The empirical support for linkage analysis is steadily increasing, but the question remains as to what method of linking is the most effective. We compared a more theory-based, dimensional behavioural approach with a rather pragmatic, multivariate behavioural approach with regard to their accuracy in linking serial sexual assaults in a UK sample of serial sexual assaults (n=90) and one-off sexual assaults (n=129). Their respective linkage accuracy was assessed by (1) using seven dimensions derived by non-parametric Mokken scale analysis (MSA) as predictors in discriminant function analysis (DFA) and (2) 46 crime scene characteristics simultaneously in a na{\"i}ve Bayesian classifier (NBC). The dimensional scales predicted 28.9% of the series correctly, whereas the NBC correctly identified 34.5% of the series. However, asubsequent inclusion of non-serial offences in the target group decreased the amount of correct links in the dimensional approach (MSA-DFA: 8.9%; NBC: 32.2%). Receiver operating characteristic analysis was used as a more objective comparison of the two methods under both conditions, confirming that each achieved good accuracies (AUCs=.74-.89), but the NBC performed significantly better than the dimensional approach. The consequences for the practical implementation in behavioural case linkage are discussed.
Winter, J, Lemeire, J, Meganck, S, Rossi, G & Mokros, A 2013, 'Comparing the predictive accuracy of case linkage methods in serious sexual assaults', Journal of Investigative Psychology and Offender Profiling, vol. 10, no. 1, pp. 28-56.
Winter, J., Lemeire, J., Meganck, S., Rossi, G., & Mokros, A. (2013). Comparing the predictive accuracy of case linkage methods in serious sexual assaults. Journal of Investigative Psychology and Offender Profiling, 10(1), 28-56.
@article{7b6e2440f2ef4bc5af1e536a3596bbc2,
title = "Comparing the predictive accuracy of case linkage methods in serious sexual assaults",
abstract = "The empirical support for linkage analysis is steadily increasing, but the question remains as to what method of linking is the most effective. We compared a more theory-based, dimensional behavioural approach with a rather pragmatic, multivariate behavioural approach with regard to their accuracy in linking serial sexual assaults in a UK sample of serial sexual assaults (n=90) and one-off sexual assaults (n=129). Their respective linkage accuracy was assessed by (1) using seven dimensions derived by non-parametric Mokken scale analysis (MSA) as predictors in discriminant function analysis (DFA) and (2) 46 crime scene characteristics simultaneously in a na{\"i}ve Bayesian classifier (NBC). The dimensional scales predicted 28.9% of the series correctly, whereas the NBC correctly identified 34.5% of the series. However, asubsequent inclusion of non-serial offences in the target group decreased the amount of correct links in the dimensional approach (MSA-DFA: 8.9%; NBC: 32.2%). Receiver operating characteristic analysis was used as a more objective comparison of the two methods under both conditions, confirming that each achieved good accuracies (AUCs=.74-.89), but the NBC performed significantly better than the dimensional approach. The consequences for the practical implementation in behavioural case linkage are discussed.",
keywords = "crime linking",
author = "Jan Winter and Jan Lemeire and Stijn Meganck and Gina Rossi and Andreas Mokros",
year = "2013",
language = "English",
volume = "10",
pages = "28--56",
journal = "Journal of Investigative Psychology and Offender Profiling",
issn = "1544-4759",
publisher = "John Wiley and Sons Ltd",
number = "1",
}