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The Costs of Testifying in One's Own Defense: An Empirical Study Highlights the Problem, But What To Do About It?


Wednesday, Jan. 07, 2009

This year in the Cornell Law Review, Professors Theodore Eisenberg and Valerie Hans will be publishing an illuminating and important article (available in draft form here) demonstrating the impact of introducing prior convictions against a criminal defendant. Their findings show, among other things, that when revealed to a jury, a defendant's record of prior convictions can, in marginal cases, significantly increase the odds of a guilty verdict.

This finding will confirm the suspicions of many defense attorneys and evidence scholars, but the next question is what the proper reaction ought to be. This column explores some possibilities, including the radical option of disqualifying all criminal defendants from taking the stand.

The "Propensity" Rules that Govern Prior Convictions

In the Federal Rules of Evidence, as well as virtually every state's evidence law, there is a more-or-less general prohibition against the introduction of evidence to support a "propensity" inference. Such evidence offers a picture of a person's alleged character trait, presented in support of the proposition that the person is likely to have behaved in a manner consistent with that character trait on a particular occasion.

An example would be the following: proof that a criminal defendant, accused of embezzling funds, has shown herself to be greedy and thieving in the past, perhaps by committing embezzlement or other similar crimes on prior occasions. Though this information might be somewhat relevant to the question of guilt or innocence, the law of evidence normally prohibits its introduction, for at least two reasons:

First, we believe that information about a person's character is much less valuable than it seems– that is, just because someone has previously acted greedily, dishonestly, or otherwise, does not tell us very much about the odds that she committed a particular alleged act. Yet, despite its limited relevance, this sort of history could nonetheless "feel" very damning (especially in a courtroom where all of the other greedy, dishonest people who might have committed the crime in question are absent).

Second, we worry about juries being less vigilant about avoiding the conviction of a possibly-innocent person if their members come to view that person as a bad or undeserving character.

As a result, if you are prosecuting Mr. Defendant for robbery, you are barred from introducing Mr. Defendant's earlier robbery conviction(s) to show that he is "a robber" who is, therefore, more likely to have committed the robbery with which he is charged than some other person without the same history.

Prior Convictions and Credibility

Though prior convictions (and other evidence of character, offered to prove behavior in keeping with that character) are generally inadmissible, they are not invariably so. One situation in which the law explicitly permits a propensity inference (along with the evidence to support it) is the case of witnesses. When a witness testifies, the jury must decide how much credence to give her testimony. To assess the witness's credibility, the jury may consider her motives to shade the truth, her potential weaknesses in observing and remembering facts to which she is testifying, other evidence that contradicts her testimony, and – most importantly, for our purposes – proof of her character for telling the truth (which is a polite way of saying evidence that the witness is – or is not – a liar). One form of "bad character for truth-telling" evidence is a record of prior criminal convictions. The allowable inference is that a person who commits a criminal act is less likely to take seriously her commitment and legal obligation to tell the truth under oath.

When a criminal defendant is deciding whether or not to take the stand in her own defense, the combination of these two rules becomes extremely significant. If the defendant who has a criminal record does not testify, then the evidence rules will likely bar her record from coming in at trial. Indeed, Eisenberg and Hans found in their analysis that when a defendant with a prior record refrained from testifying, the jury was extremely unlikely to learn of that record. Conversely, when the defendant chose to testify, his record was much more likely to emerge at trial.

In addition, Eisenberg and Hans found that having a criminal history operates as a significant factor in determining whether or not a defendant decides to take the witness stand at his own trial. And, they determined, in cases that were neither extremely strong nor extremely weak (by the jurors' own rating of the weight of the evidence), a jury's knowledge of the defendant's prior criminal record significantly increased the chances of conviction.

Interestingly, Eisenberg and Hans observed that the jury's knowledge of the prior record did not affect its assessment of the criminal defendant's credibility as a witness. This is an important observation because, as noted above, it is the supposed relevance of prior convictions to the defendant's credibility that provides the legal rationale for permitting the introduction of prior convictions against a testifying criminal defendant, while suppressing the same convictions against a nontestifying criminal defendant.

If, in other words, juries do not in fact consider prior convictions a reflection on a defendant's credibility as a witness, when the convictions have been admitted exclusively for that purpose, then the criminal record apparently plays no legitimate role in the trials at which it is offered. It instead serves, as Eisenberg and Hans conclude, only to lower the jury's threshold for conviction and thus to reduce the burden of proof on the prosecution from "beyond a reasonable doubt" to something less demanding. This diminished burden, in turn, may contribute to the conviction of innocent defendants.

A First Potential Reaction to Eisenberg's and Hans's Conclusions: Never Admit Prior Convictions

One potential reaction to this data would be to adopt a rule that a criminal defendant's prior convictions may not be admitted into evidence, regardless of whether or not he takes the witness stand in his own defense. Defendants and their attorneys would favor this option for liberating the defendant to decide whether or not to take the witness stand on the basis of factors truly relevant to the particular case, not to past history – and unburdened by fear of the revelation of a prior record.

The difficulty with attempts categorically to suppress all of a defendant's prior convictions is that at least some situations make a criminal record appear highly relevant. For example, suppose a defendant were to claim, in testifying, that he had never before had anything to do with a criminal endeavor, or that he does not even know how to fire a gun. The existence of a prior conviction could effectively rebut his claims. A guarantee of absolute suppression of prior convictions could thus free a defendant not only to take the stand, but also to lie with impunity in the service of portraying himself as wrongly-accused.

