Knox's defense team gave their last round of rebuttals, ending four months of arguments in Knox's and Italian Raffaele Sollecito's third trial for the 2007 murder of her British roommate, Meredith Kercher, in the Italian university town of Perugia.
Knox's lawyer Carlo Dalla Vedova told the court he was "serene" about the verdict because he believes the only conclusion from the files is "the innocence of Amanda Knox."
"It is not possible to convict a person because it is probable that she is guilty," Dalla Vedova said. "The penal code does not foresee probability. It foresees certainty."
Dalla Vedova evoked Dante, noting that the Florentine writer reserved the lower circle of hell for those who betrayed trust, as he asserted that police had done to Knox when they held her overnight for questioning without legal representation and without advising her that she was a suspect.
The panel of two professional judges and six lay jury members remained closed in chambers after more than nine hours of deliberations with no clear indication of when a verdict might be announced.
Knox, 26, awaited the verdict half a world away in Seattle, where she returned after spending four years in jail before being acquitted in 2011. In an email to this court, Knox wrote that she feared a wrongful conviction.
She told Italian state TV in an interview earlier this month that she would wait for the verdict at her mother's house "with my heart in my throat."
Knox's absence does not formally hurt her case since she was freed by a court and defendants in Italy are not required to appear at their trials. However, presiding judge Alessandro Nencini reacted sternly to her emailed statement, noting that defendants have a right to be heard if they appear in person.
Sollecito, on the other hand, has made frequent court appearances, always in a purple sweater, the color of the local Florentine soccer club. He was in court again Thursday morning, accompanied by his father and other relatives and said he would return for the verdict.
If convicted, Sollecito, who like Knox spent nearly four years in jail, risks immediate arrest.
Knox's situation is complicated by her absence. In the case of a guilty verdict, experts have said it is unlikely Italy would seek her extradition until a verdict is finalized, a process that can take a year.
Members of Kercher's family were expected to appear later in court and the man whom Knox wrongly accused of Kercher's murder also was on hand for the verdict.
"As I have always said, Amanda was involved," Patrick Diya Lumumba said while the deliberations were under way.
The first trial court found Knox and Sollecito guilty of murder and sexual assault based on DNA evidence, confused alibis and Knox's false accusation against Lumumba, a Congolese bar owner, which resulted in a slander verdict that has been upheld on final appeal. A Perugia appeals court dismantled the guilty verdict two years later, criticizing the "building blocks" of the conviction, including DNA evidence now deemed unreliable by new experts, and the lack of motive.
Italy's highest court ordered the third trial in a scathing dismissal of the appeals court acquittal, ordering the examination of evidence and testimony it said had been improperly omitted by the Perugia appeals court as well as addressing what it called as lapses in logic.
"Most of all, the court was instructed to evaluate all of the evidence in their complexity," said Vieri Fabiani, one of the lawyers for the Kercher family.
The Florence deliberations will either confirm or overturn the initial guilty verdict "as if the acquittal never happened," Fabiani said.
In Florence, the new prosecutor, Alessandro Crini, redefined the motive, moving away from the drug-fueled erotic game described by his colleagues in Perugia. Crini contended that the outburst of violence was rooted in arguments between roommates Knox and Kercher about cleanliness and was triggered by a toilet left unflushed by Rudy Hermann Guede, the only person now in jail for the murder.
Suspicion fell on Knox and Sollecito within days of the discovery of Kercher's half-naked body on Nov. 2, 2007, in her bedroom in Perugia. Kercher, 21, had been sexually assaulted and stabbed multiple times. Knox and Sollecito, who had been dating for only 10 days when Kercher was found dead, said they had spent the evening of the murder at Sollecito's apartment, smoking marijuana, having sex and watching a film.
Guede, a small-time drug dealer originally from Ivory Coast who had previous convictions for break-ins, is serving a 16-year sentence for the murder, but courts have said he did not act alone.
The defense teams for Knox and Sollecito are certain to appeal any guilty verdict to Italy's supreme court, which can take a year or more and could, in theory, result in yet another appeals court trial. The prosecutor general, on the other hand, could decide to let an acquittal stand, although most observers don't believe that's likely.
Crini, who has demanded 26 years on the murder charge for each of the defendants, has asked the court to take measures to ensure any verdict could be enforced. He also asked the court to raise Knox's sentence on the slander conviction from three to four years because he alleges she accused the wrong man to remove suspicion from herself.