Immediately afterwards the judge went through the last formalities and called upon the prosecution. It was nine-forty.

Cervellati got to his feet, pressing down on the table and shoving back his chair. He adjusted his robe, glanced at his notes, then raised his head and addressed the judge.

“Your Honour, ladies and gentlemen of the jury, today you are called to give judgement on a very horrible crime. A young life, a very young life, brutally cut off, as the result of an act so iniquitous that we are unable to grasp the motive or the measure of it. The consequences of this iniquity are tragically irremediable. No one can restore this child to the love of his parents. I cannot, you cannot, no one can.

“You, however, have a great power, an all-important power, of which I hope you will make good use. Of which I am sure you will make good use.”

I thought: now he is going to say they have the power, and also the duty, to see justice done. To see to it that the author of such a heinous crime does not get away with it, due perhaps to some cavil or quibble.

“You have the power to see justice done. And this is a power of great moment, because it brings with it the duty of doing justice. In the first place to the family of the little victim. But thereafter to all of us who, as citizens, expect a response when such abominable things occur.”

It was one of his favourite dictums in the Court of Assizes. I think he was convinced that it impressed the jury. Anyway, he continued in this vein and after a little my attention began to stray.

I heard his voice like a background noise. Every so often I followed his drift for a minute or two and then my thoughts went rambling off again.

He spoke of what had taken place in the course of the trial, in a monotonous drone read long chunks of the records and explained exactly why the evidence advanced by the prosecution was totally convincing, bar nothing.

One of the most tedious closing speeches I had ever heard, I thought, as I leafed through my file just for something to do.

But at a certain point he came to speak of the evidence of the bar owner, the heart of the whole trial.

He re-read Renna’s statements – but not his answers to my questions – and commented on them. I forced myself to listen carefully.

“So we must ask ourselves, you must ask yourselves: what reason did the witness Renna have for bringing false accusations against the defendant? Because the question, in fact, is very simple and the alternative is clear. One hypothesis is that the witness Renna is lying, thereby paving the way for an innocent man to be sentenced to life imprisonment. Because he is well aware of the consequences of his testimony, but nevertheless persists in it, despite the difficulties we saw in the course of his cross-examination. If he is lying, thus accusing an innocent man of a crime punishable by life imprisonment, he must have a reason. Indeed, a ferocious and ignoble personal antagonism, because only hatred of such a kind could explain so aberrant an action.

“Is there any proof, or even the suspicion, of such destructive hatred on the part of Renna with regard to the defendant? Naturally not.

“The other hypothesis is that the witness is telling the truth. And if there is nothing to tell us that the witness is lying, we have to recognize the fact that – in spite of approximations, errors, understandable moments of confusion – he is telling the truth.

“The effect on the outcome of the present trial is obvious. For do not forget that the accused denies being at Monopoli, at Capitolo, that afternoon. And if he denies it when in fact he was present in those localities – and we can assert it with complete confidence because we are told it by a witness who has no cause to lie – then the explanation is one and one only and, unhappily, is there for all to see.”

I made a note of this concept too, because it had a sense to it that had to be confuted explicitly.

Cervellati continued, following the proceedings in chronological order, and finally came to discuss the mobile-phone records.

He said what I expected him to say. The verification requested by the defence had not only failed to prove the innocence of the defendant, but, on the contrary, provided further material in favour of the prosecution.

Because that gap of four or so hours with no telephone calls, during which the instrument was probably switched off, was an item of circumstantial evidence worth exploiting. And Cervellati exploited it. There was a degree of verisimilitude – a high degree, he said – in the hypothesis that the defendant, having returned to Bari from Naples, had gone on to Capitolo, having already formed a plan of action. Or perhaps in the grip of a “raptus”, or brainstorm. It was probable that he had switched off his mobile phone so as not to be disturbed during the heinous deed. And this, better than any other hypothesis, explained the absence of calls between five and nine o’clock that evening.

I took notes on this part of the speech as well. It was an insidious argument and might well influence the jury.

There followed a hypothetical reconstruction of how Abdou might have put his plan into effect, basely and craftily exploiting the little boy’s trust in him.

What had occurred after the kidnapping could be easily imagined. The child, realizing what was happening, had tried to resist the attempted violence. Maybe he had tried to escape, and this had sparked off the lethal reaction of the accused. It is probable that no signs of sexual abuse had been found because the situation had got out of hand before such abuse – which was certainly the defendant’s object – had taken place.

