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  • #61
    Originally posted by erobitha View Post

    This is all very interesting stuff Jeff. Correct me if I misunderstood, am I thinking that the dragnet approach has been ther most accurate against the crimes you have checked thus far, providing the data points are accurate? Is there sense of using last known location / pick-up points instead of murder scene locations as that may have been the victim's choice? Would that make much difference? Is the liklihood the killer engaged with the victims closer to where they were last seen alive as opposed to found dead is my point?

    If we use the Ireland and MacArthur examples of pubs, would one not assume such an establishment could be the anchor point here too? For example, The Ten Bells actually would fit quite snugly.
    Hi erobitha,

    Over all the cases I have there's no real difference in performance between the different routines, so which routine does best for any given case one doesn't know until you try them all and compare. One of the things I'm thinking of is trying to see if there is something one can calculate from the offense pattern that suggests which routine should do best. I have to sort a bunch of series first, and see if there's anything obvious, but I always keep my eye out for any hints. In all likelihood, if I were to go through all the cases I have where I have information on "location last seen", it will end up all 3 do equally well over all. It may just be these two examples where it happens to be Dragnet that comes out on top. But one doesn't know until the analysis is done properly, though one gets all sorts of hypotheses through observations. Most of them get proven wrong, but even that's something.

    I think it is useful to do a "last location seen" analysis to see if there is some location in common between victims, a pub (in these cases), or a church, or grocery store, etc. It's probably harder for very spread out situations, like Colin Ireland, as the area for analysis is so large. Could still be a line of questioning for family members, etc, to see if they know of a reason for the victim to have been in that area though, and leads could develop as a result.

    But if the "location last scene" is thought to be the encounter location, then yes, that's very useful location information and often produces a good profile because again, it's a location that the offender has gone to by their decision making, so the encounter location will reflect the offender's decision making as well. Things like the crime scenes in Colin Ireland's case are not chosen by the offender, but in that series, all the victims chose the same pub, which is where the encounter took place. Similar with the McArthur series, the victims were around a common gathering location, which pointed to an area where McArthur also had ties, and so searching for information in that are would have a good probability of turning up information.

    And yes, I think it's possible in the JtR that a pub, like the 10 Bells, could be the anchor point. For what it's worth, in my opinion, though, given JtR is carrying organs around, I tend to think he lives in the area, but I recognize he could have travelled into the area. One of the reasons I think he does live in the area, though, is given how close to morning Annie was killed, with the sun rising, etc. I don't think he would risk a murder if he had to travel far at that time of day, especially carrying body parts (for the first time), and no doubt with blood on his hands (even if he could wipe them, it's not going to be perfect; very risky to be out in the daylight). As such, I rather suspect he lived not far from Hanbury Street. What is interesting, is that inference based upon the time of the murder fits with all the spatial analyses (the hot spots are not far from Hanbury Street). Also, there's reports of footsteps leaving Miller's Court on the morning of Mary Kelly's murder, and if that were JtR and not a police officer (which the witness said they thought it was), it's again getting close to sun up, and so again I would think he would live near by if he's willing to stick around and travel near dawn (there's no reason he couldn't have left under the cover of night, though, so this is very speculative). But if we run with it, that too fits with the idea he had to live near Hanbury since Miller's Court and Hanbury are not far apart. However, back to reality, and I don't know those things for a fact, obviously, and it is possible JtR lives outside the area, and was able to hide his hands via gloves, or just in his pocket. If he did travel in, though, I think he exits from that north west corner, probably to the north, and even then, not too far in that direction, but if it's a 15 minute walk north or north west, let's say, that's still going to get him a fair distance out of the area at a brisk pace, probably close to a mile type thing.

    - Jeff

    Comment


    • #62
      Originally posted by caz View Post

      Hi Jeff,

      I presume the ability to travel back in 1888 would have depended on the killer's personal and financial circumstances, because transport was readily available to anyone with the time and the money to use it. Even a dirt poor local killer could have walked a fair distance from where he lived or worked to find victims beyond Spitalfields if that had suited him, which is why I think it was probably a personal choice to keep dipping into the same small pool, regardless of his means and whether or not he lived among his prey.

