Conditional probative value: neoclassicism without myth.

• Author: Friedman, Richard D.

INTRODUCTION

The concept of conditional relevance is an essential aspect of the classical model of evidentiary law. Some of the great scholars of evidence have endorsed and shaped it.(1) Under Federal Rule of Evidence 104(b) it plays a crucial role in the division of responsibility between judge and jury,(2) as well as in the application of the personal knowledge(3) and authentication(4) requirements. And the Supreme Court has applied it with great force.(5)

In recent years, though, the concept has come under attack from several notable scholars. The late Vaughn Ball led the assault, calling the concept a "myth."(6) Peter Tillers, finding Ball's analysis to have some merit(7) but not to be entirely satisfying, concludes that "[a]s a device for the regulation of fact-finding chores by the jury," the doctrine of conditional relevance "seems particularly invidious since it is so susceptible of witting or unwitting manipulation by judges who are distrustful of juries."(8) Dale Nance has found Ball's criticisms convincing as applied to the hypotheticals and cases by which conditional relevance is usually explained; what "residual force" he perceives in the concept of conditional relevance should, he believes, be accounted for not on traditional grounds but as an application of the "best evidence principle."(9) Most recently, Ronald Allen, like Ball, has spoken of conditional relevance as a "myth";(10) he contends that "there is no independent scope for the concept of conditional relevanc[e]."(11)

In this article, I contend that, although the classical concept of conditional relevance is flawed in some respects, there is more to the concept than one might infer from the work of these writers.

I certainly do agree with them that the concept is traditionally expressed can be misleading. In two senses, it is too formalistic. First, as I show in Part I, it is binary when it should operate in terms of degree; thus we might speak more precisely, when precision is really necessary, in terms of conditional probative value. Second, as I argue in Part II, the traditional doctrine intrudes too much on the jury's function.(12) It attempts to divide into discrete parts a fact-finding task that is better left integral. It does this by supposing that the jury will determine the truth, not only of the ultimate factual propositions made material by the governing substantive law, but also of preliminary, or predicate, propositions on which the relevance of proffered evidence may be conditional. I will argue that the very notion of a predicate proposition, which is central to the traditional concept of conditional relevance, is an unwarranted formalization unless treated merely as a useful shorthand.

In Part III, I define conditional probative value, a concept that shares the basic theoretical foundation of conditional relevance while avoiding its formalism. This Part shows that a determination of the conditional probative value of a given piece of evidence is much like the ordinary determination of probative value -- except that the determination must be made twice, once with a prescribed evidentiary condition satisfied and once without. The essence of the concept of conditional probative value lies in comparison of these two determinations: proffered evidence has probative value subject to a given condition if its probative value is greater when that condition is satisfied than when the condition is not satisfied.

Understood in this manner, the concept is useful in various contexts, as I contend in Part IV. Thus, I believe the expression of the concept in evidentiary rules should not be discarded but rather refreshed. In Part V, I propose a redraft of Rule 104(b) and of associated rules, including those dealing with the personal knowledge and authentication requirements. The concept expressed by these proposals resembles, but lacks the rigid lines of, the traditional concept. Thus, I call it neoclassical. And it is no myth.

1. CONDITIONAL RELEVANCE AND CONDITIONAL PROBATIVE VALUE

   Rule 104(b) expresses the classical concept of conditional relevance:

   Relevancy conditioned on fact. When the relevancy of evidence depends

   upon the fulfillment of a condition of fact, the court shall admit

   it upon, or subject to, the introduction of evidence sufficient to support

   a finding of the fulfillment of the condition.(13)

   To see how the classical concept operates, consider the following

   hypothetical:

   Blanca's hypothetical: Blanca is being tried for improper disposal of

   refuse. Under the governing law, an element of the crime charged is

   the factual proposition that at the time of her alleged conduct -- mixing

   newspapers with trash -- she knew that it was prohibited. To help

   prove Blanca's knowledge, Proffer, the prosecutor, offers evidence

   that a document created before the time of Blanca's conduct stated

   the prohibition. Analysis of this hypothetical will be assisted by defining the following propositions:

   Knew is the proposition, made material by the governing law, that at

   the time of her conduct Blanca knew that it was illegal.

