Should Juries Be in the Dark?

I magine that a jury acquits a defendant of murder, believing that his wife committed suicide in the bathtub. After the trial is over, the jurors find out the defendant has a prior homicide conviction: He drowned his first wife. How would you feel if you had been a juror in such a case? Or imagine if it was a rape case, and you found out only after the acquittal that the defendant had a prior conviction for rape and had used the same defense.

You’d feel frustrated, and perhaps you’d feel that justice hadn’t been done. But ultimately, you’d be powerless. It’s a long-standing, centuries-old part of British evidentiary law that prior convictions are not admissible as evidence to show that the defendant is more likely to have committed the current crime. We’ve inherited that law here in the United States and, since the founding of the country, have preserved it.

But now, in a dramatic break with tradition, the law in Britain is changing. In just a few weeks, British juries will be allowed, for the first time, to hear about some prior convictions. Initially, prosecutors will be allowed to tell juries about defendants’ prior convictions only in cases involving theft and sex crimes against children, but the government is considering extending the rule to all felonies.

The struggle over the change in Britain has been fierce. The old rule excluded so-called bad-character evidence, including past convictions. Proponents of the old rule argued that juries were more likely to wrongly convict if they were confronted with evidence of prior misconduct. Jurors tend to overvalue such evidence, the argument goes, and in some cases are so outraged by it that they convict the defendant in the new case, even in the absence of sufficient proof.

Proponents of the new rule believe that denying the jury access to crucial evidence can lead to unwarranted acquittals. How, they want to know, can it not be relevant in a rape case that the defendant has been convicted of rape before?

The British Home Office -- the arm of government in charge of criminal justice -- has characterized the rule change as a way to simplify the system, to make the jury trial a quest for the truth and to “put victims at the heart of the justice system.”

The first step toward implementation will be in mid-December, when there will be a “strong presumption” that previous convictions for theft or sex crimes against children can be admitted at trial. A judge may exclude such evidence only if it is not relevant to “an important matter in issue,” or in cases where its prejudice outweighs its value in proving the offense. The judge determines whether juries will hear of any prior convictions.

Some British judges and lawyers do not expect the rule change to result in more convictions; others are less sanguine.

Whether the government will achieve any of its goals remains an open question. Because of the discretionary nature of the rule, case law will develop around it, possibly making it just as complicated as the existing rule.

And juries may or may not be helped by the introduction of prior-act evidence in finding the truth. At least, they should no longer feel betrayed when finding out about a defendant’s prior convictions after acquitting him.

In the United States, evidence of the defendant’s prior bad behavior and his prior convictions are not admissible at trial if their purpose is to show that the defendant is more likely to have committed the crime. The jury may hear about them, however, if they are used for other purposes, such as to explain the motive of an offender.

Despite the long pedigree of this tradition, Congress enacted one exception: sex crimes. The prosecution may introduce evidence of prior acts of similar sexual misconduct, unless there is a judicial decision that the prejudice that would be caused substantially outweighs the probity of the evidence. Despite substantial criticism, this rule has survived.

Usually U.S. jurisdictions are reluctant to borrow foreign ideas. This idea, however, may appeal to victims-rights activists, as it did in Britain. Such a rule change here would probably breed convictions not based on proof of guilt of the crime charged but rather on the jury’s revulsion over the defendant’s past conduct or unproven assumptions of recidivism.

The maxim “innocent until proven guilty” should remain the guiding principle of the criminal justice systems on both sides of the Atlantic. Evidentiary rules, while intricate and often frustrating, may be time-honored for a reason -- and we should not discard them casually.