      Another point to make about Colin Ireland is that even when they worked out that the victims were all linked to that one pub, the police had to identify the killer in order to learn that he didn't just live round the corner and use the pub as his own local. If he only went there when his object was murder, how would any witnesses be able to do more than give a description of anyone seen drinking and chatting with one or more of the victims? I believe Ireland was only caught after his image was captured on cctv, sitting next to a victim on the tube, as they travelled back to the victim's home. Without this modern technology they would have had no idea where to begin looking for a killer like Ireland, while London Underground trains had been running for 25 years by 1888.

      Love,

      Caz
      X
      Hi Caz,

      Yes, he was identified on CCTV, you recall correctly. It's hard to say what would have happened, but one possibility would have been to start watching the pub, questioning the staff, and if they recalled and could give a description, that's a start. There's also the possibility of putting someone in the pub, or having the staff contact the police should the person show up again, and so forth. With a crime range like Colin Ireland's, the suggested area is still very large, so it's still a needle in a haystack. But, it's a smaller haystack, and if that pub had been located, it provides the opportunity for information to be found. Not all opportunities are realized, of course. Again, these analyses do not solve cases, they provide information for the detectives to consider, and to suggest regions that generally provide information more than others, but that information still has to be found through hard work and investigation. Just like listing all the known contacts of a victim doesn't solve a case, they still have to be investigated. And the offender isn't always the first on the list, and sometimes, they are not a known associate. Same thing here, the location that bears fruit isn't always in zone one, and sometimes there's nothing there. More often than not, though, there's something that connects the offender to the area, though it may only come to light after they are caught what that is. In serial cases, where often the police can get hundreds, or thousands, of tips on people to check out, it can be useful to plot the suspects on the maps and then conduct interviews guided by that. Again, it can help suggest a priority list to try and make efficient use of limited resources, but by itself, it does not solve the case.

      - Jeff

      Comment


      • #63
        Hi all,

        The above got me thinking, so I've gone and marked all of the pubs I could find on the historic maps. I found nearly 200 (194 to be exact), and while I probably have missed some, there's some interesting aspects. Below I've got the pubs indicated in blue, and the crime locations in red. Below that on the left is a simple density map, showing where the density of pubs is highest (yellow), which maps along Whitechapel Road, and also the north west area particularly just west of Miller's Court, but also a bit north of that and tracking down to Hanbury Street, tracking over towards near where Baker's Row intersects Whitechapel (Nichols was last seen heading up Whitechapel towards Baker's Row as I recall). Eddowes was last seen heading towards Houndsditch, which would take her down to the most dense area of pubs on Whitechapel. The crime based profile tends to favour the north west area, which is also one of the more pub dense locations. While it's hard to be anywhere on this map and not have a pub nearby, if you're looking for victims in this area, gravitating to the areas with the most pubs, and therefore the most chance of finding a victim, would make a certain degree of sense. Avoiding the high density area on Whitechapel as a crime location sort of goes without saying, that area would be just too busy to commit a crime there, but it might be a location to make that initial contact (and could be where he bumped into Eddowes; a simple con like telling her he knew where they could go get a drink, might be all it required to get her to go with him).

        Anyway, if JtR prowled Whitechapel, Houndsditch, Bishopsgate, east on Widegate or Artillary, then up Commercial to Hanbury, along towards Bakers Row, and back down to Whitechapel, he's basically following a route through the highest density pub locations. And even getting to Stride's location is still just following along another high pub density side track.

        Now, whether that's because JtR was a heavy drinker, or just because those are areas where he might have felt he had the best chance to find a victim, is an interesting question. But either way, I bet JtR spent the early part of his evenings in the pub, and I would start by asking questions in the various pubs up around Miller's Court and Hanbury street. (Which, incidentally, is where Mrs. Fiddymonts (sp?) pub is located).

