Forensic Assessment,Witness Credibility and the Search for Truth through Expert Testimony in the Courtroom

In the legal system's search for truth, determination of the credibility of any witness is left to the fact finder. The widely recognized bar on any witness's attesting to the credibility of any other witness or claimant, however, exists in tension with certain ethical and technical requirements of the forensic psychiatric witness's role. These requirements include the need to perform an initial credibility threshold determination; the need to consider malingering in all forensic evaluations; and the need to utilize standard criteria for diagnosis, even if some diagnoses have acquired pejorative connotations. After examining the impact of Daubert v. Merrell-Dow on admissibility of scientific testimony, this article reviews the conflicts and concepts impinging on the legal system's search for truth through fairness and offers suggestions for coping with the testimonial and theoretical pitfalls that may occur during the process.