Witnesses - Opinions and Expert Testimony

Question 1

Frye standard

Answer 1

Whether the method is widely accepted by the professional or scientific community.

Question 2

Daubert standard

Answer 2

Testable, verifiable, subjected to peer review, low/high error rate, professional standards or controls, accepted by the professional community.

Question 3

Rule 702 expert testimony requirements

Answer 3

Rule 702 of the Federal Rules of Evidence lists four requirements for expert testimony.

First, the expert’s testimony must help the fact finder understand the evidence or determine a fact in issue.
Second, the expert’s testimony must be based on sufficient facts or data to support the opinion.
Third, the expert’s testimony must be the product of reliable principles and methods.
Fourth, the expert must reliably apply relevant principles and methods to the facts of the case and arrive at the same conclusion that other experts in the same field would likely reach.

1. Help fact finder understand or determine;
2. Based on facts or data to support opinion;
3. Reliable principles and methods;
4. Arrive at same conclusion as other experts likely would.

Question 4

Rule 704

Answer 4

Rule 704 of the Federal Rules of Evidence provides that

A. an opinion is not objectionable simply because it embraces an ultimate issue.
B. expert may not opine on mental state or condition of an element of the charged offense or defense.

Those matters are exclusively within the purview of the fact finder.

Question 5

Rule 703

Answer 5

1. Underlying facts or data do not have to be admissible (e.g., hearsay);
2. As long as experts in the field would rely on similar evidence (e.g., standard investigatory technique).

Lay opinions are neither facts nor data that could form the basis of an admissible expert opinion.

Question 6

Rule 705

Answer 6

1. Expert may state opinion before testifying to underlying facts;
2. May be required to disclose facts or data on cross-examination.

Question 7

Rule 702 - Topics appropriate for expert testimony

Answer 7

1. Trial judge decides whether appropriate for expert;
2. Expert may testify as long as:
3. Scientific, technical, specialized knowledge; and
4. Helps jury understand evidence or determine a fact at issue.

NOT admissible for purposes of witness credibility.

Question 8

Can expert testimony be based upon experiments?

Answer 8

Yes.

1. The experiments can be conducted inside or outside of the courtroom if
2. Substantially similar to circumstances involved in the case.

Question 9

What 4 things must be present for a lay witness to testify?

Answer 9

1. Personal knowledge
2. Able to relate facts to the jury
3. Oath or affirmation
4. Not the judge or the jury