Explaining Developmental Crime Trajectories at Places

Over the last decade, hot spots of crime have become a central focus of crime prevention theory and practice. The importance of examining micro crime places was reinforced in a recent NIJ-supported project in which Weisburd et al. examined crime at street segments over a 14-year period (1989-2002) in Seattle, Washington. Using group-based trajectory analyses they found street segments in Seattle evidenced distinct developmental trends, despite an overall crime drop in the city. Indeed, the 24 percent crime drop observed in the 14-year study period was produced by only 14% of the street segments, and 2% of the segments in the city evidence marked crime increases in this period. These findings suggest the importance of developing a more systematic understanding of why specific street segments stay stable in crime rates over time, why others show crime "drops," and still others crime "waves."
In this study we would extend the prior study, linking longitudinal crime data to a series of other databases reflecting possible causes of variability in crime trends over time. Our review of databases in Seattle suggests that there are a large group of variables that are both measured over time and capable of representing the core theoretical perspectives thought to explain changes in crime trends at micro places. We will use multinomial logit regression and joint trajectory analysis to identify factors that are important in explaining the developmental crime trends observed in the Seattle data. We will also examine the geography of developmental trajectories using visualization of space-time patterns and a variety of spatio-temporal techniques.

This research has significance not only for crime prevention theory but also for policy and practice in criminal justice. It would identify factors linked to sudden and troubling increases in crime at micro places, and thus would provide a typology or "early warning system" for identifying places that should be the focus of crime prevention efforts. It would also identify factors associated with decreasing crime trends at places and thus would provide insights into types of strategies likely to be successful in improving micro crime places over time.