resided in southeast London. The geoprofile identified the convicted offender’s home in the top 3.4% (9.1 mi2) of the hunting area.

Investigators may benefit from a geographic perspective on their crimes, independent of a formal profile. It is not just what offenders do, but also what they do not do, that is of interest. Some specific questions worth considering include:

1.Locations — What are the locations connected to this crime or crime series? Where are they? What are the distances and travel times between them?

2.Time — When did the crimes occur (i.e., time, weekday, date)? What was the weather on those dates? What are the time lags between crimes?

3.Site selection — How were the crime locations accessed? What else is in their general area? How might the offender have known of these locations? What criminal purpose or function did they serve?

4.Target backcloth — What is the geographic arrangement and availability of the target group? What degree of control did the offender have over the choice of crime locations? Has displacement (spatial or temporal) occurred?

5.Hunting — What hunting method did the offender use? Why were these sites chosen, and not other possible locations? What was the offender’s probable mode of transportation?

10.4.2 Operational Procedures

10.4.2.1 Information Requirements

Certain operational procedures are followed in the request for and preparation of a geographic profile. Assessing the appropriateness of the crimes, collection of necessary information, and coordination between the profiler and the investigator are necessary. The following is the content of a standard letter sent by the Vancouver Police Department to investigators requesting a geographic profile. It outlines basic information requirements and procedural details:

Geographic profiling is an investigative support technique for serial violent crime investigations. The process analyzes the locations connected to a series of crimes to determine the most probable area of offender residence. It should be regarded as an information management system designed to help focus an investigation, prioritize tips and suspects, and suggest new strategies to complement traditional methods.

A preliminary assessment is necessary to determine if a case is appropriate for geographic profiling. This is best done by directly contacting the Van-

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couver Police Department Geographic Profiling Section (GPS). If it is determined that a profile is appropriate, then an official letter of request must be sent to the Chief Constable. This letter should indicate the serious nature of the crimes, the fact that an initial discussion with the GPS has already occurred, and that all costs involved in the preparation of the profile will be covered. The Vancouver Police Department provides this service at no charge to requesting law enforcement and prosecution agencies, but any expenses incurred must be borne by the requesting agency.

A case information package should be prepared and forwarded to the GPS. The accuracy of the profile is determined by the quality of the information on which it is based. This package should include the following:

• A list of all locations connected to those crimes believed to be part of the series (e.g., victim encounter sites, crime scenes, body dump/victim release sites, offender directions of travel, etc. This list should be in chronological order, and include complete address information, and date, weekday, and time of offence;

•A street map with all crime locations precisely marked;

•Case summaries;

•A criminal profile (if available);

•The investigating officer’s business card; and

•Any other relevant information.

Further information may be required (e.g., crime scene photographs, demographic data, bus routes, etc.). If necessary, the GPS will advise the investigating officer of what additional information is required. All GPS casework is kept strictly confidential.

The requesting agency must decide if they wish to have the geographic profile prepared on-site. An on-site profile is more thorough, accurate, and complete, and is recommended in more serious cases. All travel and accommodation expenses (e.g., airfare, taxis, airport tax, hotel, meals, etc.) are the responsibility of the requesting agency, and must be reimbursed to the GPS within 30 days of expenditure.

In most cases the GPS will prepare a written report, complete with colour maps, indicating the area of most probable offender residence. This will be mailed, by normal post (unless otherwise specified), to the investigating officer. While this report explains the theory, process, and output of geographic profiling, and suggests certain investigative strategies, it is recommended that the officer consult with the GPS if there are any questions or if further explanation is required. If additional crimes occur or new information comes to light, an update on the profile may be necessary. When the offender is apprehended, the GPS would appreciate being notified so

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that the accuracy and utility of the geographic profile can be assessed. It is important to realize that a profile is only one tool of many, and the requesting agency is responsible for intelligently combining it with the other techniques available to an investigation. If there are any questions regarding geographic profiling, the GPS can be contacted directly.

Not every case may be geographically profiled. While a preliminary review is necessary to determine suitability, generally a profile may be developed when the following conditions have been met:

1.A series of crimes has occurred that have been linked together with a reasonable degree of certainty (i.e., they are likely the responsibility of the same offender);

2.There are at least five crime sites in the series (although in some circumstances it may be possible to provide an assessment with fewer locations); and

3.The investigation is of a serious enough nature to justify the time and effort required to produce the profile.

A geographic assessment may be appropriate in those instances where a full profile cannot be prepared, for example, in cases involving only a few crime sites. Time-distance-speed calculations, journey-to-crime estimates, mental map interpretations, Thiessen polygons, and other methods of analysis have been successfully used in both geographic profiles and assessments. Thiessen polygons (also known as a Voronoi or Dirichlet polygons) define catchment areas around central positions, and any point within a given polygon is closer to its centre than to any other “competing” centre. The technique can be applied in cases involving certain offender hunting styles. For example, plotting the locations of playgrounds as Thiessen polygon centres may determine the probable residence area for a pedophile. This method was employed to determine the catchment regions around high schools in St. Catharines, Ontario, for the Green Ribbon Task Force investigation of the abductions and murders of two teenage girls. The killers, Paul Bernardo and Karla Homolka, identified through DNA, resided near the school attended by the second victim. The geographic profile correctly predicted an offender residence area of 10 square kilometres (0.5% of the total hunting area).

10.4.2.2 Requesting a Geographic Profile

A geographic profile takes approximately two weeks to complete, though response time depends upon current case load. Requests are prioritized according to level of community risk — murder over rape, current cases over historical ones, active offenders over intermittent criminals. The process of profile preparation follows a set outline, the main steps of which include:

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1.Thorough perusal of the case file, including investigation reports, witness statements, autopsy reports, and criminal profile (if available);

2.Detailed examination of crime scene and area photographs;

3.Interviews with lead investigators and crime analysts;

4.Visits to each of the crime sites, when possible;

5.Review of neighbourhood and demographic information;

6.Study of street, land use, and transit maps;

7.Analysis; and

8.Report preparation.

The Vancouver Police Department established the world’s first geographic profiling capability in 1990, with a mandate to provide services to the international police community. It has assisted in over 100 investigations, involving 1500 crimes, for agencies such as Scotland Yard, the FBI, the New York Police Department, and the RCMP. Requests have come from across Canada and the U.S., as well as from Britain, Germany, Belgium, Greece, South Africa, Mexico, Australia, New Zealand, and the Middle East. The service is now also available from the RCMP, the Ontario Provincial Police, and the British National Crime Faculty. Their profilers successfully completed an intensive understudy training program in Vancouver, the details of which are described below. Several other agencies have expressed interest in setting up similar units. Currently, the possibility of the Police Fellowship of Profilers (ICIAF) also becoming the international professional body for geographic profilers is being examined.

Contact details for qualified geographic profilers67 are listed below:

Detective Inspector D. Kim Rossmo

Geographic Profiling Section

Vancouver Police Department

312 Main Street

Vancouver, British Columbia

V6A 2T2 Canada

Telephone: (604) 717-3247

Corporal Scot M. Filer

Geographic Profiling Unit

Pacific Region ViCLAS Centre

Royal Canadian Mounted Police

“E” Division Headquarters

4949B Heather Street

67 The RCMP will be adding an additional geographic profiling position to its Behavioural Sciences and Special Services Branch at Ottawa Headquarters in late 1999.

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