California Civil Jury Instructions (CACI)

223. Opinion Testimony of Lay Witness

A witness [who was not testifying as an expert] gave an opinion during the trial. You may, but are not required to, accept that opinion. You may give the opinion whatever weight you think is appropriate.

Consider the extent of the witness’s opportunity to perceive the matters on which the opinion is based, the reasons the witness gave for the opinion, and the facts or information on which the witness relied in forming that opinion. You must decide whether information on which the witness relied was true and accurate. You may disregard all or any part of an opinion that you find unbelievable, unreasonable, or unsupported by the evidence.

New April 2008

Directions for Use

Give the bracketed phrase in the first sentence regarding the witness not testifying as an expert if an expert witness also testified in the case.

Sources and Authority

  • Evidence Code section 800 provides:

    If a witness is not testifying as an expert, his testimony in the form of an opinion is limited to such an opinion as is permitted by law, including but not limited to an opinion that is:

    (a) Rationally based on the perception of the witness; and

    (b) Helpful to a clear understanding of his testimony.

  • Evidence Code section 802 provides: “A witness testifying in the form of an opinion may state on direct examination the reasons for his opinion and the matter (including, in the case of an expert, his special knowledge, skill, experience, training, and education) upon which it is based, unless he is precluded by law from using such reasons or matter as a basis for his opinion. The court in its discretion may require that a witness before testifying in the form of an opinion be first examined concerning the matter upon which his opinion is based.”
  • Evidence Code section 1100 provides: “Except as otherwise provided by statute, any otherwise admissible evidence (including evidence in the form of an opinion, evidence of reputation, and evidence of specific instances of such person’s conduct) is admissible to prove a person’s character or a trait of his character.”

Secondary Sources

1 Witkin, California Evidence (4th ed. 2000) Opinion Evidence, §§ 3–25

Wegner et al., California Practice Guide: Civil Trial and Evidence (The Rutter Group) ¶¶ 8:643–8:681

Jefferson’s California Evidence Benchbook (Cont.Ed.Bar 3d ed.) §§ 29.1–29.17

48 California Forms of Pleading and Practice, Ch. 551, Trial, § 551.70 (Matthew Bender)

1 Cotchett, California Courtroom Evidence, Ch. 17, Nonexpert and Expert Opinion, § 17.01 (Matthew Bender)