Informal Presentation of Geo-Spatial Analysis Project

[The Good Michael]

Chris,

Thanks. I was looking at the old dissertation which surmised 1888.

Mike

[Chris]

If Kosminski lived at 3 Sion Square or at 16 Greenfield, would that put him in the 90th percentile or greater?

He certainly didn't live at 3 Sion Square in 1888. We know his brother didn't move there until after May 1889.

[wesleyenglish]

Colin, thank you very much for pointing out the error of my crime scene locations. When I first ran the profile I used some coordinates I found unsourced on the web with no idea how accurate they were. I will rerun the profile tomorrow with the correct coordinates you so kindly provided.

I also look forward to your comments and questions.

On another note, I'm working on a researcher version of my system that I think you would enjoy playing around with. Unfortunately, it may not be done for a couple months.

[The Good Michael]

Colin,

If Kosminski lived at 3 Sion Square or at 16 Greenfield, would that put him in the 90th percentile or greater?

Thanks,

Mike

I'm still working my way through your report, but I thought I could help out a bit when I came across your mention of the Center of Minimum Distance (CMD).

My project is still in its infancy, and that portion, which I have presented thus far, is in dire need of some 'fine-tuning'. But, thank you for your interest; and many thanks, indeed, for your assistance with the CMD estimation.

I have provided more accurate 'eyeball' estimations of the six murder-sites under consideration.



(1)-(Black Dot) Martha Tabram (7 August 1888) First-Floor Stairway Landing of George Yard Buildings, George Yard, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 4' 18.45" West
Latitude: 51° 31' 0.60" North

(2)-(Black Dot) Mary Ann 'Polly' Nichols (31 August 1888) Gateway to Brown's Stable Yard, Buck's Row, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 3' 37.53" West
Latitude: 51° 31' 12.14" North

(3)-(Black Dot) Annie Chapman (8 September 1888) Back Yard of 29 Hanbury Street, Parish of Christ Church Spitalfields, County of Middlesex
Longitude: 0° 4' 21.40" West
Latitude: 51° 31' 13.67" North

(4)-(Black Dot) Elizabeth Stride (30 September 1888) Gateway to Dutfield's Yard, Berner Street, Parish of St. George in the East, County of Middlesex
Longitude: 0° 3' 56.14" West
Latitude: 51° 30' 49.44" North

(5)-(Black Dot) Catherine Eddowes (30 September 1888) Southeast Corner of Mitre Square, Parish of St. James, Aldgate Ward, City of London
Longitude: 0° 4' 41.06" West
Latitude: 51° 30' 49.35" North

(6)-(Black Dot) Mary Jane Kelly (9 November 1888) Interior of 13 Miller's Court, Dorset Street, Parish of Christ Church Spitalfields, County of Middlesex
Longitude: 0° 4' 30.47" West
Latitude: 51° 31' 7.17" North

(Green Dot) Murder-Site Mean-Center
Southwest Corner of the Intersection of Wentworth Street and Osborn Street, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 4' 14.18" West
Latitude: 51° 31' 2.06" North

(Purple Dot) My 'Rough' Estimation of the CMD

---

The aforementioned coordinates, in decimal form …

Martha Tabram
Longitude: 0.07179167° West
Latitude: 51.51683333° North

Polly Nichols
Longitude: 0.06042500° West
Latitude: 51.52003889° North

Annie Chapman
Longitude: 0.07261111° West
Latitude: 51.52046389° North

Elizabeth Stride
Longitude: 0.06559444° West
Latitude: 51.51373333° North

Catherine Eddowes
Longitude: 0.07807222° West
Latitude: 51.51370833° North

Mary Jane Kelly
Longitude: 0.07513056° West
Latitude: 51.51865833° North

Mean or 'Average' Longitudinal and Latitudinal Coordinates
Mean Longitude: 0.07060417° West
Mean Latitude: 51.51723935° North

---

I hope these coordinates will be of assistance.

I have a few questions/comments regarding your profile, but will have to address those at some point, later this week.

