Prosecutor Alessandro Crini said that Amanda Knox should receive a 30-year sentence for the 2007 murder of British exchange student Meredith Kercher, as the the retrial at an appeals court in Florence, Italy continued on Tuesday, CNN reported.

Knox's murder retrial began on September 30.

Raffaele Sollecito and Knox were convicted in 2009 of the murder of 21-year-old Kercher in 2007. Kercher was found stabbed to death at a villa in Perugia, the place she and Knox had rented out while studying abroad.

Knox's conviction was overturned for "lack of evidence," news reports said.

However, Italy's Supreme Court decided in 2012 to retry the case, "adding that the jury who acquitted them did not consider all the evidence and that discrepancies in testimony still need to be answered," CNN also reported

Knox and Sollecito have long maintained their innocence.

While the retrial began on September 30,  Knox nor Sollecito have been present. Knox has lived in Seattle since her acquittal in 2011. She indicated that she has been afraid to return to Italy where she already spent four years in jail.

"I was in the courtroom when they were calling me a devil. It's one thing to be called certain things in the media, it's another thing to be sitting in the courtroom, fighting for your life while people are calling you a devil," Knox told Diane Sawyer in a televised interview in April.