        - Jeff

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        • #64
          Originally posted by JeffHamm View Post

          Hi erobitha,

          Over all the cases I have there's no real difference in performance between the different routines, so which routine does best for any given case one doesn't know until you try them all and compare. One of the things I'm thinking of is trying to see if there is something one can calculate from the offense pattern that suggests which routine should do best. I have to sort a bunch of series first, and see if there's anything obvious, but I always keep my eye out for any hints. In all likelihood, if I were to go through all the cases I have where I have information on "location last seen", it will end up all 3 do equally well over all. It may just be these two examples where it happens to be Dragnet that comes out on top. But one doesn't know until the analysis is done properly, though one gets all sorts of hypotheses through observations. Most of them get proven wrong, but even that's something.

          I think it is useful to do a "last location seen" analysis to see if there is some location in common between victims, a pub (in these cases), or a church, or grocery store, etc. It's probably harder for very spread out situations, like Colin Ireland, as the area for analysis is so large. Could still be a line of questioning for family members, etc, to see if they know of a reason for the victim to have been in that area though, and leads could develop as a result.

          But if the "location last scene" is thought to be the encounter location, then yes, that's very useful location information and often produces a good profile because again, it's a location that the offender has gone to by their decision making, so the encounter location will reflect the offender's decision making as well. Things like the crime scenes in Colin Ireland's case are not chosen by the offender, but in that series, all the victims chose the same pub, which is where the encounter took place. Similar with the McArthur series, the victims were around a common gathering location, which pointed to an area where McArthur also had ties, and so searching for information in that are would have a good probability of turning up information.

          And yes, I think it's possible in the JtR that a pub, like the 10 Bells, could be the anchor point. For what it's worth, in my opinion, though, given JtR is carrying organs around, I tend to think he lives in the area, but I recognize he could have travelled into the area. One of the reasons I think he does live in the area, though, is given how close to morning Annie was killed, with the sun rising, etc. I don't think he would risk a murder if he had to travel far at that time of day, especially carrying body parts (for the first time), and no doubt with blood on his hands (even if he could wipe them, it's not going to be perfect; very risky to be out in the daylight). As such, I rather suspect he lived not far from Hanbury Street. What is interesting, is that inference based upon the time of the murder fits with all the spatial analyses (the hot spots are not far from Hanbury Street). Also, there's reports of footsteps leaving Miller's Court on the morning of Mary Kelly's murder, and if that were JtR and not a police officer (which the witness said they thought it was), it's again getting close to sun up, and so again I would think he would live near by if he's willing to stick around and travel near dawn (there's no reason he couldn't have left under the cover of night, though, so this is very speculative). But if we run with it, that too fits with the idea he had to live near Hanbury since Miller's Court and Hanbury are not far apart. However, back to reality, and I don't know those things for a fact, obviously, and it is possible JtR lives outside the area, and was able to hide his hands via gloves, or just in his pocket. If he did travel in, though, I think he exits from that north west corner, probably to the north, and even then, not too far in that direction, but if it's a 15 minute walk north or north west, let's say, that's still going to get him a fair distance out of the area at a brisk pace, probably close to a mile type thing.

          - Jeff
          Hi Jeff,

          One distinct advantage of travelling in from 'a fair distance out of the area' would have been that the house-to-house searches wouldn't have bothered him. A lesson for the next serial killer to take on board, if not for Jack himself.

          Love,

          Caz
          X

          "Comedy is simply a funny way of being serious." Peter Ustinov


          Comment


          • #65
            Originally posted by caz View Post

            Hi Jeff,

            One distinct advantage of travelling in from 'a fair distance out of the area' would have been that the house-to-house searches wouldn't have bothered him. A lesson for the next serial killer to take on board, if not for Jack himself.

            Love,

            Caz
            X
            Yes, but the disadvantage is you have to commit murder in an area you are less familiar with, and you have further to travel to get back to safety. In fact, balancing that idea of "get further from home" and "don't get too far from home", that is the basis for the routines behind Rigel.

