Visualising space time patterns in crime: the hotspot plot

Abstract

Part of the interest in crime mapping may be due to the relevance of geography in explaining patterns of crime. There is, however, a danger in missing other patterns (temporal patterns most notably) if the spatial domain is given disproportionate focus. A number of recent academic studies have shown reliable and meaningful spatio-temporal patterns of crime; yet their representation remains rather abstract. This article proposes a systematic method of displaying crime hot spots. It combines temporal and spatial information in an effective manner that allows the viewer to intuitively: assess temporal profiles of individual hot spots at the micro and macro levels (i.e. day and year); compare the importance and temporal signature of different hot spots; and relate the results of the first two to baseline measures.