The Scientific Basis for Expert Testimony about Risk Assessment

1. Scientific Basis for Expert Testimony about Violence Risk Assessment 1 The Scientific Basis for Expert Testimony about Risk Assessment Marnie E. Rice & Grant T. Harris www.mhcp-research.com June 2001

2. Scientific Basis for Expert Testimony about Violence Risk Assessment 2 The Scientific Basis for Expert Testimony on Risk Assessment Progress in the science of violence risk assessment Definitions of “expert” for giving expert testimony How do contemporary methods of risk assessment measure up? Conclusions & the future of expert testimony about violence risk

3. Scientific Basis for Expert Testimony about Violence Risk Assessment 3 Progress in the science of violence risk assessment Journal articles on prediction of violence or recidivism 1890- 1969 236 1970- 1979 379 1980- 1989 657 1990- 1999 1232 - Searched PsychInfo Journal Articles- Abstracts for the keywords (predict* OR recidiv*) AND (violen* OR recidiv*) June 7, 2001- Searched PsychInfo Journal Articles- Abstracts for the keywords (predict* OR recidiv*) AND (violen* OR recidiv*) June 7, 2001

4. Scientific Basis for Expert Testimony about Violence Risk Assessment 4 Journal articles on prediction of recidivism among sex offenders 1890-1969 8 1970-1979 13 1980-1989 44 1990-1999 117

5. Scientific Basis for Expert Testimony about Violence Risk Assessment 5 Prediction of Violence Before Mid-80’s Examples Baxstrom (Steadman, 1973) Quinsey & Ambtman, 1979 Pasewark, Bieber, Bosten, Kiser, & Steadman, 1982 Monahan (1981) General consensus was (and studies backed that up) that there was no expertise in the prediction of violence -Baxstrom decision in 1973 was very influential- Showed overprediction of violence- incidence of violence among men all of whom had been kept in because someone thought they were too dangerous to release - yet incidence of future crime and violence was very low-- (But short followup and men were quite old by the time they were released) -Quinsey & Ambtman psychiatrist- teacher study - Pasewark et al.- men who eloped were less likely to reoffend than those released (difference was ns.) General consensus was (and studies backed that up) that there was no expertise in the prediction of violence -Baxstrom decision in 1973 was very influential- Showed overprediction of violence- incidence of violence among men all of whom had been kept in because someone thought they were too dangerous to release - yet incidence of future crime and violence was very low-- (But short followup and men were quite old by the time they were released) -Quinsey & Ambtman psychiatrist- teacher study - Pasewark et al.- men who eloped were less likely to reoffend than those released (difference was ns.)

6. Scientific Basis for Expert Testimony about Violence Risk Assessment 6 Predictors of violent recidivism among mentally disordered offendersHarris, Rice, & Quinsey, 1993 Big predictors Psychopathy, elementary school maladjustment, age*, personality disorder Medium predictors Separated from parents < 16, Failure on prior conditional release,criminal history,never married Small predictors schizophrenia*, victim injury, alcohol abuse, male victim N=618N=618

7. Scientific Basis for Expert Testimony about Violence Risk Assessment 7 Predictors of Violent Recidivism Among MDOs (Bonta, Law & Hanson, 1998 meta-analysis) Big predictors objective risk assessment, antisocial personality, violent history, juvenile delinquency, age* Medium predictors nonviolent criminal history, adult criminal history, substance abuse, marital status, Small predictors clinical judgement, psychosis*, offense seriousness

