The bottom up approach

• Describe what is meant by investigative psychology

  Form of bottom up profiling based on psychological theory
• State what is meant by geographical profiling

  Form of bottom up profiling based on pattern shown by locations of crimes
• State what is meant by the bottom up approach

  Data driven approach where statistical techniques are used to make predictions about the likely characteristics of an offender
• State the three main aspects of investigative psychology

  • Interpersonal coherence- people are consistent with behaviour so there will be links with elements of the crime and how people behave daily
  • Forensic awareness- certain behaviours can reveal awareness of police techniques and past experience
  • Smallest space analysis- based on the principle that connections can be made between crime scenes and offender characteristics. statistical technique developed by Canter identifying three underlying themes- instrumental opportunistic, instrumental cognitive and expressive impulsive
• State the three underlying themes of criminals established in smallest space analysis

  Themes discovered by David Canter and Gabrielle Salfati:

  • Instrumental opportunistic- using murder to accomplish a goal and taking the easiest opportunities
  • Instrumental cognitive- concern about being detected and therefore planning better
  • Expressive impulsive- uncontrolled, in the heat of strong emotions, may feel provoked by victim
• What is circle theory?

  • David Canter and Paul Larkin proposed offenders have a spatial mindset- commit their crimes in an imagined circle
  • Marauder- offenders’s home is within geographical area where crime was committed
  • Commuter- offenders home is outside geographical area- offender travels to another geographical area and commits crime
• What method is used to display spatial data of time, distance and movement to and from crime scenes?

  • Criminal geographic targeting (CGT)
  • related to time, distance and movement to and from crime scenes
  • Computerised system developed by Rossmo
  • Produces 3D map
  • Map called jeopardy surface
  • Colours indicate likely closeness to crime scene
• Evaluation of bottom up approach?

  • 😊scientific basis- objective statistical techniques and computer analyses
  • 😊useful in prioritising house to house searchers, however doesn’t distinguish between multiple offenders in that area (Rosmo)
  • ☹️Gary Copson- surveyed 48 UK police forces, 75% said approach was useful but 3% said it helped identify offender , 75 cases use it/yr
  • ☹️Canter and Larkin- difficult to distinguish between commuters and marauders (identified 91% marauders out of 45 sex offenders) limits usefulness of circle theory
• What are the two examples of the data driven bottom up approach?

  • Investigative psychology
  • Geographical profiling
• how were the 3 themes in smallest space analysis identified and who identified them?

  • David Canter and Salfati
  • analysed co-occurrence of 48 crime scene and offender characteristics taken from 82 UK murder cases where the victim was a stranger
• true or false? geographical profilers are concerned with who rather than where

  FALSE- concerned with where rather than who