Creating a
Profile
Top Down Typology
Like a Jigsaw
See the picture then
find the pieces to fit it
CANADA
USA
MEXICO
Top – Down Typology
Top – Down Typology
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The American, or ‘top-down’, approach was compiled by the FBI through a
series of in-depth interviews with 36 convicted sexually orientated
murderers, including Ted Bundy and Charles Manson.
This information, along with detailed information from the FBI
Behavioural science unit, was combined with detailed examination of the
crime scene, the nature of attacks, forensic evidence, and any information
relating to the victim to develop models that would result in a profile of
the offender.
From this the FBI developed a classification system for several serious
crimes.
Murders (in particular ‘lust murders’) were classified as either ‘organised’
or ‘disorganised’ and a set of characteristics was built from this.
Organised offenders would show planning in their crimes, leave few clues,
and target a stranger; from this it was possible to infer that they would be
above average IQ, be socially and sexually competent and in a skilled
occupation.
Those categorised as disorganised would show the opposite traits.
FBI investigators, Hazelwood & Douglas in 1980 were able to classify crimes in terms of
the ‘organised’ and ‘disorganised’ offender by attempting to fit new crimes into these
existing categories based on details of the crime and intuitive analysis.
Disorganised scene
Organised murder scene
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Planned
Victim — targeted stranger
Control including restraints,
Aggression before death
Body hidden or moved from crime scene
Weapon and evidence absent
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Spontaneous
Victim — known by offender
Little control
Sexual acts before death
Body not hidden or left at crime scene.
Evidence present
Organised murderer
Disorganised murderer
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More-than-average lQ
Skilled occupation
Controlled mood
Living with partner
Mobile — for example, car
Socially competent
Sexually competent
Inconsistent discipline as child
Use of alcohol during crime
Follows crime on news
Limited change in behaviour after crime
Less-than-average IQ
Unskilled
Uncontrolled
Living alone
Lives near crime
Socially incompetent
Sexually incompetent
Harsh discipline as child
Alcohol not used during crime
Does not follow crime on news
Major behaviour change after crime
FBI
The FBI need certain information
before they can make the profile
• Colour Photos of the crime scene
• Data about the neighbourhood of
the crime (housing, income)
• Medical Examiners report
• A map of the victims travels prior
to death
• A complete investigative report of
the incident
• Background details of the victim
FBI – 4 STAGES
1.
2.
3.
4.
DATA ASSIMILATION
CRIME CLASSIFICATION
CRIME RECONSTRUCTION
PROFILE GENERATION
http://youtu.be/eSfgY8sr46o
Agents
Given the
evidence provided
your task is to
draw up a profile
of the offender.
• Use the the differences
between organised and
disorganised murders
The following exercise is taken from Howitt (2002) and is
based on a case originally reported by Ressler et al (1988).
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A nude female's body is was found at 3.00pm on the roof of an apartment block where she
lived.
She had left home for work at 6.30 in the morning.
She was 26 years of age, 90 lbs in weight, her spine was deformed and she was not dating
men.
Both of her nipples had been removed and placed upon her body.
Her face was severely beaten.
She had been throttled with the strap of her bag.
A blunt instrument had caused many face injuries.
Virtually all items used came from the victim’s bag.
The phrase "You can't stop me" was written in ink on the inner thigh and "Fuck you" on the
torso.
The pendant she usually wore was missing.
The victim’s underwear had been taken down and pulled over her face.
Her stockings were tied around her ankles and wrists but very loosely.
A pen and an umbrella were inserted into her vagina.
A comb was stuck in her pubic hair.
There was no semen in the victim’s vagina. The offender had ejaculated over her body from a
standing position.
There were bite marks on her thighs and various bruises/lacerations all over.
Faeces from the murderer were very close by. They were covered with the victim’s clothes.
There was no evidence of similar crimes being carried out in the area.
So Agents…….
Give me your profile of the
offender!
What the FBI have to say…
• A white man.
