ARTICLE
VII. OPINIONS AND EXPERT TESTIMONY
Rule 701.
Opinion Testimony by Lay Witnesses
If the witness is not testifying as an expert,
the witness' testimony in the form of opinions or inferences is limited
to those opinions or inferences which are (a) rationally based on the
perception of the witness, and (b) helpful to a clear understanding
of the witness' testimony or the determination of a fact in issue,
and (c) not based on scientific, technical, or other specialized knowledge
within the scope of Rule 702.
Rule 702.
Testimony by Experts
If scientific, technical, or other specialized
knowledge will assist the trier of fact to understand the evidence
or to determine a fact in issue, a witness qualified as an expert by
knowledge, skill, experience, training, or education, may testify thereto
in the form of an opinion or otherwise, if (1) the testimony is based
upon sufficient facts or data, (2) the testimony is the product of
reliable principles and methods, and (3) the witness has applied the
principles and methods reliably to the facts of the case.
Rule 703.
Bases of Opinion Testimony by Experts
The facts or data in the particular case upon
which an expert bases an opinion or inference may be those perceived
by or made known to the expert at or before the hearing. If of a type
reasonably relied upon by experts in the particular field in forming
opinions or inferences upon the subject, the facts or data need not
be admissible in evidence in order for the opinion or inference to
be admitted. Facts or data that are otherwise inadmissible shall not
be disclosed to the jury by the proponent of the opinion or inference
unless the court determines that their probative value in assisting
the jury to evaluate the expert's opinion substantially outweighs their prejudicial
effect.
Rule 704.
Opinion on Ultimate Issue
(a) Except as provided
in subdivision (b), testimony in the form of an opinion or inference
otherwise admissible is not objectionable because it embraces an ultimate
issue to be decided by the trier of fact.
(b) No expert witness testifying
with respect to the mental state or condition 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 constituting an element
of the crime charged or of a defense thereto. Such ultimate issues
are matters for the trier of fact alone.
Rule 705.
Disclosure of Facts or Data Underlying Expert Opinion
The expert may testify in terms of opinion or
inference and give reasons therefor without first testifying to the
underlying facts or data, unless the court requires otherwise. The
expert may in any event be required to disclose the underlying facts
or data on cross-examination.
Rule 706.
Court Appointed Experts
(a) Appointment.
The court may on its own motion or on the motion
of any party enter an order to show cause why expert witnesses should
not be appointed, and may request the parties to submit nominations.
The court may appoint any expert witnesses agreed upon by the parties,
and may appoint expert witnesses of its own selection. An expert witness
shall not be appointed by the court unless the witness consents to
act. A witness so appointed shall be informed of the witness' duties
by the court in writing, a copy of which shall be filed with the clerk,
or at a conference in which the parties shall have opportunity to participate.
A witness so appointed shall advise the parties of the witness' findings,
if any; the witness' deposition may be taken by any party; and the
witness may be called to testify by the court or any party. The witness
shall be subject to cross-examination by each party, including a party
calling the witness.
(b) Compensation.
Expert witnesses so appointed are entitled to
reasonable compensation in whatever sum the court may allow. The compensation
thus fixed is payable from funds which may be provided by law in criminal
cases and civil actions and proceedings involving just compensation
under the fifth amendment. In other civil actions and proceedings the
compensation shall be paid by the parties in such proportion and at
such time as the court directs, and thereafter charged in like manner
as other costs.
(c) Disclosure of appointment.
In the exercise of its discretion, the court may
authorize disclosure to the jury of the fact that the court appointed
the expert witness.
(d) Parties' experts of own selection.
Nothing in this rule limits the parties in calling
expert witnesses of their own selection.
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