The presentation of forensic psychiatric evidence in court

After defining the role of expert witness, the article reviews the basics of courtroom testimony under the rubrics of (a) truth (presenting under oath only that testimony that one can "swear to," to a reasonable degree of medical certainty); (b) testing (including both psychological testing and tests to assess admissibility standards); and (c) theater (including elements of drama, solemnity, and ritual as well as persuasiveness to the "audience"). Pathways to effectiveness are discussed, including use of visual materials, adjustment of language level for the jury's comprehension and attention to the narrative dimension of the case. Areas of excluded testimony are identified, such as the "ultimate issue" in the case, comments on credibility of other witnesses and comments on the legal process itself. Pitfalls that lie on the path to effectiveness are described, including narcissistic arrogance, anger, and using testimony in a personal crusade; means of avoiding these pitfalls are noted. The author concludes that effective courtroom testimony fulfills expert witness functions necessary to the legal system.