Forensic psychology revision notes
Offender profiling: The top-down approach
- It’s based on police experience and case studies rather than psychological theory.
- It’s suitable for the more extreme/unusual crimes, such as murder, rape and ritualistic crimes.
Offender profiling
- Offender profiling - also known as ‘criminal profiling’, a behavioural and analytical tool that is
intended to help investigate, accurately predict and profile the characteristics of unknown
criminals.
- Methods vary but the compiling of a profile will usually involve careful scrutiny of the crime
scene and analysis of the other evidence in order to generate hypotheses about the probable
characteristics of the offender (their age, background, occupation, etc.)
The US (Top-Down) Approach
- Offender profiling began with the FBI’s Behavioural Science Unit in the 1970s,
- They drew upon data gathered from in depth interviews with 36 imprisoned serial killers
(including Charles Manson and Ted Bundy).
- They then concluded that the data could be categorised into organised and disorganised
crimes/murders. Each category had certain characteristics which meant that if, in a future
situation, the data from a crime scene matched some of the characteristics of one category,
we could then predict other characteristics that would be likely.
Organised and disorganised types of offender
The organised and disorganised distinction is based on the idea that serious offenders have certain
signature ‘ways of working’ and these generally correlate with a particular set of social and
psychological characteristics that relate to the individual.
- Organised offender - An offender who shows evidence of planning, targets the victim
(suggesting the offeder has a ‘type’ of victim they seek out), maintains a high degree of
control during the crime (almost detached surgical precision so little evidence left behind) and
tends to be socially and sexually competent with higher than average intelligence.
- Disorganised offender - An offender who shows little evidence of planning, crime scen tends
to relect impulsive nature of attack leaving clues e.g. body usually still at the scene and tends
to be socially and sexually incompetent with lower than average intelligence. Tend to live
alone and often relatively close to where the offence took place.
Constructing an FBI profile:
- Data assimilation - the profiler reviews the evidence (crime scene photographs, witness
reports, etc.).
- Crime scene classification - as either organised or disorganised.
- Crime reconstruction - hypothesis in terms of sequence of events, behaviour of the victim, etc.
- Profile generation - hypotheses related to the likely offender, e.g. of demographic background,
physical characteristics, behaviour, etc.
Evaluation
Research Support - Canter et al (2004), smallest space analysis showed typology ‘organised
offender’ has some validity
- Using 100 US murders each committed by a different serial killer
- Analysis was used in order to assess the co-occurrence of 39 aspects of serial killings.
Counterpoint: However, Godwin (2002) says separation between ‘organised’ and ‘disorganised’ types
is on a continuum.
Wider application - can be used for burglary, Meketa
- 85% rise in solved cases in three US states
- The detection method retains the organised-disorganised distinction but also adds two new
categories: interpersonal and opportunistic
,Personality - the approach assumes consistent personality traits and also ignores situational factors.
- Situationist psychologists argue that people’s behaviour is much more driven by the situation
they are in than ‘personality’. Therefore, behaviour patterns seen at a crime scene may tell us
little about how the individual behaves in everyday life.
Flawed evidence - development of types dependent on interview of 36 serial killers, not a random or
even large sample, no variation in offender and no standard set of questions (therefore not really
comparable).
Research support - there is support for a distinct organised category of offender
David Canter et al. conducted an analysis of 100 US murders each committed by a different serial killer.
Smallest space analysis was used - a statistical technique that identifies correlations across different
samples of behaviour. In this case the analysis was used in order to assess the co-occurrence of 39
aspects of serial killings. This included such things as whether there was torture or restraint, whether there
was an attempt to conceal the body, the form of murder weapon used and the cause of death. This analysis
revealed that there does seem to be a subset of features of many serial killings which matched the FBI’s
typology for organised offenders.
This suggests that a key component of the FBI typology approach has some validity.
Counter:
However, many studies suggest that the organised and disorganised types are not mutually exclusive.
There are a variety of combinations that occur at any giver murder scene. For instance, Maurice Godwin
argues that, in reality, it is difficult to classify killers as one or the other type. A killer may have multiple
contrasting characteristics, such as high inteligence and sexual competence, but commits a spontanious
murder leaving the victim’s body at the crime scene.
