Contested DNA evidence proved vital to defence team’s case

CONTESTED DNA evidence played a pivotal role in the appeal to clear the names of Amanda Knox and Raffaele Sollecito.

But there were also several other doubts surrounding her original conviction.

Prosecutors said that tensions between Knox and Meredith Kercher had reached boiling point over disagreements about hygiene, with sex toys and condoms strewn about the home they shared.

But defence solicitors said they failed to explain how such differences would have driven Knox to kill Kercher.

Jurors in the original trial had heard prosecution claims that DNA found on a knife allegedly used in the murder, and on the clasp of Ms Kercher’s bra, implicated the pair.

But this evidence was fiercely disputed by the defence, which maintained that it was inconclusive and argued it was contaminated when analysed.

Independent experts even said there were over 50 breaches of internationally recognised protocol in collecting the evidence used to convict Knox and Sollecito.

The genetic evidence was tainted by the use of a dirty glove and failure to wear protective caps, the experts claimed.

They pointed out how the DNA count on the knife was so low that it should not be ruled as enough for a definite match — to highlight this they noted how there was not enough left to perform a second test.

No traces of blood could be found either — only potato starch — which they said would have been washed away if it had been as thoroughly cleaned with bleach as prosecutors insisted.

It also did not match a bloody outline of a knife left on Meredith’s bed and was also far too big to have caused the wounds on Meredith’s throat.

The bloodied bra clasp used as evidence was also dismissed, as it emerged that it had been left lying on the floor for six weeks before being collected by forensics officers.

A video was shown in court of the crime scene being examined and the experts highlighted how the team wore dirty gloves, picked up evidence using their hands instead of tweezers and put it in plastic bags instead of paper ones.

Shoe covers were also not changed regularly and all this they suggested led to a strong possibility of the evidence being contaminated — although the prosecutors dismissed their suggestions and called them “inexperienced”.

Defence solicitors also argued that the prosecution’s case was based on hypotheses and that any motive for the murder was lacking.

Their case was boosted when a key prosecution witness gave conflicting reports during the appeal process about whether he saw Knox and Sollecito near the crime scene on the night of the murder.

In the original trial, Antonio Curatolo, a homeless man, placed the couple near the house around the time in question.

But when called on to give evidence in the appeal, he confused the dates and was labelled completely unreliable by the defence team.

Even Rudy Guede, the Ivory Coast-born drifter who was also convicted of the murder, initially said that Knox was not in the house on the night of the murder, but changed his story a few months after his arrest: He saw Knox’s silhouette outside the house.

In one of the final hearings, the court rejected a prosecution request for new DNA tests, deeming them unnecessary.

By this stage, even the prosecutors appeared to be admitting defeat, with one, Manuela Comodi, reportedly saying that she could envisage the pair being cleared.