            - Jeff

            Comment


            • #66
              Originally posted by JeffHamm View Post
              Hi all,

              The above got me thinking, so I've gone and marked all of the pubs I could find on the historic maps. I found nearly 200 (194 to be exact), and while I probably have missed some, there's some interesting aspects. Below I've got the pubs indicated in blue, and the crime locations in red. Below that on the left is a simple density map, showing where the density of pubs is highest (yellow), which maps along Whitechapel Road, and also the north west area particularly just west of Miller's Court, but also a bit north of that and tracking down to Hanbury Street, tracking over towards near where Baker's Row intersects Whitechapel (Nichols was last seen heading up Whitechapel towards Baker's Row as I recall). Eddowes was last seen heading towards Houndsditch, which would take her down to the most dense area of pubs on Whitechapel. The crime based profile tends to favour the north west area, which is also one of the more pub dense locations. While it's hard to be anywhere on this map and not have a pub nearby, if you're looking for victims in this area, gravitating to the areas with the most pubs, and therefore the most chance of finding a victim, would make a certain degree of sense. Avoiding the high density area on Whitechapel as a crime location sort of goes without saying, that area would be just too busy to commit a crime there, but it might be a location to make that initial contact (and could be where he bumped into Eddowes; a simple con like telling her he knew where they could go get a drink, might be all it required to get her to go with him).

              Anyway, if JtR prowled Whitechapel, Houndsditch, Bishopsgate, east on Widegate or Artillary, then up Commercial to Hanbury, along towards Bakers Row, and back down to Whitechapel, he's basically following a route through the highest density pub locations. And even getting to Stride's location is still just following along another high pub density side track.

              Now, whether that's because JtR was a heavy drinker, or just because those are areas where he might have felt he had the best chance to find a victim, is an interesting question. But either way, I bet JtR spent the early part of his evenings in the pub, and I would start by asking questions in the various pubs up around Miller's Court and Hanbury street. (Which, incidentally, is where Mrs. Fiddymonts (sp?) pub is located).


              - Jeff
              It is an interesting question.

              Colin Ireland frequented a gay pub, because that gave him a good chance to find a victim, but he presumably had to act the part well if he didn't have homosexual tendencies himself, or risk standing out. I would imagine he enjoyed a drink, or at least pretended to, but he couldn't risk getting drunk, or letting his victims get too drunk, if they relied on a taxi or public transport to get to where he murdered them.

              Other killers have used drink and/or drugs in the process, and JtR might have stood out if he had spent time in a pub, eyeing up potential prey, while nursing half a pint. So I do see him as a regular drinker, and probably a user of prostitutes, who knew his way round the local hostelries as well as the females who could be found there without an obvious husband or boyfriend in tow. If he fancied his chances, he may have had a few stiffeners to give him extra courage, but overdoing it would have been risky. If he killed Stride, might drink have affected his judgement somewhat, if this was shortly after he'd left the last pub? A narrow escape from Dutfield's Yard could have had a temporary sobering effect on him as he made his way towards Aldgate, but clearly not enough to make him call it a night. The later into the night that he found a victim, the more sober he'd have been unless he knew where to get more alcohol - for example at one of the market pubs that opened early.

              Love,

              Caz
              X
              "Comedy is simply a funny way of being serious." Peter Ustinov


              Comment


              • #67
                Originally posted by JeffHamm View Post

                Yes, but the disadvantage is you have to commit murder in an area you are less familiar with, and you have further to travel to get back to safety. In fact, balancing that idea of "get further from home" and "don't get too far from home", that is the basis for the routines behind Rigel.

                - Jeff
                I would argue that getting back to safety in 1888 Whitechapel would have been a matter of putting a few streets between himself and where he left the body of his last victim. Beyond that, it wouldn't much matter if he had another mile to walk or five, if there was little risk of anyone being stopped and questioned or searched that far from the scene, because even if the police were alerted very quickly to the murder, their efforts would be concentrated in the immediate vicinity, allowing the killer to get further away with every second.

                Love,

                Caz
                X
                "Comedy is simply a funny way of being serious." Peter Ustinov


                Comment


                • #68
                  Following on from this...

