Rule 401 Definition of Relevant Evidence

This rule adopts Rule 401 of the Federal Rule of Evidence verbatim. The Advisory Committee’s Note to Federal Rule 401 explains this rule completely and concisely. It comprises the remainder of this comment, albeit in slightly altered form. The variety of relevancy problems is coextensive with counsel’s skill in mustering substantive theories to support a case and ingenuity in using circumstantial evidence as a means of proof. An enormous number of cases fall in no set pattern, and this Rule is designed as a guide for handling them. On the other hand, some situations recur with sufficient frequency to create patterns susceptible of treatment by specific rules. Rule 404 and those following it are of that variety; they also serve as illustrations of the application of the present Rule as limited by the exclusionary principles of Rule 403. Passing mention should be made of so-called “conditional” relevancy. Morgan, Basic Problems of Evidence 45-46 (1962). In this situation, probative value depends not only upon satisfying the basic requirement of relevancy but also upon the existence of some matter of fact. For example, if evidence of a spoken statement is relied upon to prove notice, probative value is lacking unless the person sought to be charged heard the statement. The problem is one of fact, and the only rules needed are for the purpose of determining the respective functions of judge and jury. See Rule 104(b). The discussion which follows in the present note is concerned with the relevancy generally, not with any particular problem of conditional relevancy. Relevancy is not an inherent characteristic of any item of evidence but exists only as a relation between an item of evidence and a matter properly provable in the case. Does the item of evidence tend to prove the matter sought to be proved? Whether the relationship exists depends upon principles evolved by experience or science, applied logically to the situation at hand. James, Relevancy, Probability and the Law, 29 Calif. L. Rev. 689, 696 n. 15 (1941), in Selected Writings on Evidence and Trial 610, 615 n. 15 (Fryer ed. 1957). The Rule summarizes this relationship as a “tendency to make the existence” of the fact to be proved “more probable or less probable.” Compare Uniform Rule 1(2) which states the crux of relevancy as “a tendency in reason,” thus perhaps emphasizing unduly the logical process and ignoring the need to draw upon experience or science to validate the general principle upon which relevancy in a particular situation depends. Ultimately, legal reasoning depends upon logic, but the logical calculus includes not only a priori knowledge but facts, insights, and principles developed by scientific methods or tested by experience. The standard of probability under the Rule is “more…probable than it would be without the evidence.” Any more stringent requirement is unworkable and unrealistic. As McCormick (2d ed.) § 185, at 436, says, “A brick is not a wall,” or, as Falknor, Extrinsic Policies Affecting Admissi- bility, 10 Rutgers L. Rev. 574, 576 (1956), quotes Professor McBaine,”…[I]t is not to be supposed that every witness can make a home run.” Dealing with probability in the language of the Rule has the added virtue of avoiding confusion between questions of admissibility and questions of the sufficiency of the evidence. The words “any tendency” in the rule suggest that the court should err, in doubtful cases, on the side of admissibility. For example, courts need not exclude all cumulative evidence. The fact that Witness 1 testifies to the existence of fact X does not compel the conclusion that testimony by Witnesses 2 and 3 to the same effect is not relevant. The probability that fact X exists may increase when it becomes apparent that several different people support it; corroboration may increase the likelihood that the fact is true. At some point further corrobora- tion will be of little help to the trier of fact, and the court will either rule that the additional evidence is not relevant or will exclude it under Rule 403. The Rule uses the phrase “fact that is of consequence to the determination of the action” to describe the kind of fact to which proof may properly be directed. The language is that of California Evidence Code § 210; it has the advantage of avoiding the loosely used and ambiguous word “material.” Tentative Recommendation and a Study Relating to the Uniform Rules of Evidence (Art. I. General Provisions), Cal. Law Revision Comm’n, Rep., Rec. & Studies, 10-11 (1964). The fact to be proved may be ultimate, intermediate, or evidentiary; it matters not, so long as it is of consequence in the determination of the action. Cf. Uniform Rule 1(2) which requires that the evidence relate to a “material” fact. The fact to which the evidence is directed need not be in dispute. While situations will arise which call for the exclusion of evidence offered to prove a point conceded by the opponent, the ruling should be made on the basis of such considerations as waste of time and undue prejudice (See Rule 403), rather than under any general requirement that evidence is admissible only if directed to matters in dispute. Evidence which is essentially background in nature can scarcely be said to involve disputed matter, yet it is universally offered and admitted as an aid to understanding. Charts, photographs, views of real estate, murder weapons, and many other items of evidence fall in this category. A rule limiting admissibility to evidence directed to a controversial point would invite the exclusion of this helpful evidence, or at least the raising of endless questions over its admission. Cf. California Evidence Code § 210, defining relevant evidence in terms of tendency to prove a disputed fact.