(FLORENCE, Italy) --Amanda Knox will not be returning to Italy.
A Knox family spokesperson said the 25-year-old does not plan on attending the new appeals trial over the 2007 killing of her British roommate, according to CNN.
The trial is set to begin in Florence on Sept. 30.
Knox spent four years in prison after being convicted of Meredith Kercher's murder in Perugia, Italy, where they were roommates while studying abroad.
An Italian appeals court threw out Knox's murder conviction in 2011. In March, however, the Italian Supreme Court rejected the Appeals Court ruling and ordered a new trial for Knox and her ex-boyfriend Raffaele Sollecito, 29.
The Supreme Court filed its "motivation," a written document that spells out the court's reasoning on June 18.
The court's 74-page document indicates that the Supreme Court judges supported the prosecutors' original theory that Kercher possibly died during a forced "erotic game" that got violent, according to the Italian news agency AGI.
The Supreme Court judges are not judging the merit or worth of the testimony or evidence, but rather the process that the Appeals Court used to reach its verdict.
The judges said the appeal had to be annulled "due to the multiple shortcomings, contradictory events and manifest lack of logical reasoning."
The sex game gone wrong theory was initially suggested by the prosecutors, but the motive later evolved during the trial into simmering enmity between the women because Knox allegedly brought boys home late at night and was sloppy, and Kercher allegedly accused her of stealing money. The prosecution ended the first trial by telling the jury sometimes people commit violence without a motive.
The judges' document mentioned looking at a "wide range of possible hypothetical options," including "the change in a program which at first only included the involvement of the English young woman in a sex game which she didn't share, to exclusively forcing her into a group kinky erotic game, which exploded, getting out of control."
Knox's lawyer Carlo Dalla Vedova said he disagreed with the court's ruling when it was announced.
"We respect the Supreme Court's decision, but we do not agree with it," Vedova told ABC News. "All the facts were analyzed already. So now we simply re-start and re-do the case. We are ready to start again in Florence, and we are looking forward to defending Amanda. She is completely innocent."
In April, Knox told ABC News' Diane Sawyer that the Supreme Court's decision to order a third trial was "incredibly painful."
"I felt like after crawling through a field of barbed wire and finally reaching what I thought was the end, it just turned out that it was the horizon," Knox said. "And I had another field of barbed wire that I had ahead of me to crawl through."
Knox does not have to return to Italy for the trial, and extradition is not currently on the table.
If she is convicted again, that ruling would most likely be appealed up to the Italian Supreme Court.
Only if the Supreme Court upholds the guilty verdict could extradition even begin.
Copyright 2013 ABC News Radio