Before the advent of the Rigel software system, utilizing the geographic profiling techniques of criminologist Dr. Kim Rossmo, a rudimentary form of geographic profiling was used by Stuart Kine before the capture of the Yorkshire Ripper, Peter Sutcliffe. This is mentioned by Dr. Kim Rossmo in a 1998 NCIS Conference, stating "I’m sure people in this room are familiar with this case. This is an example of an investigation going awry because of geography. The tape that was sent to the investigators from someone claiming to be the Yorkshire Ripper led to analysis of the accents, they felt there was a Geordie accent, the person was from the Sunderland area, and they focused on that part of England which was about a hundred miles away from where the crimes were occurring. That was wrong. Sutcliffe lived close to the area. Interesting, and I’m not sure how many people are aware of it, but shortly before Sutcliffe’s arrest through work by some patrol officers, a Home Office scientist by the name of Stuart Kine did a sort of basic geographic analysis of the crimes and was quite successful as it turned out in his predictions". He was in fact very accurate, bearing in mind the size of the killing field - and by literally sticking pins in a map - highlighted an area somewhere by Shipley, only 6 miles from the 6 Garden Lane, Bradford address of Peter Sutcliffe. View geoprofile.
Covered extensively in previous articles, had the Zodiac Killer worked a conventional Monday to Friday, 9 to 5 profession and had lived in the Vallejo area at the time of his murders, we would expect to see his first two Friday attacks relatively close to his home base. Unconstrained by time on Saturday, the Zodiac Killer would be able to venture further afield for his attacks - which is exactly what happened. However, we now have another tool in our arsenal, highlighted in this short but informative video by BCU professor Craig Jackson. Here is a small extract: "Wherever the Yorkshire Ripper was based, the time of his murders would be a vital clue to where he lived. So, if one of the Yorkshire Ripper's victims was murdered in the early evening, 8 o' clock or 9 o' clock at night, that individual could be based very far away from where the Yorkshire Ripper's base was. But if the victim was murdered in the very small hours, midnight, or one or two in the morning, that victim would probably be very close to where the Ripper's base was, assuming that the Ripper would have to be home at a reasonable time to be with their partner or families, or friends who they lived with". The type of victim targeted, the areas they frequented and their availability also has to be factored into the target backcloth. Therefore, we will use the Zodiac Killer's four attacks and see if they conform to a home base in Vallejo.
Covered extensively in previous articles, had the Zodiac Killer worked a conventional Monday to Friday, 9 to 5 profession and had lived in the Vallejo area at the time of his murders, we would expect to see his first two Friday attacks relatively close to his home base. Unconstrained by time on Saturday, the Zodiac Killer would be able to venture further afield for his attacks - which is exactly what happened. However, we now have another tool in our arsenal, highlighted in this short but informative video by BCU professor Craig Jackson. Here is a small extract: "Wherever the Yorkshire Ripper was based, the time of his murders would be a vital clue to where he lived. So, if one of the Yorkshire Ripper's victims was murdered in the early evening, 8 o' clock or 9 o' clock at night, that individual could be based very far away from where the Yorkshire Ripper's base was. But if the victim was murdered in the very small hours, midnight, or one or two in the morning, that victim would probably be very close to where the Ripper's base was, assuming that the Ripper would have to be home at a reasonable time to be with their partner or families, or friends who they lived with". The type of victim targeted, the areas they frequented and their availability also has to be factored into the target backcloth. Therefore, we will use the Zodiac Killer's four attacks and see if they conform to a home base in Vallejo.
If the Zodiac had left his house to search for victims on a Friday in the area of Columbus Parkway and Lake Herman Road, then he likely had a knowledge that young courting couples or lone individuals may be found in these remote locations. He has a mental map of the area and an optimal time he would like to return to his residence - but he knows that this sort of victim targeting is unreliable. Sometimes the opportunity may present itself immediately, while other times he may have to do several passes before a suitable target or targets appear. He has to factor this into his thinking when leaving his residence. In other words, if he wants to arrive home no later than 12:15 am, he has to allow for this when leaving his residence. In respect to Lake Herman Road and Blue Rock Springs Park, he could have left his residence at 10:00 pm to allow for this "hit and miss" technique of trawling the eastern edge of Vallejo. This may have accounted for the earlier suspicious sightings on December 20th 1968, prior to the eventual double murder of David Faraday and Betty Lou Jensen.
If we apply the model of professor Craig Jackson to our killer, then an attack at approximately 11:15 pm at Lake Herman Road and midnight at Blue Rock Springs Park, would suggest a killer who lived close by and was aiming to return home sometime in the late evening to early morning hours. If the Zodiac Killer had lived near to the Springs Road and Tuolumne Street payphone, he would have arrived home at around 11:30 pm on 12/20/68, and 12:15 am on 07/04/69. The Zodiac Killer's attack at Presidio Heights would not have been affected by a "hit and miss" targeting technique. Had the murder of taxicab driver Paul Stine been planned ahead of time, he would know where he was to find his victim, where he was going to murder the taxicab driver and where his escape route lay before him - including his journey time back to Vallejo. Paul Stine was murdered shortly before 10:00 pm on 10/11/69. The Zodiac Killer (had he parked his vehicle near the Presidio Park) would have about 5-15 minutes of walk time, followed by a 50 to 60 minute journey home via the Golden Gate Bridge. At the latest, he would arrive home at approximately 11:15 pm. Therefore, his window of time to arrive back at his residence after three of his attacks, would fall within one hour of each other (between 11:15 pm and 12:15am) - although it may be slightly more.
