Originally posted by Sam Flynn
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Originally posted by Leather_Apron View PostIm confused about the Geographic Profile. Doesnt the algorithm assume JTR chose the murder locations?
Basically, had JtR found different victims, in different locations, the pattern of those hypothetical offenses would be expected to produce an output that also reflects a similar area. And indeed, if we include, for example, Tabram (as some people argue she may have been a victim of JtR as well), things don't change all that much. If we remove Stride, as her inclusion is highly debated, things shift somewhat, but we still end up with a high probability zone in roughly the same area.
David Berkowitz (Son of Sam), lived quite far from where he committed his crimes. However, at the time he committed his first offense, he lived pretty close to it and moved away after that. He also worked at the JFK Airport for some period of time, and that location from his first address travels right through the bulk of his offenses. He was returning to an area he was very familiar with. The analysis locates his former residence in zone 13 (upper Yellow square), and the airport is around zone 19-21 (these are just crudely placed markers for illustration, and it's not a great map to begin with). He also worked in the Bronx as a postal worker, but I don't know where that was. I suspect, though, there is something in the primary zone in Queens that he was associated with, and that he could be found there quite frequently. He was eventually identified because his car got a parking ticket, and it was near the Brooklyn offense. Turns out, he used his own car during all of them, and I would suspect his car would be noted in that area as well. I don't know enough about his life to know for sure if he did have some sort of regular activity in Queens, but I would be a bit surprised if there's not something there that he was associated with. And therefore, that means, that is an area where he could potentially have come to police attention. I've not looked much into this case, and would want a far better map to work with, mostly because his residence in Yonkers makes him a commuter in that sense. However, his former residence, and his airport workplace, and other such anchor points, means he's not associated with the region of the crimes, so he's a marauder in that sense. (The marauder/commuter distinction is very blurry when one tries to define it - but for testing purposes of routines like this being able to locate residences is a way to keep the conditions all the same).
Anyway, you can think of geographical profiling as a sort of low-spatial frequency filter, the specific details of the exact locations are "blurred", and the underlying global pattern is what is being emphasized and extracted.
And finally, one must never forget, there are offenders who do not correspond to the general pattern. They are less common (which is why there is a general pattern in the first place), but uncommon situations do occur. These are not "evidence", they are, however, not random either and because investigations get solved by finding leads, what these do is prioritize an order of where to search for leads. For example, whether JtR lived in the highlighted area, or whether he only was there when "hunting", is immaterial. Police patrolling that area could be told to take note of all males walking around at night, identify them if that is within the law, and find out who is seen there regularly. Many will have valid and innocent reasons, but the offender's name may come up on that list, and that's one more chance of linking them to something else. For example, if Joe Bloggs shows up as being known to be in the area very often at night, and he turns out to be a butcher, fitting the witness descriptions, and so forth, then he would be someone worth investigating further. Further investigation might exclude him, or it might not.
I've included Berkowitz here to illustrate that. He didn't live in the area (after he moved), his former address and one of his workplaces are in the area, though neither is in the highest priority zones (13 is a bit mid-way, still way better than chance, but it would take awhile to get there from an investigative point of view). I've not come across any references to him having an association with Queens, but I've not looked that hard as he's a "on the shelf" series in my research as he's a "residence commuter", making him less useful to me for testing the routines. I'm digressing now, but just wanting to point out that while these are often pretty good, they still must not be treated as "absolutely the truth".
- Jeff
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Originally posted by Sam Flynn View PostA few thousand, in fact; Dorset Street alone had close to 800 residents at any one time.
One can also use these to prioritize who in a list to investigate first. I don't mean a list of people for which there are actual investigative leads per se, but rather, when you have a list of people, say "let's get the names of all the butchers", then you might order that list based upon those who live in high probability zones, and work your way down. Again, real investigative leads trump any probability based strategy. If the police had information that suggested Joe Bloggs, who lives in a low probability zone, was connected to the offenses, you ignore the zone and follow the real evidence. But sometimes people are dismissed from investigations prematurely, and there have been cases where noting that someone "no longer being looked at" turns out to be in a high probability zone and gets another look, and as a result turns out the case gets solved (something like this happened with Comeaux, who was police officer and the Layfaette Southside Rapist as his residence at the time of rapes was in the highest probability zone produced by Rigel, although he had moved since that time so wasn't living there anymore, when his name came up the investigating officer checked the files and found where he used to live corresponded to the profile - his DNA was later matched to the crimes). It was the real evidence that solved the case, it was the profile that helped prioritize following that particular lead earlier rather than later.
- Jeff
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Originally posted by jerryd View PostJeff,
The City Police had a suspect in mind by late September, 1888 and staked him out the night Eddowes was murdered. Whomever he was, the stakeout was in the area of your Zone 1.
I believe the city police stakeout was further south, at the location of the "teal blue" square to the east of Mitre Square. That's located in Zone 8. I've found a few more cases to test, and the 75% cutoff is at zone 7.25 (so into zone 8), making it worthy of note.
