Forensic Assessment and Psychological Testing
This domain tests instrument selection, administration, norm interpretation, and the integration of test data with collateral information into a defensible forensic opinion.
Therapeutic versus forensic posture
Forensic assessment serves the court, not the examinee. Notify the evaluee of the purpose and limits of confidentiality, seek records, interview collaterals, and keep therapeutic and forensic roles separate. Opinions are stated to a reasonable degree of professional certainty and rest on a multi-method battery, not a single score.
Instrument selection
- Cognitive ability: WAIS-5, WASI.
- Personality and psychopathology: MMPI-3 or MMPI-2-RF, PAI.
- Psychopathy: PCL-R, a structured clinical rating rather than a diagnosis.
- Violence risk: HCR-20v3 (structured professional judgement), VRAG-R (actuarial).
- Sexual risk: Static-99R, SVR-20v2.
- Symptom validity: TOMM, SIMS and embedded validity scales.
Symptom validity and malingering
Apply Slick and colleagues' criteria: improbable symptoms, inconsistency with records, and below-chance forced-choice performance. Malingering is a rule-out consideration, not a diagnosis; DSM-5-TR separates it from factitious disorder by the presence of an external incentive.
Worked example
An examinee shows marked MMPI-3 validity-scale elevation and fails the TOMM at below-chance accuracy. A defensible report declines to interpret clinical scales substantively, documents inconsistency with records, and states that cognitive and psychotic presentations cannot be reliably assessed, rather than concluding 'psychosis'.
Traps
Treating PCL-R scores as a diagnosis or standalone violence prediction; reading Static-99R as an individual probability rather than a relative risk band; ignoring the Flynn effect with old IQ norms; and using instruments outside their validated language, culture or age range.