making a case (offender profiling)

The purpose of a police investigation is to collect material evidence from the crime scene in order to reach some clusions about the person(s) who might have committed that crime.

In general, there is llittle common basis in the way that profiling is carried out, but all profiling generally has a common aim;

"At the heart of profiling is the belief that characteristics of the offender can be deduced by a careful and considered examination of the characterisitics of the offence. " Ainsworth 2001

Offender profiling was originally developed by the FBI who established the set of profiling techniques known as crime scene analysis.

;imposes a big picture onto a crime scene, which they call a typology. They then look for details in the scene which will support their hypothesis.

• Disorganised offender; is likely to have committed the crime in a moment of passion, with nor pre-planning and using whatever is to hand. They may leave blood, semen, fingerprints and the murder weapon behind. This type of offender is thought to be less intelligent and socially incompetent.
• An organised offender leads an orderly life and kills after undergoing some sort of critical event, and their actions reflect planning and control, perhaps with the use of restraints and bringing a weapon to the scene. The crime scene will therefore reflect this order and the offender is more likely to use a verbal approach with vicitims. The offender is claimed to be of average to high intelligence, socially cometent, and more likely to be in employment than a disorganised offender.
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Canter investigated the organised/disorganised theory of serial murder.

In 1990, Canter and Heritade published a paper on a model of offender profiling. The central quest was to identify associations between aspects of the offender's characteristics and offence behaviour. This is a cognitive social approach in which the criminal's interactions with others are seen as the key to their behaviour.

It is bottom-up because no initial assumption is made about the offender until a statistical analysis using correlational techniques has been carried out on the detail of the cases.

Canter's methods can be considered more objective and reliable than top-down procedures because they are always based on data analysis and a theoretical basis of human behaviour. However, in practice the police will adopt a 'whatever works' philosophy and use elements of either approach.