By Isla Binnie
ROME (Reuters) - Italy's highest court delayed until Friday a ruling on whether to uphold the conviction of American Amanda Knox and her Italian ex-boyfriend for the murder of British student Meredith Kercher.
The case has inspired books and films and riveted media attention for almost eight years. The court's decision could trigger a legal battle over Knox's extradition.
The Court of Cassation began the hearing on Wednesday and had been expected to decide later in the day but closing arguments went slowly and the court adjourned to Friday morning.
Knox, 27, and Raffaele Sollecito, 30, were convicted for the second time last year for the 2007 murder of 21-year-old Kercher, an exchange student from the University of Leeds who was stabbed to death in a house the women shared in Perugia, a university city in central Italy.
The Kercher family's lawyer Francesco Maresca said in court that he had represented them in the case multiple times and hoped this would be the last.
The court might, however, overturn the conviction and then order yet another trial. It could also acquit the two - but legal experts said the last option was unlikely.
Both Knox and Sollecito have maintained their innocence during a process which saw them first convicted in 2009. That ruling was then overturned and both were freed from prison, after which Knox returned to her home town of Seattle.
The Court of Cassation later ordered a new trial, and a Florence court convicted them again last year, saying the murder had been the result of a domestic argument, squashing the previous theory that it happened when a sex game went wrong.
At Wednesday's hearing, judge Paolo Antonio Bruno said there were "few certainties" in the case. Knox's lawyer Carlo Dalla Vedova echoed this as grounds for overturning the conviction, invoking other cases which have bounced around Italy's justice system for years.
"These are food for thought for the people responsible for Italy's legal process," Dalla Vedova said.
His client, originally portrayed as a fast-living partygoer, has come to be seen in her home country as a victim of this unwieldy system and a botched investigation.
If the sentence is confirmed, Italy could formally ask the United States to extradite Knox to serve her sentence. Sollecito, whose passport has been withdrawn and who attended the hearing, could be arrested.
Washington has refused to send military personnel to serve sentences in Italy in the past, but sparing a private citizen from extradition would be an "anomaly", Pier Luigi Petrillo, Professor of Comparative Law at Rome's LUISS university, said.
"If an American citizen has been found guilty of a crime and in particular a serious crime such as murder on Italian soil, there is an obligation by the United States to extradite the American citizen," Petrillo said.
The prosecution is now asking for jail sentences of 28 years and 3 months for Knox and 24 years and nine months for Sollecito, shaving three months off their original sentence requests due to the statute of limitations.