• Aged between 25 and 35 years similar in age to the victim.
• Sexual fantasies have been
harboured by the offender for a
long time and possibly uses and
collects sadistic pornography.
• He would fit into the context
well - might reside in the
apartment block or work there.
• Average intelligence but dropped
out of education.
• No military background.
• Possibly unemployed.
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Unskilled or skilled occupation.
Alcohol and drugs would not have
materially contributed.
Difficulties in personal relationships
with women.
Any dates would be younger so that
they could be more easily controlled
and dominated.
Sexually inexperienced and
inadequate.
Never married.
Disorganised offender - confused
and perhaps mental difficulties in
the past.
Messages challenged the police and
may indicate future killings.
Additional Info - FBI
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Killers tend to be similar in terms of age and race to their victim.
Fantasy is at the core of extreme cases like this. The fantasy may involve the thinking about
and planning for the offence. The sadistic nature of the crime is probably indicative of the
offender's fantasy. Keeping a trophy, the pendant, will help the offender fantasise about this
in the future.
Although the offender fantasised and "planned" the murder in his fantasy world, there was
little evidence of real planning. This was a disorganised crime, the offender using what came
to hand in the course of the crime....her pen, her umbrella etc.
The crime was sexual but there was no penetration by the offender, only the substitutes. It is
this that suggests sexual inadequacies and the likelihood that he lacked sexual experience
and had never married.
The victim was partially disabled, she was tied up in a crude way, and this suggests the
offence has elements of control and domination.
Defecation near a crime scene is not unusual but in this case it perhaps indicates that the
offence took place over a lengthy period of time. Potentially, this represents a considerable
risk for the offender since he was in an exposed situation (a roof top). Unless of course he
lived or worked in the area and knew he was unlikely to be disturbed.
The killer….
• Using this profile the police were able to work through their records and
identify a man whose father lived in the same apartment block.
• The police had been told that his son was in a mental hospital but they
found that security there was poor.
• The crucial piece of evidence was the bite marks on the body which
matched the dental pattern of the suspect.
What’s wrong with this
approach?
Discuss briefly and I will go
through it at the end…
Canter 2004 – serial murder and
investigation (to be researched for
Wednesday!)
Bottomup/Geographical
Offender
Profiling
The British
Way
Bottom up approaches
• Canter 1990 – UK’s foremost profiling expert, his
bottom up approach looks for consistencies in
offenders behaviour during the crime.
• No initial assumptions are made about the
offender.
• Relies heavily on computer databases.
• The British, or ‘bottom-up’, approach is more scientific than the American
approach in that it uses more psychological theories and methodologies.
• Seen as a cognitive social approach and looks at associations between the
offenders characteristics and the offence behaviour.
• This approach looks for ways in which the crime might mirror the behaviour
of the offender in every day life – the Criminal Consistency Hypothesis
(Canter (1989)).
• This consistency principle has been applied to two areas: interactions
between the victim and the offender (interpersonal consistency); and the
geographical area in which the criminal commits the offence (spatial
consistency).
• Within interpersonal consistency it is argued, for example, that the degree of
violence used in serious crimes, especially rape, may reflect how the criminal
treats other women in his non-criminal life.
• Spatial consistency is based on the idea of mental maps; criminals then draw
on these mental maps when committing a crime (so committing a crime
somewhere they are comfortable with, on the way to a friends or work).
• Two types of offenders were highlighted: the marauders who use a fixed base
(usually home) and offend around that central point (as little as 2 miles,
Canter & Gregory, 1994) ; or commuters who travel far to the location of the
crime to disassociate themselves from the geographic location.
• Called bottom-up as no initial assumption is made about the offender
until a statistical analysis using correlational techniques is carried out.
• Relies heavily on computer databases being accurate (more objective
and reliable than the American approach).
• Canter criticised the technique used in the American approach (top
down).
• He suggests that interviews with criminals are unreliable as the criminals
can be manipulative and they are often disturbed sensation seekers.
