Offender profiling - Bottom up approach

Bottom up approach - Aim is to generate a picture of the offender (characterisrics, routine behaviour, social background etc.) through analysis of the crime scene.
Unlike top down approach it does not begin with fixed typologies.

Bottom up approach involves: 
Investigative psychology  
1. the aim is to establish patterns of behaviour that are likely to occur - or c-exist across crime scenes.
2. Interpersonal coherence/time and place/ forensic awareness 
3. Specific details of an offence, or related offences, can then be collected to create a database and then used to match against to reveal important details abouth the offender, their personal history, social background. 
4. The way an offender acts at the scene may reflect ther behaviour in everyday situations 
5. Time and place may give clues as to where the perpertrator might live or work and forensic awareness may reveal details of the offender 

Geographical profiling 
1. Crime mapping 
2. Create hypothesis about the offender 
3. serial offenders will restrict their 'work' to areas they are familiar and create a spatial pattern with a centre of gravity which is likely to include the offenders base (often in the middle of the spatial pattern). 
4. Marauder operates close to their home and a commuter has travelled to commit crimes. 

A case that supports the bottom up approach 
John Duffy in the 1980s. 
24 sexual attacks and 3 murders on women near railway stations in North London. David Canter analysed geographical information from the crime scenes and combined this with details of similar attacks in the past supplied by police. Canter identified two themes in regard to how the offender commits the crime.
1. How the pffender deals with the victtim
2. How much dominance is used 
John Duffy used a minimal amount of dominance as…