After weeks of damaging reports against them, Amanda Knox and Raffaele Sollecito, could be breathing a bit easy now. For a coroner has testified that the stab wound suffered by Meredith Kercher did not match the alleged murder weapon.
The twist comes as the trial seems to be entering its last stages.
Francesco Introna testified Saturday that the cut on Miss Kercher's neck was made with a knife with a blade 3-3.5ins long.
The evidence contradicts the opinion of a forensic expert, Gianaristide Norelli, who told the court earlier this month that the wounds were compatible with the 6.5in kitchen knife found at the house of Knox's former boyfriend Raffaele Sollecito.
Further damaging the prosecution case, Dr. Introna also told the court in Perugia that Kercher perhaps was killed by a lone attacker - a claim which conflicts with the prosecution's case that she was murdered by Miss Knox, 21, Raffaele Sollecito, 25, and a drifter, Rudy Guede, 22, who has already been found guilty and sentenced to 30 years in prison.
Dr Introna said it would have been "physically impossible" for three people to have attacked Miss Kercher in her tiny bedroom. The room was not large enough for "four people to interact, as proposed by the prosecution," he said.
The prosecution have also said the knife had small traces of Miss Kercher's DNA on the blade and Miss Knox's on the handle.
But Miss Knox's lawyers and family have argued ever since she was arrested that there is no conclusive proof that the kitchen knife was the murder weapon.
They say it was natural that the handle would bear traces of Miss Knox's DNA because she had used it to chop food while making dinner at her then boyfriend's house.
They also query the scientific reliability of the traces of Miss Kercher's DNA on the blade, saying they were there as a result of a bungled police and forensic investigation in which evidence was contaminated.
The prosecution has alleged that Miss Knox, Mr Sollecito and Guede forced Miss Kercher into a group sex game on the night of Nov 1, 2007, and then killed her when she refused to take part.
Miss Kercher's half-naked body was found in the bedroom of the cottage she shared with the American and two Italian women the next morning.
Miss Knox and her former boyfriend deny any involvement in the crime.
But the two accused have given differing accounts of where they were on the night of the murder. Mr Sollecito has said he was in his flat, working at his computer.
He said he does not remember if Miss Knox spent the whole night with him or just part of it, while she has insisted that she was there all the time and that they watched a film, checked emails, smoked marijuana and also had sexual intercourse.
Guede too maintains his innocence and has launched an appeal against his conviction.
On Friday Miss Knox's mother, Edda Mellas, said her daughter had been upset and traumatised when she learned that Miss Kercher, of Coulsdon, Surrey, had been murdered and that the two young women had got along well.
Giving evidence at her daughter's trial in Italy, Edda Mellas, from Seattle, said: "She told me about all the fun times she had with Meredith.
"Amanda was very upset about the death of her friend."