• He believes that criminals, like most people behave consistently, so
criminals will reflect their normal behaviour patterns when they commit
crime, which leads to further clues.
• An analysis of the pattern of behaviour observed over a number of
crimes committed by a serial offender will give clues about the nonoffending everyday behaviour of the criminal.
• The British approach (bottom up) involves advising police officers about
correlations between sets of data, such as time, place, choice of victim.
Evaluation points?
Strengths
• Trying to build a ‘picture’ of the person who committed a crime without ever
having contact with them.
• It helps to narrow down the scope of people from where to start looking for
suspects – helps focus police resources.
• It can establish description of likely social, physical and mental
characteristics.
• This can help establish where and when they are likely to offend again and
possible victims.
• This can lead to possible interview strategies to elicit confession of guilt or
details of a crime.
• Can reduce list of potential suspects
• Could force a slip-up to enable detection
Weaknesses
• Police resources have been wasted pursuing the wrong person
• Can be an over-reliance on so-called ‘expert’ without acknowledging the
invaluable contribution of experienced police officers
• Small percentage of successes in catching offender when working with
offender profiling
Evaluation extended:
• An initial problem with research into offender profiling lies in the
researchers only focusing on one variable that could be the cause an
offender committing a crime; this is known as being reductionist.
• For example, the American approach uses topologies to categorise
offenders as either organised or disorganised.
• Some offenders could show characteristics of both topologies. In
contrast, the British approach uses a variety of psychological theories to
provide an understanding of how an offenders’ behaviour during an
offence relates to their everyday life therefore allowing for many more
variables to be taken into account and thus not being reductionist.
• Research which is reductionist is problematic as it doesn’t look at the
entire range of influences on behaviour and we may get a distorted
picture of the behaviour being investigated.
Evaluation
• The research presented in this area has many useful applications to the
real world.
• We are able to use the results to predict why some criminals offend, and
also design strategies to intercept and catch offenders.
• For example, the American approach allows psychologists to classify
offenders as one of the two topologies, and as a result provides certain
personal characteristics about the offender which could allow police to
target their enquiries more efficiently.
• Similarly, the British approach has proved it’s usefulness through
applications such as the John Duffy case (Canter (1994)).
• This case provided strong support for using the criminal consistency
hypothesis to create a profile of the offender and the profound effects a
profile can have on apprehending an offender.
Timed Essay
• a) Describe the bottom-up approach to creating a profile
• b) Assess the reliability of offender profiling
• January 2010
• a) Describe one case study as an approach to offender profiling.
• b) Compare different approaches to creating a profile.
• January 2011
Exam Questions:
January 2010
• (a) Describe the bottom up approach to creating a profile. [10]
• (b) Assess the reliability of offender profiling. [15]
January 2010
• (a) Describe the bottom up approach to creating a profile. [10]
- Offender profiling is commonly used in crimes such as paedophilia, rape,
murder as well as satanic and ritualistic crime. There are two types of
offender profiling: the ‘top-down’ approach which the American profilers
use and the ‘bottom-up’ approach which is used in the UK. The ‘bottom-up'
approach takes the evidence and data and builds up a pattern piece by
piece until a feasible conclusion is reached. It seeks out consistencies in
offender behaviour, usually from the crime scene and victims’ accounts.
David Canter is one of Britain’s foremost profiling experts, such as his work
with former detective constable Rupert Heritage on developments in
offender profiling.
(a) Describe the bottom up approach to creating a
profile. [10] - examiners report
• The bottom-up approach was sometimes well described but all too often
candidates merely described the John Duffy case study at length.
Occasional confusion with Top/Bottom/US/UK approach. Too few
candidates could explain how the bottom up approach created a profile
and simply stated aspects of Canter's theory on profiling without showing
how this is then used to generate a profile.
January 2010
• (b) Assess the reliability of offender profiling. [15]
• - Reliability refers to the consistency that exists in the data, whether all things
being equal the same test would produce the same findings at another time,
or whether two or more researchers (observers) would record the same data.
