Amanda Knox, the American at the center of a media storm during the sensational trial that accused her of murdering her 21-year-old roommate while studying in Italy, has had her acquittal overturned, reports The New York Times.

Italy’s highest court on Tuesday issued a surprise ruling overturning her previous acquittal, which means that the case against her and her former boyfriend, Raffaele Sollecito, will be sent back to an appeals court in Florence. The pair were first convicted of killing Meredith Kercher in a trial that divided public opinion, but were later acquitted on appeal.

The Times notes: "The decision by the Court of Cassation offered a further dramatic turn in a long-running case that has fascinated many people in the United States, Britain and the rest of Europe. But the full implications of the ruling were unclear, particularly the question of whether Ms. Knox would return voluntarily from the United States or be extradited to face new hearings — a process that would require several major legal steps. If she does not appear, the case could proceed in her absence."

Knox, who became the the focus of a Lifetime movie starring Hayden Panettiere, said the ruling was "painful" because "the prosecution’s theory of my involvement in Meredith’s murder has been repeatedly revealed to be completely unfounded and unfair.”

A book by Knox, called "Waiting to Be Heard," is slated for publication April 30, and on the same day, ABC News anchor Diane Sawyer will conduct the first interview with her since her release from an Italian prison.