offender profiling

• Offender profiling


  The process of identifying the offender of a crime based on an analysis of the crime scene
• Top-down approach


  Also known as the FBI approach, based on interviews conducted with violent sexually motivated offenders including Ted Bundy
• The top-down approach applies ideas and theories to the information present at the crime scene
• Data obtained from interviews and crime scene evidence helped Ressler identify two types of murders: organised and disorganised
• Organised offenders


  • Evidence of planning
  • Little physical evidence
  • Victim is most likely a stranger who cannot be traced back to the offender
  • Victim's body may have been moved to a different location
• Disorganised offenders


  • Crime scene is chaotic with no planning
  • Abundant physical evidence
  • Victim may be a stranger but could just as equally have a connection with the offender
  • Little to no attempt to conceal the victim
• Bottom-up approach


  Data-driven, uses evidence present at the crime scene to create the profile, aims to develop a theory from the data presented, uses seemingly irrelevant details from the crime scene to create a bigger picture, makes no assumption about the offender, relies on statistical analysis and database records
• Bottom-up approach


  Also known as the British approach, involves cross-referencing of crime scene details to determine the composition of the offender profile via the use of statistics
• Investigative psychology


  Consists of interpersonal coherence (how the offender behaved at the crime scene should be the same as how they behave in everyday life), the significance of time and place, and forensic awareness
• Geographical profiling


  Used to analyse the geographical locations of offences which appear to be linked with the same offender, operates under two categories that offenders fall under: marauders (commit crime within their neighbourhood) and commuters (commit crimes away from their neighbourhood)
• Circle theory is applied by drawing a circle around the seemingly linked offences
• Organised offenders


  • Likely to have a high IQ and be professionally occupied
  • Socially competent and have multiple friends
  • Likely to be in a relationship
  • May be suffering from some kind of negative mental states; depression, anxiety
• Disorganised offenders


  • Likely to have a low IQ and may be unemployed
  • Socially incompetent and have few friends
  • Likely to live alone and have a problematic relationship history
  • Likely to have been abused as a child
  • Likely to live near the crime scene
• Offender profiling is reductionist and does not account for validity across crimes
• Marauders commit crime within their neighbourhood, as they feel safe and most likely know the area well for sudden escape routes
• Commuters commit crimes away from their neighbourhood to avoid detection
• Snook et al conducted a meta-analysis of profiling research and found that most profiling was based on common sense justifications and that profilers were not significantly better at predicting offence
• Canter et al analysed 39 American serial murders and found that the labeling of the offenders are not easily applied to crime scenes and that there may be a subset of organised characteristics
• Offender profiling may be useful for identifying sexually motivated murders due to the standardised template which can be applied to such crimes
• Offender profiling has been successful in 17% of cases, which may seem like a negligible number but some very serious crimes were caught
• Offender profiling lacks temporal validity as the interviews were done in the 70s
• The railway rapist 'John Duffy' was one of the first cases that was successful with the use of geographical profiling
• Many research, such as Canter, supports the effectiveness of the bottom-up approach
• The bottom-up approach takes a more objective approach than the top-down approach with its use of statistical methods, making it more reliable
• Research tested profiling skills of various police professionals and chemistry students, and found that the chemistry students produced more accurate profiles, interestingly the more experienced the police professionals the less accurate the profiles were, suggesting that profiling may involve guesswork
• When profiling went wrong it ended horribly, with the wrong profiling completely derailing the investigation
• Offender profiling is not appropriate for all crimes as the basis of the template relies on sexually motivated murders which lacks consistency
• Offender profiling is reductionist and does not account for validity across crimes
• An offender may be organised for one crime and disorganised for another crime, or may also combine features from both typologies
• Human behavior fluctuates