Amanda Knox has said that she will take the case to Italy's Supreme Court to appeal a court decision to reinstate her conviction, for the murder of British student Meredith Kercher.
If the court confirms the conviction, a long extradition fight is expected for Knox, who is now living back in America.
Ms Kercher, 21, was found dead in the flat she and Knox shared in the town of Perugia. Her throat had been slashed and she had been sexually assaulted.
A new document by an appeal court has stated evidence of a fallout between murdered British student Meredith Kercher and Amanda Knox.
The document said: "It is a matter of fact that at a certain point in the evening events accelerated; the English girl was attacked by Amanda Marie Knox, by Raffaele Sollecito, who was backing up his girlfriend, and by Rudy Hermann Guede, and constrained within her own room."
Rudy Guede was convicted in a separate trial of sexually assaulting and stabbing Kercher.
His 16-year sentence, reduced on appeal from 30 years, was upheld in 2010 by Italy's highest court, which said he had not acted alone.
A coroner has concluded that Meredith Kercher was unlawfully killed, more than six years after her murder in Italy.
In a brief hearing at Croydon Coroner's Court in south London, coroner Dr Roy Palmer said the exchange student died from stab wounds to her neck.
Meredith was found dead in Perugia, Italy in November 2007.
Amanda Knox and Raffaele Sollecito were found guilty of murder in 2009. Knox was sentenced to 28 years and six months while Sollecito was jailed for 25 years. They were later cleared of murder.
In January they had their guilty verdicts reinstated at Italy's highest court for the murder of the Leeds University student.
The pair have always denied murder.
Rudy Guede, a drug dealer, is serving a 16-year sentence over the death, though the courts have said he did not act alone.
The judge who presided over Amanda Knox's second murder conviction said he suffered over the verdict but that he and the jury agreed about her guilt in the death of British student Meredith Kercher.
Judge Alessandro Nencini told the Italian newspaper Corriere della Sera the jury had come up with a motive that would be explained in the written explanation of the verdict, expected within three months.
He hinted at the conclusion, saying that up until 8:15pm on the night of the murder, Miss Knox and her now ex-boyfriend Raffaele Sollecito had other plans but that something changed.
He told Corriere: "If Amanda had gone to work, probably we wouldn't be here."
A White House official has declined to comment when pressed on the possible extradition of Amanda Knox to Italy.
A spokesman said: "This is a matter, as I understand it from my reading of the press, is still in a legal proceeding.
"For questions about that issue, I would refer you, as a broad principle as opposed to a matter that is still in a legal process, I would refer you to the State Department and the Department of Justice."
The former boyfriend of Amanda Knox has told NBC News that he "didn't expect" last night's Italian court verdict which found the pair guilty of the 2007 murder of British student Meredith Kercher.
Rafaelle Sollecito told the American news channel: "The first thing that came to my mind was to wait for the reasons of this verdict.
"I don't want to comment anything about that. It was completely unexpected, at least by me. But I will look into the reasons of it."
John Kercher, whose daughter Meredith was killed in 2007, told ITV News that there is nothing to celebrate today: "You don't celebrate guilty - you celebrate closure and we still don't have that.
"That's all we want. We want it to end. It's been over six years and we still have another judicial process ahead now."
He added that the American media were jumping to conclusions when they say Amanda Knox could escape extradition under the double jeopardy law."They have not been tried twice so double jeopardy should not come into this."There has only been one actual trial. This was an appeal being re-done.
"Now they can take this to the Supreme Court... to say they have been tried for the same crime twice is not right."
Lawyer and legal analyst Lisa Bloom has said that there is a good chance Amanda Knox could face extradition to Italy, saying: "I think it's certainly possible...If the conviction is upheld I would expect Italy to want to extradite her, after all she's been convicted of murder there."
Amanda Knox said she is not ready to be extradited from America to Italy following her second conviction for the murder of Meredith Kercher.
Speaking to ABC in America she said the guilty verdict has "hit me like a train."
Pictures courtesy of Good Morning America on ABC.
Amanda Knox has spoken of her shock at being found guilty of the murder of British student Meredith Kercher for the second time.
Speaking to ABC in America she spoke of her dismay when she heard the verdict.
Pictures courtesy of Good Morning America on ABC.
See more: Timeline of Meredith Kercher case