bottom up approach

• bottom up approach -

  • British approach
  • aim is to generate a picture of the offender - likely characteristics, routine behaviour and social background - through systematic analysis of evidence at crime scene
  • profile is data driven - emerges as the investigator engages in deeper, more rigorous scrutiny of details of offence
  • more grounded in psychological theory
• investigative psychology -

  • attempt to apply statistical procedures alongside psychological theory to the analysis of crime scene evidence - aim is to establish patterns of behaviour that are likely to occur
  • this is to develop a statistical database which then acts as a baseline for comparison
  • specific details of an offence can then be matched against this database to reveal important details about the offender (personal history, family background etc)
  • also may determine whether a series of offences are linked in that they are likely to have been committed by the same person
• interpersonal coherence -

  • central to investigative psychology
  • the way offender behaves at scene - how they interact with the victim may reflect behaviour in everyday situations
  • some rapists want to maintain maximum control and humiliate victims, others are more apologetic
  • might tell police about how the offender relates to women more generally
  • significance of time and place is also a key variable (eg geographical profiling)
  • forensic awareness - individuals who've been subject to police investigation before - behaviour may denote how mindful they are of covering their tracks
• geographical 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
  • based on principle of spatial consistency - people commit crimes with a limited geographical space
  • assumption is that offenders will restrict work to geographical areas they're familiar with so understanding the spatial pattern of their behaviour provides investigators with a 'centre of gravity' which is likely to include the offenders base (often in middle of spatial pattern)
• circle theory -

  • Canter and Larkin (1993) - pattern of offending forms a circle around the offenders home base - distribution leads to describing the offender in 1 of 2 ways:
  • 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
  • spatial decision making can offer the investigative team insight into the nature of the offence - planned or opportunistic, 'mental maps', mode of transport, employment status, approximate age etc