offender profiling - bottom-up approach

what is the bottom-up approach

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

who was the bottom-up approach made by

Canter - the British

characteristics of investigative psychology

• applies statistical procedures to the analysis of crime evidence

• establishes patterns of behaviour

• specific details of the crime scene can be matched against the database

• interpersonal coherence = the way an offender behaves at the scene may reflect their behaviour in different situations

• significance of time and place - may indicate where the offender lives

• forensic awareness = whose who have been subject of police interrogation before may be more mindful of covering their tracks

characteristics of geographical profiling

• crime mapping = uses info about the location of crime scenes to make inferences about the home of the offender

• spacial consistency = people commit crimes within a limited geographical space

• circle theory (Canter and Larkin 1993) = pattern of offences forms a circle around the offenders base

  • marauder = close proximity to home

  • commuter = travelled away from their residence

strength - evidence from investigative psychology

• Canter and Heritage (1990) analysed 66 sexual assault cases with smallest space analysis (programme)

• several behaviours were identified as common

• characteristic patterns helped identify if two crimes were committed by the same person

• supports principles of investigative psychology that people are consistent in their behaviour

counterpoint to investigative psychology strength

• depends on the database

• they may have been solved because it was straightforward to link the crimes in the first place

• may tell us little about crimes that have little links between them and remain unsolved

strength - evidence to support geographical profiling

• Lundrigan and Canter (2001) collected info about 120 murder cases involving serial killers from the USA

• smallest space analysis revealed spacial consistency

• the offenders base was at the centre of the ‘centre of gravity’

• effect was more noticeable for offenders who travelled long distances

• shows geographical info can be used to identify offenders

limitation of geographical profiling - may not be sufficient on its own

• must be reliant on the quality of data the police can provide

• recording of a crime isnt always accurate

• estimated 75% of crimes aren’t even reported in the first place

• questions the utility of an approach that relies on the accuracy of geographical profiling

• other factors are just as important as creating a profile e.g. the timing and the age of the offender

limitation - mixed results

• Copson (1995) interviewed 48 police departments and found advice provided by the profiler was useful in 83% of cases = validity

• however = same study revealed only 3% of cases led to identifying the offender

• Kocsis et al (2002) found chemistry students produces more accurate offender profiles than trained police