Geographic profiling is a criminal investigative methodology that analyzes the locations of a connected series of crimes to determine the most probable area of offender residence. By incorporating both qualitative and quantitative methods, it assists in understanding spatial behaviour of an offender and focusing the investigation to a smaller area of the community. Typically used in cases of serial murder or rape (but also arson, bombing, robbery, and other crimes), the technique helps police detectives prioritize information in large-scale major crime investigations that often involve hundreds or thousands of suspects and tips.
While it may not seem so, understanding an offender’s geographical tendencies and habits can tell investigators and profilers a great deal about the personality of that individual. The underlying principle is that crime-related locations provide information regarding the victim and the offender’s interaction with the geographical environment. It can even show the level of planning that went into the offence, the offender’s familiarity with the location and the extent to which the offender’s use of the crime environment reflects aspects of his non-criminal spatial lifestyle.[1] Geographical profiling is growing in popularity and, combined with offender profiling, is a very helpful tool in the investigation process of a serial murder case.
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While the use of spatial analysis methods in police investigations goes back many years (think of detectives gathered around a large city map with pins stuck in it), the formalized process known today as geographic profiling originated out of research conducted at Simon Fraser University's School of Criminology in British Columbia, Canada, in 1989.[2] The leading developer of geographic profiling is Dr. Kim Rossmo, a former detective with the Vancouver, Canada Police Department. His goal was to create a map by analytical crime mapping to display the most likely location of where the serial offender lives. Geographic profiling model is based on the assumption that offender’s are more likely to select their victims and commit a crime which would be centered near their home address. The technique has now spread to several U.S., Canadian, British, and European law enforcement agencies. Originally designed for violent crime investigations, it is increasingly being used on property crime.
Through numerous research studies, there has been an increased importance placed on the journeys offenders habitually take to determine the geographical range of criminal activity. These areas become a comfort zone for predatory offenders to commit their crime with a feeling of safety. Consequently, criminal acts follow a distance decay function, such that the further away the regular activity space of an offender is, the less likely that the person will engage in a predatory criminal activity. However, there is also a buffer zone where an offender will avoid committing crimes too close to their homes in the likely event that they will be identified by a neighbour.[3]
Also, the theoretical foundation is in environmental criminology, particularly[4]:
Furthermore, serial crimes are the easiest to develop geographic profiles, since each crime contains new spatial information and provides additional data including the fact that crime area tends to enlarge with an increase of comfort and confidence. The initial hunt and criminal acts are most likely to occur relatively close to the location of the offender’s home or workplace. As the success rate increases, there will be a burgeoning sense of confidence to seek his prey further from home and to travel a greater distance. Crimes that are suitable for analysis are those that are predatory in nature and exercises some spatial decision-making process such as the area for hunting targets, travel routes, mode of transportation and even body dump sites.[5]
Another leading researcher in this area is David Canter whose approach to geographic profiling detailed around the circle theory of environmental range. In 1993, Canter and Larkin developed two models of offender behaviour: marauder and commuter models. The distinction is that marauders operate in an area that is in close proximity of the offender’s home base while commuters commit crimes outside of the habitual zone. It hopes to differentiate the two types of serial offenders by studying the relationship of the criminal spatial behaviour to the offender’s place of residence.[6]
In developing a geographic profile, there are important factors to consider[7]:
Incorporating these factors in a profile can lead to a geographic pattern where it sheds light on an offender’s mobility, method of transportation, ability to navigate boundaries and most importantly, the possible residential location. It is important to recognize such spatial intentionality, to determine the offender’s comfort zone and their desire to commit crimes in locations where they feel a sense of familiarity. However, the reality may be more complex since an offender may have multiple spatial anchor points, such as home, workplace or the residence of their significant other.[8]
Geographic profiling is an investigative tool that can be seen as a strategic information management system to assist police with the large volume of information throughout an investigation. It concentrates its focus on the geographical aspect of the crime and was developed in response to the demands of solving serial crimes.[9] In response, Rossmo developed a computerized geographical profiling technique called criminal geographical targeting (CGT)[10] which assess the spatial characteristics of crimes. It scans the geographic coordinates of the offender’s criminal area and produces a topographic map, which assigns probabilities to different points for the location of the offender’s home base.
Further tools employed by geographic profilers include specialized software systems, such as Rigel, CrimeStat or Gemini. Similarly, system inputs are crime location addresses or coordinates, often entered through a geographic information system (GIS). Output is a jeopardy surface (three-dimensional probability surface) or color geoprofile, which depicts the most likely areas of offender residence or search base. These programs assist crime analysts and investigators to focus their resources more effectively by highlighting the crucial geographic areas.
Geographic profiling is a sub-type of offender or criminal profiling (the inference of offender characteristics from offence characteristics). It is therefore related to psychological or behavioral profiling. If psychological profiling is the "who," geographic profiling is the "where." All certified geographic profilers are members of the International Criminal Investigative Analysis Fellowship (ICIAF), a professional profiling organization first begun by investigators trained by the FBI in the mid-1980s. Furthermore, the Geographic Profiling Analysis (GPA) training programme ensures that geographic profiling analysis remains a recognized law enforcement tool; a meaningful certification for crime analysts and detectives; maintain a standard of quality through adequate qualifications in law enforcements; and finally to establish an ethical code of conduct.
Although geographic profiling is a useful tool for assisting investigations, like any other models there are numerous limitations[11]:
Washington, DC: American Psychological Association