In conclusion the public prosecutor explained why the only adequate punishment for such a crime was life imprisonment. It was the most convincing part of his whole speech, because life imprisonment was in fact the just penalty for the perpetrator of such a crime.

While this thought was in my mind Cervellati went through the ritual request for a verdict of guilty.

“For the reasons previously stated, therefore, I ask you to affirm the criminal responsibility of the defendant for all the offences of which he stands accused and therefore to sentence him to imprisonment for life with isolation by day for a period of six months, together with the application of the additional penalty of perpetual debarment from holding public office.”

I took a deep breath, glanced at my watch and realized that almost two hours had passed.

The judge said there would be a short break before counsel for the civil party was called. Subsequently there would be an hour for lunch, and when the hearing resumed I would have the floor. Following any further discussions, the court would retire to consider the verdict.

The courtroom emptied out and I too got up to go and have a smoke. Only Cotugno remained behind, putting the finishing touches to his speech.

Outside, a woman journalist I had never seen before asked me what I thought of the prosecution’s request for a sentence of guilty.

What I thought of that was that rarely had I heard such an idiotic question. I was sorely tempted to give expression to this opinion, but of course I didn’t. I said nothing, just shrugged my shoulders, shook my head and spread my hands slightly, palms uppermost. I went off, fishing out my cigarettes while the girl stared after me a bit nonplussed.

I felt fairly calm. I had no wish to look through my notes. I had no wish to do anything further until the moment came for me to speak. In any case, I didn’t feel I needed to.

This was a new sensation for me. I had always arrived breathless at important appointments, in my studies, my work or anything else. I had always left things until the last moment, the last night, the last revision; and afterwards I had always had the feeling of having stolen something and got away with it. I had managed to cheat the world yet again. Yet again they hadn’t managed to catch me out, but within myself I knew I was an impostor. Sooner or later someone would find me out. Sure to.

That morning I felt good. I knew I had done everything in my power. I was afraid, but it was a healthy fear, not the fear of being caught out, of everyone realizing I was a fake. I was afraid of losing the case, afraid that Abdou might be convicted, but not afraid of losing my dignity. I didn’t feel I was an impostor.

In the lunch hour I went up to the sixth floor, to the Bar Council. I needed to consult a dictionary to check on an idea that had come to me while Cervellati was speaking. I found the sole employee locking everything up and on the point of leaving, but I managed to persuade her that it was an emergency. She let me into the library, where I quickly looked up what I wanted and made a few notes. Then I thanked her and left.

I would have liked at that point to take a short stroll, but the heat out of doors was intolerable. So I went to the bar, ordered a smoothie and a croissant, sat at a table and whiled the time away.

When the moment came I returned to the courtroom, took off my jacket and put on my robe. Almost simultaneously the bell rang, the door opened and in filed the court. I remained standing as I watched them, arms folded, weight on my left leg. They all seated themselves and so did I. Silence reigned.

“I call on the defence,” said the judge curtly.

I was just getting to my feet when I noticed some of the court looking at a spot immediately behind me. I felt a gentle squeeze on my left arm, just above the elbow. I turned and saw Margherita. She was slightly out of breath, and there were beads of sweat on her upper lip. She flashed a smile at me, and sat down on my right without a word.

I made a brief pause before beginning.

“Your Honour, ladies and gentlemen of the jury, as the public prosecutor has already said, this trial is concerned with the most horrible and unnatural of crimes. The violent death of a child, with its aftermath of immeasurable, incomprehensible sorrow for the parents of that child.

“If our defence has in some way unintentionally been lacking in respect for that sorrow, I ask for their pardon.”

The judge looked at me without fondness. He thought that starting that way was just an expedient to curry favour with the jury. I was so sure he thought it that I felt compelled to tell him I knew, and that I didn’t care a hoot.

“It may be thought that this is just a rather shabby way of gaining the sympathy of the court. Or at least of the jury. It would not be absurd to think this, because we lawyers often get up to such tricks. And anyway, everyone is free to think of it as he pleases. Not least because criminal cases are not debated and decided on the basis of the charm of the defence counsel or the prosecutor. Thank goodness. Cases are decided – if I may state the obvious – on the basis of positive proofs. If they are present, the verdict is guilty. If they are lacking – or even if they are merely insufficient or contradictory – the verdict is not guilty.

