Psych: Offender Profiling

• Offender profiling


  Creating a set of psychological characteristics based on evidence at a crime scene to help narrow down a suspect list
• Top-down offender profiling


  Profile of offender exists and then it is applied to the crime scene details
• Bottom-up offender profiling


  Starts with the details of the crime scene and builds up towards the profile
• Data assimilation


  Step 1 : Collects the information from the crime scene
• Crime scene classification


  Step 2: Decides whether the crime scene is organised or disorganised
• Profile generation


  Step 4: Final profile is created
• Crime scene reconstruction


  Step 3: The 'story' or 'sequence of events' in the crime is determined
• Organised offender


  Will be intelligent, socially competent and use surgical precision
• Disorganised offender


  Will be less intelligent, social inadequate and messy
• Interviews with 36 serial killers


  Data the top down approach was based on
• Investigative psychology


  The use of psychological theory and statistics to build up a profile
• Interpersonal coherence


  Behaviour towards the victim in the crime scene matches behaviour towards the victim in the real world
• Criminal consistency hypothesis


  Criminals are likely to commit similar behaviour in each of their crimes, thus meaning they will commit crimes
• Spatial consistency


  Criminals are likely to commit crimes in areas they are comfortable/familiar with
• Geographical profiling


  Use of crime locations to build up a profile
• Circle theory


  David Canter's theory that collecting the locations of similar crimes you can determine where they live/work etc.
• Marauders


  Commit crimes in their local areas
• Commuters


  Travel to commit their crimes
• Big crimes'


  The only crimes that the top down approach can really generalise to (e.g. murders, assault etc.)
• Classification is too simple

  This is because most crimes have characteristics of both organised and disorganised in them, rarely definitively one or the other
• The case of Rachel Nickell


  She was murdered in Wimbledon Common, and the use of bottom up profiling found the wrong person
• Can be applied to all crimes

  A strength of the bottom up approach e.g. as all crimes have geographical data
• FBI Behavioural Unit (1970s)


  The organisation that created the top-down approach to offender profiling
• Copson et al.


  Found 82% of police officers liked the top-down approach and would use it again
• Counter-argument to Copson et al.'s research


  However, just because police officers like using it doesn't mean that it is actually more successful
• Three reasons why the top down approach has difficulty generalsing to many crimes

  It was based off a small sample (36) of very specific criminals (serial killers) from one culture (the US)
• This makes the bottom up approach more objective and scientific than the top down approach


  It's use of statistics and computer models to elp build up profiles