So in terms of creating a profile, would any two profilers produce the same
profile, and hence suspect, given the same information or would their
different interpretations colour the suggested outcome? Could other factors
confound the outcome, particularly cognitive factors such as those suggested
by Loftus?
• No more than attempting to address the question or a highly superficial
response would constitute an answer in the bottom (1-3) band. This improves
to a more accurate if somewhat limited response; a more detailed or broader
response; and at the top level a more developed and/or elaborated response
containing more precise evaluative points and/or issues. For example,
specifying inter-rater reliability or test-retest reliability, or breaking ‘reliability’
per se into demand characteristics, social desirability, accuracy due to other
factors would all suggest a better quality of response.
(b) Assess the reliability of offender profiling. [15]
Examiners report
• Many candidates were vague about the meaning of 'reliability' or did not
distinguish between reliability and validity. Those that did could not relate
the concept well to profiling. Much credit was serendipitous, relating
biases to reliability when this point was not made explicitly. Reliability
caused many problems in this question as many seemed unable to apply
it to how a profile is used or created.
June 2010 no questions
January 2011
• A) Describe one case study as an approach to offender profiling. [10]
• B) Compare different approaches to creating a profile. [15]
January 2011
• A) Describe one case study as an approach to offender profiling. [10]
- The case study of John Duffy represents an approach to profiling as
adopted by David Canter. Similarly, his methods have been developed, such
as geographical profiling suggested by Dr. Kim Rossmo. Weaker responses
may simply report some of the details of a case study, better responses will
present these as part of the case study as an approach to criminal
investigation.
Describe one case study as an approach to offender
profiling. [10]
Examiners report
• The least popular question in this section. Almost every answer used the
Canter/ Duffy case to answer this question. The best answers explicitly
related the approach to the case study giving examples of how Canter
used the Duffy case. Examples included small space analysis,
geographical profiling etc. Weaker answers simply described the case
study.
January 2011
• B) Compare different approaches to creating a profile. [15]
- Different approaches could be top-down and bottom up, American and
British (FBI and Canter), profilers such as Canter and Rossmo. Responses
could be a comparison of approach, a factual comparison, a comparison of
methodology or a comparison of a particular issue between two
approaches. Note that comparisons can be both similarities and
differences.
B) Compare different approaches to creating a profile. [15]
Examiners report
• Most candidates offered some evaluation. Candidates mentioned both
approaches although differences were less well identified. The more able
candidates were able to compare and contrast and mention evaluative
aspects such as the differing methodologies. The better answers drew
clear points of comparison between the two approaches such as
reliability, reductionism, generalisability and so on. Weaker answers
tended to simply describe the two approaches side by side.
June 2011 – no quesiton
January 2012 – no quesiton
June 2012
• Describe how top down typology is used to create a profile. [10]
• Assess the usefulness of qualitative and quantitative data when creating
a profile. [15]
June 2012
• Describe how top down typology is used to create a profile. [10]
• ‘Top-down’ is traditionally the American approach. It
proposes a hypothetical overview onto a crime scene
which is referred to as a typology. The details in the scene will be
considered within this framework to see if they support the hypothesis.
Common patterns in murder scenes help them to be categorised as
either organised or disorganised. Research may enhance the quality of
response, but is not a pre-requisite for full credit which could also be
achieved by an explanation of the FBI’s use of Top-down typology, for
example. Contextualising and thoroughly explaining the use will typify the
better response, whereas a failure to do this will result in a weaker
accreditation.
• Better candidates will not only describe the top-down typology but
address ‘how’ it can be used to create a profile.
• Weaker candidates may merely describe some components of top-down
typology but not address the ‘how’.
Describe how top down typology is used to create a profile.
[10]
Examiners report
• There were many good responses to this question. These candidates not
only referred to ‘the bigger picture’, but described what this means in
terms of profiling. Some candidates’ descriptions were confused or
unclear. Some lacked detail; others were anecdotal and often not
obviously top-down topology.
