§602 Lack of Personal Knowledge

• Library: Evidence Restated Deskbook (2021 Ed.)

§602 Lack of Personal Knowledge

A witness may testify to a matter only if evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter. Evidence to prove personal knowledge may consist of the witness's own testimony. This section does not apply to a witness's expert testimony (see §703 regarding the facts or data upon which an expert may base an opinion).

Notes

This section states the general rule that, in order to have probative value, the testimony of a witness must be based on personal knowledge, Hemeyer v. Wilson, 59 S.W.3d 574, 581 (Mo. App. W.D. 2001); Francis v. Richardson, 978 S.W.2d 70, 73 (Mo. App. S.D. 1998), and not on speculation, guesses, and conclusions, Fairbanks v. Weitzman, 13 S.W.3d 313, 318 (Mo. App. E.D. 2000); Burns v. Elk River Ambulance, Inc., 55 S.W.3d 466 (Mo. App. S.D. 2001); Cummings v. Tepsco Tenn. Pipe & Supply Corp., 632 S.W.2d 498, 500 (Mo. App. E.D. 1982); Dealacroix v. Doncasters, Inc., 407 S.W.3d 13, 30 (Mo. App. E.D. 2013) (quoting Hemeyer v. Wilson, 59 S.W.3d 574, 581 (Mo. App. W.D. 2001): '"If the testimony of a witness, read as a whole, conclusively demonstrates that whatever he may have said with respect to the issue under investigation was a mere guess on his part and that, in fact, he did not know about that concerning which he undertook to speak, his testimony on the issue cannot be regarded as having any probative value.'").

Accordingly, when "a witness admits that he has no knowledge of the subject matter he [has] disqualified himself on that subject." Davis v. Gatewood, 299 S.W.2d 504, 510 (Mo. 1957). The rationale for the rule was stated by the Supreme Court of Missouri in State v. Dixon, 420 S.W.2d 267, 271 (Mo. 1967) (citations omitted), as follows:

"(N)ot every human assertion is to be accepted as the basis of an inference that the thing asserted is true. And, it would seem to be elementary and self-evident that no witness should be heard with respect to that concerning which he does not possess the fundamental and basic testimonial qualification of knowledge; or, as succinctly stated many years ago, '(n)o one can be allowed to prove what he has never learned, whether it be ordinary or scientific facts.' So, when the testimony of a witness, read as a whole, conclusively demonstrates that whatever he may have said with respect to the issue under investigation was a mere guess on his part and that, in fact, he did not know about that concerning which he...