To the extent that prior bad acts are admissible for some purposes, however, they will evidently sway the jury to lower the standard of proof that the prosecutor must meet, regardless of how the judge instructs the jury. Furthermore, a judge will have the discretion to decide when such evidence has become necessary to rebut misstatements by the defendant. Accordingly, the defendant who testifies will continue to take a risk – albeit a reduced risk – of exposing his prior record.

A Second Potential Reaction to Eisenberg's and Hans's Conclusions: Always Admit Prior Convictions

Another possible reaction to the data would be to admit a criminal defendant's prior convictions regardless of whether or not the defendant testifies. This approach alters the incentives by making the defendant's decision to take the stand irrelevant to whether prior convictions make their way into the case. By assuring the admissibility of a prior record, in other words, a more permissive rule might liberate defendants to testify without fear of increasing their odds of conviction.

One major problem with taking this route, however, is that there is a (sometimes- forgotten) third option for a defendant in addition to taking the stand and not taking the stand, an option that an overwhelming majority of criminal defendants ultimately select – pleading guilty in exchange for "leniency." If the decision to go to trial – whether as a testifying or as a non-testifying defendant – entails the revelation of prior convictions (and the expected loosening of the prosecutor's burden of proof), then the defendant who previously would have refrained from taking the stand might instead refrain from exposing himself to a trial at all.

In this way, the presumptive admissibility of prior convictions may provide further reason for a defendant to accept an otherwise unattractive offer to waive his right to a trial, even if he is innocent, and accept punishment without any adjudication.

A Third Potential Reaction to Eisenberg's and Hans's Conclusions: Bar All Defendants From Testifying on Their Own Behalf

There is a third approach to the problem of prior convictions, though it is radical and appears to turn the clock back on defendants' rights. This "third way" is to disqualify criminal defendants from testifying in their own cases.

The "incompetency" of criminal defendants to testify at their own trials was part of the common law of England and then the United States until the Nineteenth Century, during which incompetency gave way to the notion that the basis for disqualification – the defendant's "interest" in the outcome of the trial – could instead form the basis for witness impeachment following testimony. Like other interested witnesses who had once been disqualified from testifying (including all parties to a civil case), the criminal defendant was thus allowed (and, in time, guaranteed) the option of testifying on his own behalf, with the caveat that the government could respond to his testimony by attacking the credibility of the defendant witness.

The right to testify is a mixed blessing, however. With the right comes an expectation on the part of the jury that it will hear from the defendant. Despite the defendant's right not to take the stand (and the judge's available instruction telling the jury not to draw negative inferences against the defendant for the exercise of this right), jurors nonetheless know that a defendant could testify if she wanted to, and this knowledge inevitably makes the jury wonder why the defendant has chosen not to take the stand.

In this way, the "option" to testify may rightly be experienced by many defendants as pressure to testify. This pressure, in turn, puts the defendant with a criminal record in the following bind: either refrain from testifying and leave the jury wondering why it has not heard from him (perhaps concluding that he must be guilty or that he has a prior criminal history that he wishes to conceal), or take the stand and risk the harmful impact of his prior record on the jury.

If the defendant were instead to be disqualified as a witness, the jury would not wonder why he is not testifying (it would know that defendants never testify because of the disqualification), and the jury would also have little reason to learn of his prior criminal history. In the Georgia approach (struck down by the U.S. Supreme Court in Ferguson v. Georgia, decided in 1961), for example, a defendant had a statutory right to give an unsworn statement to the jury not subject to challenge by cross-examination (because it was not provided under oath). The statement would allow the defendant to provide a narrative to the jury to explain what happened without having to put his credibility in issue.

Many will protest that a defendant must be able to tell his story on the same footing as the other witnesses – under oath, subject to cross-examination, and in other respects comparable to all the evidence before the jury. As the Court said in Ferguson, does it not deprive a defendant of the Due Process of law to disqualify him from testifying? Perhaps, but consider one implication of Eisenberg's and Hans's analysis: Recall their finding that jurors did not perceive testifying defendants whose criminal records were disclosed to them to be less credible as witnesses than defendants whose records were suppressed.

One conclusion we could draw from this is that defendants are already so low in credibility (because of their powerful interest in the outcome of the case) that a bad "character for truth-telling" seems not to register with juries. Given their low credibility, it may well be that defendants derive little actual benefit from testifying to their innocence, at least in a world in which jurors are not wondering why a non-testifying defendant who could take the stand has chosen not to do so.

I must admit that I am uncomfortable with the prospect of silencing criminal defendants who wish to testify (or, alternatively, of allowing them to offer only sub-testimonial unsworn statements that differ substantially from the form of testimony by other witnesses). It is also true that defendants with no criminal record may have little to gain from disqualification, and may therefore be sacrificing their interests in order to protect those of defendants with a prior record – a sacrifice that seems inimical to the individual-rights orientation of criminal trials.

Nonetheless, it may be time to consider something drastic like disqualification. We know that the current approach to defendant testimony is deeply flawed – defendants with prior records testify and risk substantially increasing their odds of conviction, or refrain from testifying and risk alienating the jury, which is left to wonder why anyone falsely accused would voluntarily remain silent. If it turns out – as it appears – that defendants' testifying does little to help them, then it may be in their best interests to be compelled to remain silent at their own trials.

Sherry F. Colb is Professor of Law and Charles Evans Hughes Scholar at Cornell Law School. Her book, When Sex Counts: Making Babies and Making Law, is currently available on Amazon.

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