Chapter 2 - §10. Lay opinion

• Jurisdiction: United States

§10. Lay opinion

As a general rule, a lay witness can only testify to facts that she personally perceived; testimony about the witness's opinion—the inferences drawn from those facts—is inadmissible. Such testimony is inadmissible because it usurps the role of the trier of fact to draw its own conclusions from those facts. An exception to this rule is that a lay witness can give her opinion when the facts she observed are too complex or too subtle for concrete description. See People v. DeHoyos (2013) 57 Cal.4th 79, 130; People v. Melton (1988) 44 Cal.3d 713, 744. A trial court has broad discretion to admit lay opinion testimony. Krolikowski v. San Diego Empls. Ret. Sys. (4th Dist.2018) 24 Cal.App.5th 537, 573; In re Automobile Antitrust Cases I & II (1st Dist.2016) 1 Cal.App.5th 127, 145.

§10.1. Foundational requirements. For lay opinion testimony to be admissible, the following foundation is required: (1) the opinion's subject matter must involve something within common experience, (2) the facts that support the opinion must have been personally observed by the witness, and (3) the opinion must be helpful to a clear understanding of the witness's testimony. See Evid. C. §800; People v. Dalton (2019) 7 Cal.5th 166, 231.

Federal Comparison FRE 701 is similar to California law, providing that "[i]f a witness is not testifying as an expert, testimony in the form of an opinion is limited to one that is: (1) rationally based on the witness's perception, (2) helpful to clearly understanding the witness's testimony or to determining a fact in issue, and (3) not based on scientific, technical, or other specialized knowledge within the scope of [FRE] 702."

1. Subject matter involves common experience. Lay opinion testimony cannot involve a matter beyond common experience. People v. Williams (5th Dist.1992) 3 Cal.App.4th 1326, 1333, disapproved on other grounds, People v. Randolph (5th Dist.2018) 28 Cal.App.5th 602. A matter is considered to be within common experience when people of ordinary education could reach a conclusion about it as intelligently as the witness. See People v. Cole (1956) 47 Cal.2d 99, 103.

(1) Proper lay opinion. Matters within the purview of lay opinion include the following:

(a) The measurements or dimensions of something or someone. Albrecht v. Broughton (1st Dist.1970) 6 Cal.App.3d 173, 181.

(b) The identity of a person (e.g., descriptive marks and physical characteristics; "it sounded like the defendant's voice;" "the guy had a tattoo of skull and crossbones on his left arm"). People v. Leon (2015) 61 Cal.4th 569, 601; People v. Perry (3d Dist.1976) 60 Cal.App.3d 608, 612; see, e.g., People v. Larkins (4th Dist.2011) 199 Cal.App.4th 1059, 1067 (gym manager's identification of D from video was admitted as proper lay opinion because he had seen D in 20 to 30 videos from other clubs and had seen his driver's license and booking photograph).

(c) The identity of handwriting. Evid. C. §1416; People v. Lucas (2014) 60 Cal.4th 153, 266, disapproved on other grounds, People v. Romero (2015) 62 Cal.4th 1.

(d) A person's demeanor (e.g., "he looked really angry," "his behavior was threatening"). See Molinaro v. Molinaro (2d Dist.2019) 33 Cal.App.5th 824, 828 & n.3; People v. Deacon (1st Dist.1953) 117 Cal.App.2d 206, 210.

(e) The speed of a vehicle. Jordan v. Great W. Motorways (1931) 213 Cal. 606, 612; Hastings v. Serleto (2d Dist.1943) 61 Cal.App.2d 672, 690; see Perry v. McLaughlin (1931) 212 Cal. 1, 13; see, e.g., Rash v. City & Cty. of S.F. (1st Dist.1962) 200 Cal.App.2d 199, 204 (testimony couched in general language such as "very fast" or "mighty fast" is admissible).

(f) The witness's own intent or state of mind and health (e.g., motive or emotion). See Wagner v. O'Bannon (2d Dist.1969) 274 Cal.App.2d 121, 138.

(g) A person's physical condition. See Jordan, 213 Cal. at 612.

(h) A person's character. Evid. C. §§1100 to 1109. See "Character & Related Evidence," ch. 4-A, §1 et seq.

(i) A...