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Geography of Drug Activity and Violence: Analyzing Spatial Relationships of Non-Homogenous Crime Event Types

NCJ Number
Substance Use & Misuse Volume: 43 Issue: 2 Dated: 2008 Pages: 179-201
Date Published
23 pages

This study extended previous research by examining the place-based relationship between drugs and violence.


Study findings show that in almost half of all census tracts in Seattle, WA, there was a spatial relationship between where drug-dealing occurred and where violence occurred. The spatial dependence analyses also show, however, that there were places with strong drug clustering that did not show high intensities or clustering of violence. The between-classification analyses found that there was not a consistent and strong relationship between the specific locations of drug activity and the locations of violent crime, except perhaps in those areas in which drugs and violent crimes occurred more often. Spatial clustering between drugs and violence was more likely in areas with drug and violent-crime clustering. The study used three spatial statistical approaches: measures of spatial intensity/density, measures of spatial dependence for drugs and violent separately, and a modified spatial dependence approach for non-homogeneous populations. Official crime data and digital maps were obtained from the Seattle Police Department and the City of Seattle. Four types of data were initially collected, compared, and analyzed for the study: 911 calls for service as first recorded by the dispatcher, officer-modified 911 calls for service in which incidents were modified upon the initial response of an officer, computerized records of written reports, and reports of arrest. Only crimes that occurred in the years 1999, 2000, 2001, and 2002 were used, since these were the years for which there were data from all four sources. 3 tables, 5 figures, and 71 references

Date Published: January 1, 2008