The body of the 21-year-old British exchange student Meredith Kercher was found by police in the Perugia apartment she shared with Amanda Knox on November 2, 2007.
Officers discovered Kercher's throat was slashed and she had been sexually assaulted.
Knox and her then-boyfriend Raffaele Sollecito were arrested and later convicted of murder and sexual assault in 2009.
The couple maintained their innocence, insisting that they had spent the evening together at Sollecito's home watching a film, smoking marijuana and being intimate.
Amanda Knox (left) was convicted of murdering her roommate, British exchange student Meredith Kercher (right), in their Perugia apartment in 2007 - but she was later cleared of the killing
Describing her ordeal earlier this year, Knox said: 'I was interrogated for 53 hours over five days, without a lawyer, in a language I understood maybe as well as a ten-year-old.
'When I told the police I had no idea who had killed Meredith, I was slapped in the back of the head and told to 'Remember!'
'I trusted these people. They were adults. They were authorities. And they lied to me.'
In 2011 the Perugia Court of Appeal acquitted the pair of the more serious charges, though upholding a minor conviction for Knox.
She returned to the United States that year.
Knox and her