§ 9.03 EXPERT OPINION TESTIMONY

• Jurisdiction: United States

§ 9.03 EXPERT OPINION TESTIMONY

[1] IN GENERAL

There are several illustrative scientific evidence foundations in Chapter 4 of this text. However, this section dissects the foundation for expert opinion in greater detail.

The Federal Rules of Evidence admit expert opinion testimony in addition to lay opinion testimony. The Rule in point is 702:

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods; and
(d) the expert has reliably applied the principles and methods to the facts of the case.

In reality, the proponent may use an expert witness in four different ways. First, under Rule 602 the proponent may use an expert purely as a fact witness. Suppose that the accused is being prosecuted for rape. The complaining witness testifies that during the rape, she scratched the rapist's face and drew blood. It just so happened that the accused visited his doctor the day after the alleged rape. The accused could call his doctor and elicit the doctor's testimony that there were no scratches on the accused's face. The witness certainly did not have to be an expert to observe the defendant's face, but it is equally clear that the witness is not incompetent to testify to facts solely because he or she is an expert.

Secondly, as the expression "or otherwise" in Rule 702 suggests, the proponent may use the expert to teach the jurors scientific or technical principles they need to evaluate the facts in the case. The expert witness explains the principles without applying them to the specific facts of the case; the jurors themselves apply the principles to the facts. This use of expert testimony is quite common. As we previously noted, there is a sharp controversy over the reliability of sound spectrography (voiceprint) evidence. A prosecutor offering sound spectrography evidence must not only have the evidence admitted; more importantly, the prosecutor must persuade the jurors to believe the evidence. The prosecutor might call several speech scientists to testify solely about the validity of the underlying theories of interspeaker variability and invariant speech; the witnesses might not even refer to the voiceprint examination in that particular prosecution. The witnesses' sole function would be to educate the jurors on the general theories and convince the jurors that the theories are valid.

The third possibility is to have the expert witness testify to a lay opinion about the significance of the facts in the case. As previously stated, under Rule 701, lay witnesses may opine on the subject of the speed of a motor vehicle. Suppose that a police officer, who is a certified radar operator, observes a passing car. The officer could not only testify to the speedmeter reading if the proponent laid a proper foundation for that evidence; since the officer personally saw the car, the officer could also testify to his or her lay opinion of the car's speed. Just as a witness who happens to be an expert may relate facts any layperson could observe, the witness may express any opinions which a layperson could testify to.

Finally, the proponent may have the witness express an expert opinion evaluating the facts in the case. This is probably the most common use of expert testimony. When the proponent uses an expert in this manner, the expert usually employs a general theory or principle to evaluate the facts of the case. After stating his or her qualifications, the expert's testimony follows a syllogistic structure. The expert describes a general explanatory theory, technique, or methodology (the major premise), states the case-specific facts to be evaluated (the minor premise), and derives an opinion (the conclusion) by applying the major premise to the minor premise. Experienced litigators often conclude the expert's examination by having the expert explain the opinion. The testimony therefore covers five topics: the witness's qualification as an expert, the general theory, the facts of the case, the opinion, and the explanation of the opinion. Each topic requires a foundation. The following subsections analyze the five topics and their respective foundations.

[2] THE EXPERT'S QUALIFICATIONS TO FORM THE OPINION

The law permits expert opinion testimony because the expert can draw inferences entirely beyond the capability of lay jurors or draw the inferences far more reliably. The expert can do so because the expert has knowledge or skill the jurors lack. Under Rule 702, the expert can acquire the knowledge or skill by education, experience, or a combination of education and experience. The expert's background often includes both theoretical education and practical experience.

In the past, the courts have been fairly liberal in assessing the qualifications of proposed experts. That liberality is understandable, since the test stated in Rule 702 is whether the witness possesses more knowledge or skill than the trier of fact, not whether the witness is a full-fledged specialist on the issue before the court or the best qualified expert in the field. However, in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 597, 113 S. Ct. 2786, 125 L. Ed. 2d 469 (1993), the Supreme Court indicated that the trial judge must find that the witness is competent to perform the specific "task at hand." That language has led many lower courts to raise the bar for qualification as an expert.

