Geographical profiling in a novel context: prioritising the search for New Zealand sex offfenders

Hammond, Laura (2013) Geographical profiling in a novel context: prioritising the search for New Zealand sex offfenders. Psychology, Crime & Law, 20 (4). pp. 358-371. ISSN 1068-316X

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The present work examines the use and value of geographical offender profiling methodologies within a novel context, considering both theoretical and practical issues relating to their application.
Two separate studies are presented. The first examined the effectiveness of a geographical profiling system (Dragnet) for a sample of 101 New Zealand sex offenders, comparing findings with those obtained for a U.K. serial rape sample. Search costs and search cost functions (relating proportions of the samples to the amounts by which the areas needing to be searched in order to locate offenders were reduced by the system) showed Dragnet to make significantly less accurate geographical profiling predictions for NZ offenders. It is argued that this is because the spatial behaviour of NZ offenders violates many of the assumptions that Dragnet and other similar geographical profiling systems rely upon.
A second study then explored whether calibration of the geographical profiling system to the local context enhanced the accuracy of predictions made. A logarithmic function was found to provide the best fit to data on the distances travelled by the NZ sex offenders, and was consequently incorporated into the geographical profiling predictions made by Dragnet. However, the effectiveness of the system was not significantly enhanced as a result of this calibration process.
The implications of these findings for the general utility of geographical profiling are discussed, and ways in which GP systems might be developed in order to broaden their scope and applicability are suggested.

Item Type: Article
Identification Number:
17 February 2013Accepted
10 May 2013Published Online
Subjects: CAH04 - psychology > CAH04-01 - psychology > CAH04-01-01 - psychology (non-specific)
Divisions: Faculty of Business, Law and Social Sciences > College of Psychology
Depositing User: Silvio Aldrovandi
Date Deposited: 27 Mar 2018 13:01
Last Modified: 11 Jun 2024 13:03

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