offender profiling: top-down and bottom-up approaches

offender profiling

a method of identifying the likely characteristics (psychological, behavioural, demographic) of an offender, by examining the characteristics of the crime and the crime scene.

what is the top-down approach to offender profiling

methodology based on general offender types, deductive interpretation of crime scene, relies on organised/disorganised typology of pre-set categories, focus on intuitive judgement and experience, used for violent crime (especially US)

how was the top-down approach developed

FBI profiling developed using interviews with 36 murderers in the US, 25 serial and 11 single/double, 24 organised and 12 disorgansed

how is the top-down approach used

starts with broad categories and elements of the crime scene are matched to a category, which is then used to infer/predict other likely characteristics of the offender, relies on previous experiences of crimes and a more intuitive sense of the likely nature of a crime in order to generate a profile

smallest space analysis

statistical technique identifying correlations across different samples of behaviour

strength of top-down approach - research support for distinct organised category offender

canter used smallest space analysis on 100 US murders each committed by diff serial killer, assessed co-occurrence of 39 aspects of serial killings, found there is a subset of features of many serial killings which matched FBI’s topology- key component of FBI approach has some validity

strength of top-down approach - can be adapted to other crimes

meketa - top-down profiling has recently been applied to burglary, 85% rise in solved cases in 3 US states, can be adapted to other crimes, not limited to murder/rape

limitation of top-down approach - based on flawed evidence

FBI profiling developed using interviews with 36 murderers in the US, no standard set of qs so each interview different and not comparable, lack of standardisation and lack of representative sample lowers the validity of this evidence and consequently the scientific basis of top-down profiling

limitation of top-down approach - organised and disorganised types are not mutually exclusive

godwin - difficult to classify killers as one or the other, killer may have multiple contrasting characteristics, organised-disorganised typology is probably more of a continuum, dichotomy not useful

personality in the top-down approach

based on principle of behavioural consistency - serial offenders have modus operani which should be seen across all crime scenes, allows crime linkage which helps catch the offender but situationists e.g. Mischel argue behaviour influenced by situation not personality, behavioural patterns at a crime scene may tell us little about how the individual behaves in real life

what is the bottom-up approach to offender profiling

methodology based on specific crime scene evidence and data driven, inductive interpretation, avoids pre-set categories, focus on analysis of specific details and patterns, widely used in UK across various crime types

investigative psychology

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

interpersonal coherence (investigative psychology)

offenders’ behaviours during a crime may reflect their everyday behaviours and attitudes, the way they treat victims or interact with environment often mirrors their general social behaviour

singnificance of time and place (investigative psychology)

provides insight into the offender’s routine or personal life, patterns in time and place often point to familiarity with the area, daily routines, and work or family commitments

forensic awareness (investigative psychology)

refers to knowledge and avoidance of leaving evidence, which can indicate prior encounters with the criminal justice system or an understanding of investigative procedures

geographical profiling

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

crime mapping (geographical profiling)

involves plotting locations of crimes on a map to identify clusters and patterns, helping to predict the offender’s base of operations

spatial consistency (geographical profiling)

tendency to commit crimes within familiar or convenient areas, behaviour helps profilers make inferences about the offender’s movements and daily life

circle theory (geographical profiling)

suggests that an offender's base is often centrally located within the area of their crimes, allowing for easy access and escape routes

marauder

crimes form cluster around central base, familiar with area/ possibly lives nearby, low in familiar area, comfortable blending in, use circle theory to identify central base

commuter

crimes dispersed in areas away from home, travels to unfamiliar locations, avoids home area to reduce risk of being known, consider transport routes or major roads

strength of bottom-up approach - research support for bottom-up approach

copson (1995) surveyed 48 UK police forces using investigative psychology and found that over 75% of the police officers questioned said that the profilers’ advice had been useful but only 3% said that the advice had helped to identify the offender

limitation of bottom-up approach - failures of bottom-up approach

1992 rachel nickell stabbed 47 times and sexually assaulted on wimbledon common, colin stagg targeted and the police instigated a ‘honey trap’, when the case came to court, the only link between stagg and nickell was the profile and the undercover operation, in 2008, robert napper was convicted of the murder who was initially ruled out of the enquiry because he was several inches taller than the profile

strength of bottom-up approach - evidence for geographical profiling

lundrigan and canter collated info from 120 murder cases involving serial killers in the USA, statistical analysis revealed spatial consistency in the behaviour of killers, location of each body disposal site was in a different direction from the previous, creating a ‘centre of gravity’; the offender’s base was inevitably in the centre of the pattern, effect was more noticeable for marauders

limitation of bottom-up approach - does not consider role of personality

ainsworth found that other factors are just as important in creating a profile e.g. timing of offence, age and experience of offender, eographical info alone may not always lead to successful capture of offender

strength of bottom-up approach - evidence for investigative psychology

canter and heritage - small space analysis of 66 sexual assault cases, identified common characteristics which led to case linkage, supports principle that people are consistent in their behaviour

limitation of bottom-up approach - contradictory findings regarding usefulness

when 48% of UK Police Forces were surveyed, 83% said the process was useful but said that only 3% of the time it actually helped to find the offender - profiling cannot reliably identify an offender but it can help to narrow down