Again, Many Thanks

[doris]

read Op's post

my. head. hurts.

doris

[wesleyenglish]

Center of Minimum Distance

Great work, Colin! Very thorough. I'm still working my way through your report, but I thought I could help out a bit when I came across your mention of the Center of Minimum Distance (CMD).

Unfortunately, there is no formula for the determination of a two-dimensional 'Center of Minimum Distance'. It can however, be estimated through iterative measurements of aggregate distance.

As you've noted, the key to finding the CMD is through iterative measurement. One such method is to divide the search area up into a grid, and then find the aggregate distance from the center of each cell to the crime scenes.

I used my geographic profiling system to find this point for the six victims included in your analysis. I used a grid consisting of over 38 million cells. I can increase this number if desired.

Here's my result:

Center of Minimum Distance
Longitude: 0° 4' 18.4542" West (-0.07179279686185183)
Latitude: 51° 31' 0.5982" North (51.5168333926557)

Feel free to drop it in your Google Earth and post. Until then, here's a screenshot of where the CMD lies in proximity to the crime scenes:



Click on the image to view it in full size.

The red marker indicates the CMD.

Thanks for all your great work, Colin. I hope you find this at least a little helpful. I look forward to reading through the rest your report.

I must say that this basis of known suspects abode, together with the known victim's abode, certainly should weigh heavily in favour of the "local" killer.

I agree, Phil! But it is imperative that we establish a set of parameters that would allow for an explicit definition of the term 'local', within the context of this series of murders.

It is also imperative that we distance ourselves from this sort of …

To me, it is blatently obvious that the killer proberly resided very close to the killing zone, …

…

… and if the opportunety arose again to kill, would have struck within that safety blanket.

… utterly baseless supposition!

Each of those assumptions is plainly and simply a 'shot in the dark'!


Cumulative Probability Distribution (Greatest Deviation: Polly Nichols) (Elliptical) (Click to Enlarge in flickr)
Underlying Aerial Imagery: Copyright Google Earth, 2007
Overlying Plots, Labels and Color-Shadings: Copyright Colin C. Roberts, 2009

My analysis would suggest that given a perception of late November 1888, that this series of murders would continue ad infinitum; the expectation should have been that 72.32% would occur within the specified elliptical area, i.e. within 1.22 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 72.32%.

My Geographic Profile Model would suggest a 38.18% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 1.22 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the 'killing-field' itself (elliptical perspective), should be perceived as having constituted the 61st percentile (i.e. the top 38.18%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***


Cumulative Probability Distribution (Greatest Deviation: Polly Nichols) (Circular) (Click to Enlarge in flickr)
Underlying Aerial Imagery: Copyright Google Earth, 2007
Overlying Plots, Labels and Color-Shadings: Copyright Colin C. Roberts, 2009

Here, my analysis - using the more conservative circular perspective - would suggest that given a perception of late November 1888, that this series of murders would continue ad infinitum; the expectation should have been that 77.30% would occur within the specified circular area, i.e. within 1.38 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this circular area, should have been 77.30%.

My Geographic Profile Model would suggest a 42.56% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified circular area, i.e. within 1.38 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the 'killing-field' itself (circular perspective), should be perceived as having constituted the 57th percentile (i.e. the top 42.56%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***

With respect we proberly are all barking up the wrong tree, when [a] attempting to identify the killer. and[b] attempting to pinpoint his location, and although all these attempts are praiseworthy where does it lead us?

I am not "attempting to identify the killer"! I do not presume to believe that such an endeavor would stand a 'snow-ball's chance in hell' of ever succeeding.

Nor am I attempting to "pinpoint his location"! Same as above: I do not presume to believe that such an endeavor would stand a 'snow-ball's chance in hell' of ever succeeding.

Percentile reckoning, after your model, is a serious study that I believe ALL Ripperologists should take serious note of, WHOEVER they think the killer was.

Thank you, Phil!

[Phil Carter]

Hello Caz,

Whilst being in admiration and swayed by Colin's intense project results, I must say I sat nodding my head in agreement with you with the folowing comment..

