Evaluation

• Evidence for investigative psychology


  One strength of investigative psychology is that evidence supports its use:

  • Canter and Heritage analysed 66 sexual assault cases using smallest space analysis
  • Several behaviours were consistent - impersonal language and lack of reaction to victim
  • Each individual displayed a characteristic pattern
  • Can be used to establish whether multiple crimes were committed by the same person
  • Therefore, supports a principle of investigative psychology
• Counterpoint to Canter and Heritage - flawed database


  • The database was only based on convicted offenders
  • Unconvicted offenders may be 'better' or smarter
  • Case linkage is easy if the crimes are simple to solve
  • Therefore, investigative psychology may tell us little about crimes with few links
• Evidence for geographical profiling


  One strength is evidence to support geographical profiling:

  • Canter and Lundrigan collated information from 120 serial killer murder cases in the US
  • Smallest space analysis revealed consistency in behaviour
  • Locations of disposal sites created a circle with a centre of gravity around the offender's home
  • The effect was more noticeable in marauders
  • Therefore, geographical information can be used to identify an offender
• Lack of success of circle theory


  One limitation of geographical profiling is that the usefulness of circle theory may be overstated:

  • Canter and Larkin distinguished between marauders and commuters in a study of 45 sexual assaults
  • However, 91% of the offenders were marauders - therefore, the classification doesn't seem all that useful
  • Petherick pointed out that if the offender's home base is not in the centre of the circle, police may look in the wrong place
  • Therefore, circle theory may have little usefulness