Consultation, Testimony, and Professional Practice
What the domain tests
This domain addresses the expert's non-assessment work: consultation to attorneys and agencies, report writing, deposition and trial testimony, and practice management. Know the structure of a forensic report-referral question, sources, procedures, findings, opinions, and limits-and that opinions must be tied to the referral question and supported by data.
Testimony
Understand the difference between fact and expert testimony, the role of the voir dire, and the distinction between the ultimate issue and the expert's opinion. Know that experts may offer opinions on the ultimate issue in many jurisdictions but must not usurp the jury's role. Be prepared for cross-examination tactics: leading questions, hypotheticals, and challenges to base rates and instrument validity.
Traps
Frequent traps include overstating certainty, testifying outside one's competence, and confusing the standard of proof (preponderance, clear and convincing, beyond a reasonable doubt). Also watch questions about record retention and release-retain records per law and ethics, and release only with authorization or court order. Another trap is assuming that a prior opinion binds later testimony; experts may revise opinions when new data emerge.
Worked rule of thumb
Before testifying, know your role, your data, and your limits. Answer the question asked, do not volunteer, and use plain language. When challenged on an instrument, state its purpose, its limits, and its role in the overall opinion rather than defending it as definitive.