bottom-up approach

• bottom-up approach was proposed by canter, and develops profiles based on heavily analysed eye witness testimonies and the crime scene. it relies on profile generation through investigative psychology and geographical profiling
• INVESTIGATIVE PSYCHOLOGY

  crimes are recorded on a database. newer crimes are then compared to the older crimes to look for matches which can create a hypotheses about characteristics, or motivations of the culprit. this makes it a more scientific way of investigation

  it focuses on the time and place of the crime aswell as the idea of interpersonal coherence whereby the way the offender treats the victim represents their interpersonal functioning in real life
• GEOGRAPHICAL PROFILING

  suggests offenders have an operational base which can be inferred through the mapping of previous crimes. this creates a circular shape, whereby the 'centre of gravity' is in the centre, and can be used to predict future crimes. this is based on the idea that they have the same modus operandi e.g way offenders carry out crimes is constant.

  commuters - conduct crimes away from the centre of gravity

  marauders - conduct crimes close to the centre of gravity
• A03

  — The bottom-up approach is almost certainly a useful method of offender profiling, but it does not always lead to the correct identification of the offender, and so may be considered a failure in this sense, as suggested by Copson (1995). He found that information from an offender profile only led to the successful identification of the offender in 3% of cases, but was useful 83% of the time. This suggests that offender profiling is best reserved for simply narrowing the field of enquiry, as opposed to being relied upon as a chief means of offender identification.
• A03

  + A key advantage of the bottom-up approach, compared to the top-down approach, is its reliance on scientific methods of enquiry and the use of statistical analysis. For example, many supporting studies have used the method of smallest space analysis to establish correlations between two variables or offender characteristics. This is more scientific and based on psychological theory compared to the top-down approach, which is over-simplistic.
• A03

  + Lundrigan and Canter (2001) collated information about 120 murder cases involving serial killers in the USA. The smallest space analysis revealed spatial consistency in the behaviour of killers. The location of each body disposal site was in a different direction from the previous, creating a centre of gravity. The offenders base being in the centre of the pattern. More noticeable for offenders that travelled short distances (marauders). This supports Canter's claim that spatial information is a key factor in determining the base on an offender.