Knox’s attorney says she is “shocked and very sad.”
“She thought this was the end of the nightmare,” he said.
Knox is now ordered to stand trial again for British student Meredith Kercher’s murder, but there appeared to be little the country could do to force her to return for the new hearings.
In a statement responding to the decision, Knox slammed prosecutors and vowed to fight on.
“It was painful to receive the news that the Italian Supreme Court decided to send my case back for revision when the prosecution’s theory of my involvement in Meredith’s murder has been repeatedly revealed to be completely unfounded and unfair,” said Knox, who is now aged 25 and living in the Seattle area.
“I believe that any questions as to my innocence must be examined by an objective investigation and a capable prosecution,” she added. “The prosecution responsible for the many discrepancies in their work must be made to answer for them, for Raffaele’s sake, my sake, and most especially for the sake of Meredith’s family. Our hearts go out to them.”
But prosecutors are arguing that Knox and her then-boyfriend, Raffaele Sollecito, killed Kercher after a drug-fueled sexual assault in a case that drew worldwide attention.
The case will be reheard at a new appeals court in Florence either later this year, or in 2014.