Opinion

Question 1

Opinion testimony by a lay witness

Answer 1

Opinion testimony by a lay witness is admissible when it is:
*Rationally based on the witness’s perception;
*Helpful to a clear understanding of the witness’s testimony or helpful to the determination of a fact in issue; and
*Not based on based scientific, technical, or other specialized knowledge

Question 2

Situations Where Opinions of Lay Witnesses Are Not
Admissible

Answer 2

A lay witness cannot give an opinion as to whether they (or someone.else) acted as an agent or whether a contract was made,

Question 3

expert testimony Requirements for Admissibility

Answer 3

For expert testimony to be admissible: (1) the subject matter must be one where scientific, technical, or other specialized knowledge would assist the trier of fact; (2) the opinion must be based on sufficient
facts or data; (3) the opinion must be the product of reliable principles and methods; and (4) the expert must have reliably applied the principles and methods to the facts of the case.

Question 4

Opinion on Ultimate Issues

Answer 4

An expert is generally permitted to render an opinion as to the ultimate issue in the case (for example, “X was drunk” or “X was insane” or “That is X’s signature on the document”). However, in a criminal case in which the defendant’s mental state 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