Geographical Profiling

1
Geographical Profiling

• Bernadette Doran
• Tel [phone]
• Email B.Doran_at_liv.ac.uk

2
Lecture Outline

• What is Geographical Profiling?
• Experiment (Part 1)
• 2 cases- Identify location of offenders home
• Geographical Profiling Training
• Experiment (Part 2)
• Re-examine cases
• You will be given the true location of the
  offenders home
• Have your skills as a Geographical Profiler
  improved?
• Development of Geographical Profiling Systems
  (GPS)

3
Q. What is Geographical Profiling?

• A. Geographic profiling is an
  investigative
• technique that uses the locations of
  a
• connected series of crimes to
  determine
• the most probable area of offender
  
• residence.
• Issues- Are the offences really
  linked?
• Do we have the whole
  series?

4
Experiment- Part 1Can you be a Geographical
Profiler?

• Instructions
• Split up into groups
• Read 2 cases
• As a group decide where you think the offender
  may live
• Mark X on the map where you think the offender
  lives
• Write down your reasons
• Report to rest of class (where you think the
  offender lives and your reasons for choosing this
  location)

5
TRAINING
6
Origin

• Dr. John Snow (1854)
• Cholera Epidemic
• Medical Geography

7
Origin cont

• - Shaw and Mckay (1942) The Chicago School
• Criminals do not travel far to commit their
  crimes
• (E.g Burglars 1.5 miles)
• - Brantingham Brantingham (1982)
• Environmental Psychology
• Spatial knowledge of an area is gained through
  everyday activities.
• The places frequented when not offending will
  have a bearing on areas used to offend
• Peoples spatial behaviour is also governed by
  familiarity and effort.

8
Task- Mental Maps

• Take a piece of blank paper
• Draw a map of the area around your home
• No distance limits
• Estimate the distance from one end of the map to
  the other
• 10 miles?
• 5 miles?
• 2 miles?
• 1 mile or less?

9
Criminal Mental Maps
D
Pol
Pub

• -Pub
• -Home
• -DHSS
• -Police
• -Old Home
• -Canal

H
Pub
H
D
C
OH
Pol
OH
C
10
Criminal Mental Maps Cont

• FAMILIARITY WITH CERTAIN AREAS (e.g. work,
  leisure, home)
• Offenders home central to crime locations
• Not necessarily an accurate representation of
  reality (e.g Milgram, 1976)

11
Circle Theory- David Canter

• identifying the two crime locations furthest
  apart from each other. Using these locations as
  the diameter, a circle can be drawn that includes
  all the offences. The hypothesis is that the
  criminal will be found to live inside that
  circle, possibly close to the middle of it.

12
Circle Theory Cont
H
H
Marauder
Commuter
Criminal Range
Home Range
13
Experiment- Part 2Can you be a Geographical
Profiler?

• Instructions
• Mark Y where you think the offender lives
• Write down your reasons
• Find out true location of offenders home
• Measure the distance (mm) from offenders base to
  X
• Measure the distance (mm) from offenders base to
  Y
• Have your skills as a geographical profiler
  improved?

14
Research Findings

• Marauders

87 UK Serial Rapists
86 UK Serial Murderers
50-60 UK Serial Burglars
15
Cross- cultural comparison

• Godwin Canter (1997) 85 of US Serial Killers
  live within circle
• Kocsis Irwin (1997) 71 Australian Serial
  Rapist
• Kocsis, Cooksey, Irwin, Allen (2002) 50 of
  Australian Serial Rural Burglars

16

• Attempts to emulate theory and predict offender
  residence

17

• Problems
• You cant use Dragnet to identify the base of
  criminals who are commuters
• It doesnt take into account land-use

18
Computers vs. People

• 21 Students in each group (control
  experimental)
• Ten crime series five locations for each
• Experimental group given two heuristics
• - majority of offenders homes within circle
  defined by two furthest offences
• - majority of offenders commit offences close to
  home

19
Effect of training on prediction of home
location
Snook, B., Canter, D. Bennell, C. (2002).
Predicting the Home Location of Serial
Offenders A Preliminary Comparison of the
Accuracy of Human Judges with a Geographic
Profiling System. Behavioural Sciences and the
Law, 20, pp. 109-118.
20
Implications

• Indicates that principles involved are effective
• Uniform improvement not due to intuition or
  gut feeling
• May be other principles that need to be
  identified, i.e. commuters
• Casts doubt on utility of computerized systems
  and specialized training

21
Future Directions- Incorporating Contextual
Information

• Canter Heritage (1994) Rapists who offend
• outdoors travel further than those who attack
  
• indoors
• Davies Dale (1995) Older offenders travel
• further

22
Selected Readings

• Canter, D. (2003). Mapping Murder The Secrets of
  Geographical Profiling. London Virgin
• Ainsworth, P.B. (2001). Offender Profiling and
  Crime Analysis. Devon Willan
• Canter, D., Larkin, P. (1993). The
  Environmental Range of Serial Rapists. Journal of
  Environmental Psychology, (13), 63-69.
• Snook, B. (2002). Predicting the Home Location of
  Serial Offenders A Preliminary Comparison of the
  Accuracy of Human Judges with a Geographic
  Profiling System. Behavioral Sciences and the
  Law, (20), 109-118.