It pays not to try to understand the thinking behind the prosecution of Zacarias Moussaoui in Virginia. Thought renders unintelligible what the prosecution is up to in describing the luridities of 9/11 on Flight 93. The only explanation for what they are doing is that they are covert agents for the movie “United 93,” which is simultaneously going out from Hollywood.

Look. Nobody doubts that Moussaoui, a Frenchman of Moroccan heritage, was an agent of al-Qaida. No one questions that he was in the United States for nefarious purposes. It happened – miraculously – that the FBI actually picked him up before 9/11, so that on the fated day, he was in jail, removed from mandibular contact with people actually tortured, burned or propelled to suicide.

But the law holds him as an accessory. Moussaoui is far from furtive about his association with the bloody jihadists. It is persuasively argued that he might not in fact have served as the 20th man on one of the killer flights because he was too unreliable. Not as to motives – he is entirely outspoken about wishing all Americans dead, except presumably those who are sympathizers and have not been detected by the FBI. It seems to have been a question of technical unreliability, so that boss-man Mohamed Atta evidently decided to have him stay away from that day’s suicide planes, perhaps to study them on television, preparing himself for future active participation.

Again, bear in mind that Moussaoui has been found guilty in a formal judicial procedure of collusive involvement in an operation designed to kill U.S. civilians. That has been done. What goes on and on is the question of an appropriate penalty.

This beggars analysis. Why is it so important to the prosecution to go to such lengths to prove that Moussaoui deserves to be executed? Damage is done by this undertaking, because if the government fails, then the aroma of the trial will waft toward an ambiguity concerning the entire business. If Moussaoui “prevails” in the Virginia trial – if execution is not ordered by the jury – loose-minded analysts will arrive at the conclusion that he was finally not guilty of atrocious deeds, although he has admitted that he’d happily have been a member of the suicide team if he hadn’t been detained by the FBI.

And then adding to the confusion, the public is slowly alerted to the generic question of capital punishment. The practice survives in many states, as also in the federal system. But a long, hideously detailed trial designed to do just one thing – to raise the sentence from a lifetime in prison to capital punishment – has the effect of elevating the one remedy to a distinctiveness that believers in capital punishment reject.

If the public holds that execution is appropriate for a murderer, then the public should be spared a judicial flight plan that makes it all sound as though execution depended on the number of screams recorded from people killed by the hijackers. To put this trial in Virginia on a level with Nuremberg-style offensiveness risks mitigating the horror in which Moussaoui was involved.

What will happen is a rough plebiscite on capital punishment. If Moussaoui gets off, the abolitionists will argue that even such a man as would participate in such a crime as was committed on 9/11 should not be executed: because capital punishment is yesterday’s extreme and uncivilized retaliatory measure. If they didn’t execute Moussaoui, why should they execute me? One can hear this coming from the child murderer or serial killer.

When on Wednesday the judge admitted to be heard by the jury recorded sounds of airline pilots with throats slit, and sounds of desperate passengers fighting the terrorists to the death, what were the prosecutors up to? Nobody doubted that the events on Flight 93 had taken place.

What the prosecutors clearly wanted was more blood chill. They were addressing the jurors and saying: (a) you are dealing with a man already found guilty of committing the crime; (b) the law is such that you have the acknowledged right to send that man to his death; now (c) proceed to do so – listen to the screams, and harden your determination against Moussaoui! Presumably if torture were permitted, the prosecution would have pleaded with the jury to let in a little of that to avenge the 40 lives lost on Flight 93.