It’s a plea to remember that our man managed to avoid being caught or identified, which just might have been down to his behaviour not being typical of the majority of convicted killers, while still being very far from unique among documented cases.

For whatever we think about where and when and how and why... our man certainly WAS different. Possibly unique infact. And it is that uniqueness that makes the whole case so baffling. He does fit, he doesn't fit, it is typical, it isnt typical... all those comparisons have variables to decieve and confuse...time and time again.

Simply put, nothing, in the case of the Whitechapel murders, actually makes any complete sense at all. As a series of murders, this group could be eloquently summed up by our dear friend Sherlock Holmes...

"A murderer of the singular variety, my dear Watson..."

best wishes

Phil

[Phil Carter]

Hello Colin,

This project of yours is quite exceptional. Not least the percentile calculations and basis therein of the perpetrator's location. Totally fascinating.
I must say that this basis of known suspects abode, together with the known victim's abode, certainly should weigh heavily in favour of the "local" killer.
Percentile reckoning, after your model, is a serious study that I believe ALL Ripperologists should take serious note of, WHOEVER they think the killer was.

I appreciate the time and effort given and used on this project. Thank you, again, for what I believe is a most interesting and worthy presentation for us all to study at length.

best wishes

Phil

Weighing-In the 'Suspects'

Weighing-In the 'Suspects'

I am 'jumping ahead' of my own presentation, but feel that the following 'quoted' analysis is best-suited for this thread.

In a 'nutshell' ...

- Robert Mann (Whitechapel Union Infirmary): 70th Percentile

- Robert Mann (Whitechapel Union Infirmary Mortuary): 76th Percentile

- Aaron Kosminski (34 Yalford Street): 78th Percentile

- George Hutchinson & Joseph Fleming (aka 'James Evans') (Victoria Home for Working Men): 89th Percentile

- John Simmonds (60 Wentworth Street): 95th Percentile

I am still in the process of compiling my "Informal Presentation". The following analysis will therefore require some clarification/explanation. So, ask questions, folks: … I will try to answer them.


Deviations from Murder-Site Mean-Center (Elliptical Perspective) (Click to Enlarge in flickr)
Underlying Aerial Imagery: Copyright Google Earth, 2007
Overlying Plots, Labels and Color-Shadings: Copyright Colin C. Roberts, 2009

From the outside, in …


Mary Ann 'Polly' Nichols (Victim: 31 August 1888): Gateway to Brown's Stable Yard, Buck's Row, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 3' 37.53" West
Latitude: 51° 31' 12.14" North

Standard Deviations from Murder-Site Mean-Center: 1.22
Semi-Major Axis (i.e. 'Long Radius'): 860.56 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 610.38 Yards
Area: 0.53 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 72.32%*
Portion of Probability Distribution (Geographic Profile Model): 38.18%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 72.32% would occur within the specified elliptical area, i.e. within 1.22 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 72.32%.

** My Geographic Profile Model would suggest a 38.18% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 1.22 Standard Deviations of the murder-site Mean-Center (green dot).


Elizabeth Stride (Victim: 30 September 1888): Gateway to Dutfield's Yard, Berner Street, Parish of St. George in the East, County of Middlesex
Longitude: 0° 3' 56.14" West
Latitude: 51° 30' 49.44" North

Standard Deviations from Murder-Site Mean-Center: 1.13
Semi-Major Axis (i.e. 'Long Radius'): 802.49 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 569.19 Yards
Area: 0.46 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 69.02%*
Portion of Probability Distribution (Geographic Profile Model): 35.62%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 69.02% would occur within the specified elliptical area, i.e. within 1.13 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 69.02%.

** My Geographic Profile Model would suggest a 35.62% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 1.13 Standard Deviations of the murder-site Mean-Center (green dot).