8. Scientific Basis for Expert Testimony about Violence Risk Assessment 8 Predictors of Violence Among Psychiatric Patients (MacArthur Risk Study) Big predictors: Psychopathy (PCL:SV); Adult arrests, Antisocial personality disorder, Major mental disorder without substance abuse*, drug or alcohol abuse, anger (Novaco) Moderate predictors: Violent arrests, schizophrenia*, child abuse, threat-control overrride symptoms* delusions at the time of admission* Big= Bivariate correlation >= .16 Moderate= Bivariate correlation > .09 < .16 Small = Bivariate correlation <.09 and significant Nonpredictor= nonsignificant (approx. < .06) Note: I’ve listed highest correlation for measures that had many versions (e.g. Novaco Anger Inventory- Behavior, Cognitive, Arousal) There were many other correlations, I’ve just listed ones most relevant for this talkBig= Bivariate correlation >= .16 Moderate= Bivariate correlation > .09 < .16 Small = Bivariate correlation <.09 and significant Nonpredictor= nonsignificant (approx. < .06) Note: I’ve listed highest correlation for measures that had many versions (e.g. Novaco Anger Inventory- Behavior, Cognitive, Arousal) There were many other correlations, I’ve just listed ones most relevant for this talk

9. Scientific Basis for Expert Testimony about Violence Risk Assessment 9 MacArthur Data (cont) Small predictors persecutory delusions*, male, BPRS hostility, BPRS thought disturbance, medication nonadherence on admission*

10. Scientific Basis for Expert Testimony about Violence Risk Assessment 10 Nonpredictors of Violent Recidivism From Bonta et al., Hanson et al. Psychological distress, remorse, treatment history, insight From MacArthur study: mania, depression, any delusions, hallucinations, command hallucinations, grandiose delusions, GAF, BPRS Total

11. Scientific Basis for Expert Testimony about Violence Risk Assessment 11 Contemporary methods of combining predictors to assess risk Clinical Opinion (CO) Blended Clinical (BC) variables derived from empirical and clinical literature (e.g. HCR-20) Initial Actuarial (IA) derived from actual outcome (e.g. MacArthur ICT)

12. Scientific Basis for Expert Testimony about Violence Risk Assessment 12 Contemporary methods of combining predictors to assess risk (cont.) Established Actuarial (EA) Derived from actual outcome + cross-validation (e.g. VRAG) Adjusted Actuarial (AA) use clinical judgement to adjust ? or ? (e.g., VPS, Webster, Harris, Rice, Cormier, & Quinsey, 1994)

13. Scientific Basis for Expert Testimony about Violence Risk Assessment 13 Blended Clinical Opinion (BC) HCR-20 Historical- Previous violence, Young age at first violence, Marital instability, Employment problems, Substance abuse, Mental illness, Psychopathy, Childhood maladjustment, Personality disorder, Prior failure Clinical-Lacks insight, Negative attitudes, Active psychosis, Impulsivity, Unresponsive to Tx Risk Management: Unfeasible plans, Destabilizers, No personal support, Noncompliance with remediation, Stress Manual: Do Not Total for Clinical Purposes Two follow-up studies using totals

14. Scientific Basis for Expert Testimony about Violence Risk Assessment 14 Initial Actuarial (IA) (MacArthur ICT) Psychopathy, Prior arrests, Child abuse, Recent violence, Substance abuse, Status, Symptoms*, Employed, Father arrested, suicidal*, Head injury Violent fantasies, Schizophrenia*, Hostility, Young age, Low functioning, Property arrest, Perceived coercion, Threatening, Negative relationships Classification Tree and Iterations Construction but no Replications

15. Scientific Basis for Expert Testimony about Violence Risk Assessment 15 Established Actuarial (EA) VRAG 12 Items: Psychopathy Checklist, ES Maladjustment, DSM-III Personality disorder, Young age, Separation from parents under 16, Prior conditional failure, Criminal Hx score, Never married, DSM-III schizophrenia*, Victim injury, Alcohol abuse score, Male victim Development 1993; Cross-validation 1997 Over 20 Replications; 6 and 16 Peer Review: 15 journal articles Reliability, Accuracy, Error Rates -> ROC

16. Scientific Basis for Expert Testimony about Violence Risk Assessment 16 Other Available Instruments None recommended for predicting violence in forensic patients BC: SARA, SVR-20, EARL-20B, SAC-J IA: Static-99, Mn-SOST-R EA: RRASOR

17. Scientific Basis for Expert Testimony about Violence Risk Assessment 17 Definitions of “expert” for giving expert testimony Legal Definitions U.S. Frye Daubert Canada Mohan Scientific Definitions Einhorn, Faust, Ziskin, & Dawes

