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The Whitechapel Murders: • A Linkage Analysis Brent E. Turvey, MS - Forensic Science Forensic Solutions, LLC Sitka, Alaska www.forensic-science.com
Linkage Analysis • Case linkage or linkage analysis refers to the process of determining whether or not there are discrete connections between two or more previously unrelated cases through crime scene analysis.
Linkage Analysis • It involves establishing and comparing the physical evidence, victimology, crime scene characteristics, modus operandi (MO), and signature behaviors between each of the cases under review.
Linkage Analysis • In order to refrain from misleading the court with respect to case linkage certainty, the results of such examinations are best expressed with one of four confidence statements: • behavioral dissimilarity; • investigative linkage; • behavioral commonality; and • probative link.
Linkage Analysis • Behavioral dissimilarity means that behavioral evidence components (e.g. MO, victimology, and offense signature) have been compared and they are distinctively dissimilar.
Linkage Analysis • An investigative link is a superficial connection between one or more cases that serves to inform the allocation of investigative resources (e.g. similar victim type, crime type, geographic area, and motive). • Such a link, as the name suggests, requires further investigation. It is not conclusive.
Linkage Analysis • A behavioral commonality is present when behavioral evidence components have been compared and they are similar but not necessarily distinctive (similar MO, victimology, motive, and offense signature aspects).
Linkage Analysis • A probative link is a connection between one or more cases that is sufficiently distinctive to support the inference that the same person is responsible. • In such cases, behavioral evidence components (e.g. MO, victimology, and offense signature) have been compared and they are not only the same, they also occur with limited behavioraldissimilarity.
Emma E. Smith, 45April 2-3, 1888 • Prostitute • Heavy drinker/ belligerent • History of injury • Physically assaulted • Attacked by 4 youths ?? • Raped/ stick in genitals ?? • Robbed • Died of peritonitis Behavioral Dissimilarities
Martha Tabram, 36April 7, 1888 • 5ft 3in. tall • Prostitute • Alcoholic • Husb.: Separated for 13 years • Husb.: 1/2 Crown per week • Police: Warrant against husband • George Yard Bldg. • 39 stab wounds chest/ stomach • Both knife and dagger used Behavioral Dissimilarities
Mary Ann Nichols, 45August 31, 1888 • 5ft 2in. tall • Prostitute/ Married but separated • Alcoholic • Bucks Row • Lying on back • Bruises on jaw and cheek • Bruised hands • Laceration of tongue • Throat cut deep • Abdomen cut open • Two stabs on “privates” parts Probative Link
Annie Chapman, 47September 8, 1888 • 5ft tall • Prostitute / Married but separated • Recent illness/ hospital • Alcoholic • Back yard of No.29 Hanbury St. • Legs drawn up • Bruising to face/ swollen • Throat cut deeply/ jagged • Disemboweled • Missing womb, genitals, bladder • Missing rings/ trophy or souvenir Probative Link
Elizabeth Stride, 44September 30, 1888 • 5ft tall • Prostitute/ Married but separated • Alcoholic: history of drunk/ disorderly • Inside the gates of Dutfield’s Yard • Legs drawn up • Throat cut deeply • Bruised shoulders / chest • Body found warm • “Double Event”/ Interrupted scene? Behavioral Commonality
Catherine Eddowes, 46September 30, 1888 • 5ft tall • Prostitute • Alcoholic: history of drunk/ disorderly • Just released from police custody • Mitre Square • Clothes/ legs drawn up/ abdomen exposed • Ext. cuts to the face (eyelids, nose, cheeks) • Throat cut deeply • Disemboweled/ arranged • Genital area cut/ stabbed • Womb removed Probative Link
Mary Jane Kelly, 25November 9, 1888 • 5ft tall • Prostitute • Indoor scene/ 13 Miller’s Court • Lying naked in middle of bed • Legs up and open • Defensive injuries to hands/arms • Throat cut deeply • Abdominal cavity eviscerated • Organs removed/ arranged at scene • Breasts cut off • Arms mutilated • Face hacked up Probative Link
Alice McKenzie, 40July 17, 1889 • Prostitute • Castle Alley • Throat cut deeply • Jaw cut • Bruising to chest and abdomen • 7in cut from left breast to navel • Small cut to mons veneris (pubic mound) • Farthing beneath body? • Interrupted scene? Behavioral Commonality