Meredith Kercher's father has appealed to her murderer to finally "come clean" and reveal what really happened the night she was stabbed to death.
Rudy Guede is the only person who remains behind bars in Italy for sexually assaulting and killing the British student and has "nothing to lose" from telling the truth now, John Kercher argued.
Amanda Knox, from Seattle, US, and her Italian ex-boyfriend Raffaele Sollecito walked free from prison in Perugia last October when their convictions for the murder were dramatically overturned.
And the Kercher family has been left feeling ignorant of the exact circumstances in which 21-year-old Meredith died in the Umbrian town on November 1 2007.
Mr Kercher, 69, from Croydon, south London, believes there "had to be" more than one killer involved - and does not seem to think the evidence points to a "random" culprit. "They say Meredith was killed in front of her wardrobe in her room and then the body was moved across the floor and covered with a duvet," he said. "Why would you do that if you're just a random killer?"
Yet there is little scope for the murder inquiry to be reopened and a hunt for other suspects launched, he acknowledged. "I don't see how the investigation can be reopened if there is no other evidence, but what I would like to see is Rudy Guede coming clean and saying something," he said. "If he was there then why doesn't he tell the truth?"
Guede, a small-time drug dealer from the Ivory Coast, has always admitted being present at Miss Kercher's cottage on the night of the murder but denies involvement. Prosecutors claimed he collaborated with Knox and Sollecito in the killing but that version of events was rejected by the appeal court.
Meanwhile, in the four years between the murder and acquittals, Knox was turned into "some kind of celebrity" while Miss Kercher was all but eclipsed, her father said.
In his new book, Meredith: Our Daughter's Murder and the Heartbreaking Quest for the Truth, Mr Kercher turns the spotlight back on to his daughter.
Speaking just after it hit the shelves, he said: "People wanted me to write this book because they say 'we know everything about Knox but nothing about Meredith'. You can understand that obviously Meredith is dead while Knox, Sollecito and Guede are alive so the focus is on the people who are still part of the scenario and I think that's where the fault lay."