A 3d Geovisualization Approach to Crime Mapping

This contribution presents an approach to visualize crime scene analysis results with three-dimensional geovirtual environments. Commonly, the results of those crime data analyses are published trough thematic maps. Therefore cartographic visualizations can be considered as a key element to communicate the outcomes of crime analysis. Those visualizations produced by crime analysts both in operational and academia are predominantly presented in form of traditional two-dimensional, static maps. According to defined task and analysed crime, these maps vary in subject, purpose, audience and map quality. Depending on the map topic and anticipated audience, these maps can be difficult to comprehend. A common issue, for instance, deals with the question how to define adequate threshold values for choropleth maps of certain hotspots. Against this background it is often rather ambiguous from which value precisely hot-spots can be considered “hot” (Chainey and Ratcliffe, 2005). Against this background this contribution tries to explore innovative methods of visualizing the outcomes of geospatial crime scene analysis. Therefore the main objective of this paper is to facilitate an instant grasp of complex spatial information by using three-dimensional geovisualization techniques. For this purpose crime data analysis is combined with methods from the field of 3D geovisualization. According to this concept, methods of geospatial crime scene analysis are applied using geographic information systems (GIS). By applying kernel density estimation (KDE) techniques areas are identified where robbery scenes tend to cluster. Once identified, these hotspots provide the basis for further analysis. For instance, further geovisual analysis uses a three-dimensional city model to determine the minimum distances of each building to the closest crime scene. This allows for classifying the buildings of the city model according to robbery exposure. For visualization purposes an interactive three-dimensional geovirtual environment is created. Besides the analytical power of GIS, a specialised 3D visualization system is required for this kind of interactive visualizations. The findings of crime scene analysis are integrated into this virtual environment. Consequently taking advantage of the third dimension, this contribution identifies benefits for a cartography oriented design of three-dimensional landscapes of security and insecurity by outlining several methods and functions for analysing and visualizing crime data by using three-dimensional geovirtual environments. Although demonstrated for the specific example of a German city, the presented methodology is transferable to