Offender Profiling: Bottom-up Approach

• An approach pioneered by psychologists, particularly David Canter and Paul Britton, working with the police. British bottom-up model does not begin with fixed typologies - instead it is 'data-driven' with profiling being based on scientific theory and research. It starts with small details and creates the big picture.
• The approach focuses on three factors: the data driven building up of more individualistic profiles through the identification of specific associations between particular characteristics of the offence and the offender. The use of scientific statistical analysis and the application of psychological principles. Finding what kind of criminal behaviours are associated together and therefore may be the work of the same criminal.
• Key difference between this method and the US top down method is that it relies much more on scientific principles, rather than being based on intuition.
• What is Investigative psychology?

  Aims to establish patterns that occur or co-exist across crime scenes and use this info to generate a statistical database which then acts as a baseline for comparison
• Smallest Space Analysis?

  It is based on psychological theory of matching behavioural patterns to generate data on the offender
• 3 things central to the approach of investigative psychology are?

  Interpersonal coherence, significance of time and place, forensic awareness
• Interpersonal coherence?

  The way in which an offender behaves at the scene. How they interact with the victim may indicate how they act in everyday life
• Significance of time and place?

  This may indicate where the offender is living if the crimes take place within the same forensic 'centre of gravity'
• Forensic awareness?

  Behaviour may be indicative of previous criminal experience. Their behaviour may denote how mindful they are of covering their tracks
• Geographical profiling is a technique first described by Kim Rossmo. Rossmo stated that an offender's operational base of possible future offences are revealed by the geographical location of their previous crimes - known as 'crime- mapping'. Can be used in conjunction with investigative psychology to create hyspotheses about perpetrators MO. Also helps investigators hypothesise about where they may strike next - 'jeopardy surface'
• David Canter developed a model of offender behaviour known as the circle theory (Canter and Larking), it proposes two models of offending behaviour: the circle model and the spiral model. People operate within a limited spatial mind set that creates imagined boundaries in which crimes are likely to be committed. Crucially, the pattern is likely to form a cycle around their residence and becomes more apparent the more crimes there are
• Overall the bottom up approach can combine investigative psychology and geographical profiling to create a hypothesis about how an offender is thinking as well as their modus operandi (MO)
• Canter developed this method after he assisted police in the capture of John Duffy (The Railway Rapist) in the 1980s. Duffy committed 24 sexual attacks and 3 murders close to railway stations across North London. Canter analysed geographical info from similar crimes and details of similar attacks to draw up a surprisingly accurate profile of the suspect. He found a pattern near the railways, which suggested he was getting the train so he could identify as a commuter. He lived in Kilburn - interviews with victims find he was strong (in a martial arts club), unattractive, small 5ft 4 with acne
• Adrian Babb

  Serial rapist profiled by Canter in 1994 and subsequently arrested and found guilty of 7 rapes and sent to prison for 16 years
• Pattern in the rapes

  • Clearly demonstrating control and aggression against victims
  • Responded to discomfort of victims
• Victim's complaint

  • Cold concrete against her skin
• Victim complained about cold concrete

  Babb responded by putting some of the clothing he had removed from her on the floor beneath her
• Canter argued that these details suggested the rapist would be known as helpful and considerate by those who did not know of his violent assaults
• Babb was a well-regarded swimming pool attendant seen as considerate member of the community
• Rachel Nickell was attacked and murdered, her throat cut and she was stabbed 49 times then sexually assaulted


  July 1992
• Paul Britton


  Criminal psychologist and profiler
• Offender profiling

  1. Detailed description of a suspect

  2. Directed investigation to Colin Stagg
• 'Honey Trap' operation

  Used to try and get Colin Stagg to confess
• Colin Stagg was arrested and charged with Rachel Nickell's murder, held in custody for 13 months before his trial


  August 1993
• Robert Napper

  Paranoid Sz receiving treatment in a clinic next to Wimbledon Common where Rachel was murdered, confessed in 2008 after DNA evidence linked him to the crime
• This shows that offender profiling is not always reliable - if they arrest the wrong person - offender gets away may commit again, waste of police time and money - need more profilers - improve accuracy by using inter-rater reliability
• P: There is evidence to support the effectiveness of investigative psychology

  E: For example, David Canter and Rupert Heritage conducted a context analysis of 66 sexual assault cases. Used a smallest space analysis, identified correlations across patterns of behaviour

  E:This can lead to an understanding of how offenders' behaviour may change over a series of offences or in establishing whether 2 or more offences were committed by the same person

  L: This suggests the usefulness of investigative psychology because it show how statistical techniques can be applied
• P: Bottom-up is more scientific than top-down.

  E: For example, Canter states that bottom-up is more objective as it is more grounded in evidence and psychological theory and less driven by speculation and hunches.

  E: With the aid of advanced AI, investigators are able to manipulate data quickly to produce insights and results that assist in the investigation.

  L: Similarly, the field of investigative psychology has recently expanded to include such areas as suspect interviewing and examination of material present in court, which supports its utility in all aspects of the judicial process
• Geographical profiling

  • Evidence to support:
  • Samantha Lundrigan and David Canter collated information from 120 murder cases involving serial killers in the USA
  • Smallest space analysis revealed spatial consistency in the behaviour of the killers
  • The location of each body disposal site was in a different direction from previous sites, creating a 'centre of gravity'
  • The offender's base was invariably located in the centre of the pattern
  • The effect was more noticeable for offenders who travelled short distances (marauders)
  • Spatial information is a key factor in determining the base of an offender
• E: For example, David Canter and Rupert Heritage conducted a context analysis of 66 sexual assault cases. Used a smallest space analysis, identified correlations across patterns of behaviour and found that 80% of the perpetrators had a history of sexual assault
• The data was examined using the statistical technique smallest space analysis - a computer program that identifies correlations across patterns of behaviour. Several characteristics were identified as common in most cases, such as the use of impersonal language and lack of reaction to the victim. These characteristics will occur in different patterns in different individuals.