Opinions and Expert Testimony

Question 1

Opinion Testimony by Lay Witnesses

Generally

Answer 1

a) Any testimony that a lay witness gives that is an opinion or an inference must be:
i) Rationally based on the perception of the witness; and
ii) Helpful to a clear understanding or determination of a fact in issue

Legal conclusions must be avoided and are inadmissible

Question 2

Opinion Testimony by Lay Witnesses

Proper scope of non-expert opinion includes (VEMPS)

Answer 2

V: Value of one’s own land

E: Emotional state of others

M: Measurements (i.e., speed of a vehicle, height, weight, distance)

P: Physical states (i.e., intoxicated, tall/short; healthy/sick)

S: Sensory descriptions (i.e., smell, sound, taste, color)

Question 3

Testimony by Experts

To analyze an opinion offered by an expert (mnemonic: SPOT)

Answer 3

S: Proper Subject matter

P: Proper Person (qualified)

O: Proper Opinion (basis of the opinion)

T: Proper Testimony (offered in proper form)

Question 4

Testimony by Experts

The MBE follows Daubert. The factors include (mnemonic: TAPES)

Answer 4

T: Has the theory been Tested? (If so, how extensively?)

A: General Acceptance in the relevant community

P: Peer review of the scientific theory

E: Degree or rate of Error

S: Standards

Question 5

Testimony by Experts

Frye

Answer 5

The Frye test, which requires general acceptance in the scientific community, is a minority position on the MBE; this is often a trap answer

Question 6

Basis of Opinion Testimony by Experts

Answer 6

a) Three bases for opinion testimony:
i) Personal knowledge at or before trial
ii) Facts presented to the expert at trial (i.e., hypothetical questions)
iii) Facts presented to the expert outside of court (i.e., reports from others, including inadmissible evidence)
(1) These out-of-court facts must be of the type “reasonably relied upon” by other experts in the particular field

Question 7

Opinion on Ultimate Issue

Answer 7

a) Rule: Generally, an expert may give an opinion or inference that embraces an ultimate issue, but cannot state the opinion as a legal conclusion
i) Examples (permissible): Cause of accident, illness, death; whether a product is unreasonably dangerous/defective; whether a document is forged/genuine; whether the D was insane/ mentally ill
ii) Examples (impermissible): legal conclusion that the plaintiff was contributorily negligent or legal conclusions regarding the content of the law (i.e., the D intended to kill the victim)

b) Rule: Limitation in criminal cases: an expert may not give an opinion as to whether the D did or did not possess the mental state or condition that constitutes an element (or defense) of the crime charged, as such issues are determined by the jury