¶1concurring. While I concur in the analysis and holding of the majority, I write separately to direct attention to three additional errors by the trial court which also mandate reversal. The trial court: (1) allowed a witness to testify about inadmissible hearsay statements by a child and to express his opinion that the child was being truthful in her allegations; (2) failed to properly establish the child’s competence to testify; and (3) impermissibly restricted the scope of defense counsel’s cross-examination.
¶2I
¶3At trial, the state called Dave Buchanan as a witness. Buchanan was employed as a consulting counselor at the child’s school. Buchanan testified that he possessed a master’s degree in counseling psychology, was not licensed as a psychologist and was neither trained nor qualified to conduct psychological testing. The children’s services office had asked Buchanan to be present during visitation between the child and her mother “… to make sure the contact and communication as between them was as meaningful as possible.” Buchanan also met with the child several times to assess her developmental abilities as part of an application for benefits from the Bureau of Disability filed by Mrs. Eastham, and to provide counseling.
¶4The prosecuting attorney questioned Buchanan about statements the child made to him. Defense counsel objected to the admission of hearsay. The prosecuting attorney argued that the statements were admissible under Evid. R. 803(4) as statements made for purposes of medical diagnosis or treatment. The court allowed Buchanan to testify as to the statements made by the child to him. The court’s ruling was erroneous.
¶5Evid. R. 803 provides that the *312following types of statements are not excluded by the hearsay rule:
“(4) Statements for purposes of medical diagnosis or treatment. Statements made for purposes of medical diagnosis or treatment and describing medical history, or past or present symptoms, pain, or sensations, or the inception or general character of the cause or external source thereof insofar as reasonably pertinent to diagnosis or treatment.” (Emphasis added.)
¶6The accompanying Staff Notes indicate that this exception is based upon “the assumption that a person will be truthful about his physical condition to' a physician because of the risk of harmful treatment resulting from untruthful statements.” (Emphasis added.) And further, “[t]he exception is limited to those statements made by the patient which are reasonably pertinent to an accurate diagnosis and should not be a conduit through which matters of no medical significance would be admitted.” (Emphasis added.)
¶7The rule itself and the Staff Notes dictate the conclusion that only statements to medical personnel (e.g., physicians, nurses or emergency medical technicians), made for the purpose of medical diagnosis or treatment, are excepted under this provision. See 1 Weissenberger, Ohio Evidence (1988), Section 803.47. The rule’s narrow limitation is based upon the belief that the declarant’s subjective motive generally guarantees the statement’s trustworthiness. Since the effectiveness of the treatment depends upon the accuracy of information given to the physician, the declarant is motivated to tell the truth. Id. at Section 803.45.
¶8Statements made during the course of treatment for a mental health condition, however, are not imbued with the same aura of reliability. In such situations, a patient’s veracity, perception, memory or narrative ability may be impaired.
¶9The defendant was prejudiced by the court’s error in allowing Buchanan to testify about statements made to him by the child, since Buchanan’s testimony served to enhance her equivocal testimony. Without Buchanan’s testimony, it is uncertain whether the defendant would have been found guilty.
¶10The court also erred when it allowed Buchanan to express his opinion on whether the child was being truthful. Buchanan’s opinion acted as a litmus test of the key issue in the case and infringed upon the role of the fact finder, who is charged with making determinations of veracity and credibility-
¶11The state suggests that Buchanan, because of his master’s degree and years of employment, would be more skilled than the finder of fact in measuring the veracity of the child. The argument denigrates the capabilities of the fact finder. In our system of justice it is the fact finder, not the so-called expert or lay witnesses, who bears the burden of assessing the credibility and veracity of witnesses.
¶12The state also argues that the defense attacked the child’s “character for truthfulness” and therefore Buchanan’s opinion of the child’s veracity was admissible under Evid. R. 608(A). The record, however, indicates that the defense did not attack the child’s credibility.
¶13Even if the defendant had attacked the child’s character for truthfulness, Buchanan’s opinion as to her veracity about this specific situation would not be admissible since it was not an opinion concerning the child’s general character for truthfulness. He stated that she told the truth when she made certain allegations.
