Unless someone is qualified as an expert witness in Missouri, witnesses may not ordinarily offer opinions at trial; instead, they usually testify about facts within his or her “personal knowledge.” State v. Sanders, 842 S.W.2d 916, 919 (Mo. Ct. App. 1992). In other words, lay witnesses are permitted to testify as to “perceptible facts” regarding the event(s) in question, such as what he or she hears, feels, tastes smells and sees. Peterson v. Nat’l Carriers, Inc., 972 S.W2d 349, 356 (Mo. Ct. App. 1998). A lay witness must state facts from which the jurors or court are to form their or its opinion, but when a witness has personally observed events, the witness may testify to his or her comprehension of what is experienced in a descriptive manner which is actually a conclusion, opinion or inference — provided the inference is common and accords with the ordinary experiences of everyday life Travelers Indem. Co. v. Woods, 663 S.W.2d 392, 399 (Mo. Ct. App. 1983).
Based on experience, parties and witnesses often want to “jump the gun” and testify as to their ultimate opinions about a case. This is usually not allowed. As a result, it is important to lay a factual foundation about the personal knowledge a given witness may have before the witness can testify as to his or her comprehension of what was experienced. Contact with questions.