Stop the case?

LISTENING carefully as the defendant's lawyer cross-examined the government's key witness, the judge became more and more uneasy. One indictment charged three counts of rape; a second alleged an attempt at unnatural intercourse. The direct testimony had been graphic, explicit, and reasonably convincing. With cross-examination, however, the picture altered dramatically. That in itself was not remarkable. Often a witness who paints a vivid picture in response to friendly interrogation by the district attorney crumbles like lump sugar in hot tea when the defense counsel begins putting the questions to him or her.

Nor was the problem the defense lawyer's fault. This was not an unfair type of cross-examination. He was courteous, his inquiry plain and appropriate. Indeed, almost all the questions rested on two letters whose authorship the witness freely admitted. And that was the reason for the judge's disquiet. These were not private communications. They were open letters, almost manifestoes, one of them to the district attorney himself.

Even with the text on the desk before him, the judge found them impossible to follow. Larded with references to ``satanic practices, sexual and otherwise,'' they asserted a massive plot involving the Pope, President Reagan, the United Nations, psychic investigation, a thousand-foot pit, and a series of private individuals said to be practicing witchcraft at the expense of the witness.

The defense counsel went on, asking what this line meant, or the nature of that event. The witness did not protest or resist. With unnerving calm, she insisted that each allegation was true, the result of a person (whom she named) having been able to ``get into my head.''

Unable to take meaningful notes, the judge listened with what he hoped was a faade of judicial impassivity. Watching the courtroom, however, he could see that others were not so successful. It had become plain that the woman's difficulty distinguishing reality from fantasy infected all her testimony with reasonable doubt.

At the next recess, the judge called both lawyers to the bench. ``Does the government intend to press these indictments?'' he asked the prosecutor. ``Let me talk to my witness,'' the assistant district attorney replied.

In a few minutes he returned. ``She insists on going forward,'' he said, ``so the government has no choice.''

The judge wondered. It is true that with respect to any crime, particularly a violent crime, the victim's lack of mental capacity is no defense; sometimes, in fact, it aggravates the offense.

Here, though, the problem was not the victim's mental state at the time of the crime. Rather, it was the mental state of the ``complaining witness'' -- as she is more properly referred to at the time of trial. Unless the complainant convinces the fact finder beyond a reasonable doubt, the complainant is not properly called a victim until or unless the defendant is proven guilty.

This witness was, the government admitted, suffering severe delusions. But was her account of the rape sufficiently laden with reasonable doubt to preclude conviction? Perhaps the judge thought so. Maybe others in the courtroom did, too, possibly even the prosector. But the witness wanted to go on.

Is the prosecutor obliged to stop pressing a case in which he no longer believes? When a case first comes to him he has the absolute right to exercise ``prosecutorial discretion'' and to decline going forward. Once it starts, though, must he defer to the complainant's wishes?

That is the safe thing to do, especially in politically sensitive crimes like rape and child abuse. If the woman or (in a child's case) the parents or the police want the trial to go forward, it is much easier for an elected prosecutor to put his case on and let the fact finder decide. If the verdict is not guilty, he can honestly say that the result was not his fault. If the implausible evidence produces a conviction and the trial judge or the appellate court wants to correct a ``miscarriage of justice,'' let the bench, not the district attorney, answer to the public.

It takes determination and judgment to pursue those who deserve conviction. It takes moral courage to abandon a prosecution that has gone sour. Not for nothing did Felix Frankfurter once equate prosecutors with priests.

Hiller B. Zobel sits on the Massachusetts Superior Court.