Bottom up approach

• Bottom up approach 


  = Profilers work up from evidence collected from the crime scene to develop hypothesis about the likely characteristics, motivations and social background of the offender.
• Investigative psychology

  = Matches details from the crime scene with statistical analysis of typical offender behaviour patterns based on psychological theory.

  • Aims to establish patterns of behaviour likely to occur or coexist across crime scenes.
  • A statistical database acts as a baseline for comparison.
  • Specifc details of offence can be matched against database, to reveal important details about offender- personal history, family background.
  • Can determine if crimes are linked.
• Interpersonal coherence= the way an offender behaves at the crime scene, how they interact with the victim, may reflect their behaviour.
• Significance of time and place= may indicate where the offender is living.
• Forensic awareness= describes individuals who have been the subject of police interrogation before, their behaviour may denote how mindful they are of 'covering their tracks.'
• Geographic profiling

  = Uses information about the location of linked crime scenes to make inferences about the likely home or operational base of an offender.

  • Known as crime mapping and based on the principle of spatial consistency= that people commit crimes within a limited geographical space.
  • Assumption that serial killers will restrict their 'work' to geographical areas they are familiar with, so understanding spatial pattern of their behaviour provides investigators with a 'centre of gravity' which is likely to include the offenders base.
• Canter's circle theory

  The marauder= who operates in clode proximity to their home based.

  The commuter= who is likely to have travelled a distance away from their usual residence.

  • Spatial decision making can offer the investigator team important insight into the nature of the offence.
• Evaluation- evidence for investigative psychology

  Canter and Heritage conducted analysis of 66 sexual assault cases.

  • Data examined using smallest space analysis.
  • Several behaviours were identified as common in different samples of behaviour, such as the use of impersonal language and lack of reaction to the victim.
  • Each individual displayed a characteristic pattern of such committed by the same person.
  • Supports bottom-up approach that people are consistent in their behaviour.
• Evaluation- counterpoint

  Case linkage depends on the database and this will only consist of historical crimes that have been solved.

  • The fact that they were solved may be because it was relatively straightforward to link these crimes together.
  • Suggests investigative psychology may tell us little about crimes that have few links between them and therefore remain unsolved.
• Evaluation- evidence for geographical profiling

  Lundrigan and Canter collated information from 120 murder cases involving serial killers.

  • Smallest space analysis revealed spatial consistency in behaviour of killers.
  • The location of each body disposal site created a 'centre of gravity' because when offenders start from their home base they may go in a different direction each time they dispose of a body, but in the end all these different sites create a circular effect around the home base.
  • Supports view that geographical profiling can be used to identify offenders.
• Evaluation- geographical information insufficient

  Success of geographical profiling may be reliant on the quality of data that the police provide.

  • Recording of crime is not always accurate, can vary between police forces and 75% of crimes aren't reported to police.
  • Questions the utility of an approach that relies on the accuracy of geographical data.
  • Critics claim that other factors are just as important in creating a profile, like timing, age, experience.
  • Suggests geographical information alone may not always lead to a successful capture.