The law of crime concentration states that "for a defined measure of crime at a specific micro-geographic unit, the concentration of crime will fall within a narrow bandwidth of percentages for a defined cumulative proportion of crime."[1] This law builds on the well-established empirical observation in the criminology of place that crime concentrates at very small units of geography.[2][3][4]
Criminologist, David Weisburd, first proposed a formal "law of crime concentration" in 2015 after having observed the phenomenon across many cities.[1] In their longitudinal study of street segments in Seattle, WA, Weisburd and colleagues (2012) observed not only that crime was concentrated, but across a 16-year observation period the level of concentration was remarkedly consistent: 50% of crime incidents were found at between 4.7% and 6.1% of street segments in the city each year, despite a decline of more than 20% in overall crime during that period.[3] To test whether the law of crime concentration existed in other cities, Weisburd examined 8 additional cities in 2015. While noting variability between the five larger and three smaller cities, the overall range or bandwidth of crime concentrations observed was between 2.1% and 6.0% of streets producing 50% of city crime, and between 0.4% and 1.6% producing 25% of city crime, which supported a law of crime concentration across cities.[1]
Studies examining crime concentration have used a range of micro-geographic units. However, the micro-geographic unit of the street segment has been the most commonly examined unit by researchers to date.[5]
Since 2015, scholars have continued to test the law of crime concentration in cities across the world and the results continue to support a general framework of a law of crime concentration. For example, Schnell and colleagues (2017) analyzed violent crime incidents reported to the police in Chicago, IL between 2001 and 2014 and found that 56-65% of the total variability in violent crime incidents can be attributed to street segments in Chicago.[6] Haberman and colleagues (2017) tested the law of crime concentration in Philadelphia, PA and the results closely matched the bandwidth percentages expected from Weisburd (2015).[7] The law of crime concentration has even been tested in non-urban settings. Gill and colleagues (2017) tested the law of crime concentration in the suburban city of Brooklyn Park, MN and found that two percent of street segments produced 50% of the crime over the study period and 0.4% of segments produced 25% of the crime.[8]
A law of crime concentration has important implications for crime prevention policy and practice. Knowing that a disproportionate percentage of crime occurs at a very small percentage of street segments allows jurisdictions to more efficiently allocate often limited resources.[7][8] This is particularly important for police departments who can conduct focused patrols in the areas with the most crime incidents, also known as hot spots policing.
References
edit- ^ a b c Weisburd, David (2015). "The Law of Crime Concentration and the Criminology of Place". Criminology. 53 (2): 133–157. doi:10.1111/1745-9125.12070.
- ^ Sherman, Lawrence; Patrick Gartin; Michael Buerger (1989). "Hot spots of predatory crime: Routine activities and the criminology of place". Criminology. 27 (1): 27–56. doi:10.1111/j.1745-9125.1989.tb00862.x.
- ^ a b Weisburd, David; Elizabeth Groff; Sue-ming Yang (2012). The Criminology of Place: Street Segments And Our Understanding of the Crime Problem. Oxford University Press.
- ^ Weisburd, David; Shai Amram (2014). "The law of concentrations of crime at place: The case of Tel Aviv-Jaffa". Police Practice & Research. 15 (2): 101–114. doi:10.1080/15614263.2013.874169.
- ^ Lee, YongJei; John E. Eck; SooHyun O; Natalie N. Martinez (2017). "How concentrated is crime at places? A systematic review from 1970 to 2015". Crime Science. 6 (6): 1–16. doi:10.1186/s40163-017-0069-x.
- ^ Schnell, Cory; Anthony A. Braga; Eric L. Piza (2017). "The Influence of Community Areas, Neighborhood Clusters, and Street Segments on the Spatial Variability of Violent Crime in Chicago". Journal of Quantitative Criminology. 33: 469–496. doi:10.1007/s10940-015-9276-3.
- ^ a b Haberman, Cory P.; Evan T. Song; Jerry H. Ratfliffe (2017). "Assessing the Validity of the Law of Crime Concentration Across Different Temporal Scales". Journal of Quantitative Criminology. 33 (3): 547–567. doi:10.1007/s10940-016-9327-4.
- ^ a b Gill, Charlotte; Alese Wooditch; David Weisburd (2017). "Testing the "Law of Crime Concentration at Place" in a Suburban Setting: Implications for Research and Practice". Journal of Quantitative Criminology. 33 (3): 519–545. doi:10.1007/s10940-016-9304-y.