I posted a pre-print of a paper myself, Rob Worden and Sarah McLean have finished, Replicating Group-Based Trajectory Models of Crime at Micro-Places in Albany, NY. This is part of the work of the Finn Institute in collaboration with the Albany police department, and the goal of the project was to identify micro places (street segments and intersections) that showed long term patterns of being high crime places.

The structured abstract is below:

Objectives: Replicate two previous studies of temporal crime trends at the street block level. We replicate the general approach of group-based trajectory modelling of crimes at micro-places originally taken by Weisburd, Bushway, Lum and Yan (2004) and replicated by Curman, Andresen, and Brantingham (2014). We examine patterns in a city of a different character (Albany, NY) than those previously examined (Seattle and Vancouver) and so contribute to the generalizability of previous findings.

Methods: Crimes between 2000 through 2013 were used to identify different trajectory groups at street segments and intersections. Zero-inflated Poisson regression models are used to identify the trajectories. Pin maps, Ripley’s K and neighbor transition matrices are used to show the spatial patterning of the trajectory groups.

Results: The trajectory solution with eight classes is selected based on several model selection criteria. The trajectory of each those groups follow the overall citywide decline, and are only separated by the mean level of crime. Spatial analysis shows that higher crime trajectory groups are more likely to be nearby one another, potentially suggesting a diffusion process.

Conclusions: Our work adds additional support to that of others who have found tight coupling of crime at micro-places. We find that the clustering of trajectories identified a set of street units that disproportionately contributed to the total level of crime citywide in Albany, consistent with previous research. However, the temporal trends over time in Albany differed from those exhibited in previous work in Seattle but were consistent with patterns in Vancouver.

And here is one of the figures, a drawing of the individual trajectory groupings over the 14 year period. As always, if you have any comments on the paper feel free to shoot me an email.