A01: The Bottom-up approach - offender profiling

• The Bottom-Up Approach A01


  Investigative Psychology

  • Bottom Up Approach
  • Statistical Analysis of crime scene evidence
  • Analysis based on psychological concepts e.g. interpersonal coherence

  Geographical Profiling

  • Crime Mapping
  • Marauder & commuter types of offender
  • Circle Theory
  • Jeopardy Surface
• Investigative Psychology: Bottom-Up Approach


  • Offenders leave 'psychological fingerprint'
  • Unlike US top down, UK bottom up doesn't begin with fixed typologies.
  • Profile is 'data driven' & emerges as investigator rigorously scrutinises details of particular offence/scene not just based on previous fixed typologies.
  • Aim: generate pic of offender's characteristics, routines, background thro analysis of evidence

  Starts with evidence from crime scene ---> Profilers work up from this to create scientific, statistical predictions/hypotheses based on evidence from crime scene & other crimes.
• Investigative Psychology: Statistical analysis of crime-scene evidence


  • Statistical procedures detect patterns of behaviour that are likely to occur (or coexist) 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
• Investigative Psychology Psy Concepts: Canter

  5 principles of investigative psychology for creating a profile (Canter)

  1. Interpersonal Coherence: behaviour during crime reflects behaviour in real life
  2. Time & Place Significance: To be in control, offenders pick locations familiar at convenient times
  3. Criminal Characteristics: Patterns in behaviour help categories into 'type'.
  4. Criminal Career: N.o crimes they previously committed.
  5. Forensic awareness: Evidence from scene reveal if they have previously been in contact with police; thus have some awareness of investigative processes they go through.
• Investigative Psychology: Analysis based on psychological concepts - interpersonal coherence

  • A central concept is 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 etc) i.e their behaviour 'hangs together' (has coherence).
  • This might tell the police something about how the offender relates to women (for example) more generally.
• Geographical Profiling: Crime Mapping


  Inferences about the offender based on location:

  • Geographical profiling uses info about the location of linked crime scenes (info from location of crime scene to) to make inferences about the likely home or operational base of an offender (Rossmo 1997) - known as crime mapping
  • Serial offenders restrict their 'work' to areas they are familiar with (principle of spatial consistency)
  • Understanding their spatial patterns will give investigators a centre of gravity
• Geographical Profiling: Circle Theory

  Canter & Larkin also suggest that spatial pattern of offending locations is likely to form a circle around offender's home base & this becomes more apparent the more offences there are

  • The offender's spatial decision-making can provide insight into nature of the offence (planned or opportunistic, mode of transport, employment status etc)
  • Assumption serial offenders 'restrict' their work to familiar geographical areas

  The distribution of offences leads us describe offences 1 of 2 ways = MAURDER or COMMUTER.
• Geographical Profiling: Marauder & Commuter Types of Offender

  Canter & Larkin (1993) proposed 2 models of offender behaviour:

  1. The Marauder: Operates close to their home base
  2. The Commuter: Likely to have travelled a distance away from their usual residence when committing a crime

  The distribution of offences leads us describe offences 1 of 2 ways = MAURDER or COMMUTER (Circle Theory).
• 


  Geographical Profiling use in conjunction with investigative psychology to enhance hypotheses about offenders 

  • Locations can also be used alongside psychological theory to create hypotheses about the offender & their modus operadni (habitual way of working)
• Geographical Profiling: The Jeopardy Surface


  • The more offences there are, the more apparent a circle is likely to follow around their residence.
  • This can help investigators make predictions about where killers are likely to strike next, this is known as Jeopardy Surface.
• Investigative Psychology & Geographical Profiling


  • Geographical Profiling use in conjunction with investigative psychology to enhance hypotheses about offenders 
  • Locations can also be used alongside psychological theory to create hypotheses about the offender & their modus operadni (habitual way of working)