The mere fact that the witness is insane or mentally ill does not make the person incompetent to testify in a legal proceeding. Courts have repeatedly held that the testimony of any person, regardless of his/her mental condition, is competent evidence unless it contributes nothing whatever because the witness is wholly untrustworthy. Incompetence does not follow from the fact that the witness is insane or mentally ill since what law requires is the trustworthiness of the witness. Hence the courts generally inquire into whether in each case the derangement or defect is such as to make the person highly untrustworthy as a witness[i]. Testimonial competency requires the capacity to perceive as well as to narrate and there is no basis for crediting the testimony of a witness who was mentally incapable of correctly perceiving the event, for s/he is wholly untrustworthy[ii]. A witness is disqualified to testify only if s/he is incapable of expressing himself/ herself concerning the matter as to be understood, either directly or through interpretation by one who can understand the witness, or incapable of understanding the duty of a witness to tell the truth[iii].
Determination of mental competency of a witness is the duty of the trial judge who inquires whether the witness has sufficient understanding to comprehend the obligation of an oath and is capable of giving a correct account of the matters s/he has seen or heard. At the same time, the determination of issues of credibility is to be done by the trier of fact[iv].
Under federal law, the capacity of a person offered as a witness is presumed, and in order to exclude a witness on the ground of mental incapacity, the existence of the incapacity must be made to appear[v].
Competency of a witness is generally assessed through the examination by court or counsel in the presence and under the direction of the court. Such examination is made with special reference to the scope of the inquiry and the subject matter about which the witness is to testify. The trial court’s decision on competence of a witness will not be disturbed on appeal unless there is a clear abuse of discretion. Moreover, the trial judge has discretion to deny a defense motion for a psychological examination.
The question of incompetence due to infancy is to be determined after an inquiry as to mental maturity and the trial judge’s discretion in this regard is not absolute but legal[vi]. Competency is presumed where the child is more than 14 years of age. There must be judicial inquiry as to mental capacity of children below 14 years.
A trial court may find a witness competent to testify at trial without a court-ordered psychiatric examination with respect to his/her competency, even where the witness has a history of mental disease. However, where there is an issue as to the mental capacity of a witness, psychiatric testimony is of particular significance[vii].
In the matter of psychiatric examination of a complaining witness in a sex-offense prosecution, courts have taken divergent stands. Some courts have held that a trial judge does not have the discretionary power to compel an unwilling witness to submit to a psychiatric or psychological examination in the absence of an express statute. However, some other courts are of the opinion that a trial judge has discretion to order a psychiatric or psychological examination of the complaining witness in a prosecution for rape or other sex crime, if there is a substantial showing of need and justification. However, such an examination will not be conducted if such an examination may seriously impinge on a witness’s right to privacy or the trauma attending the role of a complainant in a sex-offense prosecution is sharply increased by the indignity of a psychiatric exam[viii]. At times, the examination itself might serve as a tool of harassment. It is also to be noted that a defendant has no right, in a sex-offense case, to subject the victim to a psychiatric examination.
Further, the trial judge has no duty to order the complaining witness to submit to a psychiatric or psychological examination, absent a defense motion or request. The defendant must establish some specific ground for concluding that the witness suffers from mental problems that might affect the witness’s veracity or must produce evidence that has a direct bearing on a material issue[ix].
The courts have recognized the admissibility of opinion evidence, both lay and expert, as to the mental soundness of a witness in a civil case, of anyone who was acquainted with the witness and had good means of observing his/her behavior. Expert testimony as to amnesia or loss of memory suffered by a proposed witness is admissible on the issue of his/ her inability to testify[x].
The Federal Rules of Evidence are applicable to a proceeding in federal court to determine the defendant’s mental competency to stand trial.
Many state statutes declare that persons who are of unsound mind at the time of their production for examination cannot be witnesses[xi]. A person who can apprehend the obligation of an oath and is capable of giving a fairly correct account of the things s/he has seen or heard is competent as a witness, even though s/he may be afflicted with some form of insanity, is mentally retarded, or is merely ignorant or uneducated[xii]. Also, an individual represented by a conservator is nevertheless competent to testify, if the witness otherwise satisfies the competency requirements.
The mere fact that a witness has been committed under the mental health law is not a determination of his/her legal incompetence. Even an insane person is competent to testify if s/he understands the obligation of the oath and is capable of giving a correct account of the matters s/he has seen or heard. However, a recent adjudication of insanity creates a rebuttable presumption of his/her continued insanity. Even then, a person is deemed to be a competent witness where it is shown that s/he has a lucid interval, can comprehend the nature and obligation of an oath, and can understand and intelligently answer questions propounded to him/her[xiii]. The burden of proof of incompetence of a witness is on the party opposing the witness.
[i] Commonwealth v. Ware, 459 Pa. 334 (Pa. 1974).
[iii] State v. Cox, 344 N.C. 184 (N.C. 1996).
[iv] United States v. Gonzalez-Maldonado, 115 F.3d 9 (1st Cir. P.R. 1997).
[v] Rice v. Office of Servicemembers’ Group Life Ins., 260 F.3d 1240 (10th Cir. 2001).
[vi] Rosche v. McCoy, 397 Pa. 615 (Pa. 1959).
[vii] Knight v. State, 746 So. 2d 423 (Fla. 1998).
[viii] People v. Lopez, 207 Ill. 2d 449 (Ill. 2003), U.S. v. Snyder, 189 F.3d 640 (7th Cir. 1999).
[ix] Daniels v. State, 767 P.2d 1163 (Alaska Ct. App. 1989).
[x] Morley v. Superior Court, 131 Ariz. 85 (Ariz. 1981).
[xi] U.S. v. Weed, 184 F. Supp. 2d 1166 (N.D. Okla. 2002).
[xii] State v. Wyse, 71 Wn.2d 434 (Wash. 1967).
[xiii] Andrews v. Neer, 253 F.3d 1052 (8th Cir. Mo. 2001).