June 2012
• Assess the usefulness of qualitative and quantitative data when creating
a profile. [15]
• Candidates should assess the usefulness of qualitative
and quantitative data when creating a profile. When
creating a profile, data collected can be empirical ie quantitative or more
descriptive ie it is possible to consider strengths and weaknesses of the
approaches as well as in terms of evaluative issues. For example, the
depth and richness of data is superior in the qualitative approach.
Quantitative data is easier to record, easier and clearer to analyse and
more objective. It may lead to a more accurate profile due to exclusion of
cognitive interference such as selection, distortion and bias, for example.
The bottom up is arguably particularly quantitative, looking for patterns in
data. The top down approach moves towards a more qualitative
approach, its methods reflecting this.
Assess the usefulness of qualitative and quantitative data
when creating a profile. [15]
Examiners report
• Most candidates knew what qualitative and quantitative meant, better
candidates were able to consider how they are more or less useful when
creating a profile.
January 2013 – no question
June 2013 – no question
June 2014 – Don’t think it did!
Studies and case study
Making a case
Interviewing witnesses, suspects and creating a profile.
How can we apply the
approaches?
 Behaviourist
 Assumes that all behaviour is learned, either through association or
through reinforcement.
 They will look for habitual patterns in a criminals’ behaviour and
exploit the power of association or reward when trying to get people
to speak up.
 Cognitive
 The development of techniques to trigger memories, spot liars and
understand criminal thinking patterns have been beneficial to
forensic psychology.
 Individual differences
 Understanding that everyone’s memory of sense of guilt works in
different ways.
Theories of creating a
profile
Canter et al, Canter and Heritage, Canter
Theories of creating a profile.
 Profiling is one of the many techniques used to
solve crimes, particularly when dealing with
unusual or serial crimes.
 Profiling attempts to categorise offenders based
upon their unusual criminal activity patterns,
thought patterns and the environment in which they
commit their offences.
 The main approaches within this section are
individual differences, cognitive and social.
Top-down approaches:
 A top-down approach tries to fit everything into a
set of pre-designed categories.
 A good example is astrology and the zodiac. This
top-down approach to predicting someone's future
is because of identifying a small piece of
information about the person, their birthday, and
fitting them into an astrological type, this making all
sorts of predictions about the individual including
their personality.
Top-down approaches in profiling:
 Top-down approaches exist in criminal profiling.
 Profilers have created typologies of criminals. A
typology s a set of clear and distinct categories.
 When investigators arrive at the scene, they are looking
for clues that reveal what type of criminal was there.
 Sometimes the clues may point to more than one
typology so investigators try to go for the ‘best fit’.
 Once the type has been identified, investigators can
make predictions about whether the criminal will strike
again, where, and who the victim might be.
Bottom-up approaches:
 Bottom-up approaches make no assumptions
about the person or object they are dealing with.
 Instead, a researcher will gather together all the
information then build up a logical description
based on that.
 A bottom-up approach could be something like a
tarot card reading where all the chosen cards
meanings are put together to make a whole
prediction.
Bottom-up approaches in profiling:
 The bottom-up approach is popular in Britain and is
championed by David Canter.
 Canter started out as an environmental psychologist,
looking at how people’s behaviour in buildings stayed
the same, even in emergencies such as a fire.
 From this, he developed his criminal consistency
hypothesis which states that an offenders behaviour
while committing a crime will be consistent with their
behaviour in their daily life.
Canter et al 2004
Investigation of the organised vs disorganised theory of serial
murder
Background:
In 1980, Hazelwood and Douglas published their account of the ‘lust murderer’
whereby they outlined their theory that lust murders can be categorised as
organised or disorganised.
Organised
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Leads an ordered life
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Sexually competent
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Social competent
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Kills after a critical life event
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Premeditated
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Planned crimes
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Bring weapons which are removed from the
scene
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Use restraints for control
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Average intelligence
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Employed in skilled jobs
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Body is hidden or removed from the scene.
