FLORENCE, Italy – New forensic analysis of the knife allegedly used to kill Meredith Kercher found no DNA match to the victim, the new appeal trial of American student Amanda Knox and her former Italian boyfriend heard on Wednesday.
The results of the new test, presented by expert Andrea Berti to an appeal court in Florence, casts doubt on one of the key pieces of evidence that was originally used to convict Knox and Raffaele Sollecito of the killing.
In an exclusive interview with TODAY, American Amanda Knox said she will not return to Italy to face retrial over the murder of her former roommate. "I was already imprisoned as an innocent person in Italy, and I can't reconcile the choice to go back with that experience," she told Matt Lauer.
The only genetic profile matching the DNA on the knife was with Knox, Berti told the court. The knife was found in Sollecito’s apartment, which Knox visited frequently.
“The amount of DNA was limited, and therefore complex to analyze,” Berti added. “We therefore used high-performance techniques, and tested it twice. We found two genetic profiles. We found no trace of a man. The trace didn't show a match with Meredith Kercher.”
“In the case of Amanda Knox, there was an 83 to 100 percent match with the DNA profile," Berti said, adding that the new test had been completed twice to verify its accuracy.
Knox, 26, and Sollecito, 29, have always denied any role in the 2007 murder of British student Kercher, who was found with more than 40 wounds, including a deep gash in the throat.
They were convicted in 2009 and sentenced to 25 years in prison, but that was overturned in 2011 by an appeals court.
Oli Scarff / Getty Images
The long legal saga of Amanda Knox, an American student accused of the violent death of her roommate, British student Meredith Kercher, has made headlines around the world since it began in Perugia, Italy, in late 2007.
A new appeal trial is now re-examining evidence to determine whether Knox and Sollecito helped kill 21-year-old Kercher in the apartment the two women shared in Perugia, Italy.
Knox, now a University of Washington student in her hometown of Seattle, has not returned to Italy for the trial, and is not required by law to do so.
Sollecito is not expected to be called as witness, but on Wednesday he made a tearful statement to the court describing Knox as his “first real love” and saying the succession of court trials and appeals had been a “nightmare beyond imagination.”
He said: "Thank you for listening to me. Unfortunately, my reputation precedes me. I am trying to show you who I really am. I am proud to having grown up in a decent family, a family that taught me good values of honesty and education. I am proud to have a family that never had problems with justice.
Amanda Knox's former boyfriend Raffaele Sollecito tells TODAY' Savannah Guthrie that his life is on hold while he goes on trial a third time for allegedly murdering exchange student Meredith Kercher. He describes the past six years as a "never-ending" nightmare.
“I am now sitting here, after they described me as an assassin, I am not like this.”
He continued: "When I was in Perugia I studied hard, and I was close to graduating when [the murder] happened. Amanda was my first real love of my life, even if it came late in my life. I was 20 years old. I was shy. Me and Amanda only wanted to live our little fairy tale in private.”
“I was next to graduating...with that kind of life...it's unreasonable to think I would do something like that.”
Sollecito said he felt “persecuted” by the legal process, adding: “The evidence is clear, all those who accused me turned out to be untrustworthy, they made up a reality that never existed.”
“I humbly ask you to look at the truth...and consider the big mistake that was made...and give me my life back, because I don't have a life anymore."
NBC News' Alastair Jamieson contributed to this report.
This story was originally published on Wed Nov 6, 2013 7:24 AM EST