“We therefore have to ask ourselves on the basis of what criteria we can affirm that the evidence in a case is sufficient, enabling us to convict the defendant, or else insufficient or contradictory, in which event we must acquit him.

“In our consideration of these matters we may confidently start from the manner in which the public prosecutor proposed them.

“The public prosecutor – and I made an exact note of his statement – said: ‘There is a high degree of verisimilitude in the hypothesis that the defendant arrived in Bari from Naples, went on to Monopoli, having already worked out his criminal design in detail, or in the grip of a raptus, or brainstorm, reached Capitolo, probably switched off his mobile so as not to be disturbed, seized the child’ etc. From this ‘high degree of verisimilitude’ the public prosecutor deduces an important, if not indeed decisive, item of evidence – in order to maintain the defendant’s guilt and to ask you to sentence him to prison for life.

“Therefore, to verify how well founded and reliable is the line of argument adopted by the prosecution, we have to ascertain the meaning of the word ‘verisimilitude’.”

I paused, picked up the sheet on which I had earlier made a note in the library, and read: “Verisimilitude, we read in the most authoritative dictionary, is ‘the appearance of being true or real ... the likeness or resemblance to truth, reality or fact’.

“And under the heading ‘truth’ we read this definition: ‘conformity to fact; agreement with reality’. And under the heading ‘appearance’: ‘apparent form or look, especially as distinguished from reality’. We also find an explanation of the phrase ‘It looks real’ as being used of something artificial that imitates reality to perfection. What looks real is therefore something artificial, something which imitates reality.

“Do you remember the definition of ‘verisimilitude’? The word used by the public prosecutor? It refers to something that looks true or real, that imitates reality but does not correspond to it. Something, in short, to be distinguished from reality. By using this term the prosecutor implicitly and unconsciously admits that he cannot use the words ‘true’ or ‘real’. You see clearly how in the very words of the speech for the prosecution there lurk its irredeemable shortcomings.”

At this point, as I expected, Cervellati lost his cool and protested to the judge. It was unacceptable that the defence should be permitted to pour scorn on the function of the public prosecutor with cheap sophistical arguments. The judge did not appreciate the interruption and reminded the public prosecutor that the defence could say what it liked, short of personal abuse. Cervellati attempted to add something, but the judge told him, brusquely this time, that he could make his comments on my speech – if he so wished – when the time came for his response. That was that, he said, and he would tolerate no more interruptions. He turned to me and invited me to proceed. I thanked him, carefully avoided making any reference to the interruption, and went ahead.

“What we have said briefly about the meaning of these key words – truth, reality, the appearance of reality – therefore offers us an interesting approach to interpreting the arguments used by the public prosecutor and the psychological premises underlying those arguments.

“A trial, however, is not based on a psychological interpretation of what the public prosecutor says. Neither, in order to verify whether his reasoning is right or wrong, is it based on an analysis of what the public prosecutor has said. Because the public prosecutor might have followed a wrong line of reasoning and arrived nonetheless at correct conclusions. That is, it might be right to pronounce a sentence of guilty. In spite of the public prosecutor’s mistaken reasoning and on the basis of a different, more correct line of argument.”

Cervellati got to his feet, dumped his robe on his chair and ostentatiously left the room. I showed no sign of noticing.

“It is therefore not enough to single out the defects in the prosecution’s argument. We have to ascertain whether the evidence assembled does or does not enable us to formulate a judgement corresponding to the truth. We do not wish to shirk this task. But before we tackle it I wish to repeat one concept.

“It is a concept which I would like you to bear in mind throughout these proceedings and, above all, when you are in camera. To bring in a verdict of guilty it is not enough to say that a certain version of the facts, a certain hypothetical reconstruction of the facts, is likely, or even very probable. You must be able to say that this reconstruction is the truth. If you can do that, then it is right for you to send the defendant to prison. For life.

“The hypothesis put forward by the prosecution in this trial runs as follows: on 5 August 1999 Abdou Thiam unlawfully restrained Francesco Rubino, a minor, subsequently causing his death by suffocation.

“Can we assert, on the basis of the evidence provided, that this hypothesis is true? That is, can we assert that this is a correct description of how events happened in fact and truth, and not just a mere conjecture as to how they might have occurred?”