If we apply the model of professor Craig Jackson to our killer, then an attack at approximately 11:15 pm at Lake Herman Road and midnight at Blue Rock Springs Park, would suggest a killer who lived close by and was aiming to return home sometime in the late evening to early morning hours. If the Zodiac Killer had lived near to the Springs Road and Tuolumne Street payphone, he would have arrived home at around 11:30 pm on 12/20/68, and 12:15 am on 07/04/69. The Zodiac Killer's attack at Presidio Heights would not have been affected by a "hit and miss" targeting technique. Had the murder of taxicab driver Paul Stine been planned ahead of time, he would know where he was to find his victim, where he was going to murder the taxicab driver and where his escape route lay before him - including his journey time back to Vallejo. Paul Stine was murdered shortly before 10:00 pm on 10/11/69. The Zodiac Killer (had he parked his vehicle near the Presidio Park) would have about 5-15 minutes of walk time, followed by a 50 to 60 minute journey home via the Golden Gate Bridge. At the latest, he would arrive home at approximately 11:15 pm. Therefore, his window of time to arrive back at his residence after three of his attacks, would fall within one hour of each other (between 11:15 pm and 12:15am) - although it may be slightly more.
The Lake Berrryessa crime is altogether different. If we believe that the Zodiac Killer targeted areas he was familiar with, then he knew that the outskirts of eastern Vallejo, in the secluded areas of Lake Herman Road and Blue Rock Springs during the weekend or holiday season, was likely rich pickings for courting "couples" or "stray people" in the night. The sheer fact he wrote about killing "over a dozen people" at the weekend, showed an element of confidence in these surroundings, despite the obvious braggadocio displayed.
The Presidio Heights area must also have been familiar to him, to risk such an audacious attack in a built-up area of San Francisco. Dr. Kim Rossmo summed it up perfectly: "The San Francisco murder differs significantly from the Zodiac's other crimes. Up to this point he was hunting in locations that had a good probability of containing his desired victims. Target selection was a function of area, not of an individual. However, it is unlikely the Zodiac was successful in all his searches; serial killers typically engage in extensive hunting activities, and for every attack there are many unsuccessful search attempts. In San Francisco, however, the Zodiac controlled the situation through his selection of victim type. The need for such control could be indicative of the distance the Zodiac had to travel to the crime site. Criminals who travel longer distances to offend are less likely to use uncertain target selection techniques".
His familiarity with Lake Berryessa (09/27/69) was also obvious. The Zodiac Killer knew on this occasion that a targeted attack in the late evening hours (close to midnight), similar to Lake Herman Road and Blue Rock Springs Park, was wholly uncertain with respect to finding a suitable victim or victims in this location. But he knew that a late afternoon or early evening attack within the expanse of Lake Berryessa, would be the safest bet, The location, on this occasion, effectively governed the earlier attack time. When this constraint was unburdened during his first, second and fourth attacks (assuming he lived in Vallejo and went directly home), his arrival time to his residence would have always fell within a 60-75 minute window of time. If the Zodiac Killer had a preconceived time he wanted to return home by, then Vallejo by the payphone was a perfect fit for a good night's sleep - as well as not arousing suspicion - had he been married (with children).
The Presidio Heights area must also have been familiar to him, to risk such an audacious attack in a built-up area of San Francisco. Dr. Kim Rossmo summed it up perfectly: "The San Francisco murder differs significantly from the Zodiac's other crimes. Up to this point he was hunting in locations that had a good probability of containing his desired victims. Target selection was a function of area, not of an individual. However, it is unlikely the Zodiac was successful in all his searches; serial killers typically engage in extensive hunting activities, and for every attack there are many unsuccessful search attempts. In San Francisco, however, the Zodiac controlled the situation through his selection of victim type. The need for such control could be indicative of the distance the Zodiac had to travel to the crime site. Criminals who travel longer distances to offend are less likely to use uncertain target selection techniques".
His familiarity with Lake Berryessa (09/27/69) was also obvious. The Zodiac Killer knew on this occasion that a targeted attack in the late evening hours (close to midnight), similar to Lake Herman Road and Blue Rock Springs Park, was wholly uncertain with respect to finding a suitable victim or victims in this location. But he knew that a late afternoon or early evening attack within the expanse of Lake Berryessa, would be the safest bet, The location, on this occasion, effectively governed the earlier attack time. When this constraint was unburdened during his first, second and fourth attacks (assuming he lived in Vallejo and went directly home), his arrival time to his residence would have always fell within a 60-75 minute window of time. If the Zodiac Killer had a preconceived time he wanted to return home by, then Vallejo by the payphone was a perfect fit for a good night's sleep - as well as not arousing suspicion - had he been married (with children).
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