The Bottom-Up Approach to Offender Profiling (AQA A Level Psychology)
Revision Note
Written by: Claire Neeson
Reviewed by: Lucy Vinson
The British approach & investigative psychology
The bottom-up approach (BUA) to offender profiling contrasts to the top-down approach as developed by the FBI in the USA as it is ‘data-driven’
‘Data-driven’ means that the BUA does not begin with the assumption that each crime will fit into a typology; instead it uses the crime scene as the basis for the creation of a profile
The BUA is inductive as it uses information already present and draws ideas, theories and conclusions from it i.e. it aims to develop a theory from the data presented
The BUA starts the process of profiling using small, possibly seemingly irrelevant details from the crime scene and uses them to create the ‘bigger picture’, making no assumptions as to the offender
The BUA relies on computational/statistical analysis and database records in the collection of crime scene minutiae
The BUA is popularly known as the British approach to profiling as it was devised by a British researcher, Professor David Canter
Canter’s methods involve the cross-referencing of crime-scene details to determine the composition of the offender profile via use of statistical methods, known as investigative psychology (IP)
The statistical system used in the BUA is known as ‘smallest space analysis’ using evidence from the crime scene which renders a correlation of the behaviours that occurred most frequently across offences
Examiner Tips and Tricks
The AQA spec does not cite smallest space analysis as one of the key factors you need to know for the BUA but it will add some value to higher-mark questions (e.g.16 marks) if you can mention it alongside investigative psychology and geographical profiling. You can go online to find diagrams of smallest-space analysis examples but do be warned that these include references to violent, often distressing, acts so caution is advised.
IP may be broken down into the following components:
Interpersonal coherence - this has some relevance to the top down approach concept of modus operandi i.e. how the offender behaved at the crime scene, their treatment of the victim before, during and after the offence (this is based on the idea that ‘how someone does anything is how they do everything’ - crime scene behaviours will reflect everyday behaviours)
The significance of time and place - where was the crime committed - town, city, village, indoors/outdoors? When was it committed - at night, in the early morning, in summer/winter?
Forensic awareness - has the offender been careful to leave no trace evidence (e.g. DNA, fingerprints etc), have they avoided CCTV etc?
The BUA focuses on practical issues such as the location of crimes which may be linked.
Geographical profiling
Geographical profiling (GP), also known as ‘crime mapping’ is a key aspect of the BUA, first developed by Rosso (1997)
GP is used to analyse the geographical locations of offences which appear to be linked i.e. committed by the same offender
GP can be used alongside IP to develop a profile as together these two systems form a complete picture of the likely offender (or offenders - some serial crimes have been carried out by more than one person as was the case with John Duffy, see below)
GP operates along the assumption that serial offenders fall into two categories: marauders or commuters
Marauders commit crimes within their neighbourhood, not far from where they live/work possibly as this is where they feel safe plus they are more likely to know the escape routes to exit the scene as quickly as possible
Commuters commit crimes away from their neighbourhood which may be as a result of travelling a lot for work or as a way of avoiding detection
GP uses the ‘circle theory’ which is applied by drawing a circle around the seemingly linked offences: the offender is thought to live somewhere inside the circle
Circle theory places the offender at the heart of their crimes.
