Thursday, March 21, 2013

Summary of Findings (Green Team): Crime Mapping (4 out of 5 Stars)

Green Team
Rating (4 out of 5 Stars)

Note: This post represents the synthesis of the thoughts, procedures and experiences of others as represented in the 8 articles read in advance (see previous posts) and the discussion among the students and instructor during the Advanced Analytic Techniques class at Mercyhurst University in March 2013 regarding Crime Mapping specifically. This technique was evaluated based on its overall validity, simplicity, flexibility and its ability to effectively use unstructured data.

Crime mapping is a GIS technique that involves mapping of crimes in order to detect patterns that can focus on enforcement and prevention. Crime mapping has evolved with the shift in policing towards a more proactive approach rather than reactive, called intelligence-led policing.    


  • Visual representation of specific crimes in geographic locations
  • Provides a base for the analysis of trends pertaining to specific crimes
  • Allows for visualization of crime over time


  • Relies on reported crimes -- not all crimes are reported to the police
  • Does not ease the communication between the analyst and the decision maker
  • May not be useful for rural areas

  1. Decide on the area to investigate for crime mapping
  2. Decide what the ultimate goal is of the investigation (ex: find where assaults are most prevalent in New York City)
  3. Locate and plot relevant data applicable to the investigation
  4. Indicate area(s) where the target crime is most concentrated (ex: along a subway line, in a particular district)
  5. Analyze trends with regard to specific crimes and regions relevant to stated goals -- especially in regard to proactive measures

Personal Application of Technique:
The class individually assessed specific crimes in Philadelphia, PA as mapped on in order to identify the top three hotspots for each particular crime. They then compared the hotspot locations with a handout map provided to show the police district boundaries in the city. The class discussed their findings to compare in which districts their hotspots overlapped for the same crime as well as across different crimes. The class identified hotspots for various crimes primarily in Districts 6, 9, 18, 22, 24, and 26, primarily constituting the center and northern portions of the city. The class then discussed factors that may contribute to these hotspots, including the prevalence of subway systems and residential versus commercial areas.

Rating: 4 of 5 stars

For Further Information:


  • Directionality is frequently excluded from analysis
  • Humans are inherently poor identifiers of  hotspots

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