Catherine Eddowes (Victim: 30 September 1888): Southeast Corner of Mitre Square, Parish of St. James, Aldgate Ward, City of London
Longitude: 0° 4' 41.06" West
Latitude: 51° 30' 49.35" North

Standard Deviations from Murder-Site Mean-Center: 1.00
Semi-Major Axis (i.e. 'Long Radius'): 710.97 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 504.27 Yards
Area: 0.36 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 63.68%*
Portion of Probability Distribution (Geographic Profile Model): 31.84%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 63.68% would occur within the specified elliptical area, i.e. within 1.00 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 63.68%.

** My Geographic Profile Model would suggest a 31.84% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 1.00 Standard Deviations of the murder-site Mean-Center (green dot).


Red Ellipse – One Standard Deviation
Standard Deviations from Murder-Site Mean-Center: 1.00
Semi-Major Axis (i.e. 'Long Radius'): 707.53 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 501.83 Yards
Area: 0.36 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 63.68%*
Portion of Probability Distribution (Geographic Profile Model): 31.84%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 63.68% would occur within the specified elliptical area, i.e. within 1.00 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 63.68%.

** My Geographic Profile Model would suggest a 31.84% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 1.00 Standard Deviations of the murder-site Mean-Center (green dot).


Robert Mann (Modern-Day Person of Interest): Whitechapel Union Infirmary, Baker's Row, Hamlet of Mile End New Town, County of Middlesex
Longitude: 0° 3' 50.14" West
Latitude: 51° 31' 14.66" North

Standard Deviations from Murder-Site Mean-Center: 0.94
Semi-Major Axis (i.e. 'Long Radius'): 663.15 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 470.36 Yards
Area: 0.32 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 60.88%*
Portion of Probability Distribution (Geographic Profile Model): 30.00%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 60.88% would occur within the specified elliptical area, i.e. within 0.94 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 60.88%.

** My Geographic Profile Model would suggest a 30.00% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.94 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the documented 1888 residence of Robert Mann (i.e. the Whitechapel Union Infirmary) should be perceived as having been in the 70th percentile (i.e. the top 30.00%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***


Annie Chapman (Victim: 8 September 1888): Back Yard of 29 Hanbury Street, Parish of Christ Church Spitalfields, County of Middlesex
Longitude: 0° 4' 21.40" West
Latitude: 51° 31' 13.67" North

Standard Deviations from Murder-Site Mean-Center: 0.82
Semi-Major Axis (i.e. 'Long Radius'): 583.65 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 413.97 Yards
Area: 0.25 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 55.04%*
Portion of Probability Distribution (Geographic Profile Model): 26.42%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 55.04% would occur within the specified elliptical area, i.e. within 0.82 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 55.04%.

** My Geographic Profile Model would suggest a 26.42% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.82 Standard Deviations of the murder-site Mean-Center (green dot).


Robert Mann (Modern-Day Person of Interest): Whitechapel Union Infirmary Mortuary, Eagle Place, Old Montague Street, Hamlet of Mile End New Town, County of Middlesex
Longitude: 0° 3' 52.22" West
Latitude: 51° 31' 8.12" North

Standard Deviations from Murder-Site Mean-Center: 0.73
Semi-Major Axis (i.e. 'Long Radius'): 515.71 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 365.78 Yards
Area: 0.19 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 50.00%*
Portion of Probability Distribution (Geographic Profile Model): 23.54%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 50.00% would occur within the specified elliptical area, i.e. within 0.73 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 50.00%.

** My Geographic Profile Model would suggest a 23.54% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.73 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the documented 1888 workplace of Robert Mann (i.e. the Whitechapel Union Infirmary Mortuary) should be perceived as having been in the 76th percentile (i.e. the top 23.54%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***


Mary Jane Kelly (Victim: 9 November 1888): Interior of 13 Miller's Court, Dorset Street, Parish of Christ Church Spitalfields, County of Middlesex
Longitude: 0° 4' 30.47" West
Latitude: 51° 31' 7.17" North

Standard Deviations from Murder-Site Mean-Center: 0.72
Semi-Major Axis (i.e. 'Long Radius'): 511.49 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 362.79 Yards
Area: 0.19 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 49.62%*
Portion of Probability Distribution (Geographic Profile Model): 23.32%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 49.62% would occur within the specified elliptical area, i.e. within 0.72 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 49.62%.