Disorganised
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Committed the crime in a moment
of passion
Spontaneous
No evidence of premeditation
Leave evidence- blood, semen,
weapons
Body may be left and unhidden
Less socially competent
Less sexually competent
Unemployed or in unskilled work
Less than average intelligence
Lives alone.
Aim:
 To test the reliability of the top-down typology by
applying them to 100 cases.
Procedure:
 A content analysis of 100 cases of serial killers from the USA in
order to see if the features hypothesised to belong to each typology
would be consistently and distinctively different.
 The cases came from published accounts of serial killers and were
cross-checked with court reports and officers where possible.
 They had been collected over several years by an independent
researcher and were called the Missen Corpus.
 The third crime committed by each serial killer was analysed using
the Crime Classification Manuel in order to determine the crime as
being organised or disorganised.
Findings:
 Twice as many disorganised crimes as organised
crimes were identified, suggesting that disorganised
offenders are more common or easier to identify.
 Two behaviours in the organised typology occurred a
level significantly above chance.
 In 70% of cases, he body was concealed
 In 75% of cases, sexual activity had occurred.
 Further analysis failed to reveal any significant
differences
variables.
between
organised
and
disorganised
Conclusions:
 Canter concluded that instead of their being a
distinction between the two types of serial
murderer, all of the crimes had to have an
organised element to them.
 We might expect this as they were not caught after three
killings!
 The distinction between serial killers may be a
function of the different ways in which they exhibit
disorganised aspects in their activities.
 It would be better to look at personality differences
between offenders.
Issues:
 Usefulness
 Can be applied to identifying a murderer
 Reliability
 Had an dependent researcher
 Tested against the CCM
 Validity
 Used real-life murder cases
Debates:
 Ethnocentrism
 All cases were from the USA giving very westernised
views of murderers
 Reductionism vs Holism
 R: Top-down approach forces people into categories in
which they do not fit.
 H: Looks at social factors as well as environmental
factors- employment, etc.
Canter and Heritage
1990
Developments in offender profiling
Background:
 Canter ’ s bottom-up approach looks for consistencies in the
offenders behaviour during the crime.
 These can be inferred from the crime scene, or from surviving
victims accounts.
 No initial assumption is made about the offender until a statistical
analysis using correlational techniques has been carried out on the
details of the cases,
 The approach relies heavily on computer databases being
accurate.
 This approach can be considered more objective and reliable.
Think…
 This approach relies heavily on data held in
computer databases and this data being accurate.
What factors can affect the accuracy of police
records?
Anomalous
results?
Eye-witness
Testimony?
Not all crimes
are reported?
Data being
lost?
Leading
questions?
Not all crimes
are followed
up
Human error?
Aim:
 To identify a behaviour pattern from similarities
between offences.
Procedure:
 A content analysis was carried out on 66 sexual offences from
various police forces committed by 27 offenders to find 33 offence
variables that were clearly linked to a potential behaviour
characteristic.
 It was possible to say yes or no to each variable.
 A computer was used to work out the correlations between each
aspect of the crime and identify the key factors central to sexual
assault.
 This method is known as a smallest-space analysis, because it
presents results visually, with the most common factors closer to
the centre and less typical behaviours appearing out on the edges.
Smallest-space analysis example:
Behaviour occurs in
40-60% of cases
Behaviour occurs in
25-35% of cases
Behaviour occurs in
more than 65% of
cases
Behaviour occurs in
20-25% of cases
Findings:
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Five variables were found to be central to the 66
cases;
1.
2.
3.
4.
5.
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Vaginal intercourse
No reaction to the victim
Impersonal language
Surprise attack
Victims clothing was disturbed
This suggests a pattern of behaviour where the
attack is impersonal and sudden and the victim’s
response is irrelevant to the offender.
Conclusions:
 This has become known as the five factor theory.
