The crime scene was gruesome. The 21-year old British student was found under a duvet on the floor by her bed, covered in blood. A bloody handprint was streaked on the wall above her.
A source close to the prosecution says Kercher was held down while she was strangled and stabbed. The source says Sollecito's 6 ½-inch kitchen knife was used to slit her throat and then taken back to his apartment.
Prosecutors say just because the knife doesn't match everything doesn't mean it wasn't used.It is perhaps the biggest piece of evidence the prosecution has presented against Knox.
Knox's DNA is on the handle and that of Kercher is on the blade, said a source close to the prosecution who did not wish to be identified discussing an ongoing case.
Kercher had never been to Sollecito's apartment and wouldn't have come in contact with the knife, he said, yet there was her DNA. Those "unmistakable facts" show the knife played a role in the murder, the source said.
Bremner and experts testifying for the defense say there is no way the knife could be the murder weapon.
Dr. Carlo Torre, a leading forensics expert in Italy, testified that the knife taken from Sollecito's apartment wouldn't have made the wounds on Kercher's body.
"It doesn't match the size or shape [of the wounds,]" . "And Sollecito's knife also doesn't match a bloody outline of a knife left on the bedding."
Bremner, who offered her legal advice pro bono to the Knox family, questioned the validity of the DNA evidence, saying the knife had been "improperly transported in a shoe box