Crime Mapping & Analysis
William Jarvis & Ibrahim SabekCSCI 5715
Prof. Shashi Shekhar
Wilson, Ronald and Filbert, Katie. “Crime Mapping and Analysis.”
Encyclopedia of GIS. Ed. Shashi Shekhar & Hui Xiong. New York: Springer Science+Business Media, 2008.
Definition
●Intersection of three sciences: Geography, Sociology, and Criminology.
●A bunch of techniques●Visualizing raw geographic data.●Analysing geographic features for patterns.●Uncovering spatial interactions between features.
Background●1930 - 1970 → Social Disorganization ●Chicago School of Sociology.
●1970 - 1990 → Environmental Criminology ●Social Disorganization + GIS software.
●1990 - present.●Funding crime mapping research centers.
● Tobler’s First Law of Geography.●Places are not isolated islands of activity.
●Interactions, such as social, demographic, or economic occur within and between places ●The closer you are in space, the more related you are
●The basic foundation for the concept of distance decay
Scientific Fundamentals
Applications● Five key applications:● Thematic Mapping
● Non-Graphical Indicators
● Hot Spots
● Spatial Regression
● Geographic Profiling
Hot Spots● Hot spots (and their inverse, cold spots) are places with a
greater (lower) than average level of crime.
● Done by many agencies to provide guidance in resource allocation
● Analysis can occur at a variety of scales, macro to micro● E.g. high crime neighborhoods vs. high crime centered
around a particular bar
● Level of analysis allows police to take specific actions from more patrols to investigating and serving warrants (Champions Bar & Grill in Minneapolis)
Graffiti Hot/Cold Spots in Lincoln, NE
Source: “Extended Crime Analysis with ArcGIS Spatial Statistics Tools.” Accessed at http://www.esri.com/news/arcuser/0405/ss_crimestats1of2.html. Last accessed 10/7/14.
●Question: Given a data set, can hot/cold spots be found via SQL/OGIS query?
●No, must be calculated be calculated via spatial statistics.●Nearest Neighbor Index
●Crime incidents geocoded on map, distance between incident and neighbors calculated●Distances summed then divided by number of incidents in area of analysis●Next, map of random incidents is made, and the same calculation repeated on these random incidents.●Ratio of two numbers = NNI. NNI < 1 means data are clustered.
●STAC (Spatial and temporal analysis of crime ellipses)●Create circles of decreasing radius around each crime incident●Areas of greatest overlap indicate hotspotsImage source: http://en.wikipedia.org/wiki/Crime_hotspots. Last accessed 10/8/14.
Geographic Profiling● Technique for identifying likely anchor point of a serial
offender (for example, residence).
●Utilizes crime place and routine activities theory, with the assumption that criminals don’t go far out of their daily routines to commit crimes
● Takes into account a series of crime locations associated with a particular serial criminal and creates a probability surface to identify the offender’s anchor point
Future Developments●Work done in three areas●Research and Technology Centers●Primary resources for research, development, and
application of GIS, spatial data analysis methodologies, and geographic technologies
●Software Development●CrimeStat●GeoDa
● Law Enforcement/Criminal Justice Agencies primarily focus on utilizing data to more efficiently prevent/fight crime
Relation to CSCI 5717● Will be exposed to this topic in Chapter 7.● Applications of spatial data● Spatial data mining to discover trends
Questions?
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