Lay and Expert Witnesses

Question 1

Opinion Testimony by Lay Ws

Answer 1

Lay testimony is limited to that which is:

• (Perception)- rationally based on the Ws perception
• (Helpful)- helpful to clearly understanding the Ws testimony or to determining a fact in issue; and
• (Lay)- not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.

-Remember that Lay Ws cannot provide legal conclusions.

Question 2

Proper Scope of Non-Expert Opinion (VEMPS)

Answer 2

Includes:

• Value of one’s own property
• Emotional state of others
• Measurements (e.g. speed of a vehicle, height, weight, distance)
• Physical states (e.g. tall/short; healthy/sick)
• Sensory descriptions (smell, sound, taste, etc.)

Question 3

Scope of Expert W (SPOT)

Answer 3

A W who is qualified as an expert may testify if:

• (Subject matter)- 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
• (Person) - expert is qualified, meaning having specialized knowledge, skill, experience, training, or education specific to SM.
• (Basis of Opinion)- the opinion must be based in sufficient facts or data
• (Testimony)- the testimony about the opinion must be expressed to “a reasonable degree of certainty”

Question 4

Assessing the Reliability of Scientific Evidence (Daubert)

Answer 4

Daubert Factors include:

• Whether methodology has been tested
• Error rates
• Has the methodology been generally accepted
• Has the methodology been subject to PR

Question 5

The Frye Test

Answer 5

The minority rule for assessing the reliability of an expert’s scientific evidence. Rule merely requires general acceptance of the test in the scientific community.

Question 6

Bases of Expert’s Opinion Testimony

Answer 6

There are three bases for opinion testimony:

• Personal knowledge (expert’s own tests)
• Facts presented to expert at trial (expert’s trial observations or hypo Qs)
• Facts presented to the expert outside of court (reports, conversations).

Question 7

Reasonable Reliance Rule

Answer 7

Claims that the out-of-court facts must be of the type “reasonably relied upon” by other experts in the particular field (the facts can otherwise be inadmissible in court).

Question 8

Disclosing Underlying Facts and Data of Expert Opinion: Is it Required?

Answer 8

Unless the court orders otherwise, an expert may state an opinion and give the reasons for it without first testifying to the underlying facts or data.

-But the expert may be required to disclose those facts and data on cross-examination.

Question 9

Crossing Expert Ws

Answer 9

Experts may be properly cross-examined as to:

• qualifications
• subject matter and basis of an opinion
• compensation

-Experts are also subject to the usual impeachment methods (e.g. prior inconsistent statements, truthfulness, and bias).

Question 10

Disclosing Facts and Underlying Data: When is it Appropriate?

Answer 10

Underlying data that is otherwise inadmissible (typically hearsay) at trial cannot be revealed unless the proponent shows the probative value of the evidence substantially outweighs its prejudicial effect.

Question 11

Ultimate Issue

Answer 11

• Generally, an opinion is not objectionable because it embraces an ultimate issue. FRE 704a.
• However, an expert W may not state an opinion about whether the criminal D did or did not have a mental state or condition that constitutes an element of the crime charged or of a D. FRE 704b.

Question 12

Hearsay Exception for Impeaching Expert Ws (FRE 803(18))

Answer 12

This rule allows an expert to be cross-examined as to statements contained in any published treatise of reliable authority; such evidence may be admitted substantively and for purposes of impeachment.

Question 13

Opinion on Ultimate Issue: Permissible Testimony:

Answer 13

Includes:

• Cause of accident, illness, death
• Whether a product is unreasonably dangerous/defective
• Whether a document is forged/genuine
• Whether a defendant was insane/mentally ill; or
• Whether the doctor’s conduct met that required standard of care in a civil malpractice action

Question 14

Expert Opinion on Ultimate Issue: Impermissible Testimony:

Answer 14

An expert cannot testify about:

• A legal conclusion that the plaintiff was contributorily negligent
• Legal conclusions regarding the content of law

Question 15

Be on the Lookout for “Conduit” Experts

Answer 15

An expert cannot merely serve as a conduit for another expert’s person.