** My Geographic Profile Model would suggest a 23.32% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.72 Standard Deviations of the murder-site Mean-Center (green dot).


Aaron Kosminski (Contemporary Suspect): 34 Yalford Street, Hamlet of Mile End Old Town, County of Middlesex
Longitude: 0° 3' 56.79" West
Latitude: 51° 30' 59.31" North

Standard Deviations from Murder-Site Mean-Center: 0.67
Semi-Major Axis (i.e. 'Long Radius'): 474.10 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 336.27 Yards
Area: 0.16 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 46.74%*
Portion of Probability Distribution (Geographic Profile Model): 21.76%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 46.74% would occur within the specified elliptical area, i.e. within 0.67 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 46.74%.

** My Geographic Profile Model would suggest a 21.76% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.67 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the probable 1888 residence of Aaron Kosminski (i.e. 34 Yalford Street) should be perceived as having been in the 78th percentile (i.e. the top 21.76%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***


George Hutchinson & Joseph Fleming (aka 'James Evans') (Modern-Day Persons of Interest): Victoria Home for Working Men, 39-41 Commercial Street, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 4' 23.98" West
Latitude: 51° 31' 0.64" North

Standard Deviations from Murder-Site Mean-Center: 0.32
Semi-Major Axis (i.e. 'Long Radius'): 226.77 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 160.84 Yards
Area: 0.04 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 23.80%*
Portion of Probability Distribution (Geographic Profile Model): 10.52%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 23.80% would occur within the specified elliptical area, i.e. within 0.32 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 23.80%.

** My Geographic Profile Model would suggest a 10.52% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.32 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the self-stated 1888 residence of George Hutchinson / the self-stated 1889 residence of Joseph Fleming (aka 'James Evans') (i.e. the Victoria Home for Working Men) should be perceived as having been in the 89th percentile (i.e. the top 10.52%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***


Martha Tabram (Victim: 7 August 1888): First-Floor Stairway Landing of George Yard Buildings, George Yard, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 4' 18.45" West
Latitude: 51° 31' 0.60" North

Standard Deviations from Murder-Site Mean-Center: 0.15
Semi-Major Axis (i.e. 'Long Radius'): 103.38 Yards
Semi-Minor Axis (i.e. 'Short Radius'): 73.32 Yards
Area: 0.01 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 11.34%*
Portion of Probability Distribution (Geographic Profile Model): 4.96%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 11.34% would occur within the specified elliptical area, i.e. within 0.15 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 11.34%.

** My Geographic Profile Model would suggest a 4.96% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.15 Standard Deviations of the murder-site Mean-Center (green dot).


John Simmonds (Modern-Day Person of Interest): 60 Wentworth Street, Parish of Christ Church Spitalfields, County of Middlesex
Longitude: 0° 4' 18.56" West
Latitude: 51° 31' 1.75" North

Standard Deviations from Murder-Site Mean-Center: 0.15
Semi-Major Axis (i.e. 'Long Radius'): 103.32
Semi-Minor Axis (i.e. 'Short Radius'): 73.28
Area: 0.01 Square Miles
Portion of Probability Distribution (Impending Subsequent Murders): 11.34%*
Portion of Probability Distribution (Geographic Profile Model): 4.96%**

* Given a perception of late November 1888 that this series of murders would continue ad infinitum; the expectation should have been that 11.34% would occur within the specified elliptical area, i.e. within 0.15 Standard Deviations of the murder-site Mean-Center (green dot).

This can be loosely interpreted to mean that in late November 1888, the perceived probability of the impending subsequent murder occurring within this elliptical area, should have been 11.34%.

** My Geographic Profile Model would suggest a 4.96% probability that the perpetrator(s) of these crimes operated from a base that was situated within the specified elliptical area, i.e. within 0.15 Standard Deviations of the murder-site Mean-Center (green dot).

