Is it possible to catch a liar in the courtroom?

As a result of the experience of training police officers, judges, and lawyers over the past five years, I came across one funny thought that I now use in my seminars: it looks like the entire criminal law system was invented by a person who clearly wanted to reveal fraud in the manner of the defendant’s behavior it was in no way impossible. The suspect is given the opportunity to prepare and rehearse his answers in advance, before judges or jurors evaluate their truthfulness, and this increases his self-confidence and reduces the fear of exposure. One is zero in favor of the suspect.
Interrogation and cross-examination are conducted months, or even years after the commission of the crime, when the emotions associated with this event have already turned pale. Two - zero in favor of the suspect.
In anticipation of the beginning of the trial, appointed also by no means immediately, the suspect has time to repeat his false story so many times that he himself can finally believe in it; and, giving testimony, he, in a sense, will no longer lie. Three - zero in favor of the suspect.
As a rule, a lawyer prepares his client for cross-examination, up to rehearsals, and the questions asked often allow for monosyllabic “yes” or “no” answers. Four - zero in favor of the suspect.
Now imagine an innocent defendant who is terribly afraid that they will not believe him at the trial. If the police, the prosecutor and the judge did not believe him when he applied for release before the trial, then why should the jury believe him? The signs of this fear can be interpreted incorrectly and taken for fear of a real criminal who is afraid of being caught. Five - zero in favor of this criminal.
While judges and jurors have little opportunity to rely on behavioral signs, this cannot be said about the person who conducts the first interrogation of the suspect. As a rule, it is a police officer or sometimes, in cases involving children, a social worker. The greatest chances to determine on the basis of behavioral signs that the suspect is lying are with them. The suspect has not yet had time to rehearse his answers and, most likely, he is either afraid to be caught or has a feeling of guilt for what he has done. Despite the best intentions of the police and social workers, they are often not prepared to ask unbiased and hateful questions. They were not taught to evaluate the behavioral signs of truthfulness and lies, and they are biased, because their profession requires them to make certain kinds of assumptions ^[247] .
They believe that almost all people are guilty of something and of course they lie, which is possible, and true for most of those whom they interrogate. When I first proposed my lie test to police officers, it turned out that many of them considered everyone they saw in the film to be liars. “No one ever tells the truth,” they told me. As for the jury, they, fortunately, are not constantly dealing with criminal suspects and therefore are not so inclined to assume that the suspect is necessarily guilty.