Linking behaviour to characteristics: Evidence-based practice and offender profiling

1. 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)

2. “Let me make it very clear, poor people aren’t necessarily killers. Just because you happen to be not rich doesn’t mean you’re willing to kill” - George W. Bush (May 19, 2003)

3. 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 emphasize…that this rationally derived system has not yet been…tested” (p. 22)

4. 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

5. 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

6. = Organized = Disorganized

7. 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 > 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

8. 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

9. 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”

10. Evaluation of FBI Rape Typology(Bennett, Ogloff, & Davis, in prep) ANGER POWER

11. Evaluation of FBI Rape Typology(Bennett, Ogloff, & Davis, in prep) ANGER POWER

12. Evaluation of FBI Rape Typology(Bennett, Ogloff, & Davis, in prep) ANGER POWER 11%-39%

13. Evaluation of FBI Rape Typology(Bennett, Ogloff, & Davis, in prep) ANGER POWER 5%-10% 11%-39%

14. Thematic classification of rape(Canter, Bennell, Alison, & Reddy, 2003)

15. 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)

16. 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)

17. Conceptual model of offender profiling information Demographic Offending CharacteristicsBehaviour

18. Conceptual model of offender profiling information Personality Offending Behaviour Demographics

19. Conceptual model of offender profiling information Situational Influences Personality Offending Behaviour Demographics

20. Conceptual model of offender profiling information Situational Influences Personality Offending Behaviour Demographics

21. 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

22. 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)

23. 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

24. 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)