The foundation for the expert's qualifications can include the following elements:

1. The witness has acquired degrees from educational institutions.
2. The witness has had other specialized training in this field of expertise.
3. The witness is licensed to practice in the field.
4. The witness has practiced in the field for a substantial period of time.
5. The witness has taught in the field.
6. The witness has published in the field.
7. The witness belongs to professional organizations in the field.
8. The witness has previously testified as an expert on this subject.

Our fact situation is a civil personal injury action. The plaintiff, Mr. Nowick, alleges that the defendant, Mr. Johnson, negligently caused the collision in which Mr. Nowick was injured. The complaint alleges that the plaintiff has suffered severe brain injury as a result of the accident. The plaintiff calls Dr. Worth. The plaintiff is the proponent. Dr. Worth has already identified himself.

P WHAT is your formal education? (1)

W I have a Bachelor's degree and a medical degree.

P WHICH undergraduate school did you attend? (1)

W Arizona State University.

P WHAT degree did you obtain there? (1)

W I earned a Bachelor of Science degree.

P WHAT was your major field of study? (1)

W Biology.

P WHICH medical school did you attend? (1)

W The Johns Hopkins University Medical School in Baltimore.

P WHAT degree did you obtain there? (1)

W My M.D.

P WHAT did you do after you graduated from medical school? (2)

W I interned at the University of Southern California Medical Center.

P HOW long was your internship? (2)

W A year.

P WHAT did you do after your internship? (2)

W I became a resident at Gross Hospital in Lexington, Kentucky.

P WHAT is a residency? (2)

W You specialize in a certain field and get practical experience.

P WHAT was your specialty? (2)

W Neurology, brain problems.

P HOW long was your residency? (2)

W Three years.

P WHEN did your residency end? (2)

W In 2002.

P WHAT did you do when your residency ended? (3)

W I moved here to Denver and began practicing.

P WHAT did you have to do to practice in Denver? (3)

W I had to become licensed in Colorado.

P WHEN did you obtain your license in this state? (3)

W In 2003.

P WHAT did you do after you obtained your license? (4)

W I began my practice, specializing in neurology.

P HOW long have you practiced in this state? (4)

W Nine years now.

P HOW many clients with neurological problems have you treated? (4)

W I can't name a number. By this time, I've probably treated thousands.

P HOW much of your time do you devote to the practice of medicine? (5)

W About 80% of my working time.

P WHAT else do you spend your time on? (5)

W For one thing, I teach at the University of Colorado Medical School in Boulder.

P HOW long have you taught there? (5)

W For four years now.

P WHAT courses do you teach? (5)

W I teach three upper division courses in the field of neurology.

P WHAT else do you spend your professional time on? (6)

W I try to publish with some frequency.

P WHAT journals have published your articles? (6)

W Some of the leading medical and neurological journals, including the A.M.A. Journal.

P What is the "A.M.A."?

W I'm sorry. It's the American Medical Association.

P HOW many articles have you published? (6)

W Nine.

P WHAT topics did you discuss in these articles? (6)

W All the articles relate to neurology. (Although Rule 702 does not require that the witness be a specialist to qualify as an expert, as a matter of trial advocacy the proponent should attempt to establish the witness's stature as a specialist on the specific, narrow issue before the court.)

P WHAT professional organizations do you belong to? (7)

W Several, including the American College of Neurological Specialists and the American Board of Neurology.

P HOW do you become a member of the American College? (7)

W You have to have specialized in the neurological field for at least five years.

P HOW do you become a member of the Board? (7)

W There are strict requirements. You not only have to have practiced for several years, you also have to pass oral and written examinations.

P HOW often have you testified in court? (8)

W I'd say at least 100 cases.

P HOW many times were you permitted to give expert opinion testimony? (8)

W ...