The spatio-temporal patterns of street robbery in DP peninsula

The paper aims to uncover macro and micro spatial-temporal patterns of street robberies on DP Island of H city in southern China. DP Island, with an area of about 4 square kilometers, connects to the city via 7 bridges. There are a total of 373 street robbery incidences during the period of 2006-2011. Since street numbers are not linearly calibrated along streets in China, each incidence has to be geo-coded manually to a street network. First, all street robbery incidences are summarized by year (6 years), month (12 months) and hour (24 hours). The summary shows that street robberies reached a peak in 2007, followed by a trend of steady decrease until 2010; Just before the Spring Festival (around February), the number of incidences is much higher than that of other months. This pattern is different from those found in other countries, including the United States of America; during a day, street robberies peak during 22:00-23:00. Second, crime hotspots are revealed by kernel density mapping of all street robbery incidences. Comparisons with street network and land use suggest that hotspots tend to associate with main throughputs, intersections with high accessibilities, and areas with a high degree of land use mixture. To better characterize detailed patterns needed by policing, this paper selects 4 hotspots with the highest density for further analysis at a micro level. Prediction accuracy index (PAI) shows that these 4 spots are "hot" during all the 6 years from 2006 to 2011 and therefore warrant special attention for crime reduction and prevention. These hotspots are placed in different categories of the "hotspot matrix", which combines the spatial distribution (clustered or not) within the hotspot and the temporal distribution (clustered or not) in 24 hours. Based on these spatio-temporal patterns, the study suggests possible means for more effective policing, policing resource allocation, and crime prevention strategies. The study represents the first case study of its kind in China, and it sets the stage for future comparisons with other Chinese cites and foreign cities. Unfortunately, the name of the city cannot be revealed per confidential agreement on the crime data.