab shows there is little of significance on the driver side to have been searched from the Zodiac perspective. If he was removing fingerprints, then he had either leaned on the dashboard, touched the shift, or handled the steering wheel at some point in the course of events. But again, he should have been nowhere near this area from the standpoint of a Washington and Cherry murder.

The Zodiac Killer exited the taxicab and headed north on Cherry Street and east on Jackson Street, in what appears an unnecessary route, placing himself at greater risk for two minutes as he traversed Jackson Street parallel to the crime scene.
tt was to prove a near costly mistake, as two responding police officers crossed his path en route. The Zodiac Killer's obvious exit plan would have been to travel directly north, away from the crime scene to a waiting vehicle, or into the park. The Zodiac claimed in his October 13th 1969 letter mailed two days after the murder: "I am the murderer of the taxi driver over by Washington Street and Maple Street last night." Had this been the case, then his actions of traveling east on Jackson Street makes sense to his original true intentions of traveling north on Maple Street after murdering the taxicab driver at this location. He would have been heading toward the region of the Jackson and Maple intersection in both instances. However, circumstances forced a change of plan, which may have necessitated the Zodiac Killer commandeering the vehicle and traveling one block further, resulting in the subsequent unscheduled journey along Jackson Street, to his original destination.  

The Zodiac Killer may well have attempted to lean over the lifeless body of Paul Stine to wipe the driver side area, however, this may not have been his easiest route of access, so rounded the taxicab and entered the driver side door to complete his task of removing fingerprints - supporting himself by placing his right hand on the intersecting panel between front and rear doors, and inadvertently depositing the bloody fingerprints observed by responding personnel.

The claim of the teenage witnesses that the Zodiac Killer opened the driver side door is supported by the location of these fingerprints, deposited onto the dividing panel by the right hand of the killer, using his right hand as a supporting mechanism.
 
The absence of a heard gunshot is often touted as a reason the shooting may have occurred one block earlier at Washington and Maple, although no audible gunshot was described at this location either. The close contact wound to Paul Stine may have suppressed the propellant gases of the firearm, subduing the audible sound levels, or the killer may have attached a suppressor to the gun itself. It can be shown that even guns with suppressors attached can still give a high decibel reading.  
​The log entry of Washington and Maple, the Zodiac's claim of a murder 'over by Washington and Maple', and the taxicab parked askew to the sidewalk, begs the question of who was in control of the taxicab as it approached the Washington and Cherry intersection on the night of October 11th 1969. 

This topic has been covered before, however, on this occasion it will be the most detailed analysis regarding the timeline of the Zodiac Killer, Donald Fouke and Armond Pelissetti from the time they received the 9:58 pm dispatch, to the time the Zodiac Killer disappeared into the night. These time accurate measurements of metric distance will be utilized from Google Maps to discover exactly where the three key players were at any particular point during the night of October 11th 1969. ​What we know is the time of the attack was estimated at 9:55 pm, but both Armond Pelissetti and Donald Fouke received the dispatch at the identical time, approximated at 9:58 pm. Their actions thereafter can be quantified fairly accurately.

Firstly, we will start with Donald Fouke, who was driving his patrol car in the vicinity of Presidio Avenue and Washington Street at 9:58 pm. This is how he described the events of that night: "We were patrolling the eastern side of the Richmond District, going northbound on Presidio Avenue, we had passed Washington Street when a broadcast came in of a shooting at Cherry and Washington Street. As we approached Maple Street I noticed on the north side of the street a white male adult". This gives us a distance to the initial sighting of Zodiac - so all we need now is Donald Fouke's driving speed to work out how much time had elapsed when he made this sighting. Donald Fouke went on to say regarding his speed: "Well until I saw him probably 35 or 40 mph on a 25 mph street".  This is now enough information to calculate fairly accurately how much time had elapsed since the broadcast at 9:58 pm. 

Using Google Maps we need to calculate the distance from the intersection of Presidio Avenue and Washington Street, to the intersection of Jackson and Maple. It is 835 meters or 0.52 miles. Traveling 35 mph is the equivalent of traveling 35 miles in 3,600 seconds. So doing a quick calculation, it takes Donald Fouke 53 seconds to reach this point. So allowing for the intersections he inevitably would have slowed down for, Donald Fouke would arrive at the intersection of Jackson and Maple at approximately 9:59 pm, give or take a few seconds.

