In this forensic unit we will cover a range of explanations for criminality,
are people born criminals, so innate biological factors,
or do people learn to be criminals, and what does Freud have to say about criminality?
We will also come to the best ways to stop criminals repeating their offending behaviour.
But before we get to that we are going to discuss the psychology behind offender
profiling, now when most people think of criminal profiling they think of CSI and Sherlock Holmes.
But is the work of the real professionals like that and is it effective.
In defining offender profiling we could say the assumptions profilers make
about the characteristics of an offender based on a careful analysis of the offence they commit.
Now profilers can make these assumptions because we think that crimes or not random.
Offenders have what is called a modus operandi or MO, this is a particular way of carrying
out their crimes that they repeat in each offence. Its also called a criminal signature.
If we combine that with other gathered information from the crime scene like who the victim was, and
what time and place the crime took place we can start to build a picture of who the offender is.
These characteristics are demographic, so age, gender and ethnicity.
What is their likely occupation and how educated are they. But we could also
make assumptions about their physical features and their likely behavioural characteristics.
Serious offences like rape and murder are the most likely crimes to use offender profiling,
but its more effective when searching for a serial offender,
and a profiler is only likely to be used when the normal forensic techniques haven’t worked.
So offender profiling isn’t as common as you may think.
There are two different ways of offender profiling,
top down and bottom up. We explore them in depth in this video and consider how effective they are.
To quickly give you an idea, Top down refers to an approach is usually called
criminal investigative analysis, and was developed by the FBI in America,
profilers use pre-existing categories of offenders called organised or disorganised.
The profiler will use crime scene evidence to match the offender to one of these categories
based on their own professional experience and effectively their intuition.
Bottom up was developed in the UK, and is referred to as investigative psychology.
we could say it has a more scientific approach. It uses statistical analysis on the data collected
at the crime scene. This uses large data sets collected from other similar crimes. From that
we can make assumptions such as how far the offender travelled to commit their crime.
Now you’re probably wondering why the terms top down and bottom up are used.
Well, the terms actually come from perceptual psychology. Top-down theories suggest perception
starts with concepts pre-existing in the mind that we then compare with sensory data,
Bottom-up models suggest the brains perception starts with the sensory data.
I don’t think that’s massively helpful in understanding offender profiling,
but I know if I didn’t tell you, you would be wondering why the approaches had those names.
TOP DOWN OFFENDER PROFLING
36 serial killers including ted bundy? X and John Wayne Gacy where interviewed by the behavioural
science unit at the FBI. Analysis of the interviews separated the murderers onto two types,
24 organised offenders and 12 disorganised offenders.
The FBI developed a staged strategy of how to create a criminal profile, in stage one all
relevant data is collected from the crime scene, so witness statements, photographs of the crime
and autopsy reports, and other factors like the choice of victim and where the body was found.
Stage two. From this analysis the profiler decides
what type of offender committed the crime, organised or disorganised.
How are organised or disorganised criminals defined by the FBI?
Well there are a large range of characteristics to consider, here are a few. For an organised
offender we would expect to see evidence that the offence was carefully planned perhaps they
took their own weapon to the crime scene, the crime scene suggesting the criminal was in total
control, perhaps leaving little forensic evidence. The body may show evidence of being restrained,
and the body itself may have been moved and hidden. We would expect the offender to have
average or higher than average intelligence and to be following reporting of the crime in the media.
With a disorganised offender all of that is reversed, the crime was committed in
the heat of the moment with no planning maybe using whatever objects are around as a weapon,
there may be lots of evidence left and it’s likely the victim wasn’t restrained. The
body is left where the offence happened. This all reflects a lower-than-average
level of intelligence and the criminal is unlikely to be following media coverage.
Now this was just a small selection of characteristics, you don’t need to remember
them all, but you need enough to give a clear distinction between the two types. Now the FBI
originally published all of this in their internal training manual for FBI investigators. you can
read all 25 comparisons by pausing the video… and if you want to read the original training
document in full, with case studies you can use this link.
So now the offender has been classified as organised or disorganised
stage three involves crime reconstruction. What happened? what was the sequence of behaviour for
both the victim and the offender before during and after the offence? This of course is a hypothesis
based on all the available data and importantly the profiler’s expertise and intuition.
Stage 4 is profile generation. The profiler now makes a range of inferences about the offender
like their demographics and their likely behaviour.
There is a very good video by wired, its a former FBI investigator showing how this
technique is used in practice. I will put a link in this video’s description.
Evaluating the top-down approach If we want to evaluate top-down profiling,
we can consider the original interviews by Ressler as providing a clear typology of
organised and disorganised criminals that can help researchers focus their investigations.
But you can probably see there are some big problems with this research.
36 offenders is a very small sample, they are unlikely to be representative of all offenders,
suggesting the results may not be generalisable. Also this was a self-report method,
and the participants were convicted offenders who were very likely to lie,
either to gain notoriety or even maybe sympathy. In a review of 100 American serial killers Canter
did find evidence for organisation in most serial killings, but didn’t
find any evidence for a distinct type offender that could be classified as disorganised. This
suggests we are making a false dichotomy when classifying offenders into one of two types.