                  If he did kill Stride, he presumably did consider safety to be a few streets away. He didn't go back to the safety of home, wherever that was, but went on to the 'safety' of Mitre Square, where nobody was on the alert for a murderer. After murdering and mutilating Eddowes, and removing body parts, he still didn't go straight back to the safety of home, unless the Model Dwellings where he discarded the apron piece was on his direct route.

                  Love,

                  Caz
                  X
                  "Comedy is simply a funny way of being serious." Peter Ustinov


                  Comment


                  • #69
                    Hi Caz,

                    Yes, I suspect he would have had a few pints in the pubs as well. And yes, I agree that a few streets puts JtR is relative safety, and as you point out, if Stride and Eddowes are both JtR victims, a few streets and minutes is enough for him to feel safe.

                    - Jeff

                    Comment


                    • #70
                      Originally posted by JeffHamm View Post
                      Yes, but the disadvantage is you have to commit murder in an area you are less familiar with
                      Not necessarily. One can't dismiss the possibility that the murderer could be currently living outside the East End but is familiar with the streets because he lived there as a boy; had once worked there; had relatives in the area that he frequently visited, etc.

                      I just read of a murderer in Minnesota who dispatched his victim in a lonely desolate spot behind a warehouse. He knew the area because he had once worked nearby, but was no longer a current resident. I think the Thomas Cutbush people, if there are any left, might have something to say on this score.


                      Comment


                      • #71
                        Originally posted by rjpalmer View Post

                        Not necessarily. One can't dismiss the possibility that the murderer could be currently living outside the East End but is familiar with the streets because he lived there as a boy; had once worked there; had relatives in the area that he frequently visited, etc.

                        I just read of a murderer in Minnesota who dispatched his victim in a lonely desolate spot behind a warehouse. He knew the area because he had once worked nearby, but was no longer a current resident. I think the Thomas Cutbush people, if there are any left, might have something to say on this score.

                        or bury. if it was a non local id go with him, or someone like him. although he may be considered close enough in bow to be a local by some.
                        "Is all that we see or seem
                        but a dream within a dream?"

                        -Edgar Allan Poe


                        "...the man and the peaked cap he is said to have worn
                        quite tallies with the descriptions I got of him."

                        -Frederick G. Abberline

                        Comment


                        • #72
                          Originally posted by caz View Post
                          One distinct advantage of travelling in from 'a fair distance out of the area' would have been that the house-to-house searches wouldn't have bothered him.
                          My sense is that it might run deeper than that. Colin Ireland's desire to commit his murders 'elsewhere' could have a psychological component unrelated to mere habit or modus operandi.

                          Some depraved murderers seemingly have no problem with burying their victims under the kitchen floorboards. They have given up any pretense of normality or self-respect. They are 'all in.'

                          By contrast, maybe in Ireland's mind the 'distance' he placed between his 'normal' life and his crimes was a type of compartmentalization. He fooled himself into believing that if he killed people in a faraway place it wasn't really 'him' doing it. He allows himself to be 'Hyde' on these rare occasions, but insists on not polluting his own 'Jekyll' environs.

                          There's a whole advertising campaign based on this idea. 'What happens in Vegas, stays in Vegas.' As long as you commit your evil deeds is Sin City, you can still return home with your pretense of respectability intact.


                          Comment


                          • #73
                            Originally posted by rjpalmer View Post

                            Not necessarily. One can't dismiss the possibility that the murderer could be currently living outside the East End but is familiar with the streets because he lived there as a boy; had once worked there; had relatives in the area that he frequently visited, etc.

                            I just read of a murderer in Minnesota who dispatched his victim in a lonely desolate spot behind a warehouse. He knew the area because he had once worked nearby, but was no longer a current resident. I think the Thomas Cutbush people, if there are any left, might have something to say on this score.

                            Hi rjpalmer,

                            One should never dismiss based upon probability lists like this; there are always exceptions (it's why this sort of thing isn't proof anymore than being the spouse of a victim isn't proof of being the offender, even though by far that is the most common association). And yes, some offenders do return to areas where they are familiar from having lived there before. Generally, their former residence (or place of work, etc) is the anchor point of the profile. Berkowitz (Son of Sam), for example, moved north, but all of his offenses were from his old residence and south (he worked for a while at the airport, which would take him south from there). His new residence falls outside the crime range, even the expanded version that I've mentioned before, making him a commuter by any definition. However, his previous residence falls inside the crime range (making him a marauder) and falls within the suggested search area (zone 6; reducing the total area to 15%).