At this point Zodiac is approaching the intersection. His traveling distance from the taxicab to this point is 242 meters, at an average walking speed of 3.1 mph, would take him 175 seconds, or just shy of 3 minutes. This proves that at least on one occasion the Zodiac was not lying. In the 'Bus Bomb' letter he mailed on November 9th 1969 he stated "p.s. 2 cops pulled a goof abot 3 min after I left the cab. I was walking down the hill to the park when this cop car pulled up + one of them called me over". The distances and timeline match up perfectly for Donald Fouke and the Zodiac Killer to cross paths at exactly the point of the Jackson and Maple intersection, which both ultimately confirmed. This combined with the matching descriptions of the three teenagers and Donald Fouke, puts it beyond any reasonable doubt this was the Zodiac Killer, no matter what Armond Pelissetti stated in the 2007 documentary 'This is the Zodiac Speaking'.

After the meeting with Zodiac, Donald Fouke stated in the documentary 'This is the Zodiac Speaking' that he continued onward to the next intersection, which was Jackson and Cherry Street, turned south and met Armond Pelissetti, who was traveling up Cherry Street in pursuit of Zodiac. This course of events is actually impossible. The distance to this point in Donald Fouke's journey is 1,000 meters (0.62 miles) - allowing for his claim of briefly slowing down for roughly 10 seconds as he passed the suspect - it takes approximately 80 seconds to reach the upper limits of Cherry Street from the Washington and Presidio Avenue intersection. The time would now be 9:59:20 pm. Remember, Armond Pelissetti received the broadcast at 9:58 pm (the same time as Donald Fouke}. Cherry Street is 100 meters in length, so at an average walking speed, this would take approximately 1 minute to travel in its entirety. That means that if Armond Pelissetti had started his journey up Cherry Street at 9:58 pm, he would meet Donald Fouke at 9:59 pm - 20 seconds quicker than 9:59:20 pm. 

However, Armond Pelissetti only received the broadcast at 9.58 pm. Armond Pelissetti was close by and reacted traveling west on Washington Street and parked at the intersection of Washington and Cherry. He exited his vehicle and noticed three teenagers approaching the scene, so he ushered the kids back across the street to the alcove of their residence. At this point he was of the understanding he was looking for a negro male adult suspect. He went over to the taxicab and observed Paul Stine lying slumped over the front passenger seat with his head resting on the floorboard of the passenger side and was 99.9% certain he was dead. It is then he retook the description of the suspect. In the 2007 'This is the Zodiac Speaking' documentary he stated "it was then I was told it was a white male, I couldn't get to the radio fast enough at that point to let everybody else know. The kids had told me whoever had done this crime had left the cab, went out the door and seemed to be wiping the cab down and reaching into the cab and ambling or walking down Cherry Street in a northerly direction, kind of towards the Presidio. I walked that way myself, I did not run because there are innumerable alcoves and parked cars, so I went down following every technique I knew so I didn't get my head blown off".

There is absolutely no way Armond Pelissetti can respond to a radio broadcast at 9:58 pm, do all of the above, and then travel cautiously up Cherry Street and arrive there at 9:59:20 (in just 80 seconds), to meet up with Donald Fouke. ​This means one or other of the accounts in the documentary 'This is the Zodiac Speaking' is factually incorrect, and it happens to be that of Donald Fouke.

Armond Pelissetti needed a bare minimum of 3 minutes, likely 4 minutes, to reach the upper section of Cherry Street. So if this was where the two officers met up, and it only took Donald Fouke 80 seconds to reach this point, what was Donald Fouke doing for the other 2-3 minutes. The 'Crimes of the Century' documentary in 1989 gives us our first clue. In this documentary Donald Fouke stated;  

"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 explains clearly the missing 2-3 minutes, before Donald Fouke finally returned back to Cherry Street and met up with Armond Pelissetti. He was searching the area of West Pacific Avenue by the park. But what was he doing there? He was supposedly responding to an attack on Paul Stine at the intersection of Washington and Cherry Streets. So why was he heading away from the crime scene. Well, the Zodiac Killer may have an answer in the 'Bus Bomb' letter, where he stated "p.s. 2 cops pulled a goof abot 3 min after I left the cab. I was walking down the hill to the park when this cop car pulled up + one of them called me over + asked if I saw anyone acting suspicious or strange in the last 5 to 10 min + I said yes there was this man who was runnig by waveing a gun & the cops peeled rubber + went around the corner as I directed them + I disappeared into the park a block + a half away never to be seen again".  Why would you be heading in the opposite direction to the crime scene, when a taxicab driver is being assaulted. The answer is - he was directed there by Zodiac - which perfectly explains the missing 2-3 minutes of the timeline.    

