At PsychLaw.net we know that parental alienation (PA) is widely accepted by both mental health and legal professionals; however, a handful of authors in legal and social science publications deny the existence and/or reliability of PA as a meaningful construct. Accordingly, these few PA detractors claim that expert testimony about PA should not be admissible in North American courts, and they make specious arguments in support of this assertion. Like many deceptive arguments, absent a close reading with a complete understanding of the construct–PA, some are deceived. These blogs will examine the criteria for the admission of expert testimony, how PA meets these criteria and then outlines (and refutes) the misinformation about PA’s admissibility.
In this blog we will be discussing the legal criteria for admissibility of expert evidence. “The Importance of Voir Dire in High-Conflict Family Law Cases,” addresses in detail the standards for the admissibility of expert evidence in the U.S., so they will be addressed only briefly here.
We at PsychLaw.net understand that all relevant evidence is admitted[1] unless: [I]ts probative value is substantially outweighed by a danger of … unfair prejudice, confusing the issues, misleading the jury, undue delay, wasting time, or needlessly presenting cumulative evidence.[2]” Evidence is relevant if it: “(a) has a tendency to make a fact more or less probable than it would be without the evidence; and (b) the fact is of consequence in determining the action.[3]”
The admission of expert evidence is governed by, in addition to those for relevance, further considerations because of the “wide latitude to offer opinions, including those that are not based on firsthand knowledge or observation” that an expert enjoys.[4] It is important to note that this same “latitude” is not granted to ordinary witnesses, who must restrict their opinion testimony to those matters that the witness rationally perceived, and bear upon his or her testimony or a fact in issue.[5]
At PsychLaw.net we teach that to have expert evidence admitted, the proffering party must first present the expert either to the court in its case-in-chief or in a preliminary hearing (variously called a 104, 403, or 702 hearing or voir dire). In either situation, a similar order of examination will occur: (1) the proponent examines the witness in direct examination; (2) the opposing party examines the witness in cross-examination; and (3) the proponent follows up in re-direct examination.
If the expert is examined in a preliminary hearing and fails to establish that the testimony is useful and reliable, the evidence is not admitted to the proceedings. On the other hand, if the expert is first examined while the proceedings are ongoing and then it is revealed the evidence is not useful or unreliable, while the evidence has technically been “admitted,” the court will give it little or no weight.
[1] Fed. R. Evid. 402.
[2] Fed. R. Evid. 403.
[3] Fed. R. Evid. 401.
[4] Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 592 (1993).
[5] Fed. R. Evid. 701.