THE NATIONAL CENTER FOR JUSTICE AND THE RULE OF LAW AND THE NATIONAL JUDICIAL COLLEGE EXPERT WITNESSES DIVIDER 6 Professor Michael Johnson OBJECTIVES: After this session, you will be able to: 1. Distinguish between expert and lay opinion; 2. Define the issues in determining whether to admit expert testimony; and 3. Describe whether otherwise reliable expert testimony fits the case. REQUIRED READING: PAGE Michael Johnson, Expert Witnesses (Aug. 2011) [NCJRL PowerPoint]...1 SI: TECHNOLOGY ASSISTED CRIMES AGAINST CHILDREN: EVIDENTIARY & PROCEDURAL MATTERS AT TRIAL AUGUST 1-2, 2011 RENO, NV WB/KZ
Michael Johnson Counsel for National Programs NCJRL Copyright 2011 NCJRL All Rights Reserved Distinguish between expert and lay opinion. Define the issues in determining whether to admit expert testimony. Describe whether otherwise reliable expert testimony fits the case. Federal Rule of Evidence 702 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. 1
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 substantially outweighs their prejudicial effect. 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 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. 2
Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) Frye v. United States,, 293 F. 1013 (D.C. Cir. 1923) Fifteen States and the District of Columbia Whether the theory or technique has achieved general acceptance in the scientific or technical community. Scientific, technical or other specialized knowledge Judge as Gatekeeper Reliable principles and methods Technique reliably applied Does evidence fit the facts? Unfair prejudice, confusion, or potential to mislead jury does not substantially outweigh probative value 3
Whether the theory or technique can be or has been tested. Whether the theory or technique has been subject to peer review and publication. Whether a high known or potential rate of error exists. Whether the theory or technique enjoys general acceptance within the relevant scientific or technical community. Factors listed are illustrative, not exclusive Essential test is whether the principles and methods are sufficiently reliable to allow the jury to consider the evidence Methods and principles are reliable Methods and principles have been reliably applied to the facts of the case at hand 4
More restrictive than relevance Purpose of testimony is to assist the trier of facts Fit depends on applicable legal principles of the case Part of gate keeping function With lay opinion, the jury decides if the evidence fits by determining whether it helps with the verdict Does unfair prejudice, confusion, or misleading the jury substantially outweigh the probative value? Judges exercise more control over expert testimony than lay testimony because of the tendency for the jury to overvalue the evidence of an expert. Kumho Tire Company v. Carmichael, 526 U.S. 137 (1999) Strict application of Daubert s listed criteria is incorrect Dauber test is intended to be flexible guideline Particularly true when assessing technical field, or other specialized knowledge 5
Personal knowledge Evidence presented at trial Evidence that has not been admitted at trial, but which is the type that experts in that field generally consider and rely upon Rule 703 allows admission of the basis for an expert s opinion, if the evidence is not otherwise admissible, only upon a reverse FRE 403 showing, that is, that the probative value substantially outweighs the prejudicial effect. The basis can be brought out on cross examination without satisfying the requirement. 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, (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. 6
The opinion must be based on personal knowledge The opinion must be helpful to the jury The opinion may not rest on scientific, technical, or specialized knowledge, although it may rest on distinctive experiences in the witness s life 7