I paused as if I had lost my thread, glanced down and passed the first two fingers of my right hand across my brow. After a moment or two I looked up towards the bench, still without speaking. There was dead silence. Everyone was looking at me, expectant.

“Let us examine this evidence together. And in particular let us examine the statements of the witness Renna, proprietor of the Bar Maracaibo. To avoid any misunderstandings, I would like to say at once that I agree with the public prosecutor in saying that this witness is telling the truth. Or to be more precise, this witness is not telling lies.”

Another short pause to give them time to wonder what I was aiming at.

“Because a lie is an assertion made in the awareness that it is contrary to the truth, and I am convinced that Signor Renna did not make assertions in the awareness that they were contrary to the truth. In saying that he saw Abdou Thiam pass his bar on just that afternoon, at just that time, Signor Renna thinks he is telling the truth. And in fact he would have no reason to bring false accusations against the defendant.

“To be sure, it emerged from his examination that he has, to put it mildly, no particular liking for the non-European citizens who gravitate towards the area of Capitolo and the vicinity of his bar.

“I want to read you a brief passage from that cross-examination. We are speaking of the non-European citizens whom Signor Renna calls ‘niggers’. Counsel for the defence asks whether these persons interfere with Renna’s custom.

“The witness replies, ‘They interfere, they interfere, and how!’

“ ‘Forgive me for asking, but if they are a nuisance, why don’t you call the municipal police, or the carabinieri?’

“ ‘Why don’t I call them? I call them all right, but d’you think they come?’

“In short, Signor Renna – he tells us so himself – does not like the presence of the non-European citizens at Capitolo and in the vicinity of his bar. He would like the strong arm of the law to intervene and move them on, but this doesn’t happen. He is somewhat incensed.

“All this, be it clear, does not mean that he has deliberately told us untruths about Signor Abdou Thiam.

“But setting aside his liking for – or dislike of – ‘niggers’, and his unsatisfied demand for the strong arm of the law to act in some way against these ‘niggers’, has Signor Renna told us the objective truth? Can we affirm beyond any reasonable doubt that the version provided by this witness corresponds to the truth of the actual facts with which we are concerned?

“One element of doubt may be inferred from the little experiment with the photographs, which you will remember. Renna failed to recognize the defendant in a photograph, in fact in two photographs, which you have in the records and can verify for yourselves as to their likeness to the defendant. The very man who is here in court and, above all, the person whom the witness declares he knows well and whom he saw pass his bar that August afternoon.

“Does this mean that Renna invented the lot, that he is telling lies? Certainly not. The fact that he doesn’t like ‘niggers’ and that he sensationally failed the photographic test does not mean that he knowingly lied.

“When he says he remembers that that afternoon Abdou Thiam passed his bar, without his usual bag, walking quickly in a southerly direction, the witness Renna is telling the truth.

“In the sense that he does in fact remember this sequence of events and fixes it on that afternoon. To be more precise, he tells us what he believes to be the truth. The really interesting thing – and this introduces us to the fascinating subject of how the memory functions – is that Renna believes that that is the truth, because he remembers those events, even if they never happened. Not in the terms of his account.”

Pause. I needed these notions to settle in the minds of the court, and especially of the jury. I made a pretence of rummaging in my notes until about ten seconds had passed. Just time for them to wonder what was coming next.

“Now I want to tell you about a scientific experiment into the functioning of the memory and the mechanism by which memories are produced. A team of American psychologists, at Harvard University I believe, set out to test the reliability of childhood memories. A number of children of nine or ten years old were told a story by their elder brothers or sisters, who were instructed in what to say. The story was that at the age of four or five they had escaped an attempted kidnapping. They were told that they had been in a supermarket with their mother, and at a moment when her attention was distracted a stranger had seized them by the hand and made for the exit. Their mother had realized what was happening, had started shouting and had put the would-be kidnapper to flight.

“The episode had never in fact occurred, but a few months after being told the story the children not only thought they remembered it – and really in a certain sense they did remember it – but in telling the story they even added details that were not there in the original version.

“Were these children lying? That is, were they saying untrue things in the awareness of doing so? Certainly not.

“Did these children give an account of things that had really happened? Certainly not.

“It is an acknowledged fact – and one of the most important objects of study in modern forensic psychology – that both children and adults make mistakes about the source of their memories and are convinced that they remember contexts, facts and details which have in fact been suggested by others. Deliberately, as in the case of the experiment I have recounted to you. Or involuntarily, as in many situations in everyday life and also, at times, during criminal investigations.