¶15The court held a pretrial hearing to determine whether the child, who was six years old, was competent to be a witness.
¶16The transcript reveals the following facts. The judge began the hearing by giving the child some polished rocks and soda pop. He continued to ply her with these tangible rewards throughout the examination. The child’s attention wandered during most of the session and the judge frequently prompted her to pay attention. She primarily responded to the judge’s questions (many of which were leading) with nods of the head or monosyllabic answers. She answered several questions incorrectly or not at all. She was able to correctly identify the colors of some objects when asked and “lied” (i.e., stated the wrong color) when asked to lie about the color of an object. However, she answered ambiguously when asked if it was good or bad to lie (answered “yes” to both questions). The judge failed to ask or ascertain whether the child understood right from wrong, what happens if a lie is told or whether she knew of the responsibility involved in promising to tell the truth.
¶17Some Ohio courts have held that the test to be used in determining the competency of a witness under the age of ten is:
“… His comprehension of the obligation to tell the truth and his intellectual capacity of observation, recollection and communication. The nature of his conception of the obligation to tell the truth is of little importance if he shows that he will fulfill the obligation to speak truthfully as a duty which he owes a Diety or something held in reverence or regard, and if he has the intellectual capacity to communicate his observations and experiences.” (Emphasis added.) Hill v. Skinner (1947), 81 Ohio App. 375, 377, 37 O.O. 213, 79 N.E. 2d 787, 789; State v. Lee (1983), 9 Ohio App. 3d 282, 283, 9 OBR 497, 498, 459 N.E. 2d 910, 911; State v. Workman (1984), 14 Ohio App. 3d 385, 388, 14 OBR 490, 494, 471 N.E. 2d 853, 859.
¶18The child need not have religious beliefs or detailed knowledge of the nature of the oath. But it must be shown that the child understands the duty to tell the truth and that some punishment will follow if the child fails to tell the truth. State v. Wilson (1952), 156 Ohio St. 525, 529, 46 O.O. 437, 439, 103 N.E. 2d 552, 555; Klotter, Criminal Evidence (4 Ed. 1987) 136-137, Section 8.12. This showing was not made in the case at bar.
¶19Ill
¶20Finally, the court erred when it *314restricted the scope of defense counsel’s cross-examination.
¶21In addition to foreclosing defense counsel from cross-examining the child at the competency hearing, the court initially expressed its intent to restrict counsel’s questioning at trial by requiring them to submit proposed questions of the child prior to the trial, which then would be asked by the court. After reviewing the proposed questions, the court, recognizing the difficulty the procedure would cause, modified its ruling and permitted counsel to question the child under guidelines set by the court.
¶22However, the court warned defense counsel not to bring into evidence facts relating to the ongoing custody dispute between Sharon East-ham and Tim Walters (the natural father) and the acrimonious relationship between Mr. and Mrs. Eastham and Tim and Mary Walters (the child’s paternal grandmother). When defense counsel attempted to introduce into evidence information about the custody issue, the prosecuting attorney objected to the relevancy of the question and the court sustained the objection.
¶23The court apparently believed that inquiry into the custody issue was inappropriate in a criminal trial. However, in Ohio, “cross-examination … [must] be permitted on all relevant matters and matters affecting credibility.” Evid. R. 611(B). The defendant has adamantly and consistently denied sexually abusing his stepdaughter and has contended that the allegations were fabricated by the noncustodial father and his family to gain custody of the child. In addition, the child’s testimony was equivocal and the medical evidence was inconclusive. Indeed, the medical testimony was as consistent with a theory that the child was not sexually abused as it was with a theory that she was. Had the trial court permitted examination on the issue of the custody dispute and the nature of the relationship among all the individuals involved, relevant information concerning bias, interest or a motive to prevaricate may have been revealed.
¶24The three errors discussed above, in addition to the one noted by the majority, warrant reversal of the judgment of the trial court.
¶25 Evid. R. 601(A) and R.C. 2317.01 state that “children under ten years of age, who appear incapable of receiving just impressions of the facts and transactions respecting which they are examined, or of relating them truly,” are not competent to be witnesses.