An appeal court has given two independent forensic experts 90 days to carry out a review of controversial evidence used to convict Amanda Knox.
Knox, 23, is serving 26 years for the murder of British student Meredith Kercher, 21, who was found partially clothed and with her throat cut in her bedroom, in the house they shared.
The American's former boyfriend Raffaele Sollecito, 25, was also found guilty at the original trial and given 25 years.
Key to their conviction was a 30cm kitchen knife found in Sollecito's apartment. The court heard DNA from Knox was found on the knive's handle, while Miss Kercher's DNA was found on the blade.
Sollecito's defence team are also disputing a clasp from Miss Kercher's bra on which DNA from him was said to have been found, and in both cases lawyers say the results were so low they should not have been used as evidence.
At the hearing in Perugia, Judge Claudio Pratillo Hellman formally appointed Stefano Conti and Carla Vecchiotti, from the forensic medicine department of Rome's La Sapienza University, to carry out the review.
While the review is being carried out the trial will also hear from other witnesses.
Among them will be the prosecution's key witness Antonio Curatolo, a homeless man who during the original trial put Knox and Sollecito at the scene of the crime -- the only person to do so.
He had told the court he remembered the night "clearly" as he saw student revellers queuing up to catch buses to nightclubs. However, defence lawyers have established that he could not have done so as the night Miss Kercher was murdered was a bank holiday with venues being shut and no buses running.
Prosecutors are also appealing at the hearing and are looking to have the sentences against Knox and Sollecito increased to life.