Or we may be talking of different events? The one I'm talking about is a suspect mentioned by a PC Sagar, but I forget where I came across this (was on the board here, might be a document by AP Wolf in the dissertations maybe? That seems to ring a bell, but then, so does a rock, so that's not really a good indication).
- JeffLast edited by JeffHamm; 12-04-2019, 04:43 AM.
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Originally posted by JeffHamm View Post
Hi jerryd,
I believe the city police stakeout was further south, at the location of the "teal blue" square to the east of Mitre Square. That's located in Zone 8. I've found a few more cases to test, and the 75% cutoff is at zone 7.25 (so into zone 8), making it worthy of note.
Or we may be talking of different events? The one I'm talking about is a suspect mentioned by a PC Sagar, but I forget where I came across this (was on the board here, might be a document by AP Wolf in the dissertations maybe? That seems to ring a bell, but then, so does a rock, so that's not really a good indication).
- Jeff
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Originally posted by jerryd View Post
The stakeout I am talking about was on Windsor Street, which is directly behind the Bishopsgate Police Station.
- Jeff
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Originally posted by JeffHamm View Post
Oh, cool. Can you direct me to a source for that? I would like to read more about it. And do you know if there's an address on Windsor Street recorded anywhere? I'll add that to my collection of suspect locations. Thanks.
- Jeff
Tuesday, 2 October 1888
Many adverse remarks have been made concerning the want of vigilance on the part of the police in connexion with the outrages; but it should be remembered, as urged by them, that the women are of a class who know that they are liable to punishment if detected, and who, therefore, go alone to the places where they agree to meet their male companions. Shortly after the first horrible murders were committed some weeks ago, special precautions were taken by the City Police authorities with a view to detect the criminal or criminals, several plain-clothes constables being ordered on the beats in the district which has now become so notorious. Instructions were given to the constables to watch any man and woman seen together in suspicious circumstances, and especially to observe any woman who might be seen alone in circumstances of a similar nature. At about the time when the Mitre-square murder was being committed two of the extra men who had been put on duty were in Windsor-street, a thoroughfare about 300 yards off, engaged, pursuant to their instructions, in watching certain houses, it being thought possible that the premises might be resorted to at some time by the murderer. Five minutes after the discovery of the murder in Mitre-square, the two officers referred to heard of it, and the neighbourhood was at once searched by them, unfortunately without result. It is believed that had any man and woman been in company with each other going to Mitre-square they must have been observed, and that the man in that case would have been detected and captured. The supposition of the police is that the murderer and the ill-fated woman went to the place separately, having made an appointment. The general impression is that no man in his right senses could have perpetrated such a series of dreadful crimes. Some of the doctors who have been engaged in the examination of the bodies believe it quite possible that the murders may have been committed in from three to five minutes.
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Originally posted by jerryd View Post
Times (London)Tuesday, 2 October 1888
Many adverse remarks have been made concerning the want of vigilance on the part of the police in connexion with the outrages; but it should be remembered, as urged by them, that the women are of a class who know that they are liable to punishment if detected, and who, therefore, go alone to the places where they agree to meet their male companions. Shortly after the first horrible murders were committed some weeks ago, special precautions were taken by the City Police authorities with a view to detect the criminal or criminals, several plain-clothes constables being ordered on the beats in the district which has now become so notorious. Instructions were given to the constables to watch any man and woman seen together in suspicious circumstances, and especially to observe any woman who might be seen alone in circumstances of a similar nature. At about the time when the Mitre-square murder was being committed two of the extra men who had been put on duty were in Windsor-street, a thoroughfare about 300 yards off, engaged, pursuant to their instructions, in watching certain houses, it being thought possible that the premises might be resorted to at some time by the murderer. Five minutes after the discovery of the murder in Mitre-square, the two officers referred to heard of it, and the neighbourhood was at once searched by them, unfortunately without result. It is believed that had any man and woman been in company with each other going to Mitre-square they must have been observed, and that the man in that case would have been detected and captured. The supposition of the police is that the murderer and the ill-fated woman went to the place separately, having made an appointment. The general impression is that no man in his right senses could have perpetrated such a series of dreadful crimes. Some of the doctors who have been engaged in the examination of the bodies believe it quite possible that the murders may have been committed in from three to five minutes.
- Jeff
Last edited by JeffHamm; 12-04-2019, 05:39 AM.
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Originally posted by JeffHamm View Post
Fantastic! I've added it in. It lands in Zone 3, which makes it very interesting.
- Jeff
As has been said before there is no conclusive proof that the killer/killers lived in or near Whitechapel.
If the killer came from a location outside of Whitechapel, and simply came into the area to kill, and then left, all the geo profiling in the world is going to be to no avail.
Most of the murder sites are within a stones throw away from main thoroughfares.
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Originally posted by Trevor Marriott View Post
Jeff
As has been said before there is no conclusive proof that the killer/killers lived in or near Whitechapel.
If the killer came from a location outside of Whitechapel, and simply came into the area to kill, and then left, all the geo profiling in the world is going to be to no avail.
Most of the murder sites are within a stones throw away from main thoroughfares.
