Page 214 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Toxicology and the Law Chapter | 11 181

VetBooks.ir refer are a receipt and a case report from the diagnostic rulings that determine whether the expert may testify at
Examples of a writing to which the animal owner may
all, and if so, upon which opinions. Reliability is the pri-
facility or veterinary clinic. The receipt could be used to
mary factor in the judge’s determination of admissibility
refresh the memory of the animal owner as to precisely of expert testimony. Two approaches to determine the
when and where she purchased the feed. The case report reliability of expert testimony have evolved, these
could be used to refresh the memory of the animal owner approaches are often referred to as the “Frye test” and the
as to when the animal died, when the diagnostic testing “Daubert test.”
was performed, and the results of the testing. An expert
witness may be required, however, to interpret the labora-
tory report.
Frye
The Frye test is the original standard of reliability for
ADMISSIBILITY OF EXPERT TESTIMONY expert testimony, and it remains in several state court sys-
tems. See Table 11.1.The Frye test is often summarized
The lay witness is not the only source of testimony. Lay
testimony is a source of facts. Some of these facts must
be interpreted, which is the role of the expert. Expert tes- 28. Rule 704. Opinion on Ultimate Issue
timony is the other main form of introducing testimonial (a) Except as provided in subdivision (b), testimony in the form of an
evidence. Expert testimony is commonly used at trial and opinion or inference otherwise admissible is not objectionable because it
has become the topic of a number of evidentiary rules. embraces an ultimate issue to be decided by the trier of fact.
Federal Rules of Evidence 701 through 706 follow in (b) No expert witness testifying with respect to the mental state or condition
their entirety. 25,26,27,28,29,30 of a defendant in a criminal case may state an opinion or inference as to
whether the defendant did or did not have the mental state or condition consti-
Expert testimony must not only be relevant as with a
tuting an element of the crime charged or of a defense thereto. Such ultimate
lay witness, but it must also be reliable. Discussion of this
issues are matters for the trier of fact alone. (As amended Oct. 12, 1984.)
reliability factor constitutes most of the remainder of this
29. Rule 705. Disclosure of Facts or Data Underlying Expert Opinion
chapter. In most legal cases, the judge makes preliminary The expert may testify in terms of opinion or inference and give reasons
therefore without first testifying to the underlying facts or data, unless
25. Rule 701. Opinion Testimony by Lay Witnesses the court requires otherwise. The expert may in any event be required to
If the witness is not testifying as an expert, the witness’ testimony in the disclose the underlying facts or data on cross-examination.
form of opinions or inferences is limited to those opinions or inferences (As amended Mar. 2, 1987, eff. Oct. 1, 1987; Apr. 22, 1993, eff. Dec. 1,
which are (a) rationally based on the perception of the witness, and (b) 1993.)
helpful to a clear understanding of the witness’ testimony or the determi- 30. Rule 706. Court Appointed Experts
nation of a fact in issue, and ( c) not based on scientific, technical, or (a) Appointment.—The court may on its own motion or on the motion of
other specialized knowledge within the scope of Rule 702. any party enter an order to show cause why expert witnesses should not
(As amended Mar. 2, 1987, eff. Oct. 1, 1987; Apr. 17, 2000, eff. Dec. 1, be appointed, and may request the parties to submit nominations. The
2000.) court may appoint any expert witnesses agreed upon by the parties, and
26. Rule 702. Testimony by Experts may appoint expert witnesses of its own selection. An expert witness
If scientific, technical, or other specialized knowledge will assist the trier shall not be appointed by the court unless the witness consents to act. A
of fact to understand the evidence or to determine a fact in issue, a wit- witness so appointed shall be informed of the witness’ duties by the
ness qualified as an expert by knowledge, skill, experience, training, or court in writing, a copy of which shall be filed with the clerk, or at a
education, may testify thereto in the form of an opinion or otherwise, if conference in which the parties shall have opportunity to participate. A
(1) the testimony is based upon sufficient facts or data, (2) the testimony witness so appointed shall advise the parties of the witness’ findings, if
is the product of reliable principles and methods, and (3) the witness has any; the witness’ deposition may be taken by any party; and the witness
applied the principles and methods reliably to the facts of the case. may be called to testify by the court or any party. The witness shall be
Rule 702. (As amended Apr. 17, 2000, eff. Dec. 1, 2000.) subject to cross-examination by each party, including a party calling the
27. Rule 703. Bases of Opinion Testimony by Experts witness. (b) Compensation.—Expert witnesses so appointed are entitled
The facts or data in the particular case upon which an expert bases an to reasonable compensation in whatever sum the court may allow. The
opinion or inference may be those perceived by or made known to the compensation thus fixed is payable from funds which may be provided
expert at or before the hearing. If of a type reasonably relied upon by by law in criminal cases and civil actions and proceedings involving just
experts in the particular field in forming opinions or inferences upon the compensation under the fifth amendment. In other civil actions and pro-
subject, the facts or data need not be admissible in evidence in order for ceedings the compensation shall be paid by the parties in such proportion
the opinion or inference to be admitted. Facts or data that are otherwise and at such time as the court directs, and thereafter charged in like man-
inadmissible shall not be disclosed to the jury by the proponent of the ner as other costs. (c) Disclosure of appointment.—In the exercise of its
opinion or inference unless the court determines that their probative discretion, the court may authorize disclosure to the jury of the fact that
value in assisting the jury to evaluate the expert’s opinion substantially the court appointed the expert witness.(d) Parties’ experts of own selec-
outweighs their prejudicial effect. Rule 703. (As amended Mar. 2, 1987, tion.—Nothing in this rule limits the parties in calling expert witnesses
eff. Oct. 1, 1987; Apr. 17, 2000, eff. Dec. 1, 2000.) of their own selection.(As amended Mar. 2, 1987, eff. Oct. 1, 1987.)