 These five aspects have now been shown to
contribute to all sexual offences, but in different
patterns for different individuals.
 An analysis of these factors can enable police to
decide if an offence has been committed by the
same individual.
Issues:
 Correlational methods
 Does not show cause and effect
 Reliability
 The accuracy of the police databases as described earlier
 Application
 Can work to help stop crimes and identify the criminals
 Quantitative data
 Objective and not influenced by personal opinions
Canter
The case of John Duffy the ‘Railway Rapist’
Background:
 In November 2000, John Duffy, who was serving
life for the rape and murder of several women,
confessed to his prison psychologist that in fact he
was responsible for many more cases and that he
had committed many of these acts with an
accomplice- David Mulcahy.
 He therefore testified in front of the jury at
Mulcahy ’ s trial, giving evidence to ‘ clear his
conscience’.
Background:
 In 1982, a woman- KJ- was raped near London’s Hampstead
station and dozens more were attacked over the next 2 years.
 The police set up a workshop to find the perpetrators, called
Operation Hart.
 The press called the attacker the ‘ Railway Rapist ’ but this
changed to the ‘Railway Killer’ in 1985 when Alison Day was
dragged off of a train in Hackney and repeatedly raped and
strangled with a piece of string.
 In April, a 15 year old was raped and murdered and her body was
set on fire.
 A month later, a local TV presenter was abducted and murdered
after leaving a train in Brookman's Park.
Background:
 The police investigation was getting nowhere,
because although the surviving women could give
details accounts of the attacker ’ s methods of
working, they were uncertain about his height and
appearance.
 They were possibly distracted by the weapons
focus effect.
Aim:
 To show successful application of a “bottom-up”
approach of profiling to solving a crime.
Procedure:
 In 1988, Canter was invited by the Metropolitan Police
to draw up a profile of the ‘Railway Rapist’.
 Cater examined the details of each crime and built up a
profile of the attacker’s personality, habits and traits.
 He used the bottom-up approach to identify two
significant themes in the attacks;
 The attacker seemed prepared to try to relate to the victimsuggesting a previous abusive relationship.
 Minimal amount of force was used to the victim- suggesting a
weak, insecure individual.
Procedure:
 Canter also studied the location of the crimes,
going back 4 years, laying transparent acetate
sheets with the crime scenes marked on top of the
map of the area surrounding London.
 This built up a geographic profile which helped
him pin down where the attacker lived because he
pattern suggested he was a marauder who
committed crimes in his own neighbourhood.
The profile:
 Canter’s profile included that the offender;
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Lived in Kilburn or Cricklewood
Was married
Had no children
Had marriage problems
Was a loner with few friends
Was physically small
Had feelings of unattractiveness
Has an interest in martial arts or body building
Had a need to dominate women
Had a fascination with weapons- especially knives
Had fantasies about sex and violence
Was in a semi-skilled job
Had little contact with the public
Was aged between 20 and 30 years old.
Findings:
 John Duffy was 1505th on the police’s list of 2000
suspects with the right blood group to be the
attacker.
 He as on the police database because of a
previous incident where he had threatened his wife
at knife point.
 John Duffy fit the profile Canter had made very
closely.
Findings:
 John Duffy;
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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
Findings:
 John Duffy was reinvestigated as a result of Canter’s profile
and was convicted for the two murders and five rapes.
 Canter had also predicted that the attacker would have a
signature- most likely he took ‘souvenirs’ from his victims.
 John Duffy had a collection of 33 house keys that he had
taken from the women he had raped and murdered.
 Police suspected Duffy’s friend David Mulcahy to be his
collaborator, but could not prove this.
 Mulcahy was a married father of 4 and was eventually
convicted in 2001.
Conclusions:
 This case study lends support to Canters bottomup approach to profiling.
Issues:
 Usefulness
 Can help with identifying and finding offenders
 Generalisability
 A case study with a sample size of 1 cannot be easily
generalised.