The DNA in question was found on the bra clasp of victim Meredith Kercher as well as on a knife the prosecution says was used to stab her, according to The Associated Press.
"Finally, a little bit of good news," Knox's mother Edda Mellas said.
Knox was convicted in 2009 of sexually assaulting and killing her roommate Kercher, 21. She was sentenced to 26 years, along with her then-boyfriend, Raffaele Sollecito. A third person, Rudy Guede, had been convicted and sentenced earlier.
The Amanda Knox Case
Amanda Knox attends a session of her appeal against her murder conviction in Perugia's court of Appeal on Saturday in Perugia, Italy. Knox and her Italian ex-boyfriend Raffaele Sollecito were convicted of the murder of Knox's former British flatmate Meredith Kercher in 2007. Their trial took place in December 2009 with Knox and Sollecito receiving sentences of 26 and 25 years respectively. Rudy Guede, an unemployed man from Ivory Coast, was also convicted of the Meredith Kercher's murder. On Saturday, an Italian judge ruled that independent experts can review DNA evidence used in the case against Knox.
American Amanda Knox, center, returns to an Italian court on Nov. 25 to appeal her conviction and 26-year prison sentence for the murder of her British housemate, Meredith Kercher. Knox, 23, could have her sentence increased to 30 years if the appeal fails.
An Italian jury in December convicted Knox, an exchange student from the University of Washington in Seattle, and her Italian ex-boyfriend, Raffaele Sollecito, right, of killing Kercher. The 21-year-old British student's body was found Nov. 2, 2007, in the house in Perugia, Italy, she shared with Knox.
Lead prosecutor Giuliano Mignini initially said Kercher, above, was killed during a drug-fueled sex game in which she was an unwilling participant. He later said Knox killed Kercher because she didn't like her. When Kercher's body was found, she was half-nude and had a slashed throat. According to Mignini, Knox hit Kercher's head against a wall, then tried to strangle her; Sollecito held Kercher and Rudy Hermann Guede, who was also in the home, sexually assaulted her.
Guede, center, a drifter from the Ivory Coast, was convicted in a separate trial. He was sentenced to 30 years in prison, but the term was reduced to 16 years on appeal.
Knox appears in court in Perugia, Italy, on June 1 for a preliminary hearing on charges that she slandered Italian police. She has said police beat her during questioning in Kercher's death. Police are also pursuing a slander case against Knox's parents for repeating their daughter's allegations.
Knox's parents, Curt Knox, right, and Edda Mellas, speak to reporters last year after visiting Amanda in prison. The pair could be sentenced to up to three years in prison if convicted of the slander charges.
Knox's attorneys plan to argue in the appeal that the forensic and DNA evidence in the case was mishandled and inconclusive. They also contend that prosecutors failed to come up with a motive and that the conviction was based on false hypotheses.
This is the house in Perugia, a university town in central Italy, where Kercher and Knox lived. Witnesses said the two roommates had a falling out over a number of issues, including Knox's sanitary habits, alleged thefts of cash and her alleged habit of bringing "strange men" back to the home.
Knox's father, Curt, and her sister Deanna leave an Italian prison in Capanne after visiting her in December. The family is convinced she is innocent. "We will take this as far as we have to take this, because she is walking out of there totally free of anything related to this," Curt Knox later told The Seattle Times.
Kercher, a student from Surrey, England, was found with her throat slit in the house she shared with Knox in Perugia, Italy, in November 2007.
Prosecutors argued against the review, saying that Knox's DNA was found on the knife and Sollecito's was on the bra clasp.
Knox's lawyers argued that the DNA evidence was inconclusive and may have been contaminated. The Seattle native wept when the court announced its decision today, according to Sky News.
The DNA review wasn't the only victory for Knox today. The court also agreed to allow several witnesses who challenge testimony that put Knox near the scene of the crime, the AP said.
Defense attorneys also will be permitted to re-question a homeless man whose testimony they say was unreliable, since it mentions buses that may not have been running on the day in question.
Kercher was studying in Perugia as part of her degree from Leeds University in the U.K. She had been in Italy two months when she was found dead.
For now, Knox's best hope appears to be the DNA evidence. The court selected experts from Sapienza University in Rome to review the evidence, the AP reported.
They will be formally assigned the task on January 15, during the trial's next session.
"It looks like they have an open mind to really look at this case again and see a mistake has been made," Mellas said, according to Sky News.