Bottom Up approach Flashcards
what is the bottom up approach
- takes evidence and data from the crime scene and builds up the profile until a reasonable conclusion about the offender is reached
- Uses similar techniques to the US approach but TYPOLOGIES are NOT INVOLVED and it relies much more on scientific principles- EVIDENCE from the crime scene over INTUITION about the perpetrator.
what was the development of the bottom up approach
- Canter studied the crime scenes of 66 sexual assault cases (he did not interview the perpetrators).
- This evidence revealed clusters of events that commonly occur together e.g. choice of and interaction with the victims including speech patterns/content, Location, time of the offence
- By using statistical analysis Canter was able to develop an understanding of which factors might be associated with each other and which were less likely to be connected.
- The following were identified, through statistical analysis, as being of critical importance in the bottom-up approach:
what are the critically important factors in the approach (4 factors)
- Interpersonal coherence
- Time and place
- Criminal career
- Forensic awareness
what is the factor: Interpersonal coherence
- how the perpetrator behaves at the crime scene is likely to reflect the type of person they are in real life (e.g. if they apologise for their behaviour that rules out a number of suspects)
what is the factor: time and place
The positioning and timing of crimes gives clues as to where the perpetrator might work or live
what is the factor: Criminal career
- This considers how far into their criminal experience offenders are, and how their pattern of crime might progress
what is the factor: forensic awareness
- This highlights the fact that offenders who show an awareness of forensic investigation
- E.g. by cleaning a crime scene, will probably have committed a crime before and been through the criminal justice system
what is the AO1 geographical profiling (Canter)
- The study of spatial behaviour in relation to crime and offenders.
- This method suggests that locations of crime are not in any way random- familiarity is important to the offender
- Based on the notion of schema theory and mental mapping
- The more crimes that have taken place in one area, the more effective this technique can be
- The pattern of offences is likely to form a ‘circle of gravity’ around the offender’s base
- Canter proposed there are 2 types of offenders:
–> Commuters – who travel to commit the crime(s)
–> Marauders- who stick close to home
what is the AO3 for geographical profiling
Research Support +VE:
- Canter and Lundrigan (2002) collated information from 120 murder cases involving serial killers in the USA
- Statistical analysis revealed significant geographical consistency in the behaviour of all killers
- The offender’s base was found to be in the centre of the pattern –> support for the “centre of gravity” theory.
what are the +ve AO3 points for the bottom up approach
- Research Support - The Railway Rapists/Killers (Canter 1994)
- Further Support- Adrian Babb
- “Scientific” Technique
expand on the +ve AO3 point: Research Support - The Railway Rapists/Killers (Canter 1994)
- From 1982 to 1985 there was a series of rapes committed close to railway stations in the south east of England
- Then 3 women were killed through strangulation after the rape, and it seemed that the crimes were escalating
- The police brought Canter, a criminal profiler, in to help them.
- Canter used his method to identify patterns in the perpetrator’s behaviour.
- The rapist talked to his victims, forming a ‘relationship’ with them, he also showed them consideration and used a minimal amount of force
Canter’s profile was:
- A sexually experienced man
- late 20s
- With partner
- semi-skilled job
- little contact with women
- had been arrested before
- lived in Kilburn (London)
- knowledge of the London railway network
John Duffy was arrested:
- He was a 29-year old carpenter who worked as a railway worker
- who was separated from his wife and had a criminal record for raping his ex-wife
- He lived in Kilburn
- This case study shows how effective the bottom-up approach to offender profiling can be.
expand on the +ve AO3 point: Further Support - Adrian Babb
- A serial rapist who was profiled by Canter in 1994
- Arrested and found guilty of seven rapes
- Canter noticed patterns in the rapes
- Perpetrator responded to the discomfort of his victims
- One complained about the cold concrete, perpetrator’s response - put clothing on the floor beneath her
- Canter argued that these details suggested that the rapist would be known as helpful and considerate by those who did not know of his violent assaults
- Babb was indeed a well-regarded swimming pool attendant who was seen as a considerate member of the community
expand on the +ve AO3 point: ‘scientific technique’
- In comparison with the FBI’S Top-Down model, this is a much more scientific method of profiling.
- It is centred on statistical analysis of evidence at the crime scene rather than based on intuitive reports from unreliable criminals themselves
- It can therefore be considered to be more valid if we hold the view that Psychology is a Science and therefore all of its methods should be rigorous and rooted in science.
what are the issues with the bottom up approach (-ve AO3 point)
- A study by Kocsis (2002) examined the importance of investigative experience by testing groups of detectives and undergraduate chemistry students on their ability to successfully profile from a real (closed) case.
- Inexperienced Chemistry students produced the most accurate profiles of all the groups, consistently outperforming experienced detectives.
- There was also some evidence of an inverse relationship between investigative experience and profile accuracy.
- Is this due to psychology of schemas?