One of the first cases of the successful use of GP was in the identification of the ‘Railway Rapist’ John Duffy
Duffy had committed several rapes and murders around railway stations in North London in the 1980s
David Canter was asked to analyse the crimes and to come up with a profile of the likely offender
Canter studied the location of the crimes using circle theory: this helped him to identify where the attacker lived and the resulting pattern suggested that the offender was a marauder
Here is Canter’s profile alongside facts about Duffy which emerged once he had been arrested:
CANTER’S PROFILE | FACTS ABOUT JOHN DUFFY |
Likely to live in Kilburn or Cricklewood Likely to be married Probably has no children Likely to have marriage problems Will be a loner with few friends Will be physically small Will have feelings of unattractiveness Will be interested in martial arts/bodybuilding Will have a need to dominate women Likely to have a fascination with weapons Will have fantasies about sex and violence Will have a semi-skilled job Will be aged between 20 and 30 years old | Lived in Kilburn Was married Was infertile Had separated from his wife Only had 2 male friends Was 5”4 Had acne Was a member of a martial arts club Was violent and often attacked his wife Was a collector of martial arts weapons Was a collector of hard core porn videos Was trained as a British Rail carpenter Was aged 28 |
Years later (2001) it emerged that Duffy had a partner in these crimes - David Mulcahy - which is something that the police had suspected but which they had no proof of until Duffy confessed this detail in prison
Research which investigates the bottom-up approach to offender profiling
Canter (1996) - spatial activity based on 45 males convicted of sexual assaults showed that 87% of the sample were marauders, using their home base to carry out the attacks plus they travelled the same distance from their home to carry out each offence
Beauregard (2009) - recommends that IP be used to identify sex offenders as it has good application to these type of offences
Evaluation of the bottom-up approach to offender profiling
Strengths
Much research - particularly by Canter (alone or with colleagues) supports the effectiveness of the BUA in identifying and (more importantly) apprehending dangerous offenders
The BUA takes a more objective approach than the TDA (which uses as its basis the results of interviews conducted over 50 years ago) with its use of statistical methods which means that it is more reliable than other approaches to profiling
Weaknesses
Kocsis et al. (2002) tested the profiling skills of various police professionals compared to a sample of Chemistry students: the Chemistry students produced the most accurate profiles (interestingly the more experienced the police professionals were, the more inaccurate their profiles were) hence profiling may involve little more than guesswork
When profiling goes wrong it can be catastrophic: British psychologist Paul Britton’s profile of the killer of Rachel Nickell completely derailed the police investigation and resulted in the murderer going on to claim more victims
Worked Example
Describe and evaluate the two approaches to offender profiling. Refer to relevant research in your answer. [16]
AO1 = 6 marks, AO3 = 10 marks.
For 13-16 marks knowledge of offender profiling will be accurate, well detailed and evaluation will be effective. The response will be clear, coherent and focused with effective use of terminology.
For 9 – 12 marks knowledge of offender profiling will be present but with occasional inaccuracies/omissions and mostly effective evaluation. It will be mostly clear and organised with an occasional lack of focus and some use of terminology.
For 5 - 8 marks there will be limited knowledge of offender profiling with the main focus of the answer being on description. Evaluation will be fairly limited with a lack of terminology. Clarity, accuracy and organisation will at times be lacking.
For 1 - 4 marks knowledge of offender profiling will be very limited with weak discussion (evaluation may be entirely absent). The answer will lack clarity, have many inaccuracies and be poorly organised with sparse or absent terminology.
Possible answer content could include:
AO1:
The FBI’s top-down approach focuses on offender typology, based on data collected from 36 interviews with serial killers, providing a template from which to match crime-scene details to produce a profile of the type of offender per crime scene
Offenders therefore classified according to the criteria ‘organised’ or disorganised’ e.g. an organised offender is likely to bring weapons and exercise great control at the scene
In contrast, the British bottom-up approach focuses on systematic statistical analysis of the crime scene and then works its way up to a profile based on that evidence
The British approach does not work with fixed typologies, instead the profile is ‘data-driven’ and is more grounded in psychological theory
AO3:
The TDA is based on outdated accounts from interviewees which may be unreliable as the 36 killers may have had mental disorders or could easily have enjoyed lying about their crimes
Classifying of offenders according to type is only based on the interview information and it may well be overly reductionist and deterministic
The TDA reduces crimes to only two broad categories where in fact there may be overlapping features and the labelling of ‘organised/disorganised’ does not allow for offenders to change the M.O. from crime to crime
The BUA applies statistical procedures to crime scene evidence in order to obtain an objective overview of the crime and the potential criminal
Geographical profiling is used alongside IP to produce the ‘smallest space analysis’ which calculates spatial consistency in the behaviour of killers
The BUA is more scientific than the TDA and is therefore less likely to be biased (Canter, 1996)
The BUA has a wider application than the TDA as it is based on practical, achievable methods rather than on a subjective appraisal (e.g. the crime scene must fit into one of two typologies)
It could be argued that the TDA is in need of modernising although neither approach is without flaws - Copson (1995) showed that offender profiling only resulted in accurate identification of the offender in 3% of cases.
Last updated:
You've read 0 of your 10 free revision notes
Unlock more, it's free!
Did this page help you?
