ARE YOU STILL following the psychiatric testimony at the Hinckley trial? Is anyone, save lawyers, psychiatrists and the principals at the trial still reading accounts of these medical opinions? At the outset, it was fascinating and even seemed relevant to know of John's adolescent problems, his moods and his dreams. But now, after seven weeks of listening to psychiatrists who offer widely divergent opinions on the mental health of the defendant, public interest has begun to flag. Many of us had dropped out around the time one doctor testified that John's parents encouraged infantile dependence by signing a birthday card "Moo, Poo and Tigger the Cat." Others stayed right through the accounts of the Jodie Foster fantasies. But by now almost everyone has begun to sympathize with the jury.

All this expert testimony does not come cheap. It is estimated that fees for expert witnesses already total between $350,000 and $450,000, not counting salaries paid to psychiatrists who are government employees. Add this to the defendant's legal fees-- which could total $1 million--and the government cost of paying prosecutors and court personnel, and providing elaborate courtroom security, and it is easy to see why the Hinckley trial has been called the longest, most expensive and most elaborate trial in the modern history of the insanity defense.

Is all this testimony really relevant to the guilt or innocence of John Hinckley? Of course it is, and it doesn't matter one whit if the rest of us are bored. The defendant's state of mind, his intention, or lack thereof, to do harm, is of vital interest to the jury. For if, at the time of the shooting, he lacked the capacity to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of the law, an essential element of the crime is missing. As Harvard law professor Alan Dershowitz has written on the obvious importance of the insanity defense, ". . . it's unthinkable to eliminate it. Would anyone seriously think of convicting someone for murder who thought he was shooting a robot or squeezing a melon?" It is just as important for John Hinckley to present all possible evidence on this aspect of the crime as it would be for him to present an alibi defense. What is unique in this case is the wealth of the defendant's family, which enables it to provide extensive expert testimony in his behalf, something that any of us probably would do for a child if we had the means.

Does the simple volume of the expert testimony on insanity make acquittal in this case more likely? Not necessarily. Insanity defenses attract public attention because they are usually raised in especially bizarre or notorious cases, but the fact is that they are seldom successful. Insanity acquittals by juries are even more rare, for expert witnesses cannot advise the jury to convict or acquit. In the end, it is 12 ordinary citizens, sitting behind closed doors, who will sift the evidence and make a moral judgment on behalf of society. Miraculously, they are very seldom wrong.