American college student Amanda Knox is on her way home to the United States Tuesday, a free woman after a jury in Italy overturned her murder conviction.

But the prosecution has voiced disbelief over the controversial ruling and has vowed to appeal the verdict to Italy's highest criminal court, the Court of Cassation.

Knox collapsed in tears and the courtroom erupted Monday evening when the court's decision was read. Knox's former Italian boyfriend and co-defendant, Raffaele Sollecito, also was exonerated and freed from prison.

Knox was appealing her 26-year prison sentence on charges of murdering her roommate, Meredith Kercher, in 2007. A court-appointed independent forensic expert said the DNA used to convict Knox was unreliable and possibly contaminated by police.

The verdict also stunned the disappointed family of Kercher, who said they are still trying to absorb the decision. They say the search for Kercher's killer will go on.

A third suspect, former drug dealer Rudy Guede, was given a 30-year prison sentence. He also has pleaded innocent but was not part of Monday's jury decision.