“On the basis of these considerations we can give an answer to the question put by the public prosecutor in the course of his speech, regarding the reliability of the witness Renna. The public prosecutor asked himself, and above all he asked you: what reason did Renna have for lying and therefore falsely accusing Abdou Thiam?

“We can answer that question with perfect confidence: no reason at all. And in fact Renna did not lie. Between lying – that is, knowingly uttering falsehoods – and telling the truth – which is giving an account of the facts as they really and truly happened – there exists a third possibility. A possibility which the public prosecutor did not take into consideration, but which you must take into very close consideration. That of a witness who gives a certain version of the facts in the erroneous conviction that it is true.

“We are here concerned with what might be defined as involuntary false witness.”

They seemed interested. Even the judge and the military-looking juryman. The pair who – I was convinced of it – had already decided to find Abdou guilty.

“There are many ways of building up involuntary false witness. Some are deliberate, as in the case of the experiment with children that I told you about. Others are themselves involuntary and often prompted by the best intentions. As in this case.

“Let us together try to reconstruct what happened in the inquiry which led to the indictment of Abdou Thiam, and therefore to this trial. A little boy disappears and two days later his dead body is found. It is a deeply disturbing event, and those whose task it is to put the investigations in hand – the carabinieri, the public prosecutor – feel it is their urgent, their pressing duty to discover the culprits. There is justifiable eagerness to satisfy to the demand for justice provoked by such a horrible crime. By questioning the child’s relatives, and other persons who knew him well, the carabinieri discover this apparent friendship existing between the boy and this African pedlar. It is something strange, unusual, that arouses suspicions. And also the feeling that perhaps they are on the right track. Perhaps it is possible to satisfy that demand for justice and to placate that anguish. The investigation is no longer groping in the dark; it now has a possible suspect and a theoretical solution. This redoubles the efforts made to find confirmation for this theoretical solution. This is how things stand when the witness Renna is heard for the first time, by the carabinieri. The investigators are understandably excited by the possibility of solving the case, and they realize that the statements of this witness could well constitute a decisive step. It is at this stage that we see the construction of the involuntary false witness.

“Attention please, I beg of you. I am very far from saying that there was any deliberate manipulation of the inquiries. And even less am I speaking of the grotesque hypothesis of plots on the part of the investigators to the detriment of the defendant. The question is, at one and the same time, both simpler and more complex, and to explain what I wish to say I will borrow a famous phrase of Albert Einstein’s. The phrase, if I remember rightly, goes more or less like this: ‘It is the theory that determines what we observe.’

“What does this mean? It means that if we have a theory – a theory we like, that we are satisfied with, that seems to us good – we tend to examine the facts in the light of that theory. Rather than objectively observing all the available data, we look only for confirmations of that theory. Our very perception is strongly influenced, is indeed determined, by the theory we have settled on. As Einstein said in speaking of science, it is indeed the theory that determines what we succeed in observing. In other words, we see, we hear, we perceive what conforms to our theory and simply pass over all the rest. There is a Chinese saying that expresses the same concept in a different way. The Chinese say: ‘Two-thirds of what we see is behind our eyes.’

“We have all had experience of how our very perceptions are determined by what, for the most varied reasons, is in our heads or, as the Chinese would put it, behind our eyes.

“Have you never bought a new car and suddenly, driving along, you notice dozens of the same model on the roads? Where were they before?

“Perception filters, the psychologists call them.

“Paraphrasing Einstein, who, I imagine, must be turning in his grave at my intrusion, we can state that it is the investigatory hypothesis that determines what the investigators see. But not only that. It determines what they look for. It determines the questions they ask. It determines the manner in which they draw up their reports. And all this does not in the least imply bad faith.

“Allow me to repeat: all these things I have mentioned can produce errors in the investigations – and it is the business of the trial to correct such errors – but they do not in the least imply bad faith.

“If anything, in a case such as this, we are faced with an excess of good faith.

