bottom-up approach

• bottom-up approach


  - profile is data driven and emerges as the investigator rigorously scrutinises the details of a particular offence

  - the aim is to generate a picture of the offenders' characteristics, routines and background through analysis of the evidence
• statistical analysis


  - statistical procedures detect patterns of behaviour that are likely to occur across crime scenes

  - this is done to develop a statistical database which then acts as a baseline for comparison

  - features of an offence can be matched against this database to suggest potentially important details about the offender, their personal history, family background etc.
• interpersonal coherence


  - the way an offender behaves at the scene, including how they interact with the victim, may reflect their behaviour in everyday situations e.g. controlling, apologetic

  - this might tell the police something about how the offender relates to women more generally
• inferences about the offender based on location

  - locations of crime scenes are used to infer the likely home or operational base of an offender (crime mapping)

  - serial offenders restrict their 'work' to areas they are familiar with (spatial consistency)

  - location can also be used alongside psychological theory to create hypotheses about the offender and their modus operandi (habitual way of working)
• types of offender


  Canter and Larkin (1993) proposed two models of offender behaviour:

  1. marauder - operates closes to their home base

  2. commuter - likely to have travelled a distance away from their usual residence when committing a crime
• circle theory


  - Canter and Larkin suggest the pattern of offending locations is likely to form a circle around the offender's usual residence, and this becomes more apparent the more offences there are

  - the offender's spatial decision making can provide insight into the nature of the offence (planned or opportunistic, mode of transport, employment status etc.)
• strength


  P - evidence supports investigative psychology

  E - Canter and Heritage (1990) conducted an analysis of 66 sexual assault cases using smallest space analysis. Several behaviours were identified in most cases e.g. using impersonal language

  E - each individual displayed a pattern of such behaviours, helps establish whether two or more offences were committed by the same person (crime linkage)

  L - this supports one of the basic principles of investigative psychology that people are consistent in their behaviour

  COUNTERPOINT

  - however, the database is made up of only solved crimes which are likely to be those that were straightforward to link together - a circular argument

  - this suggests that investigative psychology may tell us little about crimes that have few links between them and therefore remain unsolved
• strength


  P - evidence also supports geographical profiling

  E - Lundrigan and Canter (2001) collated information from 120 murder cases in the US. Smallest space analysis revealed spatial consistency - a centre of gravity

  E - offenders leave home base in different directions when dumping a body but created a circular effect, especially in the case of marauders

  L - this supports the view that geographical info can be used to identify an offender
• limitation


  P - geographical profiling may not be sufficient on its own

  E - recording of crime is not always accurate, can vary between police forces and and estimated 75% of crimes are not even reported to police

  E - even if crime data is correct, other factors matter e.g. timing of offence and age and experience of the offender (Ainsworth 2001)

  L - this suggests that geographical info alone may not always lead to the successful capture of an offender