                            Just like one should not dismiss someone simply because they are not a victim's spouse or close family member (the most common offender) and one can point to cases where the offender didn't have that close family tie, doesn't mean it's the most common event. Commuters are less common, but they are not so rare that the idea should be dismissed out of hand (which I think I've been pretty careful to point out). But in terms of ranking probabilities, a local with ties in the area is more probable than a commuter. And a commuter with previous ties to the area more likely than a commuter with no other ties to the area. So, without anything more to work with, the rankings are a local (within the crime range area), a commuter with current or former ties to the area, a commuter with no known ties to the area. I would suggest they will have ties, but it may be like Colin Ireland where as far as I know his ties to the area was only because he chose that pub to find victims (though perhaps he had others).

                            Again, it is a misinterpretation of what this sort of analysis does. It does not identify a person, it does not tell you what the association the offender has with that area is (it often is reported as if it is telling you where the offender lives, but while that often turns out to be the case, that's only because a stable residence can result in a strong anchor point). What this does is suggest areas that the offender is likely to have some sort of association with. As I say, often it turns out that association is the offender's residence if they are living in a stable location, but it need not be, particularly for those who are more mobile. Like your example, it could be a former residence, it may be a place of work (or former), or some other location that the offender had reason to go to in their day to day lives, creating familiarity with that location. Over longer series of crimes, spanning years, the issue of an offender moving to a new location is important to consider, as the areas they are familiar with will change. That often results in a slow change in terms of the area in which they start offending.

                            - Jeff

                            Comment


                            • #74
                              Originally posted by JeffHamm View Post

                              Hi rjpalmer,

                              One should never dismiss based upon probability lists like this; there are always exceptions (it's why this sort of thing isn't proof anymore than being the spouse of a victim isn't proof of being the offender, even though by far that is the most common association). And yes, some offenders do return to areas where they are familiar from having lived there before. Generally, their former residence (or place of work, etc) is the anchor point of the profile. Berkowitz (Son of Sam), for example, moved north, but all of his offenses were from his old residence and south (he worked for a while at the airport, which would take him south from there). His new residence falls outside the crime range, even the expanded version that I've mentioned before, making him a commuter by any definition. However, his previous residence falls inside the crime range (making him a marauder) and falls within the suggested search area (zone 6; reducing the total area to 15%).

                              Just like one should not dismiss someone simply because they are not a victim's spouse or close family member (the most common offender) and one can point to cases where the offender didn't have that close family tie, doesn't mean it's the most common event. Commuters are less common, but they are not so rare that the idea should be dismissed out of hand (which I think I've been pretty careful to point out). But in terms of ranking probabilities, a local with ties in the area is more probable than a commuter. And a commuter with previous ties to the area more likely than a commuter with no other ties to the area. So, without anything more to work with, the rankings are a local (within the crime range area), a commuter with current or former ties to the area, a commuter with no known ties to the area. I would suggest they will have ties, but it may be like Colin Ireland where as far as I know his ties to the area was only because he chose that pub to find victims (though perhaps he had others).

                              Again, it is a misinterpretation of what this sort of analysis does. It does not identify a person, it does not tell you what the association the offender has with that area is (it often is reported as if it is telling you where the offender lives, but while that often turns out to be the case, that's only because a stable residence can result in a strong anchor point). What this does is suggest areas that the offender is likely to have some sort of association with. As I say, often it turns out that association is the offender's residence if they are living in a stable location, but it need not be, particularly for those who are more mobile. Like your example, it could be a former residence, it may be a place of work (or former), or some other location that the offender had reason to go to in their day to day lives, creating familiarity with that location. Over longer series of crimes, spanning years, the issue of an offender moving to a new location is important to consider, as the areas they are familiar with will change. That often results in a slow change in terms of the area in which they start offending.

