June 29, 2011 -- Amanda Knox, an American college student who is appealing her Italian murder conviction, was "extremely happy" today after hearing that a court-appointed panel of DNA experts concluded that key DNA evidence used to convict her may have been contaminated.
"She's extremely happy," said her father Curt Knox in an exclusive interview with ABC News. "It's a weight off of her shoulders... She knew she was innocent, but having independent experts say that the DNA evidence is unreliable and potentially contaminated is a big step towards bringing her home."
Knox, 23, has been in an Italian prison since her arrest in November 2007 for the murder of her British roommate Meredith Kercher. She and her ex-boyfriend Raffaele Sollecito, 27, were convicted in 2009 and Knox was sentenced to 26 years in prison. Sollecito was given 25 years.
The report filed today in a Perugia court by court-appointed forensic experts, and obtained by ABC News, give credence to the defense lawyers of both Knox andRaffaele Sollecito, who had argued that the evidence against their clients had been contaminated by police during their investigation.
"When I got the news today, you know, it was extraordinary," her father said. "We're still very hopeful that the court will see all of these compounding things and free her in September."
"We are thrilled," Knox's mother, Edda Mellas, told ABC News from Italy where she is waiting to visit with her daughter in prison. "This is what our experts said all along. This is great news. We"ve always known Amanda is innocent."
For complete coverage of Amanda Knox, check out "THE AMANDA KNOX STORY: A Murder in Perugia," a new ABC Video Book, on sale everywhere enhanced eBooks are sold. Click here for more information and an exclusive excerpt.
The forensic experts were charged with examining the two main pieces of evidence in the case, Kercher's bra clasp and a knife found at Sollecito's apartment.
Italian Panel Questions Key DNA Evidence in Amanda Knox Conviction
"One cannot exclude that the results obtained could have derived from phenomena of environmental contamination and/or contamination, which could have taken place in any of the phases of the evidence gathering and/or manipulation" of the evidence, the experts write in their conclusion.
Prosecutors maintained in the trial that Knox's DNA was found on the handle of a kitchen knife they believe to be the murder weapon, and that the DNA of victim Meredith Kercher was found on the blade. Prosecutors also argued that Sollecito's DNA was found on the clasp of Kercher's bra.
Defense lawyers argued that there was so little DNA on the knife that it couldn't be retested or be reliable. They said the bra clasp wasn't collected by police until weeks after the murder and after it had been moved around Kercher's bedroom during their probe.
The two court-appointed forensic experts -- Carla Vecchiotti and Stefano Conti, both from the Legal Medicine Institute of Rome's La Sapienza University -- initially were not able to retest the DNA on the bra clasp and the knife because there was not enough DNA to retest.
They were then assigned to judge "the degree of reliability of the tests carried out by the forensic police on the evidence based on court documents, specifically with reference to any possible contamination."
Amanda Knox "Extremely Happy" With DNA Experts' Conclusions
"This is not a surprise," said another member of the Knox legal team Carlo Dalla Vedova. "For us, it's confirmation of what we have known all along, that the DNA results were not reliable, they were uncertain."
Dalla Vedova said the report's conclusion on the knife was that it was impossible to "relate the DNA said to be Meredith's to her with certainty" and that there is the possibility of contamination with knife too.
"We have asked all along for an independent review of DNA which we were denied during the trial. Finally, after three and a half years, independent experts confirmed that the DNA results were not reliable and they were inconclusive."
The 144 page report filed in court today will be discussed in court in Perugia on July 25.
A third person was also convicted of the murder. Ivory Coast drifter Rudy Guede is serving a 16 year prison sentence. Earlier this week, Guede appeared before the appeals court and prosecutors read a letter that Guede wrote to his lawyer in which he stated that Knox and Sollecito were present during the murder.
"I was hoping that Rudy would actually own up to his responsibility and essentially tell the court that Amanda and Raffaele had nothing to do with it," Curt Knox said. "It was very disappointing that he wouldn't fess up to that."
Guede was rebutting testimony from a former cellmate that he had confided to him that Knox and Sollecito were not present during Kercher's murder.
Knox's seemingly bizarre behavior after the murder has been cited by prosecutors. Police told the court in 2009 that she had a "strange attitude" after discovering her roommate had been killed and did a cartwheel in the police station, among other things.
"[The report] should glean a very shining light on that fact and while she may not have reacted the way people would expect, it really does not mean she's a murderer," her father said.