*** This would suggest that the self-stated 1888 residence of John Simmonds (i.e. 60 Wentworth Street) should be perceived as having been in the 95th percentile (i.e. the top 4.96%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations. ***

With the benefit of hindsight, I am able to see that my most recent post to this thread appears to be an overwhelming mass of statistics: It is, admittedly, extremely difficult to decipher.

I will, therefore, present a brief summary.


Deviations from Murder-Site Mean-Center (Elliptical Perspective) (Click to Enlarge in flickr)
Underlying Aerial Imagery: Copyright Google Earth, 2007
Overlying Plots, Labels and Color-Shadings: Copyright Colin C. Roberts, 2009

From the outside, in …

- Robert Mann (Modern-Day Person of Interest): Whitechapel Union Infirmary, Baker's Row, Hamlet of Mile End New Town, County of Middlesex
Longitude: 0° 3' 50.14" West
Latitude: 51° 31' 14.66" North

My Georaphic Profile Model would suggest that the documented 1888 residence of Robert Mann (i.e. the Whitechapel Union Infirmary) should be perceived as having been in the 70th percentile (i.e. the top 30.00%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations.

- Robert Mann (Modern-Day Person of Interest): Whitechapel Union Infirmary Mortuary, Eagle Place, Old Montague Street, Hamlet of Mile End New Town, County of Middlesex
Longitude: 0° 3' 52.22" West
Latitude: 51° 31' 8.12" North

My Georaphic Profile Model would suggest that the documented 1888 workplace of Robert Mann (i.e. the Whitechapel Union Infirmary Mortuary) should be perceived as having been in the 76th percentile (i.e. the top 23.54%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations.

- Aaron Kosminski (Contemporary Suspect): 34 Yalford Street, Hamlet of Mile End Old Town, County of Middlesex
Longitude: 0° 3' 56.79" West
Latitude: 51° 30' 59.31" North

My Georaphic Profile Model would suggest that the probable 1888 residence of Aaron Kosminski (i.e. 34 Yalford Street) should be perceived as having been in the 78th percentile (i.e. the top 21.76%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations.

- George Hutchinson & Joseph Fleming (aka 'James Evans') (Modern-Day Persons of Interest): Victoria Home for Working Men, 39-41 Commercial Street, Parish of St. Mary Whitechapel, County of Middlesex
Longitude: 0° 4' 23.98" West
Latitude: 51° 31' 0.64" North

My Georaphic Profile Model would suggest that the self-stated 1888 residence of George Hutchinson / the self-stated 1889 residence of Joseph Fleming (aka 'James Evans') (i.e. the Victoria Home for Working Men) should be perceived as having been in the 89th percentile (i.e. the top 10.52%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations.

- John Simmonds (Modern-Day Person of Interest): 60 Wentworth Street, Parish of Christ Church Spitalfields, County of Middlesex
Longitude: 0° 4' 18.56" West
Latitude: 51° 31' 1.75" North

My Georaphic Profile Model would suggest that the self-stated 1888 residence of John Simmonds (i.e. 60 Wentworth Street) should be perceived as having been in the 95th percentile (i.e. the top 4.96%) of all 'reasonable' possibilities for the location of the perpetrator's base of operations.

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In a 'nutshell' ...

- Robert Mann (Whitechapel Union Infirmary): 70th Percentile

- Robert Mann (Whitechapel Union Infirmary Mortuary): 76th Percentile

- Aaron Kosminski (34 Yalford Street): 78th Percentile

- George Hutchinson & Joseph Fleming (aka 'James Evans') (Victoria Home for Working Men): 89th Percentile

- John Simmonds (60 Wentworth Street): 95th Percentile

[Sam Flynn]

Hi Edward, All,

What shouldn’t be forgotten is the fact that the killer merely had to stroll along one of the following main roads: Commercial St, Commercial Rd, the Whitechapel Rd, or Whitechapel High St/Aldgate High St

Why not (e.g.) Lambeth High Street, Praed Street W1, Tottenham Court Road and its offshoots, Poplar High St, Ratcliffe Highway, Covent Garden, Greenwich, Woolwich or the slums of Southampton, Portsmouth, Liverpool, Hull, Cardiff, Glasgow, Bristol...?

