Linking behaviour to characteristics: Evidencebased practice and offender profiling

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Linking behaviour to characteristics
Evidence-based practice and offender profiling

• Michael R. Davis
• School of Psychology, Psychiatry, and
  Psychological Medicine, Monash University,
  Australia
• and
• Victorian Institute of Forensic Mental Health
  (Forensicare)

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• Let me make it very clear, poor people arent
  necessarily killers.
• Just because you happen to be not rich doesnt
  mean youre willing to kill
• - George W. Bush (May 19, 2003)

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Crime Classification Manual(Douglas, Burgess,
Burgess, Ressler, 1992)

• Homicide, Arson, Sexual Assault
• Detailed DSM-type classification
• Potential profile information
• At present there have been no systematic efforts
  to validate these profile-derived
  classifications (p. 22)
• We want to emphasizethat this rationally
  derived system has not yet beentested (p. 22)

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Sexual Homicide(Ressler et al., 1986, 1988)

• Organised/Disorganised - 36 murderers interviewed
• Organised
• Scene planning, controlling, sexual acts with
  live victim
• Offenders intelligent, skilled job, angry
  depressed
• Disorganised
• Scene position dead body, necrophilia,
  depersonalisation
• Offenders low birth-order, know victim,
  confused, live alone
• Problems with statistical analyses

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Profiling expressed as a Canonical Equation(See
Canter, 1995 Youngs, 2004)

• B1A1 B2A2 BnAn D1C1 D2C2
  DnCn
• Where
• A Actions during offences
• C Characteristics of offender
• B and D weightings

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Organized
Disorganized
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Homicide

• Sexual homicide of elderly (Safarik et al., 2000,
  2002)
• White victims more likely to be attacked by black
  offenders
• Race, age, distance from house predictable
  (approx 70 accuracy)
• Sexually-oriented child homicide (Aitken et al.,
  1995)
• Age, previous convictions, victim-offender
  relationship predictable
• Classification rate gt 70
• U.S. Serial killings (Hodge, in press)
• SSA (thematic structure of crime scene actions)
• Themes of offender-victim interaction
• Victim viewed as an object, vehicle, or person

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Stranger Homicide (Salfati, 2000a, 2000b
Salfati Canter, 1999)

• Instrumental and expressive offence actions
• Three themes (65 classified)
• Expressive (impulsive)
• Married, previous violent, property, sexual,
  drug offences
• Instrumental (Opportunistic)
• Previous offences for burglary, unemployed,
  familiar with area
• Finnish Stranger Homicides (Santtila et al.,
  2003)
• Instrumental offenders unlikely to confess

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Sexual Assault

• FBI rape typology (Warren et al., 1991)
• Power and anger motivations
• Behaviour classified as proposed by typology
  (71-91 of cases)
• Increased violence in subsequent rapes
  predictable
• Excessive binding, Prolonged Transport, No
  negotiation, Macho

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Evaluation of FBI Rape Typology(Bennett, Ogloff,
Davis, in prep)
ANGER
POWER
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Evaluation of FBI Rape Typology(Bennett, Ogloff,
Davis, in prep)
ANGER
POWER
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Evaluation of FBI Rape Typology(Bennett, Ogloff,
Davis, in prep)
ANGER
POWER
11-39
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Evaluation of FBI Rape Typology(Bennett, Ogloff,
Davis, in prep)
ANGER
POWER
5-10
11-39
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Thematic classification of rape(Canter, Bennell,
Alison, Reddy, 2003)
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Sexual Assault

• Links with characteristics
• History of burglary (Canter et al., 1991 Davies
  et al., 1998)
• Higher levels of violence in rape linked to
  personality disorder
• Sadistic schizoid, avoidant, dependent
• Opportunistic antisocial, narcissistic, paranoid
• (Proulx et al., 1994, 1999)

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Arson

• FBI-motivational typology (Icove Estepp, 1987)
• Classification supported by 1016 interviews
• Empirical classification four themes
  (Canter Fritzon, 1998
  Fritzon, 1998 Fritzon et al., 2001)
• Instrumental and expressive arson
• Person or object focussed
• Four corresponding themes of background
  characteristics
• Supported in active case (Santtila et al., 2003)
  

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Conceptual model of offender profiling
information

• Demographic
  Offending
• Characteristics Behaviour

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Conceptual model of offender profiling
information

• Personality
  Offending
• Behaviour
• Demographics

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Conceptual model of offender profiling
information

• Situational
• Influences
• Personality
  Offending
• Behaviour
• Demographics

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Conceptual model of offender profiling
information

• Situational
• Influences
• Personality
  Offending
• Behaviour
• Demographics

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Progress in geographical profiling is more rapid

• Data is more precise
• Attack or disposal sites are obviously influenced
  by the situation, but less so than interpersonal
  behaviour
• Theoretically barren use of demographics is not a
  component of the calculations

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Future research directions

• Determine offence behaviours least influenced by
  situational factors
• Respondent vs operant behaviour
  (Funder Colvin, 1991
  McClelland, 1984)
• Focus on personality traits
• Hypotheses from existing SSA plots
• Causal-theoretical statistics
• Interviews with offenders
• Well-validated personality inventories
• Determine conditional traits (Alison et al.,
  2002 Wright Mischel, 1987)

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Future research directions

• Personality (Youngs, 2004)
• 207 young offenders
• Delinquency and personality questionnaires
• Expressive/instrumental and person/property
  distinction
• Expressive-person related to power and control
• Property offenders perceived more controls from
  others
• Offenders targetting people perceived more
  emotional closeness
• Decision-making in individual profiles
• Determine situations where research is inaccurate
• Beneficial for theory development

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Conclusion

• Current empirical literature
• Broad demographic features themes of
  interaction
• Purely actuarial approach not feasible
• Structured Professional Judgment (Davis, 2003)
• Use empirical evidence to anchor inform
  judgment
• Add to vary opinion based on case-specific
  features
• Base variations on theory or clearly explained
  deduction (rather than intuition)
• Clear parallels with pragmatism (Alison, 2005)

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