18. Scientific Basis for Expert Testimony about Violence Risk Assessment 18 Legal Definitions in theUnited States Frye Assist trier of fact Witness qualified by virtue of knowledge, skill, experience, training, or education General acceptance by respective field

19. Scientific Basis for Expert Testimony about Violence Risk Assessment 19 Legal Definitions in theUnited States Daubert Has or can be tested Peer review and publication Known error rates Nonjudicial uses General acceptance in scientific community

20. Scientific Basis for Expert Testimony about Violence Risk Assessment 20 Legal Definitions in Canada Mohan Relevant to decision before trier Necessity in assisting trier of fact No exclusionary rule Properly qualified expert (specific)

21. Scientific Basis for Expert Testimony about Violence Risk Assessment 21 Scientific DefinitionsEinhorn, Faust, Ziskin, & Dawes Relevance Different from layperson (and clinical opinion) Reliable Valid (more accurate than layperson) Specialized Replication and peer review

22. Scientific Basis for Expert Testimony about Violence Risk Assessment 22 Clinical vs. actuarial Grove & Meehl, 1996 “Every day thousands of predictions are made by parole boards..., psychiatric teams, and juries hearing civil and criminal cases.… Freedom of convicted felons or risk to future victims, millions of taxpayer dollars expended by court services, hundreds of millions involved in individual and class action lawsuits...-- these are high stakes indeed. To use the less efficient of two prediction procedures in dealing with such matters is not only unscientific and irrational, it is unethical.” ( p. 320)

23. Scientific Basis for Expert Testimony about Violence Risk Assessment 23 Actuarial vs. clinical prediction -- Monahan 2001 In commenting on the designing of the MacArthur risk assessment study in the late ‘80’s : “More research demonstrating that the outcome of unstructured clinical assessments left a great deal to be desired seemed to be overkill: that horse was already dead.” (Monahan et al. in press)

25. Performance of the VRAG

27. Relative Operating Characteristic

28. Relative Operating Characteristic

29. Replications of VRAG/SORAG (n=24)

30. Scientific Basis for Expert Testimony about Violence Risk Assessment 30 How do contemporary methods of risk assessment measure up? Assumptions Frye Witness qualified by virtue of knowledge, skill, experience, training, or education General acceptance by respective field

31. Scientific Basis for Expert Testimony about Violence Risk Assessment 31 How do contemporary methods of risk assessment measure up?  Mohan Necessity in assisting trier of fact No exclusionary rule Properly qualified expert (specific)

32. Scientific Basis for Expert Testimony about Violence Risk Assessment 32 How do contemporary methods of risk assessment measure up? Daubert Has or can be tested Peer review publication Known error rates Nonjudicial uses General acceptance in scientific community

33. Scientific Basis for Expert Testimony about Violence Risk Assessment 33 How do contemporary methods of risk assessment measure up?  “Scientific” Standard Different from layperson (CO) Reliable More accurate than layperson Specialized Replication and peer review

34. Scientific Basis for Expert Testimony about Violence Risk Assessment 34 Clinical decisions using only actuarial instruments Considerable expertise Different (and more accurate) judgments than other “experts” (and laypersons) More reliable than laypersons Use special instruments- diagnosis, psychopathy , VRAG, SORAG, MnSOST-R

35. Scientific Basis for Expert Testimony about Violence Risk Assessment 35 The Scientific Basis for Expert Testimony About Violence Risk Assessment: Conclusions By most standards, CO not expert By almost any standards, EA expert EA and the VRAG: Not perfectly accurate (à la DNA) “Dynamic” variables Absolute rates Unstudied populations Universal Acceptance Illusive

36. Scientific Basis for Expert Testimony about Violence Risk Assessment 36 The Future Hilton & Simmons, in press; Rice & Harris, 2001 Legal standards will continue to become more sophisticated wrt scientific evidence Actuarial instruments to predict violence will continue to improve Court battles will increasingly be “a battle of actuarial instruments”