Bottom up approach

• Bottom up offender profiling - data is collected from the crime scene and analysed using statistical techniques to generate predictions
• Bottom up profiling is used in the UK
• Two examples o the BUA:

  Investigative psychology

  Geographical profiling
• The bottom up approach scrutinises details of the offence and evidence to generate a picture of the offender
• Investigative psychology was developed by David Canter, who proposed that profiling should be based on psychological theory and research, not gut feeling
• Main features of Investigative Psychology:

  Interpersonal coherence

  Forensic awareness

  Smallest space analysis
• Interpersonal coherence - people are consistent in their behaviour and so there will be links with elements of the crime and how people behave in everyday life.
• Forensic awareness - certain behaviours may reveal an awareness of particular police techniques and past experience E.g. Davies et al found that rapists who conceal fingerprints often had a previous conviction for burglary
• Smallest space analysis - a statistical technique developed by Canter. Data about many crime scenes and offender characteristics are correlated so the most common connection can be identified
• Smallest Space Analysis - research

  Canter ( 1999 )

  Analysed the co occurrence of 48 crime scenes and offender characteristics taken from 82 UK murder cases where the victim was a stranger

  They identified three underlying themes
• Canter et al ( 1999 ) found three underlying themes when researching smallest space analysis:

  Instrumental opportunistic

  Instrumental cognitive

  Expressive impulsive
• Canter et al ( 1999 ) Instrumental opportunistic:

  Instrumental - using the murder to obtain something or accomplish some goal

  Opportunistic - the offender took the easiest opportunities
• Instrumental cognitive - a particular concern about being detected and therefore more planned
• Expressive impulsive - uncontrolled, in the heat of strong emotions, may feel provoked by the victim
• Geographical profiling:

  Kim Rossmo ( 1997 )

  Location of linked crime scenes to make inferences about the home, workplace, base of an offender - crime mapping

  This assumes that offenders will restrict their crimes to familiar places, and spacial patterns of behaviour can provide a centre of gravity ( their base ) and where they are likely to offend
• Canter’s circle theory:

  Marauder - operates in a close proximity to home base

  Commuter - travels a distance away from home base

  The pattern of offending is likely to form a circle around their usual base
• Criminal geographical targetino ( CGT )

  Computerised system developed by Rossmo and based on his formula.

  This proposes a three dimensional map displaying spatial data related to time, distance and movement to and from crime scenes
• BUA AO3. A limitation to the BUA is that the data gathered is only as good as the data input. The data that is input is from criminals that have been caught, and tells us little about the behaviour of unsolved crime. This means that the BUA is inevitably biased. However, he BUA is considered more scientific than the TDA due to its use of statistical techniques and computer analysis. 
• BUA AO3. A strength of the BUA is that it has research support. Copson surveyed 48 UK police forces using investigative profiling and found over 75 % said the profiler’s advice had been useful, and most would use it again. However only 3 % said that the advice had helped them identify the actual offender. This suggests that the approach may not actually be that useful when catching offenders, but it gives a benefit that makes it worthwhile. 
• BUA AO3. There are flaws in Canter’s circle theory. Canter and Larkin et al studied 45 sexual assaults and showed support for their model by distinguishing between marauders and commuters, however 91 % of offenders were identified as marauders. If most offenders are classified as marauders then the classification seems not to be useful Petherick found a number of flaws with the model, for example if an offenders home base is not in the circle the police may look in the wrong place. This shows that the theory is not completely useful. 
• BUA AO3. Rossmo was dismissed from the Vancouver Police Department, where he introduced geographical profiling, as they believed it was not useful. One issue is that it can’t distinguish between multiple offenders in the same area and the method is limited to spatial behaviour. Although the geographical approach may not solve crimes specifically it can be useful in prioritising house to house searches. 
• BUA AO3. Sticking too closely to one profile can be dangerous. For the case of Rachel Nickell, psychologist Britton identified Colin Stagg using profiling. Time and resources were spent on trying to convict Stagg, however he was innocent, meaning those resources were wasted. The real murderer was originally ruled out as he was taller than what the profile said. This shows that BUA profiling is not always useful.