BOTTOM UP OFFENDER PROFLING
This approach is normally referred to as investigative psychology
and even though the end goal is also to create a criminal profile from available evidence,
how investigative psychology gets to that profile is very different to the top-down approach.
All the data collected at the crime scene, like choice of victim and the crimes location
is analysed statistically, comparing it to large data sets collected from other crimes. This
suggests likely characteristics of the offender. David Canter the creator of investigative
psychology created a five-factor model to interpreting a crime scene.
Interpersonal coherence means we would expect how the criminal interacts with the victim
is the same kind of behaviour they show to people in their lives.
So, for example if they are aggressive to the victim, they are likely to be more physically
aggressive in their personal lives. Some criminals may be manipulative, shy or talkative.
Time and place significance, this means we should carefully consider where and when the crime took
place. This factor of the crime would have been chosen by the criminal and gives an insight into
their mental map of their environment. It’s likely a place they know well as this would give them
a greater sense of control. For example, they would know of escape routes, if they could get
easy access a victim, or if they were likely to be disturbed by a member of the public.
Criminal characteristics, this is using statistical analysis to infer the probability
of the criminal’s demographic characteristics based on the case history of previous crimes.
Criminal career, this recognises that the criminal’s MO will change between crimes,
this is due to learning from experience. Maybe in one offence the victim struggled
more than expected so in the next attack the criminal restrained the victim.
Forensic awareness is linked to the criminal’s knowledge of criminal justice,
if they are aware of forensic techniques, they are more likely to know how to effectively
hide evidence. This could suggest they have already been arrested for previous crimes
and forensic evidence used against them.
Geographical profiling. This is one aspect of
investigative psychology that has been significantly developed. Its used to help
investigators focus their resources by narrowing down search areas, based on the assumption that
the location of the crime isn’t a random choice. One assumption is the least effort principle,
if the criminal has the choice between two equally attractive locations,
they will choose the one closest to their base. A related assumption is distance decay,
because the offender prefers closer locations the further you get from their home base the fewer
crimes there will be. But as you can imagine, there will be a buffer zone around their house
that they won’t offend in, reducing the chances of being recognised.
The circle hypothesis is the idea that if you draw a circle with the two furthest offenses
on the circumference line, then the offenders home base is likely to be within the circle.
The offender is using what they know about their environment and their crimes are radiating out.
Now this behaviour is that of what Canter called a marauder, there is an alternate type of offender
called a commuter who travels from their home base to a defined area to commit their crimes.
This circle design is a little simplistic, including parts of the geography that the
criminal is not likely to like parks and rivers, but there is a more complex versions called
criminal-geographic targeting. It takes into consideration features of the environment to
create a 3D heatmap, showing different colours depending on the probability it
contains the criminals home base, this is called a jeopardy surface.
To evaluate the bottom-up approach Canter demonstrated that 87% of a sample of 45
British serial sexual assaulters fitted the marauding definition. This provides evidence
for the idea that criminals chose of offend around their home base and using the circle hypothesis
is a useful technique directing police resources.
A problem with this however is there is no way of knowing if a criminal is a commuter
until they are caught, if all of their offenses are recorded or even if all the offenses in an
area are from the same criminal. This could lead to a misuse of limited police resources.
But as it is based on careful statistical analysis we could say that investigative psychology is a
more scientific approach than the top down method, that places too much emphasis on police intuition.
Offender Profiling General evaluations
Its really hard to be sure if any form of offender profiling is actually effective.
That’s because offender profiling is never the only strategy used by police,
its used in combination with other forensic techniques. So, it’s often difficult to identify
exactly what factor led to a case being solved. But generally, when customer satisfaction surveys
are used, police are positive about the role of profilers. Snook found 94% of Canadian officers
agreed that profiling helped solve cases. But the idea that this positive feedback
suggests that profiling is actually effective is questioned by the results of study by Alison
Two groups of highly experienced officers were given the same offender profile,
but then each group was given the case file of very different offenders that they were told had
actually committed the crime. When asked if the profile was accurate both groups had the same
response. 75% agreed that the profile was somewhat accurate and 50% generally or very accurate.
Alison explained these results as due to the Barnum effect. This is when the statements are
so general and vague, they really could apply to almost anyone, but are tricked into accepting them
as true and insightful. It’s a technique you often see in used in horoscopes and personality tests.
A final evaluation is this, any attempt at offender profiling is going to fail when
trying to catch a statistically abnormal offender. Their behaviour isn’t going to match previous data
or the expectations of an experienced profiler. Much of what we know about
offenders is based on the ones that got caught Here are some real exam questions you can try
out. Patrons can see a walk though video of these over on my website. For everyone else
make sure your subscribed, and see you in the next video, biological explanations of offender