“Let us therefore return to what we were saying a few minutes ago. The investigators want to solve this dreadful crime. They want to do it for the best reasons and with the best intentions. They want to do it for the love of justice. They want to do it quickly, so that the perpetrator of such a horrible deed remains at liberty – and in a position to strike again – for as short a time as possible. In this state of mind they find a track to follow and single out a possible suspect. Not fantasies, mind you, or hypotheses used as pretexts. The track was a good one and the suspicions with regard to Abdou Thiam were plausible. On the basis of this good track, the investigators set off in pursuit of the man they considered to be the probable culprit.

“From that moment on the carabinieri and the public prosecutor have a theory which – as we learn from Einstein – will determine what they see, how they will act with witnesses, what they will ask them, how they will draw up the records and even what they will record. In perfect good faith and eagerness to see justice done.

“You will now understand the reason for those questions put by the defence to the carabinieri sergeant-major regarding the manner in which the report was drawn up. Because if I make a complete record – complete, that is, with tape recording, stenotyping and so on – there is no difficulty in understanding what happened during that examination. Everything is on record – questions, answers, pauses, the lot – and we have only to read the transcription or listen to the tape recording. If the examiner has involuntarily influenced the witness, we can verify the fact simply by reading. Then each of us can come to his own conclusions.

“If the report is a mere summary, such a verification is impossible. And if the summarized report is that of the very first contact between the investigators and the witness, the risk of involuntary manipulation of the witness’s statements and memories is very high indeed.

“Would you like a little example of how this can happen?

“I am the investigator and I have before me someone who might be an important witness, perhaps a decisive one. I have strong suspicions of a certain subject, Abdou Thiam.

“I ask the witness: Do you know Abdou Thiam? The name means nothing to me, perhaps you could show me a photo. Here’s a photo, do you know him? Yes, yes. He’s one of those niggers who often hang about outside my bar. They’re such a nuisance. Did you see him pass your bar on the day the little boy disappeared?

“The witness pauses, thinking back. The investigators feel they are nearing a solution.

“Think hard. The afternoon of the child’s disappearance. It’s a week ago.

“It seems to me I did. Yes, he must have passed by. Seems to me it was certainly him.

“At this point the sergeant-major dictates this for the records, because he wants to get it down in black and white before the witness changes his mind. Which happens all too often, alas. He dictates it to the lance-corporal at the computer. He dictates it in his bureaucratic jargon, not in the language used by the witness.”

From my documents I selected the copy of Renna’s first statement and read from it.

“In the report concerned we find expressions such as ‘in the management of the aforesaid commercial premises I am assisted by ...’ and so on. Obviously these are not the words of the witness Renna. Obviously we do not know what questions were addressed to Renna. We do not know because we are given only the answers. What were the questions put to the witness? Were they questions which influenced him? Were they leading questions, that is, questions so put as to suggest or prompt the expected answer? Were they questions which, quite involuntarily, created a memory?

“There is no need for bad faith. It is enough to have a theory to confirm and our brain does the rest on its own, perceiving, working out, setting down in the records in such a way as to adapt the facts to fit the theory. Creating, or shall I say assembling, a false memory.

“I say ‘false’ not because Renna invented anything or the carabinieri with criminal intent suggested a false story for him to tell. It is simply that in the course of the first interrogation Renna’s memories were reprogrammed in the light of the investigatory theory adopted, for which no objective verification was sought, but only confirmation. Those memories were reprogrammed, and how this happened in concrete fact we shall never know. Because the interrogation of this witness was not taped, only summarized in writing. In the manner which we have seen.

“Would you like to know how far it is possible to influence the reply of a witness, or even modify his memory, simply by putting the question in a different way? Let me tell you of another experiment, this time carried out in Italy. Three groups of psychology students – not children, not uninformed persons, but students of psychology who knew they were being submitted to a scientific test – these students, I say, were shown a film sequence. In this sequence a woman was seen leaving a supermarket with a trolley. A young man approached the woman from behind, seized a handbag lying on top of the trolley and made off with it. The three groups were asked to give an account of what they had seen, but in answer to different questions. The first group was asked ‘Did the thief barge into the woman?’ The second group was asked ‘In what way did the aggressor push the woman?’ The students of the third group were simply asked to tell what they had seen. Needless to say, in the film there had been no push and no barging.

“I think you will already have guessed the result of the experiment. Among the students of the third group – those who had simply been asked to give an account of the facts – only 10 per cent or just over spoke of a bump or any kind of physical contact between the aggressor and the woman. Of the students of the first group only 20 per cent spoke of a shove. While in the second group – to whom the most strongly suggestive question had been put – almost 70 per cent of the answers spoke of the non-existent contact. As in the case of the children, moreover, all those who spoke of it embroidered their accounts with details about the manner, the violence and the direction of this non-existent shove.

