Opinion and Expert Testimony Flashcards
Opinion Testimony by Lay Witness (701)
If the witness is not testifying as an expert, any testimony he or she gives that is an opinion or an inference must be:
- Rationally based on perception; must be based on first-hand knowledge
- Helpful to a clear understanding of the witness’s testimony or the determination of a fact in issue
- not based on scientific, technical, or other specialized knowledge
Proper scope of non-expert opinion
V.E.M.P.S.S.
Value
Emotional state of others
Measurements
Physical states
Sensory descriptions
Sanity of the testator
When is expert testimony admissible?
When it is:
- Qualified;
- Relevant; and
- Reliable
When is an expert qualified?
Experts must have:
- Special skill
- Knowledge
- Experience
- Education; or
- Training
When is expert testimony relevant?
- Subject matter must be appropriate, and
- opinion must be helpful/relevant to assist the jury
When is expert testimony reliable?
Expert testimony is reliable when the Daubet Standard is met (T.A.P.E.S)
What is the Daubert Standard?
Expert opinion must be based on scientific evidence that is:
T: peer tested and reviewed
A: reasonably accepted in the field of study
P: published
E: has a low error rate
S: standards
3 bases for opinion testimony
- Personal knowledge at, or before, trial
- Facts presented at trial
- Facts presented to the expert outside of court
Disclosure of Facts or Data Underlying Expert Opinion
- An expert may testify and give reasons without first testifying to the underlying facts or data unless the court requires otherwise
Opinion on Ultimate Issue
Generally, an expert may give an opinion or inference on any ultimate legal issue
EXCEPTION: experts cannot give opinion on ∆’s mental state in a criminal trial, if it is an element of a crime or defense
Court-Appointed Experts
An appointed expert witness must
- advise the parties of his findings and
- allow either party to depose him
An appointed expert may be called to testify and cross-examined by either party
