The Role Of Geographic Profiling In Serial Violent Crime Investigation
Thanks to films like silence of the lambs, many people associate criminal profiling with the methods and techniques developed by the FBI at the Behavioral Science Unit at Quantico.
There are, however, a number of other approaches that can be used in the course of a criminal investigation. The role of one of these other approaches, geographic profiling, will be outlined in the course of this article.
Geographic profiling is an information management system and investigative methodology that evaluates the locations of connected serial crimes to determine the most probable area of offender residence.
It can be applied in cases of serial murder, rape, arson, robbery and bombings.
Background and History
The name most closely associated with geographical profiling is Kim Rossmo. Rossmo began studying geographical profiling as part of his PhD studies at Simon Fraser University (British Columbia, Canada).
He studied under professors Paul and Patricia Brentingham, who had developed a theoretical crime model which examined where crimes were most likely to happen, based on offender residence, workplace and leisure activity.
Put simply, the Brentingham model maintains that we all have an ‘activity space’ related to the areas in which we live, work and play and that this activity space produces a discernible pattern of movement around the city.
In relation to criminal activity, therefore, it follows that an offender has to know about a particular geographical area before he or she begins selecting crimes to commit; and where the offenders movement patterns intersect within this geographical area, will to a large extent determine where the crime takes place.
Kim Rossmo noted that the Brentingham model was examined primarily in relation to crime prevention and was interested in approaching the topic from the opposite perspective i.e. asking the question, what does the location of a crime say about where the offender might live?
Acknowledging the potential investigative use of this research the Vancouver Police Department established the worlds first Geographic Profiling Section in 1995. Since it’s launch, Scotland Yard, The FBI, The New York Police Department and The Royal Canadian Mounted Police have all called upon the services of the geographic profiling section.
How Does Geographical Profiling Work?
Geographic profiling works on the premise that the location of a crime site can provide the police with vital information. It assesses and predicts the offender’s most likely place of residence, place of work, social venues and travel routes etc.
Geographic profiling consists of both quantitative (objective) scientific geographic techniques and qualitative (subjective) components e.g. a reconstruction and interpretation of the offender’s mental map.’
The primary geographic technique is a computerised system known as Criminal Geographic Targeting (CGT). Put simply, spatial data i.e. data relating to time, distance and movement to and from the crime scenes is analysed to produce a three-dimensional model known as a jeopardy surface.
The jeopardy surface contains height and colour probability codes which when superimposed onto a map of the area in which the serial crimes have been committed give an indication of the likelihood of offender residence or place of work.
Although the science underpinning geographic profiling can be difficult to comprehend, it’s easy to see how this approach can offer practical assistance in the course of a criminal investigation. As Rossmo points out:
‘By establishing the probability of the offender residing in various areas and displaying those results on a map, police efforts to apprehend criminals can be assisted. This information allows police departments to focus their investigative efforts, geographically prioritise suspects, and concentrate patrol efforts in those zones where the criminal predator is likely to be active’.
Geographical Profiling Process
A geographic profile would typically fit into a criminal investigation as follows:
A series of crimes is committed.
The crimes are investigated via traditional means.
Linking analysis conducted to ascertain which crimes are connected.
Psychological profile of the unknown subject conducted.
Geographical profile constructed.
New investigative strategies developed and pursued.
Geographical Profiling Methodology
In preparing a geographic profile, a number of operational procedures will be followed. These include:
Examination of the case file: Witness statements, autopsy reports & psychological profile (if available).
Inspection of the crime scene.
Meetings and discussions with lead investigators.
Visits to the crime sites when practical.
Analysis of local crime statistics and demographic data.
Study of street, zoning and rapid transit maps.
Overall analysis and report submission.
To find out more about geographic profiling and criminal profiling in general visit www.all-about-forensic-psychology.com