The knife: The prosecution in 2009 said that a knife found in Raffaele Sollecito's house has the DNA of Amanda Knox on the handle and the DNA of victim Meredith Kercher on the blade, suggesting it's the murder weapon. The defense said the knife doesn't match the shape and size of wounds on Kercher's body or an outline of the knife left on her bed. The defense also presented experts who said DNA on the blade was too small to be definitive.
DNA on Kercher's bra clasp: The prosecution said that a bra clasp that was ripped from Kercher's bra and found on the floor of her room has Sollecito's DNA on it, proving he was in the room when she was killed. The defense said the bra clasp is contaminated and essentially tainted evidence because it was moved around the crime scene and left there for more than six weeks before it was picked up as evidence.
Knox's confession: The prosecution said that during her interrogation, Knox said she could hear Kercher screaming. She also pointed the finger early on at Patrick Lumumba, who was eventually released. The prosecution said Knox's false statement proves she is lying and was at the home when Kercher was killed. The defense said that Knox's statements were made when she was asked to imagine what would have happened that night in her apartment. The defense said Knox pointed the finger at Lumumba because she was confused and pressured. Eventually, the confession was thrown out because Knox was not questioned with a lawyer present.
Bloody footprint on bathroom rug: The prosecution attributed a bloody footprint on a rug in the bathroom to Sollecito, which they said proves he was there at the time of the murder. The defense, in this instance Sollecito's lawyers, presented forensic experts who said the print was in no way a match to Sollecito, but instead a match to Rudy Guede, a man from the Ivory Coast who was convicted in a separate trial for murdering Kercher. The defense focused on Sollecito's hammer toe, which they said wouldn't leave an imprint like the print found on the mat.
The window: The prosecution said a broken window in the home Knox shared with Kercher was an attempt by the American to stage a break-in as a cover for the murder. The prosecution said it would be impossible for someone to break the window and climb through the window as proposed by the defense. The defense said the window was broken by Guede, a known drifter who had broken into homes before. Defense expert Francesco Pasquali simulated how glass would break if a rock were thrown from the outside. His testimony included that he believes a burglar could have thrown a rock that way.
Allegations of crime scene contamination: The defense argued that several pieces of key DNA were contaminated at the scene. Crime scene video shows investigators sometimes not wearing gloves or hair coverings, prodding their fingers in Kercher's wounds, leaving key pieces of evidence at the scene for weeks and moving them around, and at one point breaking a window for no reason. The prosecution argued that all the evidence was indeed properly handled and that it isn't their job to prove the crime scene work was good enough. Instead, they said, that's the job of the defense.
Bloody shoe print in Kercher's room: The prosecution said the bloody shoe print found next to Kercher's body belonged to Sollecito and placed him in Kercher's room when she was murdered. The defense said that after Guede was found to have a shoe box for shoes matching the print, they argued for a re-examination of the print. Francesco Vinci, a coroner and forensic specialist for Sollecito, testified he believes it was wrongly attributed to Sollecito and belongs to Guede.