Abstract
Purpose: To conduct a test of the principles underpinning crime linkage (behavioural consistency and distinctiveness) with a sample more closely reflecting the volume and nature of sexual crimes with which practitioners work, and to assess whether solved series are characterized by greater behavioural similarity than unsolved series. Method: A sample of 3,364 sexual crimes (including 668 series) was collated from five countries. For the first time, the sample included solved and unsolved but linked-by-DNA sexual offence series, as well as solved one-off offences. All possible crime pairings in the data set were created, and the degree of similarity in crime scene behaviour shared by the crimes in each pair was quantified using Jaccard's coefficient. The ability to distinguish same-offender and different-offender pairs using similarity in crime scene behaviour was assessed using Receiver Operating Characteristic analysis. The relative amount of behavioural similarity and distinctiveness seen in solved and unsolved crime pairs was assessed. Results: An Area Under the Curve of.86 was found, which represents an excellent level of discrimination accuracy. This decreased to.85 when using a data set that contained one-off offences, and both one-off offences and unsolved crime series. Discrimination accuracy also decreased when using a sample composed solely of unsolved but linked-by-DNA series (AUC =.79). Conclusions: Crime linkage is practised by police forces globally, and its use in legal proceedings requires demonstration that its underlying principles are reliable. Support was found for its two underpinning principles with a more ecologically valid sample.
| Original language | English |
|---|---|
| Pages (from-to) | 123-140 |
| Number of pages | 18 |
| Journal | Legal and Criminological Psychology |
| Volume | 24 |
| Issue number | 1 |
| Early online date | 15 Dec 2018 |
| DOIs | |
| Publication status | Published - 1 Feb 2019 |
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Keywords
- assumptions
- behavioural linking
- case linkage
- comparative case analysis
- linkage analysis
Cite this
}
Linking serial sexual offences : Moving towards an ecologically valid test of the principles of crime linkage. / Woodhams, Jessica; Tonkin, Matthew; Burrell, Amy; Imre, Hanne; Winter, Jan M.; Lam, Eva K.M.; ten Brinke, Gert Jan; Webb, Mark; Labuschagne, Gerard; Bennell, Craig; Ashmore-Hills, Leah; van der Kemp, Jasper; Lipponen, Sami; Pakkanen, Tom; Rainbow, Lee; Salfati, C. Gabrielle; Santtila, Pekka.
In: Legal and Criminological Psychology, Vol. 24, No. 1, 01.02.2019, p. 123-140.Research output: Contribution to Journal › Article › Academic › peer-review
TY - JOUR
T1 - Linking serial sexual offences
T2 - Moving towards an ecologically valid test of the principles of crime linkage
AU - Woodhams, Jessica
AU - Tonkin, Matthew
AU - Burrell, Amy
AU - Imre, Hanne
AU - Winter, Jan M.
AU - Lam, Eva K.M.
AU - ten Brinke, Gert Jan
AU - Webb, Mark
AU - Labuschagne, Gerard
AU - Bennell, Craig
AU - Ashmore-Hills, Leah
AU - van der Kemp, Jasper
AU - Lipponen, Sami
AU - Pakkanen, Tom
AU - Rainbow, Lee
AU - Salfati, C. Gabrielle
AU - Santtila, Pekka
PY - 2019/2/1
Y1 - 2019/2/1
N2 - Purpose: To conduct a test of the principles underpinning crime linkage (behavioural consistency and distinctiveness) with a sample more closely reflecting the volume and nature of sexual crimes with which practitioners work, and to assess whether solved series are characterized by greater behavioural similarity than unsolved series. Method: A sample of 3,364 sexual crimes (including 668 series) was collated from five countries. For the first time, the sample included solved and unsolved but linked-by-DNA sexual offence series, as well as solved one-off offences. All possible crime pairings in the data set were created, and the degree of similarity in crime scene behaviour shared by the crimes in each pair was quantified using Jaccard's coefficient. The ability to distinguish same-offender and different-offender pairs using similarity in crime scene behaviour was assessed using Receiver Operating Characteristic analysis. The relative amount of behavioural similarity and distinctiveness seen in solved and unsolved crime pairs was assessed. Results: An Area Under the Curve of.86 was found, which represents an excellent level of discrimination accuracy. This decreased to.85 when using a data set that contained one-off offences, and both one-off offences and unsolved crime series. Discrimination accuracy also decreased when using a sample composed solely of unsolved but linked-by-DNA series (AUC =.79). Conclusions: Crime linkage is practised by police forces globally, and its use in legal proceedings requires demonstration that its underlying principles are reliable. Support was found for its two underpinning principles with a more ecologically valid sample.
AB - Purpose: To conduct a test of the principles underpinning crime linkage (behavioural consistency and distinctiveness) with a sample more closely reflecting the volume and nature of sexual crimes with which practitioners work, and to assess whether solved series are characterized by greater behavioural similarity than unsolved series. Method: A sample of 3,364 sexual crimes (including 668 series) was collated from five countries. For the first time, the sample included solved and unsolved but linked-by-DNA sexual offence series, as well as solved one-off offences. All possible crime pairings in the data set were created, and the degree of similarity in crime scene behaviour shared by the crimes in each pair was quantified using Jaccard's coefficient. The ability to distinguish same-offender and different-offender pairs using similarity in crime scene behaviour was assessed using Receiver Operating Characteristic analysis. The relative amount of behavioural similarity and distinctiveness seen in solved and unsolved crime pairs was assessed. Results: An Area Under the Curve of.86 was found, which represents an excellent level of discrimination accuracy. This decreased to.85 when using a data set that contained one-off offences, and both one-off offences and unsolved crime series. Discrimination accuracy also decreased when using a sample composed solely of unsolved but linked-by-DNA series (AUC =.79). Conclusions: Crime linkage is practised by police forces globally, and its use in legal proceedings requires demonstration that its underlying principles are reliable. Support was found for its two underpinning principles with a more ecologically valid sample.
KW - assumptions
KW - behavioural linking
KW - case linkage
KW - comparative case analysis
KW - linkage analysis
UR - http://www.scopus.com/inward/record.url?scp=85058424123&partnerID=8YFLogxK
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U2 - 10.1111/lcrp.12144
DO - 10.1111/lcrp.12144
M3 - Article
VL - 24
SP - 123
EP - 140
JO - Legal and Criminological Psychology
JF - Legal and Criminological Psychology
SN - 1355-3259
IS - 1
ER -