Module 5 - Criminal Profiling

Tools employed by geographic profilers include various software systems such as Rigel, Predator, and CrimeStat. Input data typically consist of suspect-victim encounter sites, victim or body recovery locations, suspicious vehicle sightings, related public complaints or tips, and residential and employment locations of known suspects. The greater the number of data points one has to work with, the greater the degree of accuracy within the map. This information is entered into a geographic information system (GIS) that creates a three-dimensional surface map, sometimes referred to as a geoprofile. This map depicts the most likely area in which the primary suspect resides.

The use of such software in crime scene analysis involves entering various coordinates into an algorithm to interpret an offender’s pattern of behaviour. Geographic profiling assumes that the commission of serial crimes follows an identifiable pattern and that most people commit crimes relatively close to home or work. This system incorporates all methods of transportation a person could access and recognizes that an offender will usually maintain a buffer zone around his or her home to ensure some personal sense of anonymity.

Three-dimensional maps are based on occurrence locations. Areas of red represent hot spots of criminal activity. The combination of red and blue areas on the map constitutes what is known as a jeopardy surface, a type of topographical map with each ‘hot’ zone resembling the peak of a volcano. These peaks of criminal activity indicate areas in which an offender is assumed to reside. Investigators can then focus on neighbourhoods or places of work located in the immediate vicinity of these peaks, effectively narrowing the field of suspects who must be interviewed. Although a geographic profile does not produce a suspect’s name, it assists investigators by reducing the list of people police interview.

The geographic profile is then superimposed on a street map that pinpoints where the crimes being investigated have occurred. This map is often referred to as containing the ‘fingerprints’ of the offender's cognitive map. The program's predictive power is related to the number of crime sites entered into the program, which means that a suspect’s increased activity may increase the chances that he will be apprehended. After the map is created, police may assign surveillance teams to specific areas based on their assumptions of where the offender may strike next, or more commonly, they will use it to reduce the size of an area that must be canvassed for information on possible suspects.

When entering the data for analyzing the geographical patterns, three principle elements are involved:

• Distance: Perceptions of distance of criminal activity from home or work vary from one criminal to another, but they can be influenced by the availability of transportation, the number of barriers (such as bridges or state boundaries), the type of roads, and the criminal’s familiarity with the area.

• Mental map: A cognitive image of a person’s surroundings developed through experiences, travel routes, reference points, and centres of activity is a mental map. The places where we feel safe are taken for granted within our mental maps. Investigators consider that this principle is also true for offenders. As offenders grow bolder, their mental maps may change to produce an increase in the range of their criminal activity.

• Mobility: Some criminals are geographically stable (they stay in a certain region) and some are transient (they travel around). Whether they tend toward stability or mobility depends much on their experience with travel, means for travel, sense of personal security, and predatory motivations. For example, Ted Bundy travelled from the U.S. Pacific Northwest to Florida before being arrested by police. He eventually admitted to killing people in ten different states.

Geographic profiling focuses on these three factors in studying predatory behaviour. Criminals are thought to have certain awareness spaces—places where they feel comfortable enough to seek potential victims. Investigators see these to be the offender’s primary focus of activity. Serial killers are thought to display highly formatted predation patterns, but those suffering from mental disorders may pose difficult challenges for profilers because of their irrational and erratic actions. Richard Chase, also known as the Vampire Killer for his psychotic and highly aberrant behaviour that resulted in the murder of six people during a one-month period in 1977-1978, is such an offender. Only because of his reckless behaviour and disregard for being captured were police able to identify him so quickly. When Rossmo applied the software program Rigel retroactively to the Richard Chase investigation while testing the algorithm for his doctoral thesis, it showed that Chase's home was within 1.7 % of the total hunting area.

The Use of Geographic Profiling by Law Enforcement

Geographic profiling is used typically in cases of serial murder or serial rape, but it may be used in arson, bombing, and robbery. Geographic profiling helps police investigators prioritize information in large-scale major crime investigations that often generate hundreds or thousands of tips and suspects.

This system has had much success, as in the case of the Southside Rapist who sexually assaulted more than 12 women from 1985 to 1999 in Lafayette, Louisiana. When Dr. Rossmo was called to assist in the investigation, his geographic profile reduced the number of possible suspects to a list of twelve. He was initially disappointed to see that DNA testing cleared all twelve suspects, but the validity of the profile was supported when the culprit was later identified through a tip to police. This individual, who was not on the original list of suspects, actually lived within the topographical hotspot generated by Rossmo’s profile map.

Geographic profiling was used with a lesser degree of success in the Beltway Sniper attacks that occurred near Washington, DC, in October 2002. The two killers responsible for the murder or wounding of thirteen people were eventually apprehended after a tip from the public. Rossmo was called to assist in the investigation, but he discovered later that the transient lifestyle of the two offenders negated the use of ‘anchor points’ critical to successful geographic profiling. Because both men were living in their car during the shootings, there was no way to identify a pattern of behaviour incorporating travel between home, work, and recreational areas.

How Police Construct a Geographic Profile

The construction of a geographic profile involves

To assist from a scientific perspective, geographic profilers rely on software that assesses the spatial characteristics of a crime. Using specific measurements, the program makes numerous calculations and produces a topographic map based on the locations of similar crimes. In providing these results, the program takes into account known movement patterns, comfort zones, and ‘hunting’ patterns exhibited by the suspect.

The case of Clifford Robert Olson, one of the most dangerous serial killers in Canadian history, was another source of information that Dr. Rossmo referred to when he tested his theory of geographic profiling. In 1981, Olson murdered 11 children and teens in the Vancouver area. Rossmo later generated a map of Olson’s crimes and pinpointed his address to within a four-block radius encompassing areas of activity related to the abduction of his victims.