Amanda Knox has been granted a review of the forensic evidence used to convict her of the murder of London student Meredith Kercher.
The 23-year-old American is trying to overturn her conviction after being jailed last year for 26 years for the killing in Perugia, Italy, in 2007.
A review would include the disputed DNA evidence found on a knife and on the clasp of Miss Kercher's bra.
Knox's ex-boyfriend is also appealing against a murder conviction.
Raffaele Sollecito was found guilty at the end of the same trial and sentenced to 25 years in prison.
Miss Kercher, 21, from Coulsdon, south London, was found with her throat cut.
The original trial heard the pair had cornered Miss Kercher after starting a sex game with Ivorian drug dealer Rudy Guede, who was jailed for 30 years for the killing after a separate hearing, although that was reduced to 16 years on appeal.
Guede failed to get his conviction overturned by Italy's highest court this week.
Leeds University student Kercher's semi-naked body was found partially covered by a duvet in her bedroom in the house she shared with Knox in Perugia.
Knox's defence team maintains the DNA evidence in the case was inconclusive and argued it may have been contaminated.
It particularly focuses on disputed traces of DNA found on the knife the prosecution said was used in the murder.
The defence says the knife was too big to have inflicted the wounds on Miss Kercher's neck.
The forensic evidence also focusses on the clasp of Miss Kercher's bra. It was cut away from her bra during a struggle, but not found until six weeks after the murder.
It held DNA of Sollecito, which placed him at the scene, but the defence says it could have been contaminated before it was found.
The defence team says there is no DNA evidence that puts Knox in the bedroom.
Knox's mother, Edda Mellas, was in court for the announcement.
"Finally a little bit of good news," she said.
Knox's parents, from Seattle, have said they are hopeful their daughter will be released once judges in Italy have re-examined the evidence.
The next hearing will take place on 15 Janaury.
However, if her conviction is upheld, her sentence could be increased.
As in the original trial, the verdict will be decided by the judge, a fellow magistrate and six jurors.