Expert Testimony

Question 1

If the witness is not testifying as an expert, any testimony he or she gives that is an opinion or an inference must be based on what?

Answer 1

Rationally based on perception,meaning the witness must have first-hand knowledge

Question 2

What is the scope of non-expert opinions?

Answer 2

A layman can testify about the:

1. Value of one’s land
2. Their emotions
3. Measurements
4. Physical states (intoxicated, short, fat tall, healthy)
5. Sensory descriptions
6. Sanity of the testator (when probating a will)

Question 3

What are the limits on layman opinions?

Answer 3

Opinions stated in conclusory terms are not appropriate. Legal conclusions must be avoided.

Examples of Legal Conclusions:

1. The plaintiff was contributorily negligent
2. A contract existed
3. Defendant assaulted victim

Question 4

What are the requirements for expert testimony?

Answer 4

1. Qualified: An expert must have special knowledge, skill, experience, education, or training
2. Relevant: Subject matter must be appropriate, and the opinion must be helpful/relevant to assist the jury
3. The discipline used must be reliable
   * More Info:* Expert Testimony

Question 5

What must an expert opinion be based upon?

Answer 5

Reliable methods, devices, or techniques

Question 6

What is the reliability of scientific tests determined by?

Answer 6

The trial court

Question 7

What are the daubert factors for expert evidence?

Answer 7

Weighs:

1. Whether the method has be tested
2. If the method is accepted in the relevant community
3. If the method is peer-reviewed
4. The degree of possible errors
5. Standards employed
   * More Info:* Daubert Factors

Question 8

What is the majority/minority split on factors used to examine an expert’s theory?

Answer 8

Majority: Daubert Factors

Minority: Frye (general acceptance in the community standard)

Question 9

What are the three bases for opinion testimony of experts?

Answer 9

1. Personal knowledge at or before trial of the expert
2. Hypothetical question given to an expert at trial
3. Facts given to the expert outside of court

Question 10

What is the requirement for out of court facts that are given to an expert in preparation for testimony?

Answer 10

The facts must be the type reasonably relied upon by experts in that particular field

Question 11

What is the consequence when out of court facts that the expert relies upon consist of evidence that is inadmissible at trial?

Answer 11

The facts cannot be revealed unless the proponent shows the probative value of the evidence substantially outweighs its prejudicial effect.

Question 12

Does an expert have to testify to the underlying facts or data used in forming his testimony?

Answer 12

No, unless the court requires or required to disclose them on cross.

Question 13

Which type of witness can give an opinion testimony on an ultimate issue?

Answer 13

Only experts

Question 14

List the circumstances in which an expert can pass an opinion on the ultimate issue of a case.

Answer 14

1. Cause of accident, illness, death
2. Whether a product is unreasonably dangerous/defective
3. Whether a document is forged/genuine
4. Whether the defendant was insane/mentally ill

Or

5. The standard of care in a civil malpractice action or a crime

Question 15

When can an expert not pass an opinion on the ultimate issue of a case?

Answer 15

1. Legal conclusion that the plaintiff was contributorily negligent

Or

2. Legal conclusions regarding the content of law (e.g. defendant intended to kill the victim)

Question 16

In criminal cases, what can an expert not pass an opinion on?

Answer 16

In a criminal case, an expert cannot give an opinion as to whether the defendant had the mental state or condition that constitutes an element of the crime charged. It is an issue determined by the jury.

Question 17

If an expert is appointed by the court, what must the expert do?

Answer 17

1. Give the parties his findings

And

2. Give the parties an opportunity to depose him. The expert may be called to testify by either party.