Where the action is at places: Examining spatio-temporal patterns of juvenile crime at places using trajectory analysis and GIS

Crime Places have recently emerged as an important focus of crime prevention theory and practice. Interest develops in part from the underlying assumptions of recent theoretical perspectives that focus on opportunity structures for crime. Building upon these theoretical innovations a number of studies beginning in the late 1980s show that crime is concentrated in specific places in urban areas. This has led many scholars to argue that crime places would be a more effective focus of crime prevention activities than people involved in crime. Previous studies have shown that crime is concentrated at such micro places, but they have not examined critically whether our understanding of crime across place would have been seriously altered if we had used larger geographic units of analysis to characterize changes in crime rates over time. Our study uses trajectory analysis and GIS to examine this question. Our geographic analysis reveals a tendency for members of the same trajectory to be clustered. However, tremendous block by block variation in temporal patterns of juvenile crime is also exposed. These findings show that much would have been lost if we would have aggregated up from the street block and examined only units such as census block groups. We think these data suggest that much of the action of crime at place occurs at very micro units of geography such as street blocks, and that researchers should begin with micro units of analysis before moving to larger aggregates such as census block groups.