Now, Donald Fouke stated "as we arrived at Arguello Street the description of the suspect was changed to a white male adult". This is the update issued by Armond Pelissetti. The distance from the beginning of Donald Fouke's journey to Arguello Street is 1.16 km (0.72 miles). This would take, allowing for slowing down passing Zodiac, approximately 100 seconds (1 minute 40 seconds). That would mean Armond Pelissetti had given the updated broadcast to a white male 100 seconds after receiving the initial broadcast at 9:58 pm. In other words his actions were fairly swift. 

Donald Fouke is now at Arguello Boulevard at 9:59:40. ​If Armond Pelissetti met Donald Fouke at the north edge of Cherry Street, considering we calculated he needed a minimum of 3 minutes to reach this point from the initial broadcast time, then Armond Pelissetti from the time he updated the broadcast at 100 seconds, took 1 minute and 20 seconds to reach the north edge of Cherry. Considering he was proceeding very cautiously, and it takes 1 minute to walk at a normal walking speed, Armond Pelissetti actually only took 20 seconds longer than the average. It also meant Donald Fouke spent 1 minute 20 seconds traveling from Arguello Boulevard, into West Pacific Avenue, and back to Cherry Street, before they met up. This was his cursory search of the Presidio park area from the roadside edge, after being directed there by Zodiac. It is extremely likely Armond Pelissetti needed closer to 4 minutes to reach the top of Cherry Street, thereby allowing Donald Fouke an extra minute to search West Pacific Avenue and the area by Julius Khan playground. 

When Donald Fouke was updated to the white male description at Arguello Boulevard, he, according to statements, traveled along West Pacific Avenue to the area of the Julius Khan Park, which is about one and a half blocks further east of the Jackson and Maple intersection, where he stated he last viewed the Zodiac Killer heading towards. Strange that, because Zodiac stated in the Bus Bomb Letter about an alleged discussion with police, that "I disappeared into the park a block + a half away never to be seen again".

​Crucially however, the timeline of Donald Fouke described above, relied on his version of slowing down and passing Zodiac. Had he, as suspected, called Zodiac from the sidewalk and took his instruction of "yes there was this man who was runnig by waveing a gun", and the Zodiac directed them toward Arguello Boulevard, then his timeline would have been delayed by approximately 20-30 seconds. Nevertheless, the timeline remains perfectly viable, give or take a few seconds. But the bottom line is - had Donald Fouke traveled straight to Cherry Street, as described in the documentary 'This is the Zodiac Speaking', then the whole timeline fails to work - proving it simply didn't happen that way.

The Paul Stine police report contains a few anomalies that appear to contradict the view that Officer Donald Fouke somehow withheld his sighting of the unknown white male, observed walking along Jackson Street minutes after the murder of Paul Stine on October 11th 1969. This is depicted in the 2007 Zodiac movie, with Dave Toschi expressing consternation at the revelation that the two officers (Eric Zelms and Donald Fouke) had spotted the unknown white male, yet had subsequently failed to stop and question him. The sighting by Donald Fouke failed to make it into any newspaper reports in the following months, however, when the Zodiac Killer mailed the 'Bus Bomb' letter on November 9th 1969, stating "2 cops pulled a goof", three days later a typed Donald Fouke memorandum was issued on November 12th 1969 ratifying the sighting.
​
Donald Fouke's description of the likely Zodiac Killer was a "WMA, 35-45 yrs, about 5'10", 180-200 lbs, medium heavy build, barrel chested, medium complexion, light colored hair possibly graying in rear, crew cut, wearing glasses. Dressed in dark blue waist length zipper type jacket (Navy or royal blue). Elastic cuffs and waist band zipped part way up. Brown wool pants pleated type baggy in rear (Rust brown). "  

