Searching for the serial offender, An experiment on search strategies for interpreting geographical offender profile maps.
Jasper J. van der Kemp & Rixt Brouwer
Geographical offender profiling as an investigative method seems to have a lot of potential in making investigations more efficient. An analysis of the geographical distribution of crime sites can determine a likely anchor point of a serial offender and therefore focus the search for a suspect on a specific area. Most of the debate about geographical profiling has been about the mathematical models and measuring accuracy, but little attention has been given to adding psychology and so fine tuning geographical profiling (Van der Kemp & Van Koppen, 2007). Central in this debate are search strategies that are needed in order to make use of the mathematical predictions, the geographical offender profile maps. Although geographical offender profiling contains more than just maths, little is known about that process of creating geographical offender profiles beyond the mathematical analysis. Even less is known about the interpretation of geographical offender profile maps and the search strategies deployed based on them. In an experiment we have searched for the search strategies used in different types of predictions, using distance decay and centroïde models, by people without geographical profiling experience. Respondents were randomly assigned to different sets of predictions and questions about their strategies and preferences for map type were asked. As a variation we also test the effect of simple training for the potential of improving the search for the offender. The design of this study allows us to investigate claims made about which method of geographical offender profiling allows the best search strategies and sheds light on practical issues concerning geographical profiling predictions.
31 Mar 2011
12th Conference of the International Academy of Investigative Psychology