"Knox would also then be under threat of arrest and deportation to Italy if she travelled to any other country that holds an extradition treaty with Rome. This includes Canada, several major Latin American states, Australia, New Zealand and most of Europe.
...
Some supporters of Knox have argued that having been acquitted in 2011, she would be protected under the U.S. constitution from double jeopardy. Yet the U.S.-Italy extradition treaty only protects
Americans who face prosecution again in Italy for an offence that has already been dealt with by the U.S. This is not applicable in this situation, said Prof Julian Ku, who teaches transnational law at Hofstra University in New York.
For extradition candidates such as Knox, who have already been convicted, the treaty states that
Italy must merely produce a brief statement of the facts of the case, as well as the text of the laws governing the crime committed, the punishment the person would receive, and its statute of limitations.
The Obama administration could find some reason to decline a request. However, it would need to weigh this against the
potential blow to cooperation on organized crime and other areas between the two governments."
http://news.nationalpost.com/2014/0...ller-says-she-wont-willingly-return-to-italy/