Now here is the description given by the teenagers who observed the Zodiac Killer in and around the taxicab on Washington Street from a residence across the street. This link is from Zodiackiller.com and details their observations. 
​http://www.zodiackiller.com/Stine.html  
"A white male, 25-30 years old, 5'8" to 5'9", stocky build, reddish-brown hair worn in a crew cut, heavy rimmed glasses and dark clothing."
The second page of the police report was countersigned by Armond Pelissetti and Frank Peda, the first respondents to the crime scene, and was date stamped  6.29 am October 12th 1969. Indicating this typed report was completed only 8 and one half hours after the murder. ​It states this on the second page 
"#2 SUSPECT: WMA, in his early forties, 5'8", heavy build, reddish-blond, crew cut hair. wearing eyeglasses, dark brown trousers, dark (navy blue or black) "Parka" jacket, dark shoes. Suspect should have many blood stains on his person and clothing, suspect may also be in possession of the keys to the Yellow Cab, possibly has wallet belonging to the victim. Last seen walking north on Cherry Street, from Washington Street".
 
So, who furnished this description in the police report. Since the last line stated "last seen walking north on Cherry Street, from Washington Street" and no future sightings of the suspect were mentioned in the report, one would have to assume the description came from the teenagers. However, the description in the police report appears a mesh of both Donald Fouke's description and the three teenagers. The teenagers stated "reddish-brown" hair, yet Donald Fouke in the memorandum stated "light colored" hair - to become "reddish-blond" in the police report. The teenagers recalled dark clothing, Donald Fouke recalled "brown wool pants" and a "zipper jacket" (navy or royal blue). This was meshed in the police report as "dark brown trousers" and the jacket as a "Parka", navy blue or black. Finally, the three teenagers described the suspect as 25-30 years, wildly different to the police report of a man in his "early forties", but much more in line with Donald Fouke's memorandum of 35-45 years. So who provided the information for #2 SUSPECT?

If the police report is describing part of Donald Fouke's description that night, why has he not countersigned the foot of the report, along with Armond Pelissetti and Frank Peda, despite the fact his observations were apparently crucial to the investigation. We know Armond Pelissetti crossed paths with Donald Fouke that night - and it is highly likely that Donald Fouke shared his observations with Armond Pelissetti, but this should not detract from the fact that Donald Fouke should be pivotal to the Paul Stine police report. However, it is clear his description and observations did surface in the police report, either by his own hand or via Armond Pelissetti.

This tends to dispel the notion that Donald Fouke kept the sighting of the white male suspect to himself and from his superiors. It is fairly evident that his commanding officers knew about his encounter with a lone male on Jackson Street by the following day of October 12th 1969. This, furthermore, casts doubt on the police report claim of a suspect "last seen walking north on Cherry Street, from Washington Street."​
The teenagers sketch of the Zodiac Killer was amended, with the second version showing a distinctly more furrowed, older portrayal of the first, and believed to have been revised by the teenagers, however, it is equally conceivable it was updated with input from Donald Fouke's sighting.
 
Thirty-eight years later, Donald Fouke stated in the 2007 documentary 'This is the Zodiac Speaking' "When the composite drawing came out at Richmond Station and was posted on the wall, he looked similar to the man I had seen on October 11th. I then wrote a scratch or inner departmental memorandum to my lieutenant to forward to homicide division, so they would have the additional information about the appearance of the subject." He went on to say "I never spoke to Toschi that I personally know of or remember. He may have been the inspector who came out and asked me about the composite drawing and I told him the suspect was older and heavier, beyond that I had no further contact with the investigation." Despite this statement, there is nothing here that contradicts the notion he most likely informed his superiors of the suspect description the night of the crime.

​Since the suspect in the police report was supposedly last seen heading up Cherry Street, then presumably no input had been typed from the Donald Fouke encounter, as this was distinctly a later sighting. Therefore, we have to explain the discrepancy of the teenagers description of 25-30 years, radically changing to a man in his "early forties" on page 2 of the police report. This description could not be accredited to the three teenagers, unless we conceive the notion that the teenagers had a significant change of opinion, and reconstructed the original composite sketch to an older version with no external influence.        

​The San Francisco Chronicle ran an article on October 21st 1969 entitled 'Lawmen Pool Their Zodiac Clues', continuing the theme that only three eyewitnesses had viewed the killer stating "Meanwhile police circulated a new composite drawing of the "Zodiac" suspect based on further questioning of the three witnesses to Stine's killing. He looks older with a heavier jaw. He is described as being 35-40 years." So, if this reporting is factually correct, the description is at least starting to sound more like Donald Fouke's description.

