Professor David Canter

www.davidcanter.com

警察の捜査の心理学: 新しい展望

EVOLUCIÓN DE LA PSICOLOGÍA

EN LAS INVESTIGACIONES PENALES

The whole

area now

developed in a

major new

textbook.

ProfileLived in area of early offence in 1983

Arrested after October 1983, for violence not necessarily sexual.

Lived with wife/girlfriend – childless

Mid to Late 20’s

Light Hair

5’9”

Right Handed

‘A’ secretor

Semi-skilled, no public contact

Keeps to himself, with one or two close friends.

Development in

Crimes:

More determined

More planned

Weekday from weekend

Solo from Duo

The ‘Railway Rapist’

“To begin with it was in areas we knew well. We would plan it quite meticulously. We would have balaclavas and knives. We used to call it hunting. We did it as a bit of a joke, a bit of a game. It added to the excitement.”

“You get into the pattern of offending - it is very difficult to stop."

Why a systematic, scientific

approach to supporting

investigations is essential

But….

…a profile

can be

wrong!

Murders of 5 Females

Fairbanks, Alaska

….Profiles can be wrong!

FBI PROFILE:

Single

Around 40

NOT in armed services

ACTUAL – BUNDAY:

Married (2 Children)

34 years old

Airforce instructor

The profiles slowed down the investigation because

Bunday was excluded from computer searches due

to the ‘profile’

Two psychics were no use either!

Psychologist set

Honeytrap for Stagg

The Honourable Mr Justice Ognall-Regina v Colin Stagg

The conventional view of Investigative Psychology

Support for Investigations – ‘offender profiling’

Investigative Psychology Support

for Investigations

* Simplified ideal, analogous

to Design Decision Making

The systematic, scientific study of

a)Investigative information, its retrieval, evaluation and utilisation,

b)Police actions and decisions,their improvement and support, and

c)The inferences that can be made about criminal activity,

its development, differentiation and prediction,

With the objective of

improving criminal and civil investigations.

Investigative Psychology is

INFORMATION RETRIEVAL

De recuperación de información

効果的な情報

The 12 photographs used to identify Al Megrahi

1. Interviewer did not know identity of suspect in line up

2. Interviewer knew identity of suspect in line up

‘On the sheet that you have been given are photographs of 12 men, one of which is the man believed to be responsible for the Lockerbie bombing. This is the man in position number 8.What we would like you to do is to ask people to look at the pictures and decide which of the people they think is most likely to be the man who did it. Please record the number that each respondent picks as the most likely culprit on the sheet provided. Hopefully most people should correctly identify the suspect from the line-up.’

CONDITION Someone other than

suspectselected

from Line Up

Suspect (Megrahi)Selectedfrom Line

Up

TOTAL N

Interviewer did NOT

know identity of Suspect in

line up

20 0 20

CONDITION Someone other than

suspectselected

from Line Up

Suspect (Megrahi)Selectedfrom Line

Up

TOTAL N

Interviewer knew

identity of Suspect in

line up

21 15 36

CONDITION Someone other than suspectselected from

Line Up

Suspect (Megrahi)

Selected from

Line Up

TOTAL N

Interviewer did NOT know identity of

Suspect in line up

20 0 20

Interviewer

knew identity

of Suspect in line up

21 15 36

TOTAL 41 15 56

P < .0001

The Central Issue of INFERENCE

(‘profiling’)

Actions

Characteristics

1. Features – what distinguishes the

offence/offender?

2.Characteristics – what can we assume

about the offender?

3. Linking – which other crimes has the

offender committed?

4. Location – where might s/he be based?

5. Prediction – what might s/he do next?

Science is a way of ‘going

beyond the data’. (una forma de ir más allá de los datos)

This is done be building

models/theories/explanations

or ‘laws’.

We need these to develop

inference processes.

UNDERSTANDING

CRIMINAL BEHAVIOUR

Entender el comportamiento criminal

犯罪者の行動を理解する

Offenders live implicit narratives

Los delincuentes viven narrativas implícitas

Narratives of

Murder

Significant event –◦ Kids using his house to doss, so I threw them out,

battered them all

Murder◦ To let him know he just couldn’t do that. (“That was

my night ruined”) .

Life as Film◦ Brave Heart or Rob Roy, dishing out punishment for

wrongdoing.

Significant event –◦ Fell on concrete because showing off to girls but did not

indicate he was hurt.

Murder◦ Angry because he could not be the bread-winner. Hit his

son because he would not listen to him.

Life as Film◦ Cub turns into a full grown man. Would win the Oscars.

A Personal Construct Perspective* on the Narratives of Terrorists

* George

Kelly (1956)

Bombing

in

Mombai

REPERTORY GRID DERIVED FROM

AN INTERVIEW

WITH A CONVICTED TERRORIST

PCA of Grid for Activist Leader

PCA of Grid for Terrorist Subordinate

DECISION SUPPORT

Soporte a la Decisión

技術は、意思決定を支援する

Many Publications that show how you can

determine where an offender is living from

where he commits a crime. Known as

‘geographical profiling’.

• Dragnet

•DragnetP

•An interactive system designed for use on a PC with minimal training, allowing context sensitive modification.

•Developed as a support tool to indicate the likelihood of the offender living at any given location and the implications of linking local crimes.

•Has features that enable it to be an effective research tool.

1. Studies of criminal spatial behaviour –

basic research.

2. Development of decision support tools

that incorporate research findings.

3. Studies of the effectiveness of these

applications.

4. Explorations of how such tools may help

police investigations and relates training

etc.

Geographical Offender Profiling

Consists of:

Published

1977

An Offender’s ‘Mental Map’ of his crimes

‘MARAUDERS’

The ‘Circle Hypothesis’

The Decay Function (one off or series)

0

100

200

300

400

500

600

700

8000

1 5

10

1

15

20

Frequency of

Offending

Distance from Home (km)

Average Distances

for Burglary

0.9 to 2.9 km

Schematic Decay Function

Offence Map:

Developing the Search Tool

1st Crime2nd

3rd

4th

5th

Home base

The Mardi Gra Bombings

Interface with crime sites

The Mardi Gra Bombings

Dragnet analysis superimposed on a map of London

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Rank

Cu

mu

lati

ve

% o

f S

am

ple

Centre of Circle

Centroid

First Offence

Last Offence

Logarithmic Function

Exponential Function

Offender 1:

34 CRIMES

1 HOME LOCATION

Offender

34 crimes

1 home location

Offender 2:

34 CRIMES

1 HOME LOCATION

Offender 34 crimes1 home location

2 Offenders with different distributions of crimes in relation to Sopping Centre

Southside Centre

Offender

34 crimes

1 home location

Offender 34 crimes1 home location

The Future: Taking account of local conditions

The next generation

Current Development:

A Ψ - GOP Integrated into •GIS with •Temporal search capability

Time slider

Burglary Location

Offender Residence

Two crime locations

Probability surface

Most probable home location

Three crimes

Integrating with GIS allows detailed examination

Street view of crime location

Street view of offender residence

Five crimes

16 Crimes

56 Crimes

International Research Centre for Investigative Psychology

The University of Huddersfieldwww.davidcanter.com www.ia-ip.org