I think you'll find I already indicated that above, but yes, you're right and if JtR was a commuter, which about 20% of offenders are, then the spatial analysis is not going to result in his residence. It will, however, still highlight areas of importance. It might, for example, highlight a major intersection, which could help suggest what route the offender enters the area, for example. I suppose the JtR profile could be viewed to highlight the intersection of Commercial and Hanbury, as that's in zone 1. So if one fancied a commuter, then if they lived in a location where that might be a reasonable entry point to the area, then this would fit that suspect. If the suspect lived south, for example, then the profile would not fit them (but if there were actual evidence against that suspect, as I've repeatedly said, the profile gets set aside).
Here's an example. In Toronto a few years back they arrested Bruce McArthur. I was able to find the locations of where 4 of his 8 victims were last seen on the nights they disappeared. And, I was able to find the location of where one of their cars was found abandoned. I didn't enter the location where they found their bodies in the planters, and where McArthur had his work (he ran his own landscaping/gardening business, and used a friend's garage to store his tools and things - he burried the bodies in large planters on their property in return). McArthur actually lives off the map below. However, he frequented the gay village, and was known to frequent a bar called "Zipperz", which is where at least one of the victims was last seen, and was a popular club in the gay community.
I called his work place the main anchor point in the crime area (blue square), and I've marked Zipperz as a place of interest (yellow square). Given the locations I've entered are where the victims were last reported being seen, and one abandoned car, these locations are probably more about where he met the victims rather than where he actually killed them (most were taken back to his residence and killed there apparently). So the profile does not find his actual residence. It does, however, locate his work place in zone 5, and Zipperz is in Zone 2, border zone 3. So no, while it won't find a commuters residence, it can still find locations associated with the offender that are in the area. And if you invest your time looking in areas where there is a greater probability of the offender having a connection, then real evidence can be found sooner. But once real leads are obtained, the profile should be ignored - any real evidence trumps a probabilistic suggestion. I would think I've made that clear by now though.
Basically, I think if you read what I've actually been saying you'll find I'm quite clear, these sorts of analysis are not magical, and they are not evidence, they are probability maps, they add probabilistic "weight" when comparing two suspects, or "persons of interest" if you prefer, meaning "person A lives in an area that is more typical of this sort of spatial pattern than person B", but that doesn't mean person B couldn't be the actual offender - it's not definitive. It does mean, though, that without something more, choosing person A will result in you being right more often than choosing person B.
- Jeff
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Originally posted by JeffHamm View Post
Hi Trevor,
I think you'll find I already indicated that above, but yes, you're right and if JtR was a commuter, which about 20% of offenders are, then the spatial analysis is not going to result in his residence. It will, however, still highlight areas of importance. It might, for example, highlight a major intersection, which could help suggest what route the offender enters the area, for example. I suppose the JtR profile could be viewed to highlight the intersection of Commercial and Hanbury, as that's in zone 1. So if one fancied a commuter, then if they lived in a location where that might be a reasonable entry point to the area, then this would fit that suspect. If the suspect lived south, for example, then the profile would not fit them (but if there were actual evidence against that suspect, as I've repeatedly said, the profile gets set aside).
Here's an example. In Toronto a few years back they arrested Bruce McArthur. I was able to find the locations of where 4 of his 8 victims were last seen on the nights they disappeared. And, I was able to find the location of where one of their cars was found abandoned. I didn't enter the location where they found their bodies in the planters, and where McArthur had his work (he ran his own landscaping/gardening business, and used a friend's garage to store his tools and things - he burried the bodies in large planters on their property in return). McArthur actually lives off the map below. However, he frequented the gay village, and was known to frequent a bar called "Zipperz", which is where at least one of the victims was last seen, and was a popular club in the gay community.
I called his work place the main anchor point in the crime area (blue square), and I've marked Zipperz as a place of interest (yellow square). Given the locations I've entered are where the victims were last reported being seen, and one abandoned car, these locations are probably more about where he met the victims rather than where he actually killed them (most were taken back to his residence and killed there apparently). So the profile does not find his actual residence. It does, however, locate his work place in zone 5, and Zipperz is in Zone 2, border zone 3. So no, while it won't find a commuters residence, it can still find locations associated with the offender that are in the area. And if you invest your time looking in areas where there is a greater probability of the offender having a connection, then real evidence can be found sooner. But once real leads are obtained, the profile should be ignored - any real evidence trumps a probabilistic suggestion. I would think I've made that clear by now though.
Basically, I think if you read what I've actually been saying you'll find I'm quite clear, these sorts of analysis are not magical, and they are not evidence, they are probability maps, they add probabilistic "weight" when comparing two suspects, or "persons of interest" if you prefer, meaning "person A lives in an area that is more typical of this sort of spatial pattern than person B", but that doesn't mean person B couldn't be the actual offender - it's not definitive. It does mean, though, that without something more, choosing person A will result in you being right more often than choosing person B.
- Jeff
I dont believe you can compare modern day serial killings with the Whitrechapel murders. So much has changed in the past 131 years which make them incomparable.
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