​But why would Donald Fouke's observations be contained, other than damage limitation, and the embarrassment of letting a suspect slip through their fingers? Despite this, superiors still felt compelled to incorporate his input into the composite sketch to aid in the capture of the killer, which was still foremost in their minds. On the flip side, the police department may have no ulterior motive in containing this encounter, wanting the public and newspapers to concentrate their efforts to apprehending the Zodiac Killer, as opposed to focusing their attention back onto the police department itself.
The Donald Fouke memorandum was deemed a response to Zodiac's revelation of an encounter on Jackson Street, but equally they could have stayed quiet on the matter, simply dismissing Zodiac's claims - and nobody would be any the wiser. After all, Zodiac was deemed a liar and a psychopath by many. 

There is a thread being discussed on Zodiac Killer Site forum entitled Zodiac Minimum Age, for which I will post a link later - but it is attempting to narrow down Zodiac's likely age at the time of the four confirmed Zodiac attacks, along with the Cheri Jo Bates murder. Since the Bates murder in 1966 has yet to be fully incorporated into the Zodiac timeline as a definite Zodiac crime, the following analysis will examine the three confirmed attacks bearing eyewitnesses, along with the Zodiac communications, to narrow down a possible answer on the age of our killer during the years of 1968 and 1969. The following will be a personal opinion and by no means definitive, however, the following will recollect under one banner the relevant eyewitness statements and what they actually stated about their assailant. 

Michael Mageau survived the attack at Blue Rock Springs Park on July 4th/5th 1969.

​It can be said with confidence that Michael Mageau's recall of the events that night are sketchy, often contradicting himself in the police report, nevertheless, his description of the killer is as follows: On page 6 of the police report Michael stated "A white man drove up in a car, got out, walked up to the car, shined flashlight inside and started shooting. Man was older than me". On page 10 of the police report Michael stated "Subject was not blubbery fat, but real beefy, possibly 195-200, or maybe even larger. Stated he had short curly hair, light brown, almost blond. States he just saw subject's face from the profile, side view, and does not recall seeing a front view. Michael reemphasized that he really did not get a good look at subject other than his profile. Stated subject was a white male, approximately 26-30 years". ​It is fair to say, this is understandable, as the killer carried a high-powered flashlight and began firing immediately upon arriving at the passenger side door of the Corvair. 

The Lake Berryessa attack on September 27th 1969.

Bryan Hartnell survived the vicious stabbing at Lake Berryessa, whereas Cecelia Shepard sadly died two days after the attack. Cecelia Shepard saw the assailant unmasked at a distance for a brief period, but during the close quarter interaction with the young couple the Zodiac Killer was masked throughout. Bryan Hartnell's recollections were stated on page 23 of the police report: "Victim thought suspect was possibly 20-30 years of age by voice concept".

The question here, is how reliable is pinpointing somebody's age by the sound of their voice, and probably why a 10-year estimation range is given. Then finally, at Presidio Heights on October 11th 1969, the police got the best descriptions to date, when the Zodiac Killer continued his murderous campaign two weeks later in the heart of San Francisco.  

Paul Stine was murdered in his taxicab on October 11th 1969 at the intersection of Washington and Cherry, and was observed by three teenagers from a property across the road. The murder was logged at 9:55 pm, with the teenagers approximated distance from the taxicab about 50 to 60 feet away from an elevated position. A short time later, Officers Donald Fouke and Eric Zelms were driving along Jackson Street when the Zodiac Killer was spotted by Donald Fouke. Here are the respective parties descriptions of the killer.

The three teenagers were attributed with the description of the killer as "A white male, 25-30 years old, 5'8" to 5'9", stocky build, reddish-brown hair worn in a crew cut, heavy rimmed glasses and dark clothing". Although this conflicts with the description in the police report.

Donald Fouke in his typed memorandum from November 12th 1969 stated he was a "WMA, 35-45 yrs, about 5'10", 180-200 lbs, medium heavy build, barrel chested, medium complexion, light colored hair possibly graying in rear, crew cut, wearing glasses". Donald Fouke corroborated the teenagers sketch of the killer in the 2007 documentary with the addendum that the killer was "likely older and heavier".