                              - Jeff
                              So after reading all of this, even with modern technology, and even with a respected modern investigation tool as geographic profiling is even this has no common ideal of THIS IS Where he likely lived? As a layman in this I am seeing multiple techniques in this. Am I missing or misinterpreting it when I ask...According to Geographic profiling, using the pub the Ripper met the victims at, or the murder sites areas as an anchor where did the Ripper Him or Herself likely live?

                              Comment


                              • #75
                                Originally posted by clark2710 View Post

                                So after reading all of this, even with modern technology, and even with a respected modern investigation tool as geographic profiling is even this has no common ideal of THIS IS Where he likely lived? As a layman in this I am seeing multiple techniques in this. Am I missing or misinterpreting it when I ask...According to Geographic profiling, using the pub the Ripper met the victims at, or the murder sites areas as an anchor where did the Ripper Him or Herself likely live?
                                Hi clark2710,

                                Spatial analysis (called geograhical profiling by some) is about extracting information from location information. Basically, and this is a bit over simplistic, the idea is to try and identify the location of common origin for a set of independent journeys. So, the idea is that each offense location represents a journey, with a common origin (call that location O). Now, that doesn't necessarily mean on the night of the offense the offender started from O and headed out to the crime scene, rather, that the offender has become familiar with that location during their usual daily routines. They become aware of the layout of a geographical region, and know where to find targets for their particular crime. For most offenders, but of course not all, the area they are most familiar with will be anchored around their place of residence, so in the public we often hear about how this "locates where the offender lives". And while that is often the case in general, there are times when that anchor point will be some other location, such as a the offender's place of work, or a pub that they frequent, and so forth. Deciding whether the area signaled in the JtR case is reflecting the offender's residence, or the pubs they frequented, etc, is an interpretation of the analysis. The analysis is just a mathematical calculation that produces probabilistic output map. What it "means" is an interpretation issue, and that's where consideration of things like "what information are represented by these locations we're entering?", "Other than their residence, what else might be serving as an anchor point?", "what if the offender is a commuter?" and so forth.

                                The different techniques (Rigel, Dragnet, etc), while the maps may look very different, are underneath very similar. There's a few different assumptions, some changes in the specific equations, and so forth, but despite what look like very different outputs, on the whole they are all equally accurate.

                                So, would I say I'm confident that JtR lived within the indicated areas? Of course not, there's a 20% chance he's a commuter and didn't live in the area at all. But, I am confident (not 100% of course, but confident nonetheless), that there is something associated with JtR in that upper northwest area. And while it wouldn't surprise me if it was his residence, I would not dismiss the possibility that that was where he went to drink at night, particularly given the high density of the pubs up there, and the tendency for all of the murders to have occurred after the pubs closed. Of course, if he was heading out from the pub to prowl, he probably lived near by as well since presumably one goes to the local pub near home. But if he heads in to slum it, that may be the area he frequents the pubs, and then from there prowls the area, developing his familiarity of where things are, before heading back off out of the region. I could see that being the case too.

                                It's not magic, it's maths. Geographical profiling is highly misrepresented in both the press and the entertainment industry with regards to how specific it is, and what the high probability zones represent, and so forth. Why that area might be an anchor point is a matter of interpretation of the analysis, and that's where a good investigator makes a difference. They can use this spatial analysis as it is intended, probability information for them to consider, and then apply their knowledge to work out how best to utilize it. Just like a good investigator knows that a spouse is the first person to rule out of an investigation, followed by close family members, friends, neighbors, work colleagues, etc because as they work through that list, more often then not, they're going to find there's someone they cannot rule out, and as they focus on them for that purpose they start finding more and more leads that connect them. Same here, working through the indicated areas, the chance of coming across information that produces leads should happen sooner. That information might then help tell us if the anchor point is a residence, or a pub, or a place of work, or an entry way to the crime area (like a motorway offramp).

                                It's not DNA or fingerprints, it doesn't identify a person, but it's not tea leaves either.

                                - Jeff

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