[Ben]

Hi Caz,

When a serial killer’s crimes are as closely clustered as those attributed to Jack, they invariably point towards an offender who resides, if not completely centrally to that cluster, then certainly within easy walking distance of them. This may be due to limitations in terms of transport – which would assume a particular resonance for the Victorian East End – but not always. Some kill within a relatively small, circumscribed region despite the availability of transport. In this case, the killer might only have approached his victims by using only the main arterial thoroughfares (we don’t know that he actually did), but even so, the vast majority of people walking those streets would have been men and women who lived within easy walking distance of those same streets. There are also the escape routes to consider. However he may have encountered Catherine Eddowes, his likely escape route to the Northern end of Goulston Street (i.e. the one avoiding PC Long) would have taken him down the alleyways.

That isn’t to discount the possibilities in terms of his abode, but I have little doubt as to the more probable scenarios. For example, the idea that he kept “commuting” from a considerable distance into one tiny pocket of the East End, despite having the means and transport to seek prostitution pastures anew (and prostitution ran rampant throughout London), and despite police and vigilant committee activity stepping up after each murder, just isn’t plausible, which may explain why it has occurred only rarely, if ever, in documented serial cases.

Certainly, there are examples of killers who selected their victims from a particular location (Ireland, Picton etc) before dispatching them elsewhere, but this is a different ballgame entirely because the offenders in question would not have been forcing investigative focus specifically on that location. In some cases, the authorities wouldn’t have even known that a serial killer was active. The “police and vigilant awareness” factor would have been mitigated in such a scenario, which it simply wouldn’t have been in the “commuter Jack” scenario. In any event, most prostitute serial killers tend also to be prostitute users, and the majority of men who used prostitutes from that particular district also lived within very easy walking distance of that district.

“It’s a plea to remember that our man managed to avoid being caught or identified, which just might have been down to his behaviour not being typical of the majority of convicted killers”

Possibly, but I’d much sooner attribute it to an inexperience of serial crime coupled with the fact that policing in general was in its infancy in 1888. We certainly shouldn’t use the fact that Jack wasn’t caught to argue that he was somehow more organized and intelligent than his captured counterparts. He could have made more errors of judgement that any one of his captured counterparts but had the good fortune to continue killing in spite of those errors, perhaps courtesy of the limitations and inexperience of the time.

“The fact that they failed to flush Jack out doesn’t mean he wasn’t there, but not being there for most of the time they were trying would have given him one heck of an edge over anyone choosing to pick up and murder women where he lived or worked, then spending the time in between hanging around lamely for a knock on the door.”

Regardless of whether or not it gave him an edge, the notion of the killer as the proverbial needle in a haystack and one who hid in plain sight is axiomatically valid given what we’ve learned from other serial cases. It happens, and it does so more often that the commuter who disappears from his operations base as soon as the police decide to investigate it, regardless of which is the two would seem the more immediately desirable option to us. My own opinion is that the killer continued to make the best of his limited options in terms of geography, transport and domesticity. He couldn’t travel far so he made the best of the locality with which he was most familiar. He couldn’t dispatch his victims in the privacy of his own home a al Nilsen, Gacy and Dahmer, and he couldn’t transport them to a dump-site far away, so he did his business on the spot.

The chances of the killer being identified and captured as a result of house-to-house searches were very slim in any event. Short of him carrying around decaying viscera in his pocket and behaving in an openly “crazy” manner, the police were all but powerless. And sorry, but there is most assuredly “much use arguing that the man who avoided exposing himself as the Whitechapel Murderer was more likely to have risked offending close to home on the basis of what we know about most criminals.” It’s the application of knowledge derived from a study of pertinent history, without which we’d be engaging in creative writing and little more, especially if it’s based on the assumption that uncaught killers must be cleverer than caught ones.

All the best,
Ben

[caz]

I assume that the perpetrator was walking. I am of the opinion that Jack lived within the area of the murders. I also believe that Jack was reasonably comfortable with the areas in which the murders were committed. When walking about, one's impression of distance from "home" is based upon the distance that has been travelled, not necessarily the direct line distance from home. In all probability. Jack did not walk directly to the murder site, but went to a location where a victim would likely be found, then moved about the area until a victim is identified. Thoughts?