Summing up: Michael Mageau viewed what could be described as a fleeting glimpse of the killer, Bryan Hartnell estimated his age range on voice analysis, whereas the three teenagers and Officer Donald Fouke viewed the killer for an extended period. The three teenagers, although affected by distance and street lighting, got an unrestricted view of the murderer for at least 3-5 seconds as the killer exited the taxicab, wiped down the passenger side and headed toward the driver side door. This is the time period where the teenagers got a full frontal, unobscured view of the Zodiac Killer's face.

Officer Donald Fouke on the other hand, stated he observed the suspect as he approached the intersection of Jackson and Maple. He stated in the 2007 This is the Zodiac Speaking documentary, that he "Slowed down as we passed him, we were still rolling, saw that it was a white male, step on the gas, 5, 10, 15 seconds tops from first spotting him to passing him".  Combined, the three teenagers and Officer Donald Fouke got the longest view of the Zodiac Killer by far. The question being, do we place more credence in Officer Donald Fouke's description, being a police officer trained in observation and being distinctly closer to the Zodiac Killer than the three teenagers.   

Let us take the median values of all the eyewitness estimations, Michael Mageau's 26-30 = 28, Bryan Hartnell's 20-30 = 25, the three teenagers 25-30 = 27.5 and Donald Fouke's 35-45 = 40. Combining all these median ages and dividing by 4 we get 28+25+27.5+40 = 120.5 / 4 = approximately 30 years.
If we take only people who actually saw Zodiac, then it is approximately 32 years. If we take the two longer sightings at Presidio Heights then it's 32.5 years. This gives us an age range of 30-33 years of age.

​If we value Officer Donald Fouke's description, being a trained observer, over the three teenagers, then this estimation of 32.5 years would rise. It is important to factor in the time each eyewitness was observing the killer, in association with the distance they observed the killer from. In this respect, Donald Fouke viewed the suspect closer and longer, followed by the teenagers, and then Michael Mageau, who never furnished a sketch of the suspect at the time. If we attribute credibility to the eyewitnesses in this format, then the likelihood is that Officer Donald Fouke's sighting would take top billing and raise the likely age of the Zodiac to the high 30s.
​
It has been speculated that Officer Donald Fouke stopped the Zodiac Killer, based upon him continuing toward Arguello Boulevard rather than turning south into Cherry Street when responding to the crime, The Zodiac claimed he was stopped in the Bus Bomb letter on November 9th 1969, stating "2 cops pulled a goof". Later statements by Officer Armond Pelissetti in the documentary This is the Zodiac Speaking indicated as such. Reported statements of Diane Zelms (wife of Eric Zelms), who Eric allegedly told they stopped the Zodiac that night, along with Donald Fouke's extensive description of the suspect walking on Jackson Street, appeared to suggest Zodiac was questioned that night. If this was the case, then Donald Fouke's eyewitness description of "35-45 years" in accompaniment to the age of "about 40" reported in the October 12th San Francisco Chronicle by other eyewitnesses, would carry far greater weight, placing Zodiac in the median range of 40-41 years of age. If you believe the Zodiac Killer was stopped, then it is more likely the Zodiac Killer is of the higher age range, in direct contradiction to the younger Zodiac suggested by the other eyewitnesses. It is also important to remember that Donald Fouke stated in his memorandum one month after the murder of Paul Stine, that the unknown male on Jackson Street was "possibly graying in the rear", which coupled with a description of a widows peak, may suggest a man at least in his 30s. The average age for a man to start graying is 30-35 years. 

Then we have the Zodiac correspondence and his reference to his victims as "boy" and "girl", suggesting a generational difference, along with his historical references from theatrical influences such as The Mikado (1885) and others. 

The question to be asked, is​ which eyewitnesses do you lend the most credence to? The median values averaged out, suggests the Zodiac Killer was likely 30-33 years of age in 1969. However, I personally tend toward the eyewitness testimony of Officer Donald Fouke, with an estimated range of 35-45 years.
Taking this, and everything else into account, my conclusion is that the Zodiac Killer was approximately 40 years of age in 1969.

THIS ARTICLE HAS BEEN BEEN REEXAMINED IN 2019 TO OFFER GREATER REASONING TO THE ESTIMATED AGE OF 40. THE THREE TEENAGE EYEWITNESSES NEVER STATED THE SUSPECT WAS 25 TO 30 YEARS OF AGE.
THE AGE OF THE ZODIAC WAS 40 IN 69.

To view this topic on Zodiac Killer Site forum visit here.