In People v. Trump witness Michael Cohen will take the stand as a prosecution witness next week. Any circus atmosphere of the previous weeks will be trumped–so to speak–by the show that wack-job Cohen will put on in both direct and cross-examination, all in the presence of his nemesis, defendant Donald Trump.

The facial expressions and body language of these two in the courtroom will test the adjectival talents of even the most gifted reporters.

Trump’s failings and oddities need no repetition here. But it’s time to air Cohen’s unique perfidy as a moral leper and to examine the effect that his testimony may or may not have on the outcome.

Cohen has depicted himself as a confessed criminal who acted in thrall to Trump in the devil-made-me-do-it excuse frequently adopted by crooks of his ilk to sanitize criminal intent. In this case, Cohen claims he has seen the light and now hates Trump. I don’t buy the former but I believe the latter.

The facts of Cohen’s crimes leave Trump out in most instances. While Cohen explains his pleas of guilty to lying to Congress and a federal grand jury as provoked by his Trump obsession, there is no Trump connection to his guilty pleas to tax evasion and bankruptcy fraud.

Cohen is uncontrollable. He is the whirling dervish of liars. His direct examination will detour into major excess.

What effect will all this have on the jury?

In summation, the district attorney will tell the jurors that the state would like to prove Trump’s alleged crimes through the testimony of nuns, rabbis and priests but those people do not participate in crimes. For example, testimony in a murder case may come from a murderer testifying for the prosecution. The real issue in this case, prosecutors will say, is not Cohen’s crimes but whether he is telling the truth now. And to buttress their point, prosecutors will suggest that the jury should reject testimony of Cohen unless corroborated.

Judge Merchan will give the “exclusio unis” charge, instructing the jury that if it finds that a witness lied in one instance, then all of his testimony may be rejected but it may accept the parts that it finds to be true.

Cohen’s behavior leading up to his trial appearance has been that of an uncontrollable nut. This behavior came to a head when he appeared in a Tik Tok interview wearing a shirt depicting Trump behind bars.

The prosecution needs Cohen to prove that Trump created or caused the creation of the false records as charged in the indictment. While previous witnesses have testified that Trump generally had a firm grasp of back-up documentation of the checks he signed, there has been no direct testimony on relevant records here.

The defense cross-examination will vigorously undermine Cohen’s veracity, as well it should. But I have not been impressed with its previous cross-examinations, especially of Stormy Daniels. On the other hand, Cohen is incapable of the dry wit demonstrated by Ms. Daniels on her cross.

Finally, the state must prove its case beyond a reasonable doubt. The judge will tell the jury that the words define themselves: a doubt for which you can give a reason. Perhaps Cohen will prove to be a baron of reasonable doubt because the jury’s reason for doubt may be that Cohen is a liar. On the other hand, most criminal cases rest upon testimony of co-conspirator liars who are believed by juries because corroborated. My hunch is that Cohen will be believed.