“Need I say more? Do we have to waste more words in explaining how far the manner of conducting an interrogation can influence not only the answers but the very reconstruction of the memories of the person being interrogated? I think not.

“We have now understood how vital it is to know which questions – and in what order, at what speed, in what tone of voice – have been put to a witness in his most important deposition, which is his first.

“In this case this vital information is denied us, because in the carabinieri report we only read: ‘Witness replied.’

“Replied to what question? What questions?”

I raised my voice slightly. It was not my practice, but the jury were beginning to tire, and just as I was approaching the crucial point. I simply had to keep them alert.

“We have said that if we do not know what the question was, we cannot say if the reply is genuine, or has been influenced or even manipulated. We will never be able to say because of that examination, that first examination of the witness Renna, all we have is a brief summary. We can only make conjectures. But in making them there is one fact we must not overlook. A fact that occurred before our eyes, during a hearing, in this trial. And that fact is the cross-examination of Renna. In the course of which we learned a series of very important things on the basis of which to assess the reliability of this witness. Which does not mean to assess whether the witness is lying or is telling his subjective truth. It means to verify how far his account corresponds with the objective course of events.

“I will summarize these points. Signor Renna does not like non-European citizens and wishes the police would do something about them. Signor Renna does not know Abdou Thiam very well if – having two photographs of him in his hand and being in the same courtroom – he fails to recognize him. Signor Renna, finally and consequently, doesn’t have much of a memory for faces and does not find it easy to distinguish between one non-European citizen and another. From his point of view ‘they are all niggers’, to use the very words he used himself in replying to a question from the defence.”

I was about to launch one of the decisive offensives, so I paused once more and gave the court at least twenty seconds. They had to wonder why I had stopped speaking and give me all the attention they could, after so many hours in the courtroom. When I started again, I pitched my voice higher. It had to be clear that we had reached the climax.

“And on the basis of the statements of this witness, these statements from a dubious source – dubious on account of what we have said concerning the first interrogation by the carabinieri – the public prosecutor is asking you to inflict a sentence of imprisonment for life.

“Bear in mind that to inflict not life imprisonment but even a single day in prison, you must not apply the criteria of verisimilitude, you must not apply the criteria of probability. Even supposing that in this case and with reference to the content of Renna’s deposition we are entitled to speak of verisimilitude or probability. You must apply the criteria of certainty. Absolute certainty!

“We may speak of certainty in the reconstruction of an occurrence when every other alternative hypothesis is implausible and must therefore be rejected. Is that the case here? Is it implausible to think, for example, that Renna saw someone else that afternoon, not Abdou Thiam, in view of the fact that for him ‘niggers’ are all alike? Is it implausible to think that this witness was in some way mistaken? This witness who – mind you – failed miserably before your eyes to recognize the photographs. Could he not be mistaken? Can you with untroubled mind entrust your entire decision, and the whole life of a man, to the declarations of a witness whose fallibility has been revealed before your very eyes?”

A pause. Seven, eight seconds.

“And please take note: even if against all the evidence you still choose to maintain that Renna’s account is reliable, this would not amount to proof of the defendant’s guilt.

“Because the other evidence against him isn’t worth the paper it’s written on.”

And I went on to examine the statements of the two Senegalese, the results of the searches and all the rest of the evidence.

I spoke of the mobile-phone records. Even if we agreed to speak in terms of the famous “verisimilitude”, I said, the prosecution’s reconstruction didn’t hold water. In fact it was almost grotesque. The prosecution held that the defendant had returned from Naples in the grip of a raptus, and had gone to Capitolo with the insane intention of kidnapping, violating and killing little Francesco. In that case he was mad. Because only madness could account for such preposterous behaviour. In which case, why had he not been subjected to any psychiatric examination? If to explain his behaviour it was necessary to fall back on mental illness, then this illness should have been ascertained. Otherwise that hypothesis remained simply an attempt to influence the court.

I raised all these points fairly briefly. The jurors were tired, and I was convinced that when the moment came to decide they would primarily discuss Renna’s evidence.

So I began to wind up. To end at the point from which one started gives the idea of completeness and lends strength to an argument. So I believe.

