Offender profiling: bottom-up approach

define the bottom-up approach

Profilers work up from evidence collected from the crime scene to develop hypotheses about the likely characteristics, motivations & social background of the offender

define investigative psychology

A form of bottom-up profiling that matches details from the crime scene with statistical analysis of typical offender behaviour patterns based on psychological theory

define geographical profiling

A form of bottom-up profiling based on the principle of spatial consistency - that an offender’s operational base & possible future offences are revealed by the geographical location of their previous crimes

the bottom-up approach aims to generate…

a picture of the offender (their likely characteristics, routine behaviour & social background) through systematic analysis of evidence at the crime scene

Unlike the top-down approach, the British bottom-up model does not …

begin with fixed typologies.

The profile is ….

‘data driven’ & emerges as the investigator engages in deeper & more rigorous scrutiny of the details of the offence.

Bottom-up profiling is more grounded in…

psychological theory than the top-down approach.

Investigative psychology is an attempt to …

apply statistical procedures alongside psychological theory to the analysis of crime scene evidence

The aim of investigative psychology is to establish…

patterns of behaviour that are likely to occur across time scenes.

investigative psychology develops a…

statistical database which then acts as a baseline for comparison for possible suspects.

what are the 3 main features of investigative psychology

interpersonal coherence, smallest space analysis, forensic awareness

what is interpersonal coherence

people are consistent in their behaviour so there will be correlations between elements of a crime & how people behave in their everyday life

what is smallest space analysis

a statistical technique involved in finding correlations between crime scenes & offender characteristics to see what the most common connections are. If we know one characteristic, we know it is likely the offender will have other characteristics

what is forensic awareness

certain behaviours may reveal an awareness of police techniques (an ability ‘to cover their tracks’) suggesting individuals who have been the subject of police investigation before

geographical profiling uses

information about the location of linked crime scenes to make inferences about the likely operational base of an offender

geographical profiling can be used in conjunction with psychological theory to…

create hypotheses about how the offender is thinking as well as their modus operandi

what are the 2 main features of geographical profiling

circle theory & criminal geographic tragetting

what is the circle theory

serial killers will restrict their work to geographical areas they are familiar with & so understanding their behaviour provides investigators with a centre which is likely to include the offenders base (usually in the centre of the spatial pattern)

criminals can be categories as….according to the circle theory

maurader or commuter

what is a maurader

an offender who operates in close proximity to their home

what is a commuter

a offender who is likely to have travelled a distance away from their usual residence

explain the strength evidence for investigative psychology

researchers conducted an analysis of sexual assault cases and examined the data using smallest space analysis & several behaviours were identified as common in different samples (e.g. use of impersonal language). Each individual displayed a characteristic patterns of such behaviours & this can be used to help establish whether two or more offences were committed by the same person

explain the weakness case linkage depends on the database & this will only consist of historical crimes that have been solved

the fact that these crimes are solved may be because they were straightforward to link them together in the first place

explain the strength evidence to support geographical profiling

researchers collated information from murder cases involving serial killers in the US to find a spatial consistency in the behaviour of killers. The location of each body created a ‘centre of gravity’ where the offender’s base was invariably located in the centre of the pattern

explain the weakness geographicanl profiling is insufficient on its ow

the success of geographical profiling may be reliant on the quality of data that the police can provide. Recording of crime is not always accurate & 75% of crimes aren’t even reported. This calls to question the utility of an approach that relies on the accuracy of geographical data