There are several key ways in which statutes relevant to mental health evaluations and testimony differ between Arkansas and Federal jurisdictions. I will describe these below:
When can an expert testify? The Federal Rules of Evidence Rule 72 states a witness may testify in the form of an opinion or otherwise if: (a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue; (b) the testimony is based on sufficient facts or data; (c) the testimony is the product of reliable principles and methods; and (d) the expert has reliably applied the principles and methods to the facts of the case. Conversely, Arkansas statute applies a lower threshold, allowing an expert to testify only so long as their knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue. The language in Arkansas’ statute is entirely contained within the first point of the Federal Rules of Evidence Rule 72. No explicit language directly addresses the following three points in Arkansas’ statute. Though this may, on the surface, appear to allow an expert witness to testify without reliable principles and methods, Arkansas uses a Daubert standard for admission of testimony. For further information, please review Farm Bureau Mut. Ins. Co. of Ark., Inc., v. Foote, 14 S.W. 3d 512 (Ark. 2000). There the Arkansas Supreme Court wrote, “This court has not previously adopted the holding in Daubert. We do so now.”
What is expert testimony based on? Here federal and Arkansas Rules of Evidence Rule 703 are quite similar. Both statutes note the facts or data upon which an expert bases an opinion or inference may be those they are aware of or have personally observed (or perceived). If such information is reasonably replied upon by experts in the particular field, the factors or data need not be admissible in evidence. However, federal statute adds, if the facts or data would be otherwise inadmissible, the opinion may only be disclosed if the probative value in helping the jury substantially outweighs the prejudicial value.
Can an expert testify to an ultimate issue? Here there is a sharp difference, and one worth noting. Federal Rules of Evidence Rule 704 notes that, though an opinion is not objectionable simply because it embraces an ultimate issue, there is a critical exception. In a criminal case, an expert witness must not state an opinion about whether the defendant did or did not have a mental state or condition that constitutes an element of the crime charged or of a defense. Those matters are for the trier of fact. Arkansas Rules of Evidence do not include this exception. However, an examination of case law shows this to be considered historically. A 1995 ruling specifically stated an expert opinion on whether the defendant had the intent required to be found guilty of murder, or whether the defendant had the intent to kill when he shot a murder victim was inadmissible. DeGracia v. State, 321 Ark. 530, 906 S.W.2d 278 (1995). The court ruled, “Rule 704 does not permit expert opinion on whether one had the required intent to be found guilty of murder; the testimony in question was potentially misleading and confusing to the jury.” Both state and federal case law supports the expert opinion when presented in psychological, not legal, terms and when it leaves the ultimate opinion to the jury when determining the defendant’s degree of intent.