Offender Profiling and Risk Assessment
Dr Malcolm James Cook – 4th April 2013
Referenced items to follow:
These two topics seem, in some people’s minds easily linked together because they might at
first glance appear to rely upon the same information sources. The degree of evidential
overlap is not, however, as comprehensive as one might imagine, as risk assessment can
more readily bring in a wider body of information and make practical use of it than offender
profiling.
Considering offender profiling, it is not a unitary entity, because there are many variants that
exploit different types of information, related to the crime scene, geographical knowledge of
offenders, other similar types of offenders and which might vary between the deductive logic
of Sherlock Holmes and the inductive logic of qualitative methods in psychology. One might
argue though that Holmes actually used both methods but let us set discussion aside for
another time. To develop this question one needs to consider the evolution of profiling and
look for the common themes that arise in connection with its application and use.
Most people will, probably as a result of Silence of the Lambs be aware of the FBI
Behavioural Sciences Unit and their work in developing profiling. Their concern was with
serial offenders, especially murderers but also those committing sexual assault. They
interviewed a group of offenders, who were considered extremely dangerous to identify
common themes that might enable investigators to narrow down the suspect field to quickly
identify a smaller group of potential suspects that more correctly matched the profile. As with
later profilers they created clusters of information that they felt created super-ordinate
categories of profile. As anyone with even a passing acquaintance of factor analysis will
know this is a process fraught with difficult choices. The higher order factors are never a
precise fit and are usually less powerful in predictive terms, it is simply the nature of the
maths and the error in measurement of any characteristic. The lower order items are more
precise and a better fit, but they don’t tend to predict general behaviours that one might one
to apply to model and predict offender behaviour. This is essentially the reason why
psychologists have expended so much time, effort and debate on what is essentially a futile
matter that at first hand seems empirical but is actual mathematical and associated with the
science of measurement. Most but not all psychologists are poor mathematicians and
unskilled at the science of measurement, even though some are trained to conduct
psychometric tests.
The next issue is that the types of people that commit the more bizarre and extreme
offences on a repetitive basis are normal in the statistical sense of the word. Normal for the
purposes of this argument would be at or about the central tendency. The average, the man
so beloved of lawyers on the Clapham omnibus. Some may have personality disorders
which have a rigid thinking, feeling or behavioural style. This is where it becomes confusing
and we need to digress. Some personality disorders, like ASPD (and the more extreme
psychopathy) have a rigid style because they lack the moderating influences of control
(impulsivity) and emotion (lack of empathy and callousness) that normal people have. This
means that their behaviour does not vary as much, so appears rigid. There is another type of
rigidity which is about instability, those with Borderline Personality Disorder may have this
type of personality. The rigidity in this case is about volatility and not behavioural patterns
per se. One can easily apply this to paranoid personality disorder and dependent personality
disorder, and so on.
The behavioural rigidity of those with a personality disorder makes them easier to profile
because the evidence of their behaviour should be apparent in the crime scene, and in that
sense the FBI profilers might be correct, to a degree. The motivation and intent of the
individual committing the crime should or could be apparent but t may not be.
One reason that rigidity might be good is that it implies greater predictability but the key
question is whether that predictability applies to the evidence at the crime scene. Others who
have been sceptical of the FBI approach, like Canter, but they have used cluster analysis
techniques such as smallest space analysis to identify clustering in offender behaviour,
again accepting the idea that behaviour changes slowly, so that many of the components of
one murder scene would be replicated in another. The critical question is why this should be
so.
Before attempting to answer this question, concerning behavioural drift or change, let us
consider the reasons why behaviour changes.
First, learning can take place and as dark as it sounds, murdering people is a skill. If one
considers the accounts of murder in Wade and Myers book on Juvenile Sexual Homicide
one can infer immaturity of technique from the lengths that the murderers went to in order to
kill people. The murders indicated that the murderers had not selected a choice of
instrument, a method of dispatch, or a method of disposal. Contrast these accounts with that
of Ted Bundy’s rape kit consisting of cable ties, duct tape, a knife to threaten and various
implements to gain access to the properties. Bundy’s methods had matured into a skilled
and economical approach which reflected his industrious approach to his craft.
Sophistication of craft usually relies upon practical experience because preparatory fantasy
would not normally allow the development of narratives of failure. The difficult victim who is
not compliant, has a weapon or generates some surprise or fear of failure will influence
changes in behaviour, even amongst those slow to learn. Thus, the Peter Sutcliffe (The
Yorkshire Ripper) modified his behaviour over time and the method of dispatch, preferring to
use a ball pane hammer, with a long shaft for leverage and heavy weighted end for
momentum.
