Section 13.2 Limits of Lay Opinion Testimony

• Library: Sources of Proof (2014 Ed.)

A. (§13.2) Limits of Lay Opinion Testimony

Lay witnesses can testify as to their observations and describe matters within their direct knowledge. “[A] lay witness ‘may testify as to what he hears, feels, tastes, and smells, as well as [to] what he sees. . . .’” Peterson v. Nat’l Carriers, Inc., 972 S.W.2d 349, 356 (Mo. App. W.D. 1998) (quoting Williams v. McCoy, 854 S.W.2d 545, 553 (Mo. App. S.D. 1993)); Roy v. Mo. Pac. R.R. Co., 43 S.W.3d 351, 359 (Mo. App. W.D. 2001). But the ability to testify as to observations does not necessarily mean that the witness may offer an opinion about what the observations mean. Lay witnesses are limited in the opinions, conclusions, or inferences that they may draw from the facts. That is the task of the jury or court as the fact-finder. “The witnesses, as a general rule, must state facts, from which the jurors are to form their opinion.” Housman v. Fiddyment, 421 S.W.2d 284, 289 (Mo. banc 1967).

“The basis of the opinion rule is that inferences and conclusions of unskilled witnesses are superfluous because they can be drawn by the jury as well as by the witness and, therefore, the witness should be required to give the jury the facts and data he has observed so that they may do so.”

Mohr v. Mobley, 938 S.W.2d 319, 321 (Mo. App. W.D. 1997) (quoting Kennedy v. Union Elec. Co. of Mo., 216 S.W.2d 756, 761 (Mo. banc 1948)). In Roy, 43 S.W.3d at 359–60, it was held that a lay witness could testify to the location and length of skid marks but could not opine which vehicle they came from.

This does not mean that a lay witness can never express an opinion. Under Federal Rule of Evidence 701, opinion testimony is allowed by a lay witness when the testimony is “(a) rationally based on the witness’s perception; [and] (b) helpful to clearly understanding the witness’s testimony or to determining a fact in issue . . . .” Missouri law sets a similar standard:

But when it is impossible or extremely difficult for a witness to convey an accurate and actual meaning, and the nature of the thing described may be more clearly and practically conveyed to the jury by a summary of the witness’s impressions, or by comparison with some ordinary object or condition familiar to the court or jury, then the practical administration of justice requires acceptance of the testimony even though it may be, in a sense, the conclusion of the witness.

Mohr, 938 S.W.2d at 321; see also Travelers Indem. Co. v. Woods, 663 S.W.2d 392, 399 (Mo. App. S.D...