Advanced Hotspot Analysis: Crime, Intelligence and Community Safety

The methods and techniques you'll learn about on the course include the following:

Techniques such as dual kernel density estimation allow for a secondary variable (e.g. population) to be considered in determining hotspots. That is, these techniques can be used to identify hotspots based on not only the distribution of crime, but how the underlying population influences this spatial distribution. We examine the use of dual KDE and its practical application.

A common analytical requirement is to determine how patterns of crime have changed over time. One approach for observing changes in crime is with map subtraction, where hotspot maps are created for two time periods, and a change map is produced showing those areas where crime has reduced or has increased. A problem with the map subtraction approach is that the change map can result in identifying a large number of areas where crime has increased, restricting the ability to be selective in the targeting of resources. On this course we introduce a more useful analytical approach which involves identifying areas that have contributed most to an increase. By doing this we can help to target response resources more specifically.

This group of spatial statistics provides a means of extending beyond methods such as kernel density estimation by identifying those areas where the clustering of crime points is significant. That is, they can determine areas that can be statistically defined as hot from those that are not, plus rank each hotspot according to significance thresholds (i.e. 95%, 99%, 99.9%). This part of the course guides you through these techniques and discusses their practical application. Particular emphasis is placed on using the Gi* statistic.

Some of the functionality we teach on the course is unavailable in standard GIS packages. ArcGIS v9.3 and above has the functionality for most of what we teach on this course, whereas MapInfo is still rather limited. We therefore make use of freeware software that includes the Dispersion Calculator, CrimeStat and RooksCase to perform some of the analytical techniques.