Testimonial Evidence: Opinion Testimony (lay and expert - come back to expert)

Question 1

What is the general rule re: opinion testimony of lay people?

What is CA’s rule?

Answer 1

Admissible if:

1. RATIONALLY BASED on witness’s perception
2. HELPFUL to a clear understanding of his testimony or determination of fact in issue;
3. not based on scientific, technical, or specialized knowledge

CA —> Same, except does not have requirement 3

Question 2

What are examples of situations where lay person’s opinion testimony is generally admissible (8)?

Answer 2

1. GENERAL APPEARANCE or CONDITION of a person
   - he was about 60 years old
   - she seemed ill
2. STATE OF EMOTION of a person
   - she was angry
   - he was distraught
3. Matters involving SENSE recognition
   - the suitcase was heavy
   - he smelled of garlic
4. VOICE or HANDWRITING ID
   - it sounded like Mark
   - that’s Fran’s handwriting
5. SPEED of moving object
   - it was going fast
6. VALUE of his own services
   - my time is worth $50/hour
7. RATIONAL or IRRATIONAL nature of another’s conduct
   - he was acting crazy
8. INTOXICATION of another
   - she looked drunk

Question 3

What are examples of situations where lay person’s opinion testimony is generally NOT admissible (8)?

Answer 3

Generally, lay opinion is NOT admissible as to:

• whether one acted as an agent
• whether an agreement was made

Question 4

What is the rule re: opinion testimony by expert witnesses ?

What is the CA rule?

Answer 4

Expert’s opinion IS Admissible if:

1. Subject matter is APPROPRIATE for expert testimony AND opinion is HELPFUL to jury
2. Witness is QUALIFIED as an expert
3. Witness BELIEVES in opinion to REASONABLE DEGREE of certainty
4. opinion is RELIABLE and supported by proper factual basis

CA rule –> SAME

Question 5

May an expert render an opinion as to ultimate issue in the case?

Answer 5

Under federal rules –> YES

HOWEVER –> in a CRIMINAL CASE where D’s state of mind constitutes an ELEMENT of the crime or defense, an expert MAY NOT state an opinion as to whether the accused DID or DID NOT have the mental state in issue

Question 6

What is the rule re: authoritative texts and treatises? [come back to p 22] ?

Answer 6

come back to

Question 7

What is the rule re: determining reliability of scientific opinion (daubert) ?

What is the CA rule (Kelly-Frye)?

Answer 7

FRE (Daubert) –>

1. publication/peer review
2. low error rate
3. results are tested and there is ability to re-test
4. reasonable level of acceptance among scientists

CA (Kelly-Frye) –> scientific opinion is RELIABLE and ADMISSIBLE ONLY IF based on scientific principles that are generally accepted in the relevant field