Crime & Geographic Profiling
Theory -v- practical solutions
Neil Trainor
Professional Lead
Geographic Profiling
NCPE Operations
Some recent quotes
“I cannot stress the importance of
influencing police managers” (JR)
¾ “It’s not just about dots on the map its
where and when the dots happen” (JR)
¾ “Hindsight is a powerful thing” (SC)
¾ “Oooo it’s a hot spot” (SA)
¾
Consider the following scenarios
In each case be specific in respect of:
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locations (i.e. state exactly where you
would go),
If you use transport what means of
transport you would use.
Consider the following scenarios
1. Following a dispute with one of your
neighbours you decide to set fire to
his/her car.
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¾
¾
Where would you do it?
How would you get there?
Why that location?
Consider the following scenarios
2. You are a sex offender and require a
victim aged 18 to 25 yrs of age.
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¾
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Where would you go to find a victim?
How would you get there?
Why would you choose that location?
Consider the following scenarios
3. During the attack on the victim you have
just selected, you strangle the victim
resulting in his/her death.
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What would you do with the body?
Where would you take it?
How would you transport it?
Why that location?
Geographic profiling - the debates
¾ The
academic debate
¾ The software systems debate
¾ The cost debate
What really matters..
Relevant training and skill sets of analysts
¾ Accuracy of the analytical process/product
¾ Utility of the analysis/results and
¾ Effectiveness within the operational field
¾
Underlying Academic Principles
‘Routine activity’
‘Rational choice’
‘Crime pattern theory’
‘Least effort principle’
‘Distance decay’
Some additional theories
¾
Some academics/researchers are
suggesting that a number of simple
cognitive strategies can be used to predict
the location of an offender responsible for
a series of crimes and that it is possible to
train people in these strategies so that
they can be as accurate as some of the
more sophisticated systems.
Equidistant heuristic
predicted offender lives
approx. in the centre of
Where do
youcrimes
think
all the
2
the offender lives?
Cluster heuristic
predicted offender lives
close to the majority of
the crimes
1
3
2
1
3
2
1
3
Circle heuristic
Serial offenders often live
within a circle, the diameter of
which is the distance between
the two furthest crimes
2
1
Decay heuristic
3
Serial offenders often
do not travel far from
home to commit their
offences
2
1
3
2
1
3
2
1
3
10 Forces
24 Armed
Robberies
1995-2005
11,300
sq. miles
Practical difficulties
Using these theories in actual ‘unsolved’ serial
cases (not as in an academic study where
home of offender is known)
¾ Identifying the home base/anchor point of the
offender in any series of crimes
¾ Hunter (marauder) v Poacher (commuter)
¾ Utility of the resultant search area within a
police investigation
¾
?
?
Think
outside the
box
?
?
Abduction & Robbery
Family drop off point
Work location
H/A
?
Captive location?
Information from witnesses
Had brief glimpse of watch @ 22:40hrs
¾ Heard jet planes coming into land
¾ Two jets were 15 to 20 mins apart and approx
within 1 hour of looking at watch
¾ Another jet heard coming into land sometime
later during the night
¾ Sounds of trains moving in the distance
¾ Driven approx 30 mins after offence
¾
Sexual assault and criminal damage
Armed robbery series
10 Forces
24 Armed
Robberies
1995-2005
11,300
sq. miles
Peak Profile
Area = 1.9%
Home location = 0.1%
Work location = 1.6%
Geographic Profiling
and
Volume Crime
Back to the scenarios given to you at
the start of this presentation
Consider the following scenarios
1. Following a dispute with one of your
neighbours you decide to set fire to
his/her car.
¾
¾
¾
Where would you do it?
How would you get there?
Why that location?
Consider the following scenarios
2. You are a sex offender and require a
victim aged 18 to 25 yrs of age.
¾
¾
¾
Where would you go to find one?
How would you get there?
Why would you choose that location?
Consider the following scenarios
3. During the attack on the victim you have
just selected, you strangle the victim
resulting in his/her death.
¾
¾
¾
¾
What would you do with the body?
Where would you take it?
How would you transport it?
Why that location?
Linked series of locations
Expected Hit
Score 1.7%
Suspect hit
score 1.2%
In summary
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Science and academic theories have a part to play
in solving crime BUT
The people using them need to understand the
limitations of these methods when applying them
in a ‘live’ situation.
The production of a ‘geographic profile’ prior to
the offender being caught is very different and
difficult to one that is based on post conviction
data.
Operational utility is key to the success of what
analysts do.
Another quote
“In the real world of geographic profiling
the dots on the map represent actual
victims, and the wrong shortcut can have
serious consequences”
Rossmo D.K. (2005)
A final quote – honest!
“If hindsight is such a powerful thing – how
powerful is turning that hindsight into
foresight - i.e. predictive analysis”
Me - today