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Empirical Methods for Assessing CST

Empirical Methods for Assessing CST. Kimberly Miller Forensic Neuropsychology June 8 th , 2006. Dusky Standard. Competency defined as: Ability to assist lawyer in own defense RATIONAL as well as FACTUAL understanding of proceedings against him/her What does rational mean?.

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Empirical Methods for Assessing CST

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  1. Empirical Methods for Assessing CST Kimberly Miller Forensic Neuropsychology June 8th, 2006

  2. Dusky Standard • Competency defined as: • Ability to assist lawyer in own defense • RATIONAL as well as FACTUAL understanding of proceedings against him/her • What does rational mean?

  3. Florida Rules of Criminal Procedure 3.211 A In considering competence to proceed, examining experts shall consider and include in their report defendant’s capacity to: • Appreciate allegations against him/her • Appreciate possible penalties • Understand adversary nature of legal process • Disclose to counsel facts pertinent to the proceedings • Manifest appropriate courtroom behavior • Testify relevantly

  4. Link between Incompetence and Mental Disease • Expert must show: • Incompetence due to mental illness or retardation • Must specify how this illness affects competency

  5. Competency Screening Test • 22-item sentence completion task: “When I go to court, the lawyer will…” • Time: ~25min • Each item scored on 3-point scale in terms of competency reflected in response • Designed to be used as screener, with Competency Assessment Instrument as a follow-up semistructured interview (13 Qs about legal knowledge and case specifics)

  6. Competency Screening Test: Pros • Good as general screener to recognize those who are clearly competent • Excellent inter-rater reliability (70-85%; see Nicholson, Robertson, Johnson, & Jensen, 1988) • Good agreement with forensic examiners (71-86% correctly classified; see Nicholson, Robertson, Johnson, & Jensen, 1988)

  7. Competency Screening Test: Cons • Criticized for subjective scoring and idealized view of legal system • Many validity concerns: high false positive rate, inconsistent factor structures (reviewed in Melton et al., 1997)

  8. Fitness Interview Test- Revised (FIT-R) • 70 questions divided into 3 main areas: • Ability to understand nature of the proceedings/ knowledge about criminal procedure • Ability to understand the possible consequences of proceedings • Ability to communicate with counsel/assist in own defense • Evaluator rates on 3-point scale level of impairment • Designed as a screener • Time: ~ 30min

  9. FIT-R: Pros • Inter-rater reliability across 4 professions: for most items in .80- .9 range, overall score reliability .98 (Viljoen, Roesch, Zapf, 2002) • Good convergent validity with MacArthur Competency Assessment Tool (Zapf & Roesch, 2001) • Good sensitivity and negative predictive power: identified 82% of individuals clearly CST (Zapf & Roesch, 1997)

  10. FIT-R: Cons • Designed for Canadian jurisdictions • No norms • No scoring criteria • Other cons???

  11. Georgia Court Competency Test (GCCT-MSH) • Revised from original GCCT • 21 questions assessing knowledge of criminal procedure, current changes, relationship with attorney • Time: ~ 20 min

  12. GCCT-MSH: Pros • High test-retest reliability, inter-rater reliability, and internal consistency (Nicholson, 1992) • Good criterion validity: 82% agreement with classification by forensic staff (Nicholson, Robertson, Johnson, & Jensen, 1988) • Quick screener

  13. GCCT-MSH: Cons • Assesses factual knowledge about legal system, but not rational/decisional knowledge • Susceptible to malingering: Gothard, Rogers, & Sewell added Atypical Presentation Scale • Take home message: screener only, to augment competency assessment

  14. Competence Assessment for Standing Trial for Defendants with Mental Retardation (CAST-MR) • Designed to overcome problems with using open-ended questions with MR defendants • 50 items: 40 multiple choice basic legal concepts/ skills to assist defense, 10 MC of defendant’s specific case • Normed on 4 groups: not MR, MR but not referred for evaluation, MR- CST, MR- IST • Time: ~30-40 min

  15. CAST-MR: Pros • Excellent internal consistency, inter-rater reliability, test-retest reliability (Everington, 1990) • Agreement with forensic examiners: 63-72% (decent)

  16. CAST-MR: Cons • Probably easy to fake incompetency • No research into impact of malingering on results

  17. MacArthur Competency Assessment Tool- Criminal Adjudication (MacCAT-CA) • 22 items in 3 domains: • General legal understanding • Reasoning about legal relevance • Appreciation (legal factors applied to one’s own case) • Scores for first two domains involve case vignette • Appreciation domain involves individual’s own circumstances • Time: 30-60 min

  18. MacCAT-CA: Pros • Has standardized administration • Criterion scoring • Normed on a large competent/ incompetent, mentally ill/healthy forensic sample (over 700 people), large age range, 6 states, not just Caucasians • Manual has cut-off scores, sensitivity, specificity, NNP, PPP • Good inter-rater reliability (.75-90; Poythress et al., 1999) • Good internal consistency (~ .8; Otto et al., 1998) • Takes into consideration both decisional and factual knowledge

  19. MacCAT-CA: Cons • Low IQ individuals or those with poor mental flexibility may have difficulty with case vignette portion • This may also reduce real-life utility of measure

  20. Discussion Question • Can neuropsych measures alone be used to determine CST? Case example

  21. Discussion Question • Can neuropsych measures add anything to a traditional competency evaluation? If so, what?

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