profiling- bottom-up approach Flashcards
what is the bottom-up approach?
data-driven
uses evidence collected from crime scene to develop hypotheses about likely characteristics, motivations, routine behaviour and social background of the offender
how does it differ from the top-down approach?
doesn’t begin with fixed typologies
deeper and more rigorous scrutiny of offence
more grounded in psychological theory
investigative psychology
applies statistical procedures and psych theory to the analysis of crime scene evidence.
aim- to establish patterns of behaviour that are likely to occur across crime scences.
this develops a statistical database which then acts as a baseline for comparison.
investigative psychology method
1) details from crime scene matched with statistical analysis of offender behaviour patterns based on psychological theory
2) specific details of an offence can be used to reveal important details about offender (personal history, family background, etc.)
may also determine whether series of offences are linked/committed by same person
interpersonal coherence
the way an offender behaves during a crime reflects their everyday behaviour (Dwyer 2001). e.g. some ra[ists want to maintain maximum control and humiliate victims. may give insight into how offender relates to women in everyday life.
significance of time and place- indicates where live
forensic awareness- individuals who have been subject to police interview before aware of how to cover tracks
geographical profiling
uses info about location of linked crime scenes to make interferences about likely home or operational base of offender (crime mapping)
what does geographical profiling assume?
serial offenders restrict their work to geographical areas they are familiar with
the spatial pattern of their behaviour provides a centre of gravity and may help investigators predict next crime scene
Canter’s circle theory
the distribution of offences leads us to describe an offender in one of two ways:
- the Marauder is likely to operate in close proximity to their home
- the Commuter is likely to travel a distance away
gives insight into nature of offence (planned or opportunistic) and other important factors about offender, such as mode of transport, employment status, etc.
research support- investigative psychology
canter and heritage (1990)- smallest space analysis of 66 sexual assault cases. several behaviours identified as common in diff samples of behaviour, e.g. use of impersonal language and lack of reaction to victim.
each individual displayed characteristic pattern of such behaviours. helps case linkage.
supports basic principle that people consistent in their behaviour.
counter
case linkage depends on database. only consists of historical crimes that have been solved. perhaps solved because straightforward to link crimes. circular argument.
IP may tell us little about crimes that have few links between them and may be an ineffective method
research support- geographical profiling
lundrigan and canter (2001)- smallest space analysis of 120 murder cases (US serial killers). spatial consistency in behaviour. location of each body disposal site created ‘centre of gravity’. go in diff directions to dispose body but in end create circular effect around home base.
offender’s base invariably located in centre. more noticable in marauders.
supports view that geographical info can be used to identify offenders.
limitation- geographical profiling
success reliant on quality of data police can provide.
recording of crime not always accurate, can vary between forces. around 75% crimes not even reported.
question utility of approach that relies on accuracy of geographical data.
even if info correct, other factors may be just as important, e.g. timing of offence, age and experience of offender (ainsworth 2001).
suggests geographical profiling may be insufficient when used alone.
