Thursday, December 24, 2009

What are the purposes of the law of evidence and proof?

An opinion I read today (see below) got me to thinking (again) about the purposes of the law of evidence and proof and the constraints to which is it is subject. What are those purposes and constraints? How are they related to each other? Can questions about such purposes and constraints even be addressed without a theory of society? How can a lowly scholar of evidence and the law of evidence hope to develop such a theory (or even a theory of the workings of a particular society)? But can judges avoid matters such as "fairness," "truth-finding," "efficiency," "dignity of witnesses," and so on? If not, is it better for courts to talk explicitly about such considerations than to remain silent about such matters? If so, must not the lowly Evidence scholar do his or her best to explain the role that such matters play and should play in judicial proof (or in specific parts of it)? Or not?


See the node on the purposes of the law of evidence (and the material under it) in the evidence module of Spindle Law.


State v. Guinn, 114 Idaho 30, 39 at 39-41 (Idaho Ct. App. 1988) (Burnett, J., concurring):

I join the Court in setting aside the judgment of conviction and in remanding the case for a new trial. For guidance on remand, the Court has discussed the defendant's attempt to discredit a prosecution witness by showing that the witness used marijuana. The discussion focuses on I.R.E. 608(b). I write separately to offer a critical evaluation of Rule 608(b) and to comment on its application, together with other rules, in the present case.


Impeachment is a vexatious subject because it brings into conflict several objectives of our judicial system. On one hand, we seek to ascertain the truth in factual disputes. If there is reason to doubt the credibility of a witness, the triers of fact should be so informed in order to make an intelligent assessment of the testimony. On the other hand, we also strive for judicial efficiency. If challenges to the credibility of witnesses are not regulated in some fashion, trials may become sidetracked by the pursuit of collateral issues. In addition, we seek to uphold the integrity of judicial processes and to protect the dignity of persons who participate in them. If attacks on witnesses are unrestrained, citizen respect for -- and cooperation with -- the courts may be impaired.

Before the Idaho Rules of Evidence were adopted, the scope of impeachment was tightly confined. It reflected a dominant concern for efficiency, court decorum and witness protection. Impeachment was regulated by Rule 43(b)(6), I.R.C.P. This civil rule prohibited impeachment of a witness "by evidence of particular wrongful acts, except . . . [by] prior conviction of a felony . . . relevant to his credibility . . . ." Thus, it was impermissible to attack the credibility of a witness by attempting to show that he had engaged in bad acts, other than felony convictions, which called his character for truthfulness into question. Of course, if evidence of such bad acts was relevant to another issue in the case, it could be admitted -- but only for that limited purpose. E.g., State v. Dayley, 96 Idaho 527, 531 P.2d 1172 (1975); see generally REPORT OF THE IDAHO STATE BAR EVIDENCE COMMITTEE at C 608, p. 3 (December 16, 1983).

Today the Idaho Rules of Evidence and the similar federal rules reflect an increased concern for the truth-seeking objective of a trial. They broaden the opportunity to challenge the credibility of a witness on the basis of his prior misconduct. Rule 608(b) authorizes the trial judge, in the exercise of discretion, to allow inquiry upon cross-examination into any specific acts which are probative of the witness's character for untruthfulness.

The rule must be read carefully. It is important not only for what it says but also for what it does not say. It says that impeachment to show character for untruthfulness is limited to an inquiry upon cross-examination. The impeaching party may not introduce extrinsic evidence of prior bad acts for this purpose. However, the rule is silent regarding impeachment by specific acts to challenge credibility on other grounds. The rule says nothing, for example, about impeachment to show bias or improper motive for testifying. Commentators on the federal rule have treated this silence as pregnant -- that is, as an indication that extrinsic evidence can be used to show bias or improper motive on the part of a witness. See, e.g., 1 G. JOSEPH & S. SALTZBURG, EVIDENCE IN AMERICA Section 42.3 (1987). Indeed, some jurisdictions have added language to their rules of evidence explicitly distinguishing between impeachment to show character for untruthfulness and impeachment to show bias or improper motive. See, e.g., Rule 609.1, Hawaii Rules of Evidence.

