offender profiling - the bottom up approach

• Bottom-up approach

  1. Profilers work up from evidence collected from the crime scene

  2. Develop hypotheses about the likely characteristics, motivations and social background of the offender
• Investigative psychology

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

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

  • British
  • aim is to generate a picture of the offender - characteristics, routine behaviour and social background
  • through statistical analysis of evidence at crime scene
  • 'data-driven' - emerges as investigator engages deeper into details of offence
• bottom-up - investigative psychology

  • attempt to apply statistical procedures alongside psychological theory to analysis of crime scene evidence
  • to establish patterns of behaviour that are likely to occur
  • specific details about offender can be matched against database to reveal important details about offender - helps determine whether the same person committed series of offences
  • interpersonal coherence - the way an offender behaves at the scene may reflect their behaviour in more everyday situations
  • forensic awareness - subject of police interrogation before - mindful behaviour
• bottom-up - geographical profiling

  • crime mapping = uses information about the location of linked crime scenes to make inferences about the likely home or operational base of an offender
  • based on the principle of spatial consistency
  • used with psychological theory to create hypotheses about how the offender is thinking
  • serial offenders will restrict their work to geographical areas they are familiar with - centre of gravity which is likely to include the offender base
• bottom-up - geographical profiling

  • Canter's circle theory - pattern of offending forms a circle around the offender's home base
  • the distribution of offences leads us to describe an offender
  • The marauder - who operates in close proximity to their home base
  • The commuter - who is likely to have travelled a distance away from their usual residence
  • offers the investigative team important insight into the nature of offence (planned) as well as revealing factors about offenders such as mode of transport, employment status, age
• AO3 - bottom-up - strength

  P: evidence to support the use of investigative psychology

  E: Canter and Heritage - analysis of 66 sexual assault cases - examined using smallest space analysis

  Several behaviours identified as common in different samples of behaviour - use of impersonal language and lack of reaction to the victim

  E: Helps establish whether two or more offences were committed by the same person

  L: supports one of the basic principles of investigative psychology that people are consistent in their behaviour
• AO3 - bottom-up - strength

  P: evidence to support geographical profiling

  E: Lundrigan and Canter - collated information from 120 murder cases involving serial killers in the US - smallest space analysis revealed spatial consistency in the behaviours of the killers

  Location of body disposal site created a centre of gravity - offenders base located in centre of pattern

  L: this supports the view that geographical information can be used to identify an offender
• AO3 - bottom-up - limitation

  P: geographical profiling may not be sufficient on its own

  E: the success of geographical profiling may be reliant on the quality of data that the police can provide - recording of crime not always accurate

  75% of crimes not reported to police

  E: calls into question the utility of an approach that relies on the accuracy of geographical data

  L: geographical information alone may not always lead to the successful capture of an offender