Bold added below to the relevant portion of the Toronto Sun article, 3/29/13. The article came after the Italian supreme court annulled the appeals acquittal. It discussed what holding the appeals again meant, and whether Knox would be extradited.
“In Italy, prosecutors and lawyers for interested parties, such as Kercher’s family, can file an appeal. Unlike American courts of appeal, which only consider legal errors in the courts below, Italian courts of appeal, which are comprised of both judges and jurors, can reconsider the facts of a case.
Depending on the Italian high court’s reason for overturning Knox’s acquittal, it is possible that the court of appeals could consider new evidence that’s introduced, said Dalla Vedova. As a result, a defendant can effectively be retried in the course of one case in Italy.
Dalla Vedova said the high court’s decision does not raise a double jeopardy problem because the retrial would not be a new case but rather a continuation of the same case on appeal.
Other defendants who have been acquitted in other countries and then convicted on appeal have attempted to raise the double jeopardy principle to avoid extradition, without much success, said Mary Fan, a law professor at the University of Washington who specializes in cross-border criminal law.
The text of the treaty prevents extradition if the person has already been convicted or acquitted of the same offense by the “requested” country, which would be the United States in Knox’s case because Italy would be requesting extradition from the United States. Because Knox was never prosecuted or acquitted for homicide in the United States, the treaty’s double-jeopardy provision would not prevent Knox’s extradition, said Fan.””