Despite being found guilty of the murder of British student Meredith Kercher, Amanda Knox could remain in the US for the rest of her life if the American government protects her from extradition to Italy.

While the US rarely extradites, it is said that Barack Obama's government will have few grounds for turning down an extradition request after an Italian court court in Italy reinstated the guilty verdicts against Knox and co-defendant Raffaele Sollecito.

This week, Knox was sentenced to 28 years and six months in prison for killing Ms Kercher, who was found with her throat slit in the apartment they both shared with Sollecito.

Raffaele Sollecito (L) with his father Francesco outside court in Florence, ahead of the Meredith Kercher murder trial verdict
Raffaele Sollecito with his father Francesco outside court in Florence, ahead of the Meredith Kercher murder trial verdict Reuters

In 2011, she was acquitted at a trial in Seattle, which Italian prosecutors appealed. Now, her lawyers will appeal the recent conviction to the Italian Supreme Court.

Knox is currently in the US, as she did not attend the retrial, but if her lawyers fail in their appeal, she may be handed over to Italy under the 1983 extradition treaty between the US and Italy.

The US Secretary of State, John Kerry, may approve a request which will be passed to the US Justice Department. It Kerry rejects it, Knox will be unable to travel to any other country that holds an extradition treaty with Rome, which includes Canada, Australia, New Zealand and the majority of Europe.

Giuliano Matei was the last reported extradition from the US to Italy. In February 2012, the 34-year-old was deported to face charges of raping and trafficking a teenage girl.

Raffaele Sollecito Talks Meredith Kercher Murder Retrial IBTimes TV

Will Knox be protected by the US government?

Seen in some quarters as the victim of a miscarriage of justice, Knox has some support from the US. However, the State Department has not revealed what action it will take.

In a briefing in March 2013, a spokesperson stated only that the final verdict had not yet been made. Patrick Ventrell said they could not comment on extradition on individual cases.

While others agree Knox has no case to argue extradition, some laywers have stated she may be protected under the "double jeopardy" clause of the US Constitution. It is a procedural defence that prohibits a defendant from being tried twice for the same charge.

US Secretary of State John Kerry
US Secretary of State John Kerry could reject the request for extradition

Still, the US-Italy extradition treaty only protects Americans from extradition in order to face prosecution again in Italy, for an offence already dealt with by the US legal system.

As she has already been convicted, the treaty states that Italy must provide the text of the laws governing the crime, the punishment, its statute of limitations and "a brief statement of the facts of the case".

The US government could decline a request for Knox's extradition for other reasons, if placed under pressure from her supporters. The US has been criticised for failing to adhere to extradition treaties previously. In 2009, 23 American CIA officers were charged for kidnapping a terrorist suspect in Milan, yet were not extradited to Italy.

In addition, concerns of reciprocity may affect the decision. Speaking to the Seattle Times, Mary Fan, a professor at the University of Washington Law School, said: "Someday, the U.S. might seek extradition of someone convicted of a serious crime, such as murder, from Italy.

"So, it's reciprocity that's the major consideration. Not just in this case, but in future cases. That's something that the State Department has to consider."