Hi Edward, All,

What shouldn’t be forgotten is the fact that the killer merely had to stroll along one of the following main roads: Commercial St, Commercial Rd, the Whitechapel Rd, or Whitechapel High St/Aldgate High St, and allow himself to be approached by a prospective victim, who had probably already decided exactly where she was (or was not) prepared to take the next man who a) was up for it, b) had the gin tokens to pay for it and c) seemed reasonably harmless. In effect the procedure may have looked no different from any regular punter seeking anonymous sexual relief from a woman - any woman - for the least effort and expense on his part, except that a handful of women in 1888 would not walk away from their brief encounter with one particular man.

It might help to show just how many possibilities there were for this one man’s abode, fixed or otherwise, if we had reliable information about the countless other men who regularly went with the women who plied their trade along these main roads specifically. I don’t recall seeing any percentages for the men who lived or worked just as closely to these main thoroughfares as the women they picked up there, versus men from any other area (including those who regularly used one or more of these roads to get from A to B and took advantage of the opportunities found en route).

A couple of posters have claimed that the ‘vast majority’ of prostitute users fell into the former category, but I don’t know what their sources are and I’m not sure how useful any available figures would be, given that the customers willing to stand up and be counted would almost certainly make up a tiny fraction of the total numbers and are hardly going to be representative of the whole. The talkative few are not likely to include many family men, for instance, or those with any kind of ‘respectable’ position to maintain at home or work. If those most likely to boast about it were the single working men, unashamedly satisfying a basic biological urge on their own doorstep and not caring who knew it, the figures would merely reflect that fact and be useless in terms of painting an accurate overall picture.

As I’ve tried to explain to others, this is not a plea to leave the ‘local’ man out of it. It’s a plea to remember that our man managed to avoid being caught or identified, which just might have been down to his behaviour not being typical of the majority of convicted killers, while still being very far from unique among documented cases. The only truly effective way for Jack to have avoided the police searchlight was not to be anywhere near it while they had it switched on. In 1888, the local house-to-house searches were the primitive equivalent of taking DNA from as many local men as possible, in the hope that the killer would be flushed out among the last men to be eliminated. The fact that they failed to flush Jack out doesn’t mean he wasn’t there, but not being there for most of the time they were trying would have given him one heck of an edge over anyone choosing to pick up and murder women where he lived or worked, then spending the time in between hanging around lamely for a knock on the door. He’d have faced the reality that the police would be sniffing about very close to him and only very close to him for the foreseeable future, whether he continued to crap on his own doorstep or saw the sense in taking a break. He’d have been infinitely more likely to be flushed out by incriminating evidence found in his home or place of work, or still on his person, than anyone choosing to prowl the main streets in one reasonably familiar area, then simply vanishing (possibly via one of those streets, within minutes of each encounter) without leaving anything of himself within the designated sniffing distance.

It’s not much use arguing that the man who avoided exposing himself as the Whitechapel Murderer was more likely to have risked offending close to home on the basis of what we know about most criminals. One may as well observe that Jack’s blood was more likely to have been O positive than any other group if more men alive at the time had this type than any other. At least that would be logical and relate to a group that would definitely have included Jack, rather than a subsection of identified offenders, to which we can safely say he is unlikely ever to belong.

But observations based on statistical likelihood alone are of very limited use and can only lead the observer astray on the inevitable occasions when ‘more likely’ won’t apply to Jack. It’s a gamble if you rely on it to favour certain possibilities or reject others, and it’s one that you will lose at some point, but you won’t know when it happens or why, or how spectacularly it could have taken you off the scent.

Love,

Caz
X

[The Grave Maurice]

Colin, your work, as always, is very impressive but, for heaven's sake, get out of the house for a while. Take a walk on the beach or something. As my grandmother used to say: "If we were meant to think all the time, we wouldn't be mostly leg."