Geographic Profilers

Question 1

Introduction

Answer 1

Geographic profiling: An investigative methodology used to determine most probable location of an offender’s anchor point (usually their residence, by analysing crime related spatial temporal data).

Similar procedural use:

• Animal hunting behavioural activity (Haglund 1997).
• Origin of disease (Le Comber, Rossmo et al 2011).

Only certainty in a crime is that the offender and victim come together at a time and location.

Geo is where? – Home address, work place & travel patterns.

Question 2

Least effort principle (Zipf 1950):

Answer 2

When multiple destinations are of equal desirability, the closest one will be chosen. Everything else being equal we will use least effort.

Eight robberies: the robber lives in an area around the spot that has the lowest total distance to the eight crimes, the so-called centre of minimum distance.

An interactive computation is necessary for this task. Then the profiler needs to determine how large the area around that spot has to be to have an acceptable probability that the offender lives there.

Question 3

Distant Decay (Branitingham & Braintingham 1984)

Answer 3

The function shows that most offenders commit their crimes at locations relatively short distance from their residencies; further away from home, the fewer crimes are committed. But only a few crimes are committed in the area immediately around the offender’s residence.

Becker (1968) argued that offenders, like other people, base their decisions on a cost and reward analysis.

Assumed the method chosen will be the least effort and costs and that renders the most profit (Baldwin 1976 & Turner 1969). Chances of being caught in a familiar area is high, offenders seem to have a buffer zone. Indicating that the area immediately around the offender’s residence is associated with low traveling costs but higher costs of getting caught.

The areas far away, however, are associated with higher traveling costs but lower costs of getting recognized and caught. An optimum will be found at or around the top of the function where there is a balance between the costs of traveling and getting caught. For commercial robberies in the Netherlands, for instance, this top is 3.5 km from the residence of the offender (Koppen & Jansen 1998).

Some studies have shown no buffer zone (Kocsis & Irwin 1997; Warren et al 1998). If profiling is done it is just as effective either way (Canter et al 2000).

Question 4

Routine Activity Theory (Cohen & Felson 1979)

Answer 4

People know best the environment around the place where they live, the places they visit often, and the routines between them, commute to work. Organise knowledge of their environment around these anchor points (Garling & Golledge 2000). Named activity nodes (Brantingham & Brantingham 1984;1993;1991).

Indeed, crime trips into unknown territories to locate crime sites are relatively rare (Reppetto 1974). This contention is based on the socalled routine activity model (Clarke & Felson 1993; Cohen & Felson 1999). In this model, “opportunity” is an important concept to explain criminal behaviour. Offenses occur as a result of the convergence in space and time of three important elements: a motivated offender, a suitable and vulnerable target, and the absence of a capable guardian against crime (Felson 1986).

Question 5

Rational Choice Theory Clarke & Felson 1993; Cornish & Clarke 1986

Answer 5

Crimes are outcomes of choices made by offenders:
• Involvement & Planning
• Execution & Opportunity

Cost-Benefit Analysis: Goals, Resources & Risk

Factors affecting Rationality: State of mind

Individual differences

Choices change over time: Knowledge and Experience

This adapted model, called the bounded rational choice model (Simon 1986; Johnson & Payne 1986), proposes that possible crime locations close to an offender’s residence will probably be avoided because of the higher perceived risk of apprehension. Furthermore, possible offense locations very far from home will often be avoided because the perceived costs of traveling are too high when alternatives closer to home can be found. If, however, faraway targets are very promising, a longer journey is undertaken (Koppen & Jansen 1998).

Question 6

Physical and Mental Components:

Answer 6

Geographic Profiling works because criminal behaviour and human movement are not random processes. Patterning of crime involves both physical and mental components

• Motivation
• Opportunity
• Mobility
• Perception

Question 7

Aggregated Journey to Crime Stuides K (Rossmo et al 2004)

Answer 7

Murder: Less than 1 mile
Rape: 1.50 miles
Robbery: 2 miles

Online grooming: this may not be the case, use hotels etc.

Colin Sutton: Geographic profiling Is much more exact science that can help target resources and enquiries into a specific place. (Colin Sutton)