“Verisimilitude or veracity, ladies and gentlemen. Probability or certainty. The choice ought not to be difficult. But instead it is. Because if on the one hand there is the perception – which I am sure we all share – that this trial has produced no answer, on the other hand there is the feeling of dismay at the idea that a horrible crime can remain unpunished, without a known culprit. It is an intolerable idea, and one that brings with it a very grave risk.”

At that moment Cervellati re-entered the courtroom. He sat down and propped his head on his right hand, using the hand as a kind of barrier. Between him and me. His gaze was ostentatiously directed at a point in the courtroom high up on the left. Where nothing was.

It was the position closest to turning his back on me that was physically possible with the tables and chairs arranged in parallel rows.

I thought he was a turd and carried on.

“The risk is that we may try to rid ourselves of this anguish by finding not the culprit but a culprit. Anyone at all. Someone who has suffered the mischance of getting ensnared in the proceedings.

“Without – having – done – a – thing. Let me repeat that: without – having – done – a – thing.

“Some may not share the categorical tone of my statement. Very well. Everyone is entitled to doubts. I am the defending counsel and for many reasons I am convinced of the innocence of my client. You have the right not to share this certainty. You have a right to your doubts. You have a right to think that Abdou Thiam could be guilty, despite what his counsel says.

“He could be guilty. Despite the absurdity of the reconstruction put forward by the prosecution, you have the right to think that the defendant could be guilty.

“He could be. In the conditional.

“Verdicts of guilty, however, are not written – cannot be written – in the conditional mood. They are written in the indicative, they affirm certainties. Certainties!

“Can you make affirmations of certainty? Can you say it is certain that the witness Renna was not mistaken? Can you say that at the end of this trial you are left with no reasonable doubt?

“If you can say all this, then convict Abdou Thiam.”

I had raised my voice and I became aware that this time I was not play-acting.

“Sentence him to life imprisonment and nothing less. If you can say that there is not a single doubt, that you are absolutely certain, then it is your duty to sentence this man to prison for ever. You must have the courage to do it. The great courage.”

For an indefinable time everything hung in the air. Until I heard my voice once more. Low now, and with a crack in it.

“If, however, you do not have this certainty, then you require even more courage.

“In order not to suppress your doubts in the name of summary justice, and therefore to acquit, you will need enormous courage. I am confident that you will have it.

“Thank you for hearing me out.”

I sat down, scarcely able to believe that I had really finished. From behind me on the public benches came a murmur of voices. I sat with lips compressed and head slightly bowed, staring dumbly to my left at the grain of the wood on my desk.

I heard the judge speaking and his voice seemed to come from far away. He asked the prosecution and the civil party if they had any responses. They said no.

Then he asked Abdou if he wished to make a concluding statement, before the court retired in camera. As was his right by law. The murmur died and there were a few seconds of silence. Then came Abdou’s voice speaking into a microphone inserted between the bars of the cage. It was quiet but firm.

“I want to say one thing. I want to thank my lawyer because he has believed I am innocent. I want to tell him he did right, because it is true.”

The president gave an imperceptible nod. “The court will retire,” he said.

He got to his feet, and almost at once the others did likewise.

I got up too, mechanically. I watched them disappear one by one through the door and only then did I turn to Margherita.

“How long did I speak for?”

“Two and a half hours, more or less.”

I looked at my watch. It was a quarter past six. It seemed to me I had spoken for no more than forty minutes.

We stood for a while in silence. Then she asked me why I didn’t take off my robe. I did so and laid it on the desk, while she regarded me with the expression of one who wants to say something and is searching for the way, for the words.

“I’m not very good at paying compliments. I’ve never really liked doing it, and I think I know why. In any case, that doesn’t matter now. What I wanted to say was that ... well, listening to you was ... extraordinary. I’d like to give you a kiss, but I don’t think this is the time and place for it.”

I said nothing, because I was at a loss for words, and what’s more I had a lump in my throat.

A journalist came up and complimented me. Then another, and then the girl who had asked me what I thought of the prosecutor’s request for a verdict of guilty. I felt a pang of remorse at not having been kinder to her earlier.

While the journalists jabbered on at me without my listening, Margherita gave a gentle tug at my sleeve.

“I must dash. Good luck.” She raised her left fist to her brow and briefly bowed her head.

Then she turned and made off, and I felt lonely.