offender profiling: the bottom up approach

What is the bottom up approach in offender profiling?

The aim of the bottom up approach is to generate a picture of offender - their likely characteristics, routine behaviour and social background

This is done through systematic of evidence at the crime scene. The British bottom up model does not begin with fixed typologies, instead the profile is ‘data driven’ and emerges as the investigator engages in deeper and more rigorous scrunity of the details of the offence

Investigative psychology

Is an attempt to apply statically procedures, alongside psychological theory to the analysis of crime scene evidence. The aim in relation to offender profiling is to establish patterns of behaviour that are likely or occur to coexist across crime scenes

This is in order to develop a statistical database which then acts as a baseline for comparison

Specific details of an offender, or related offences can then be matched against this data base to reveal important details about the offender, their personal history , family background etc

This may also determine whether a series of offences are linked toed in that they are likely to have been committed by the same person

What is interpersonal coherence?

The way that an offender behaves at the scene including how they ‘interact’ with the victim may reflect there behaviour in more everyday situations

The significance of time and place is also a key variable and may indicate where the offender lives

What is forensic awareness?

Forensic awareness describes those individuals who have been the subject of police intergration before their behaviour may denotes how mindful they are ‘ covering their tracks’

Geographical profiling

Uses info about the location of linked crime scenes to make inferences about the likely home or operational base offender - known as crime mapping and based on the principle of spatial consistency

It is used to create a hypotheses about how the offender is thinking as well as their modus operandi

The assumption is that the serial offender will restrict their work to geographical areas they are familiar with and so understanding the spatial pattern of their behaviour provides investigators with a centre of gravity which is likely to include the offenders base

Canters circle theory

The pattern of offending forms a circle around the offenders home base. In addition to distribution of offenders leads us to describe an offender in one of two ways:

• The marauder - who operates in close proximity to their home base

• The commuter - who is likely to have travelled a distance away from their usual residence

What can spatial decision making do?

Can offer the investigative team important insight into the nature of the offence ( whether it was planned or opportunistic ) revealing other important factors about the offender such as their ‘ mental maps ‘ mode of transport, employment status, approximate age

Evidence for investigative psychology

P. One strength of investigative psychology is that evidence supports its use

E. Canter and heritage conducted an analysis of 66 sexual assault cases. The data was examined using smallest space analysis serval behaviours were identified as common in different samples of behaviour such as lack of reaction to victim

E. Each individual displayed a characteristic pattern of such behaviours and this can help establish whether two or more offences were committed by the same person ( case linkage)

L. This supports one of the basis principles of investigative psychology that people are consistent in their behaviour

Depends on the database

P. One limitation of investigative psychology is case linkage depends on the database and this will only consist of historical crimes that have been solved.

E. The fact that they were solved may be because it was relatively straight forward to link crimes together in the first place

E. Which makes this a circular argument

L. This suggests that investigative psychology may tell us little about crimes that have few links between them and therefore remain unsolved

H. It is more scientific than TD as it uses objective statistical techniques and systematic computer analysis

Evidence for geographical profiling

P. One strength of evidence to support geographical profiling

E. Lundrigan and canter collected info from 120 murder cases involving serial killers in the US. Smallest space analysis revealed spatial consistency in the behaviour of the killers. The location of each bodies disposal site created a ‘centre of gravity’

E. The offenders base was invariably located in the centre of the pattern. The effect was more noticeable for the offenders who traveled short distances (marauders)

L. This supports the view that geographical info can be used to identify an offender

Geographical information insufficient

P. One limitation is that geographical profiling may not be sufficient on its own

E. As with investigative psychology the success of geographical profiling may be reliant on the quality of data that the police can provide. It is estimated 75% of crimes are not even reported to police in the first place

E. This calls into question the utility of an approach that relies on the accuracy of geographical data. Even if the info is correct, critics claim that other factors are just as important in creating a profile such as the timing of offence and the age and experience of the offender ( ainsworth)

L. This suggests that geographical info alone may not always leas to the successful capture of an offender