The success of Amanda Knox and Raffaele Sollecito’s appeal rested on a few key pieces of evidence during the original conviction.

The bra clasp: Investigators claimed the clasp of Meredith Kercher’s bloodied bra contained DNA belonging to Raffale Sollecito. It was a key part of the evidence as it was the only item to show traces of his DNA in the flat. But during the appeal it was revealed Italian investigators had left it on the floor of the flat for six weeks before bagging it. They had also used dirty gloves, picked things up with their hands instead of tweezers and used plastic rather than paper bags.

The knife: A knife found in the flat initially indicated blood on the blade believed to be Meredith Kercher’s and DNA on the handle of Amanda Knox. Police said they believed the knife had been thoroughly cleaned with bleach. But during the appeal, the defence counsel argued there was little DNA on the knife that it could not be considered a definite match. It also did not match a bloody outline of a knife left on Meredith's bed and was far too big to have caused the wounds on Meredith's throat.

Other evidence: Amanda Knox had confessed to being at the flat the night of the murder. But this evidence was deemed inadmissible after the defence claimed she had been subjected to 14 hours of questioning, which breached civil rights.

The prosecution had also claimed the murder was committed by more than one person as Meredith showed no signs of defensive wounds as if she was held down. But the defence claimed Rudy Guede, who had his conviction upheld, was known for breaking into houses and acted alone.