   Statement is the proposition that a document created before the time

   of Blanca's alleged conduct stated the prohibition.

   Learn is the proposition that Blanca read or otherwise learned of the

   contents of the document by the time of her alleged conduct.

   Proffer's evidence of Statement would clearly be relevant to Knew if Learn were known to be true.(14) If Learn is known not to be true, however, Statement does not appear relevant with respect to Knew.(15) Accordingly, under the classical concept, Statement is said to be relevant conditionally upon sufficient proof of the truth of the predicate Learn.

   Some critics have pointed out that one problem with this classical concept of conditional relevance is that it does not square well with the broad, basic concept of relevance.(16) Generally speaking, they say, evidence that is conditionally relevant under Rule 104(b) must, even without evidence of the predicate, satisfy the ordinary standard of relevance, which is expressed in Federal Rule of Evidence 401:

   "Relevant evidence" means evidence having any tendency to make

   the existence of any fact that is of consequence to the determination

   of the action more probable or less probable than it would be without

   the evidence.(17) Given sufficient proof of Learn, evidence of Statement is clearly relevant to Knew, a fact "that is of consequence to the determination of the action," because Knew is more probable given both Learn and Statement than it would be given Learn but without any proof of Statement.(18) But even if there is no proof of Learn, Statement is still relevant with respect to Knew, so long as Learn is possible: evidence leading a jury to believe that Statement is true will probably lead the jury to believe that the conjunction of the two propositions, Statement-and-Learn, and therefore also Knew, is more. likely true than it would be in the absence of the evidence. Proof that one hurdle -- here, Statement -- has been jumped makes more likely the proposition that both this hurdle and one other have been jumped.(19)

   What can be said of this case can be said of most others: If an item of evidence is relevant assuming the truth of a particular factual condition, then so long as that factual condition is possible the item of evidence will be relevant, in the broad sense that it alters the probability of a material fact, even if the factual condition is unproven. But the significance of this proposition is limited in at least two important respects.

   First, there are in fact cases in which an item of evidence has substantial probative value given proof of another proposition but is irrelevant absent such evidence. Consider an assault case in which identity is at issue. Suppose that an eyewitness has identified the accused as the assailant and that the accused has denied that he was even present at the scene. In this context, evidence of proposition A, that the accused has blood type A, does not appear to have any probative value at all; so far as I am aware, there are no studies suggesting that a given person is more or less likely to commit crimes if he has blood type A than if he has other types. But if the defense offers proof of proposition B, that the assailant, whoever it was, had blood type B, then the evidence of proposition A gains great -- indeed, nearly dispositive -- probative value. Various forms of identification evidence -- identifying a person or thing as the one that played a given role in the case by showing that each shares a given characteristic that has no relevance to the case but for that commonality -- fit this mold of what might be called absolute conditional relevance.(20)

   Second, and more important, that a proffered piece of evidence is relevant to a material factual proposition, even absent proof of another proposition, does not in itself generally have much significance. For example, to say that evidence of Statement is relevant in proving Knew, even absent proof of Learn, does not take us very far. It says that Knew is more likely given the evidence, but it does not tell us how much more likely. This is crucial. Often an item of evidence is technically relevant, in that it raises or lowers the probability of a material fact, but the extent of that impact -- the probative value of the evidence -- is too minuscule to warrant admissibility.(21)

   If, for example, the document in question is a private letter between two people having no apparent connection to Blanca, a reasonable jury would have to believe, absent proof of Learn that the probability of Learn is rather low. Thus, evidence of Statement probably would not, absent proof of Learn, raise the probability of Knew very much at all. In such a case, we might say that evidence of Statement has significant conditional probative value, dependent on proof of Learn: evidence of Statement has significant probative value given proof of...