Admissibility of Lay and Expert Opinion Testimony Flashcards
Requirements for Lay Witnesses
FRE 602 requires lay witnesses only testify on the basis of their personal knowledge about the matter
Requirements of Expert Witnesses
FRE 702 allows expert witnesses to testify based on the witness’s scientific, technical, or other specialized knowledge to interpret information
Nature of Information
The nature of the information is what differentiates lay testimony from expert testimony, so the same witness could be called to give both.
Sources of Information for Expert Testimony
FRE 702 provides that experts may rely on facts and data from four sources
- Firsthand observation
- Information provided prior to trial
- Information provided during the trial through asking the witness hypothetical questions
- Information provided during the trial by having the expert attend other parts of the trial and hear the testimony establishing the facts
Types of Evidence Experts May Use
Experts can use admissible and inadmissible evidence to form their testimony. FRE 703 permits experts to rely on inadmissible evidence if experts in their field would reasonably rely on those kinds of facts and data in forming an opinion on the subject
Disclosure of the Facts or Data Underlying Expert Testimony
Proponent
The proponent can have its expert disclose any admissible facts or data that the expert relied on in forming her conclusions, but the FRE does not require the proponent to do so. But parties usually have their experts explain to the jury how the data led them to their conclusions.
The FRE provides that the proponent generally may not have its experts disclose inadmissible evidence to the jury. But FRE 703 allows the judge to let the proponent disclose inadmissible evidence if the probative value of the inadmissible evidence substantially outweighs its prejudicial effect
Disclosure of the Facts or Date Underlying Expert Testimony
Adverse Party
FRE 703 does not limit an opposing party’s ability to ask the proponent’s expert about any of the bases of the expert’s testimony, so on cross-examination the opposing party is free to have the proponent’s expert disclosed inadmissible evidence to the jury
Common Law Approach to Opinion Testimony
Lay witnesses were not allowed to give opinion testimony. They were only allowed to present facts because we wanted to let the jurors decide how to interpret the facts.
Expert witnesses were allowed to give opinion testimony. But they were not allowed to offer opinions about ultimate issues in the case because they were seen as the province of the jury. For example, experts couldn’t say the defendant acted intentionally
FRE Approach to Opinion Testimony
Lay and expert witnesses are allowed to give opinion testimony.
Expert witnesses could give their opinion about all matters when the rules were adopted in 1975. After the assassination attempt on President Reagan, FRE 704 was amended and returned to the common law approach for some types of expert opinions.
FRE 704(b) Opinion on an Ultimate Issue
In a criminal case, an expert witness must not state an opinion about whether the defendant did or did not have a mental state or condition that constitutes an element of the crime, charge, or defense. Those matters are for the trier of fact alone.
Reliability of Expert Testimony
Pre-Frye Common Law Approach
Courts admitted expert testimony if it would be helpful to the jury. A judge evaluating scientific evidence would primarily consider whether that evidence was “beyond the ken” of the average juror. There was no examination about whether the testimony was relevant or reliable.
Frye v. United States
D.C. Cir. 1923
The defendant wanted to introduce expert testimony saying that the results from a lie detector test showed he didn’t lie when he said he didn’t commit the murder. Because lie detector tests were not generally accepted yet, the court wouldn’t allow it. The court added to the common law approach. Scientific evidence must be “beyond the ken” of an average juror and must be reliable as measured by its general acceptance by the relevant scientific community
Post-Frye / Pre-Daubert Era
As Frye became widely adopted as the test to admit expert testimony, questions and concerns arose
- The test did not ask whether the underlying science was reliable
- The test excluded too much evidence because science moves very slowly and Frye only let in evidence that was generally accepted in the field
- The test didn’t explain the meaning of general acceptance
- The test didn’t explain what relevant scientific community meant
Original FRE 702
The original FRE 702 did not mention Frye and did not appear to have any text governing the judge’s duty to ensure the reliability of scientific evidence beyond FRE 403, which grants the trial judge discretion to keep out any evidence that might mislead the jury.
Daubert v. Merrell Dow Pharmaceuticals Inc.
1993
Facts and Procedural History
Pregnant women took a medication for morning sickness and the medication caused birth defects. The plaintiffs had drug analysis, animal studies, animal test tube studies, and expert-examined past studies to prove it. The defendant claimed the plaintiffs had no admissible scientific evidence because the techniques used were not generally accepted. The district court granted summary judgment for the defendant and the circuit court affirmed
Daubert v. Merrell Dow Pharmaceuticals Inc.
1993
Basis for Test for the Reliability of Expert Evidence
In addition to the “beyond the ken” inquiry, Rule 702 contains an implicit requirement that the admitted evidence must be sufficiently reliable. SCOTUS derived this from Rule 702’s use of the words scientific and knowledge.
- Scientific implies a grounding in the methods and procedures of science
- Knowledges connotes more than subjective belief or unsupported speculation. The term “applies to any body of known facts or any body of ideas inferred from such facts or accepted as truths on good grounds.”
Daubert v. Merrell Dow Pharmaceuticals Inc.
1993
Role of the Trial Judge
Factors to Detemine Reliability
The court held that trial judges must serve as gatekeepers and independently ensure that the scientific evidence is not only relevant, but also reliable. The Court identified a non-exhaustive list of factors judges can use to determine whether evidence is sufficiently reliable
- Whether the theory or technique can be tested
- Whether the theory or technique had been subject to peer review and publication
- The known or potential rate of error
- The existence, and maintenance, of standards controlling the technique’s operation
- Whether the theory or technique has been “generally accepted.”
Daubert v. Merrell Dow Pharmaceuticals Inc.
1993
SCOTUS’s Ruling
Because the lower courts only looked at the Frye analysis, SCOTUS vacated the judgment and remanded it to the Ninth Circuit.
Additional Factors Courts Developed After Daubert
- Whether experts are “proposing to testify about matters growing naturally and directly out of research they have conducted independent of the litigation, or whether they developed their opinions expressly for the purpose of testifying.”
- Whether the expert has unjustifiably extrapolated from an accepted premise to an unfounded conclusion.
- Whether the expert had adequately accounted for obvious alternative explanations
- Whether the expert “is being as careful as he would be in his professional work outside his paid litigation consulting.”
- Whether the field of expertise claimed by the expert is known to reach reliable results for the type of opinion the expert would give
General Electric Co. v. Joiner
1998
SCOTUS held that if there is an appeal of a trial court’s decision to admit or exclude expert scientific evidence, appellate courts must review those claims using the abuse of discretion standard. This means appellate courts will largely defer to the decisions made by the trial judge.
Kumho Tire Co. v. Carmichael
1999
SCOTUS held that Rule 702 does not distinguish between “scientific” knowledge and “technical” or “other specialized” knowledge. So Daubert’s gatekeeping obligation applies to all expert testimony
FRE 702 Testimony by Expert Witnesses
A witness who is qualified as an expert by knowledge, skill, expertise, training, or education may testify in the form of opinion or otherwise if
- The expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or determine a fact in issue
- The testimony is based on sufficient facts or data
- The testimony is the product of reliable principles and methods and
- The expert has reliably applied the principles and methods to the facts of the case