This suggests that the organised-disorganised typology is probably more of a continuum.
Wider application - application to other kinds of crime, such as burglary
Critics of top down profiling have claimed that the technique only applies to a limited number of crimes,
such as sexually motivated murder. However, Tina Meketa reports that top down profiling has recently been
applied to burglary, leading to an 85% rise in solved cases in three US states. The detection method retains
the organised-disorganised distinction but also adds two new categories: interpersonal (offender usually
knows their victim and steals something of significance) and opportunistic (generally inexperienced young
offender). Suggesting the top down profiling has wider application than was originally assumed.
Flawed evidence - due to the evidence on which it is based
As we have seen, FBI profiling was developed using interviews with 36 murders in the US - 25 of which
were serial killers, the other 11 being single or double murders. At the end of the process, 24 of these
individuals were classified as organised offenders and 12 were disorganised. Canter et al. have argued that
the sample was poor - the FBI agents did not select a random or even a large sample nor did the sample
include different kinds of offender. There was no standard set of questions so each interview was different
and therefore not really comparable.
This suggests that top down profiling does not have a sound, scientific basis.
Extra:
Personality
The top down approach is based on the principle of behavioural consistency - that serial offenders have
characteristic ways of working (their modus operandi). However, situationist psychologists, for instance
Walter Mischel, argue that people’s behaviour is much more driven by the situation they are in than by a
thing called ‘personality’. Behaviour patterns seen at a crime scene may tell us little about how the
individual behaves in everyday life.
, Offender profiling: The bottom up approach - reduces confirmation bias
- The aim of the bottom up approach is to generate a picture of the offender - their likely
characteristics, routine behaviour and social background - through systematic analysis of
evidence at the crime scene.
- The profile is ‘data driven’ and is much more grounded in psychological theory than the top
down approach.
Investigate Psychology
Aim is to establish patterns of behaviour in order to develop a statistical database which then acts as
a baseline for comparison so that specific details of an offence can be matched against this database
to reveal important details about the offender e.g. personal history, family background etc, this may
also determine whether a series of offences have been committed by the same person.
- Interpersonal coherence - this is the way in which an offender behaves at the scene. How
they interact with the victim may indicate how they act in everyday life. For example accent or
style of attack.
- 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 - This focuses on those who have been the focus of police interrogation
before. Their behaviour may denote how mindful they are of ‘covering their tracks’.
Geographic profiling
Geographical profiling uses inflation about the location of linked crime scenes to make inferences
about the likely home or operational base of an offender - known as crime mapping and based on the
principle of spatial consistency (that people commit crimes within a limited geographical space).
The assumption is that serial offenders will restrict their ‘work’ to geographical areas they are familiar
with, creating a ‘centre of gravity’.
Canters Circle theory - proposes two models of offender behaviour, either:
- The Marauder: the offender operates in close proximity to their home base.
- The Commuter: the offender is likely to have travelled a distance away from their usual
residence. E.g. the yorkshire ripper
This offers insight into the nature of the offence, i.e. whether it was planned or opportunistic, as well
as the offender themselves, such as mode of transport, approximate age etc.
Evaluation
Evidence for investigate psychology - evidence supports its use
David Canter and Rupert Heritage conducted an analysis of 66 sexual assault cases. The data was
examined using the smallest space analysis. Several behaviours were identified as common in
different samples of behaviour, such as the use of impersonal language and lack of reaction to the
victim. Each individual displayed a characteristic pattern of such behaviours and this can help
establish whether two or more offences were committed by the same person (referred to as ‘case
linkage’).
This supports one of the basic principles of investigative psychology (and the bottom up approach)
htat people are consistent in their behaviour.
Counterpoint -
However, case linkage depends on the database and this will only consist of historical crimes that
have been solved. The fact that they were solved may be because it was relatively straightforward to
link these crimes together in the first place. Which makes this a circular argument.
This suggests that investigative psychology may tell us little about crimes that have few links between
them and therefore remain unsolved.
Evidence for geographical profiling
Lundrigan and Canter collated information from 120 murder cases involving serial killers in the US.
Smallest space analysis revealed spatial consistency in the behaviour of the killers. The location of
