Offender profiling - the bottom up approach

• Offender profiling - the bottom-up approach

  The bottom-up approach to offender profiling is sometimes known as the British approach. The aim of this approach is to generate a picture of the offender - their likely characteristics, routine behaviour and social background - through systematic analysis of evidence at the crime scene. Under this approach, people are seen as consistent in their behaviour.
• Bottom-up approach vs US top-down approach

  Unlike the US top-down approach, this model does not begin with fixed typologies of organised vs disorganised offenders. Instead, the profile is 'data-driven' and emerges as the investigator engages in deeper and more rigorous scrutiny of the details of the offence. Bottom-up approach profiling is also much more grounded in psychological theory than the top down approach.
• Investigative psychology


  Investigative psychology attempts to apply statistical procedures and psychological theory to the analysis of crime scenes. The aim is to establish patterns of behaviour that occur across crime scenes. Each crime and details of the offender are recorded onto a statistical database, then details of new crimes can be matched using this database in order to develop hypotheses about the likely characteristics, social demographic and motivations of the offender. This may also determine whether a series of offences are linked. There is a much greater emphasis on scientific methods of investigation and statistical analysis, compared to the top-down approach.
• Investigative psychology


  • Central the to approach is interpersonal coherence - that the way in which the founder behave at the scene, including how they 'interact' with the victim, may reflect their behaviour in more everyday situations. The significance of time and place is also a key variable as it may indicate where the offender lives. Forensic awareness describes those individuals who have been the subject of police interrogation before, their behaviour may denote how mindful they are of 'covering their tracks'.
• Evidence supporting investigative psychology

  • Canter and Heritage 2001 conducted an analysis of 66 sexual assault cases. The data was analysed using smallest space analysis to analyse the co-occurrence of certain aspects of crimes, such as the use of impersonal language and lack if reaction to the victim. It was found that each offender displayed a characteristic pattern of such behaviours across crimes, making it easier to establish case linkage.
• Geographical profiling


  Geographical profiling uses information about the location of linked crime scenes to make inferences about the likely home or operational base of an offender. It is based on the idea of spatial consistency, which suggests that serial offenders will restrict their work to geographical areas that they are familiar with. Understanding the spatial pattern of behaviour allows investigators to determine a centre of gravity for the offender - which is likely to include the offender's base, most often at the middle of this pattern.
• Geographical profiling


  • Offenders can be classified as marauders (carrying out crimes in close proximity to their home base) or commuters (carrying out crimes a distance from their usual residence). This can be useful to know as it can offer the investigative team important insight into the nature of the offence (eg. planned or opportunistic, offenders 'mental maps', mode of transport, employment status, approximate age). It may also help investigator make educated guesses about where the offender is likely to strike next (known as the 'jeopardy surface').
• Evidence supporting geographical profiling

  • Following the smallest space analysis of 120 serial murder cases, Lundrigan and Canter 2001 were able to identify characteristic traits of spatial consistency, such as the presence of a jeopardy surface (which could be used to predict the locations of future crimes) as well as the centre of gravity (which was often the offender's operational base).
• Geographical profiling may not be sufficient on its own. For example, other factors such as the timing of the offence are just as important a geographical information in creating a profile.
• An estimated 75% of crimes are not reported the police which is often referred to as the 'dark figure of crime'. This then calls into question the usefulness of the geographical profiling approach as it relies on the accuracy of geographical data as not all of it is present.
• The bottom-up approach has a mixed history, with it being a useful method but it does not always lead to the correct identification of the offender.
• Copson 1995 surveyed 48 police departments and found that the advice provided by the profiler was judged to be 'useful' in 83% of cases, but it led to the successful identification of the offender in only 3% of cases.
• The case of Rachel Nickell clearly shows the misuse of profiling.
• Offender profiling may actually have little practical value when it comes to solving cases. It may focus police investigations and offer new lines of inquiry but in terms of what it is designed to do (lead to identification of the offender), it may fall somewhat short.