Second, the elements of the crime that appeal to the murderer and those incorporated in
fantasy between assaults, will result in drift of the crime to provide paraphillic and fetishistic
cues that heighten and enhance the enjoyment of the criminal act. There is a suspicions in
some quarters that there is a sexual element to murder, even where no sexual act appears
at the scene. There is no doubt that emotion gives the basis for the motivation for the crimes,
but it is debatable whether it is pleasure or some cathartic release of negative emotion that
drives such crimes. Given the presence of these thoughts in the mind of the perpetrator
access is problematic. Indeed, the FBI’s approach of asking the incarcerated for evidence
seems altogether naive in the extreme.
Thus, one can accept that crimes change over time. However, profiling is based on the joint
principles of homology and consistency. Homology is a principle that suggests that similar
individuals will behave in the same way at their crimes and this allows for a scientific
approach to offender profiling. One of the criticisms of psychodynamic and psychoanalytical
approaches to psychology is the idiosyncratic nature of the explanatory mechanisms that
make them less amenable to scientific investigation based on repetition of observation and
development of general rules for thought, feeling and behaviour. The second principle,
consistency appeals to the fact that behaviour tends to remain similar from one observation
to the next. The obvious question is how similar can one expect behaviour to be from one
murder to the next. If a normal person experiences a very stressful and traumatic event then
they would normally produce stereotyped responses and revert to the most familiar pattern
of behaviour. Thus, one might expect murderers who feel the events of the murder are
stressful to produce stereotypical behaviours. The difficulty is that those with psychopathic
traits might not experience the acute distress and panic, so their behaviour would be more
flexible. However, psychopaths may not have the motivation to improve or perfect their
behaviour, they simply do enough to get by. Thus, it isn’t unreasonable to believe that
behaviour might not change. In this argument one can detect the theoretical arguments of
those favouring situational modification of behaviour (like Mischel) and those favouring
personality theories that suggest internal biological mechanisms that influence behaviour
(like Eysenck, Gray, Blair, Zuckerman).
Most psychologists would accept that whether one favours learning or biology as the
explanation for personality traits, both are unlikely to change quickly as instability in
behaviour would be problematic for social relationships and for survival. Thus, one would
expect that there is a reasonable degree of consistency in behaviour at a crime scene. In
conclusion, one can see that offender profiling relies on factors that might be considered
appropriate for risk assessment. Now consider the case for risk assessment.
Risk assessment normally considers two types of variables, static factors and dynamic
factors, there are a number of scales in use for sex offenders, domestic violence, murder,
stalking, and a variety of other crimes. If we risk assess a person at time one, we are
assuming that the assessment can be used to predict behaviour at some late date with some
degree of accuracy, which probably declines with time as other factors that influence
behaviour intervene. The most influential one might argue the most robust and reliable are
static factors that do not change. Thus, early developmental experience, genetic inheritance,
and the interaction between the two and their substrates such as IQ, personality, and mental
health would be significant and measures such as the HCR-20, PCL-R and the SCID reflect
this. Thus, in line with offender profiling risk assessment makes use of the principle of
reliability or consistency over time. What is different is that risk assessment accepts that this
inherent risk can change because of other factors. Major life events can cause people to
exhibit unusual patterns of behaviour. For that reason dynamic factors are often included in
risk assessments and scenario planning occurs to consider events that would make
behaviour better, have no effect or much worse, with regard to anti-social content.
Implicit in risk assessment is the principle of homology. Thus, with equivalent assessment
profiles for risk one would expect that an individual will given the appropriate sequence of
unfortunate events exhibit the expected behaviour. Equivalent profiles, equivalent types of
risk. The exact acts remain to be determined because in some cases the individual
experiments with a variety of actions that are equally problematic but share a common
theme.
Thus, one can see that both risk assessment and offender profiling share many similar
principles. The narrow window of evidence available at the crime scene makes the offender
profiling activities more speculative and potentially misleading, as the mapping of offence
behaviour to specific underlying traits is blurred by the chaotic and random nature of the
perpetrator-victim interaction. By comparison, it is often assumed that risk assessment of
individuals is a pretty exact science, based of high quality evidence and statistical inference.
However, recollect the basic problem beyond the mathematics. Measurement. It is the
process of measurement that is weak, an offenders offence history is rarely complete and it
is unlikely that one would ever have a completely accurate record, even if based on the
offenders candid and open account from memory. The assignment of values in assessment
systems is compromised by so many factors, starting with quality of the assessor, the
procedure for assessment, the quality of the instrument and the list goes on. Psychology is
rarely and may never be an exact science of behaviour, it is an approximation and as such
there is always room for uncertainty.