The distinction, simply restated, is between a propensity to lie and a reason to lie. The witness with a character for untruthfulness has a propensity to lie; the witness with a bias or improper motive has a reason to lie. By allowing the issue of untruthful character to be raised only in cross-examination, but allowing bias or improper motive to be shown by extrinsic evidence, Rule 608(b) reveals an hidden hypothesis. The hypothesis is that the truthseeking objective of a trial is threatened less by a propensity to lie than by a reason to lie.

This hypothesis is grounded in the conventional wisdom that a propensity to lie is a general trait; it may or may not be exhibited on a particular occasion or on a particular subject. In contrast, a reason to lie is specific; it may be triggered by the occasion and subject matter of the trial itself. Accordingly, it is thought to be a more direct threat to the truth-seeking process.

Such conventional wisdom is valid in the abstract; but it breaks down when a propensity to lie actually manifests itself in the courtroom. If a witness on cross-examination denies a prior bad act which indicated a character for untruthfulness, and if it can be shown that the denial is false, the witness's lack of credibility is confirmed. He has demonstrated his willingness to lie under oath during the trial itself. The triers of fact would have strong reason to doubt his testimony on any issue. Their skepticism would be no less abiding than if the impeaching party had presented facts from which a possible bias or improper motive might be inferred. Nevertheless, Rule 608(b) prevents the triers of fact from learning that the witness has testified falsely about a fact relating to his character for untruthfulness. Extrinsic evidence to contradict the false testimony may not be presented. The cross-examiner must accept the witness's answer.

The anomaly is obvious, yet the limitation persists. One reason, perhaps, is that a crafty lawyer may be able to impugn a witness's character on cross-examination, without resorting to extrinsic evidence. As a distinguished federal judge has noted:

[T]he very question itself can convey the theoretically barred information to the jury. A skillful but unscrupulous cross-examiner can, with a great flourish of impressive-looking papers, ask the witness about incidents in his life in such detail as to time and place as to render his denials completely suspect.
3 J. WEINSTEIN, WEINSTEIN'S EVIDENCE (1984), at 608-25 and 608-26. But if Rule 608(b) is intended, at least in part, to uphold the decorum of the court and to protect the dignity of witnesses, then Judge Weinstein's observation tells us that the rule is not working. It would be a strange logic that justifies a rule-imposed limitation on the ground that the rule can be circumvented anyway.

The other rationale for Rule 608(b) is judicial efficiency. The rule shortens a trial by avoiding a dispute over extrinsic facts relating to a witness's character for untruthfulness. Efficiency is a valid purpose. However, an absolute bar on extrinsic evidence accomplishes this purpose at a cost. It withholds from the triers of fact evidence that the witness has lied on cross-examination. Of course, this cost may be insignificant where the cross-examiner has succeeded in casting aspersions upon the witness by the use of thespian techniques. But in many cases the cross-examiner is neither so skillful nor so unscrupulous. In those cases the cost of an absolute rule is high.

Do we need the rigid restriction imposed by Rule 608(b) in order to achieve judicial efficiency? I think not. Elsewhere in the Idaho Rules of Evidence are provisions granting judges discretionary authority to prevent trials from becoming embroiled in collateral matters. Rule 403 authorizes a judge to exclude evidence, although relevant, "if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence." In addition, Rule 611(a) empowers the judge to "exercise reasonable control over the mode and order of interrogating witnesses and presenting evidence so as to (1) make the interrogation and presentation effective for the ascertainment of truth, (2) avoid needless consumption of time, and (3) protect witnesses from harassment or undue embarrassment."

Both of these rules authorize the judge to limit questions or presentations of evidence where the probative value is outweighed by other considerations. In my view, these rules are sufficient to serve the objective of judicial efficiency. There is no persuasive reason to add the narrow and absolute prohibition against extrinsic evidence of untruthful character now found in Rule 608(b). Although this prohibition has an historical lineage, and exists in the rules of many other jurisdictions, we should consider abolishing it in Idaho. It does not serve well the purposes ascribed to it, and it is not consistent with the flexible tenor of the Idaho Rules of Evidence, taken as a whole.


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