Abstract
Family court judges in contested custody matters increasingly face competing testimony from two structurally different categories of mental health experts. The first is a court-appointed neutral evaluator selected through a vetting process. The second is a mental health professional retained and compensated by one party to challenge the court-appointed evaluator’s findings. Courts already evaluate expert testimony case by case on its quality and relevance, but the structural features that distinguish these two roles are not always visible from the witness stand. This article describes those structural features and connects them to existing evidentiary frameworks rather than proposing new ones. Although the analysis is illustrated with Maryland Rule 5-702, the rule is used only as a familiar reference point to connect the authors’ lived experience. However, the great majority of American jurisdictions apply the Daubert standard or an analogous rule. The article draws on three sources. The first is the empirical literature on adversarial allegiance, the documented tendency of a retained expert’s opinion to drift toward the party that retains the expert. The second is the established distinction between the forensic evaluative and forensic advocacy roles. The third is the authors’ combined six decades of practice as court-appointed psychologists in Maryland’s family court. From these sources, the article offers a practical framework of questions a judge may find useful when weighing the testimony of a court-appointed evaluator against that of a party-retained reviewer who has not conducted an independent examination of the parties. The article does not argue that retained experts should be categorically disfavored. It argues that a specific subset of retained witnesses, whom the authors term retained trial advocates, occupies a position that is structurally incompatible with the role of independent expert evaluator, and that this incompatibility has practical implications under the rules of evidence and the professional standards that already govern admissibility, weight, and clinical practice.