GIS and Crime, Part I, 16 March 2015
The ability to visualize crime is essential for the identification of hotspots and reduction of crime rates. Not all branches of criminology understand the importance of geography in understanding crime, but environmental criminology does understand that crime is not randomly distributed. There are three ways to understand the spatial distribution of offenses and offenders: Routine Activity Theory, Rational Choice Theory, and Criminal Pattern Theory.
Routine Activity Theory is described by the following formula:
likely offender + suitable target – capable guardian = crime opportunity
By looking at nodes of activity, the theory takes into account the routine activities of both criminals and victims, and it account for socioeconomic variables.
Rational Choice Theory assumes that offenders make a rational decision about whether to commit a crime. The theory supposes that criminals will balance rewards against the chances of getting caught.
Criminal Pattern Theory states that offenders will be affected by the routines of their daily lives. For example, they will commit crimes in areas they are familiar with.
Environmental criminology combines these three theories to better understand the links between crime, time, and space. By comparing the spatial distribution of offenders with that of offenses, researchers can understand how the two factors are related over space.
In Vancouver, GIS is incredibly important. Because there is so much data and too many classes, GIS is the only way to sort through and utilize the information. Dr. Kim Rossmo uses GIS in the city to aid in geographic profiling. Profiling does not solve crimes, per se, but it does help find answers, particularly in cases of serial killers, as people tend to commit crimes in areas they are familiar with. The Donut Theory states that while people will want to commit crimes in familiar areas, they do not want to do it too close to home, so there will be a ring of possible crime areas around their residence.
Crime analysis is “the qualitative and quantitative study of crime and law enforcement information in combination with socio-demographic and spatial factors to apprehend criminals, prevent crime, reduce disorder, and evaluate organizational procedures.” GIS can be used to assist crime analysis is many applications, including intelligence analysis, criminal investigation analysis, tactical crime analysis, strategic crime analysis, and administrative crime analysis. I have listed these analyses in by level of aggregation from low to high.
Definitions are as follows:
Intelligence analysis: “the study of ‘organized’ criminal activity in order to assist investigative personnel in linking people, events, and property”
Criminal investigative analysis: “the study of serial criminals, victims and/or crime scenes as well as physical, socio-economic, psychological, and geographic characteristics to develop patterns that will assist in linking together and solving current serial criminal activities”
Tactical crime analysis: “the study of recent criminal incidents and potential criminal activity by examining characteristics”
Strategic crime analysis: “the study of crime and law enforcement information integrated with the socio-economic and spatial factors to determine long term ‘patterns’ of activity”
Administrative crime analysis: “the presentation of interesting findings of crime research and analysis based on legal, political, and practical concerns to inform large audiences within law enforcement, administration, city government, and citizens”
As well, here is a brief history of crime mapping:
- “Early 1800’s: Social Theorists: Single symbol point and graduated area maps
- early 1900’s: New York City Police Department and others: Single symbol point maps, ‘pin maps’
- 1920s and 30’s: Urban sociologists at the University of Chicago: Graduated area maps of crime and delinquency
- 1960-60’s: First computer-generated maps of crime
- 1980’s: Desktop computers available for (limited quality) mapping; Environmental Criminology Theory
- 1990’s: Desktop GIS and integration with law enforcement systems and data; government funding, etc.”