Lack of personal knowledge

Article VI. Witnesses Rules of Evidence A witness may not testify to a matter unless evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter. Evidence to prove personal knowledge may, but need not, consist of the witness's own testimony. This rule is subject to the provisions of Rule 703 relating to opinion testimony by expert witnesses. Advisory Commission Comments. Basic to relevancy concepts is that a witness must know about the subject matter of testimony. This is the familiar requirement of first-hand knowledge. Under Rule 703, experts may base an opinion on the factual findings of others. Also, party admissions need not be based on first-hand knowledge. Rule Name Rule 602: Lack of personal knowledge.