Expert Witnesses

1. Expert Witnesses Texas Rules of Evidence Article VII. Opinions and Expert Testimony Judge Sharen Wilson

2. 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.

3. 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 of the determination of a fact in issue.

4. 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, reviewed by, or made known to the expert at or before the hearing. If the type reasonably relied upon by experts in the particular field in forming opinion or inferences upon the subject, the facts or data need not be admissible in evidence.

5. Rule 704 Opinion on Ultimate Issues 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.

6. Rule 705 Disclosure of Facts or Data Underlying Expert Opinion • Disclosure of facts or data underlying expert opinion. The expert may testify in terms of opinion or inference and give the expert’s reasons therefor without prior disclosure of the underlying facts or data, unless the court requires otherwise. The expert may in any event disclose on direct examination or be required to disclose on cross-examination, the underlying facts or data.

7. Rule 705 (b) Voir dire. Prior to the expert giving the expert’s opinion or disclosing the underlying facts or data, a party against whom the opinion is offered upon request in a criminal case shall, or in a civil case may, be permitted to conduct a voir dire examination directed to the underlying facts or data upon which the opinion is based. This examination shall be conducted out of the hearing of the jury.

8. Rule 705 (c) Admissibility of opinion. If the court determines that the underlying facts or data do not provide a sufficient basis for the expert’s opinion under Rule 702 or 703, the opinion is inadmissible.

9. Rule 705 (d) Balancing test: limiting instructions. When the underlying facts or data would be inadmissible in evidence, the court shall exclude the underlying facts or data, if the danger that they will be used for a purpose other than as explanation or support for the expert’s opinion outweighs their value as explanation or support or are unfairly prejudicial. If otherwise inadmissible facts or data are disclosed before the jury, a limiting instruction by the court shall be given upon request.

10. Admissible Expert Testimony • HGN • Rules of the game of craps • Shoe and tire print comparison • Battered spouse syndrome • Gunshot residue analysis • Blood spatter analysis • Meaning of words “Swedish deep muscle rub”

11. What makes a credible expert witness? • An expert is not an advocate. • Don’t have to win the case with your answer. • A concession may be the honest answer on cross examination.

12. Impact of Expert Witness Testimony • CSI effect • Death qualified jurors are not as able to draw appropriate conclusions from flawed science.