The Bottom-up Approach

• What is the aim of the bottom-up approach?

  The aim of the bottom-up approach is to generate a picture of the offender. This includes their personal characteristics, everyday behaviour and social background.
• How does the bottom-up approach generate a picture of an offender?

  This is done through the systematic analysis of evidence found at the crime scene. Unlike the top-down approach, this approach does not start with fixed typologies and instead the process is data driven.
• The bottom-up approach is data driven and does not start with fixed typologies, what does this mean in regards to how the profile emerges?

  This means that the profile begins to emerge as the profiler engages in deeper and more rigorous scrutiny of the details of the offence.
• The Bottom-up approach is underpinned by much more psychological theory than the Top-down approach.
• What is investigative psychology?

  This is a form of bottom-up profiling based on understanding the relationship and interactions between the offender and their victims. This is done by matching details of the crime scene with the statistical analysis of typical offender behaviour patterns based on psychological theory.
• Investigative Psychology

  By understanding the interactions between the offender and their victim(s), bottom-up profilers can establish patterns of behaviour that are likely to co-exist across crime scenes and develop a statistical database (which acts as a baseline for comparison). When a new offence occurs, profilers are able to match specific details of an offence against the database to objectively analyse evidence and reveal information about an offender.
• What are the 5 key assumptions of David Canter's five factor model for interpreting a crime scene?

  • Interpersonal coherence - interaction with victim.
  • Time and place -
  • Criminal characteristics - How the crime was committed suggests...
  • Criminal career - criminal becomes more experienced.
  • Forensic awareness - knowledge of the system.
• What is interpersonal coherence?

  This suggests that a persons interaction style with the victim is the same as with other people in their lives, e.g. aggressive, shy, manipulative.
• What is the assumption of "time and place" in David Canter's five factor model for interpreting a crime scene?

  The location is chosen by the offender and so is significant to them. This ties into the offenders mental model of their environment (schema’s). Offenders are likely to feel more comfortable and in control in a place they know better.
• What is the assumption of "criminal characteristics" in David Canter's five factor model for interpreting a crime scene?

  This suggests that how the crime has been committed suggests aspects of the offenders characteristics, based on evidence from previous criminal studies.
• What is the assumption of "criminal career" in David Canter's five factor model for interpreting a crime scene?

  This is how following crimes by the same offender change due to the criminal becoming more experienced (e.g. use of restraints in later murders).
• What is the assumption of "forensic awareness" in David Canter's five factor model for interpreting a crime scene?

  This looks into if the criminal shows some knowledge of the criminal justice system and uses techniques to reduce the evidence at the crime scene.
• What is geographical profiling?

  This is a form of offender profiling based on the principle of spatial consistency - the idea that an offender’s operational base and possible future offences are revealed by the geographical location of their previous crimes. Canter and Youngs (2008) identified that there are a number of telling clues regarding the location that crimes are committed in relation to the offender. The data from these clues is used to form systematic evidence to locate the offender.
• What is Systematic crime location selection

  This is the assumption that crime scenes are not random. The offender will likely have some kind of connection with the area or at least familiarity.
• In geographical profiling several locations are likely to be relevant. For example, an offender may meet the victim, attack, dispose, etc. in different locations. All of these locations are part of building an accurate picture.
• What is crime mapping in geographical profiling?

  This is when information about known locations of linked crime scenes is used to plot and make inferences about the home or operational base of the offender.
• What is circle theory?

  Canter argued that serial offenders will restrict their offences to a geographical area that they are familiar with, and if given two options, will choose the one closest to their base (the principle of least effort).
• What is distance decay and a 'buffer zone' in circle theory?

  This is an idea suggested by Canter that the number of crimes will decrease the further away from the offender's ''home base' they are. There will also be a 'buffer zone' around their home base where they will not offend to decrease the chances of being recognised.
• Canter believed that a circle drawn around the two offences furthest away from each other would likely reveal the offender's home base, at or near the circle centre.
• What are the two types of criminal behaviour suggested by Canter in geographical profiling?

  Marauders (don't travel) and Commuters (travel)
• What is the Jeopardy surface?

  This is a more complex version of criminal-geographical targeting that includes geographical data and features of the environment to create a 3D heat map of where the offender's base may be located.