13. EXPERT OPINIONS
Analyzing the admissibility of expert testimony consists of asking four questions:
1) Is there an appropriate issue for expert testimony because the witness's "specialized knowledge" will help the jury. Rule 702. This is a 2-step analysis:
a) Is there an appropriate issue for SOME expert to testify because it is beyond the knowledge of most jurors? E.g., whether spine injury is permanent
b) Is it appropriate for THIS PARTICULAR expert to testify because s/he comes from a relevant field of expertise? E.g., a chiropractor.
2) Does the witness have the qualifications to be an expert, "by knowledge, skill, experience, training or education." Rule 702. No PhD required.
3) Does the expert have adequate data upon which to base opinions? Rule 702. Personal knowledge or review of files.
4) Are the particular opinions offered "the product of reliable principles and methods ... reliably applied .. to the facts of this case?" Rule 702. To meet this requirement, the expert testimony must:
a) be confined to the expert's area of expertise
b) be rationally related to the data
c) not contradict basic scientific principles
d) be derived by following accepted procedures, practices and protocols in the expert's field
e) be "scientifically reliable" under Daubert
Experts give three kinds of testimony:
1) Background information, e.g., how DNA testing works
2) What the expert did, e.g., treated the victim in the emergency room
3) Opinions, e.g., diagnosis, prognosis
The first two are matters within the personal knowledge of the expert, and no special rules are required. The third requires an exemption from the usual rule that witness opinions must be based on personal knowledge, because experts rely on all sorts of 2nd-hand information, e.g., a doctor diagnoses a medical condition based on blood tests, MRI results, reports from nurses, and self-description by the patient. This is where Rules 702-705 come into play. We allow experts to form critical opinions based on all kinds of data, not just facts personally perceived.
CORE CONCEPT: RELIABILITY
The primary principle of expert testimony is that we want a foundation laid that all such opinions are at least minimally reliable because the jury (not being experts) is not necessarily going to be able to evaluate them properly. This is a higher standard than the “rational” standard for lay opinions.
The main analytical problem is distinguishing among similar rules:
1) Is the witness sufficiently qualified to form reliable opinions in his or her field?
2) Is the field itself sufficiently reliable that the jury will benefit from hearing from one of its experts?
3) Does the expert have sufficient data to support each of his or her opinions?
4) Did the expert arrive at each opinion in a reliable manner (this focuses on procedures and protocols, not results)
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Suppose you are the prosecutor in a murder trial in which the defense is mistaken identity. The defense attorney proposes to call to the stand a psychic detective, Noreen Renier, who claims she went to the scene, touched an item of the victim's clothing, and saw an image of the killer, and it was not the defendant. Ms. Renier has been a professional psychic for 40 years, has appeared on Nancy Grace, Larry King Live, and Dr. Phil, and has worked on more than 600 unsolved murder cases with the police. She won the IPAA, International Paranormal Assoc Award in 2010. See http://www.noreenrenier.com
What objection(s) could the prosecution make? When you think you know the answer, click here .