Amanda Knox, the American student from a respectable family, seemed to have everything going for her: looks, plenty of friends and the wherewithal to travel the world at a young age.
But behind the smiles and innocent looks lay what Italian prosecutors said was a she-devil whose aggressive self-regard caused her to build up an implacable hatred of the studious Briton who shared her apartment in Perugia.
Meredith Kercher was a hard-working pleasant young woman who had little in common with Knox.
Knox, in her short time in Italy had already managed to snare herself a local boyfriend and was in touch with the seamier side of life there, on personal terms with known drug dealer Rudy Guede.
Police believe she felt that Miss Kercher somehow looked down on her behaviour and general lack of standards which only encouraged her irrational dislike of the Briton.
One night in November 2007 her hatred, probably fuelled by drink and drugs, boiled over into murderous rage.
Police are still not certain why Knox, her boyfriend Raffaele Sollecito and Guede were all at the house in Perugia together, although they suspect that a drug deal was behind the meeting.
They cornered Miss Kercher in her room and what began as some kind of sex game ended with Guede and Sollecito holding her down while Knox cut her throat with a six-inch kitchen knife.
In panic afterwards they clumsily tried to make the death look like part of a burglary gone wrong - breaking the window in Miss Kercher's room to look like forced entry, but doing it from the inside which was soon spotted by police.
And Knox's odd behaviour after the discovery of the body immediately sparked suspicions.
While waiting to be questioned at the police station, she was reported to have performed a cartwheel and done the splits.
During her police interrogation, she went on to accuse an innocent man of the murder, bar-owner Diya "Patrick" Lumumba who employed her as a barmaid.
Mr Lumumba's lawyer Carlo Pacelli described Knox as a "talented and calculated liar, who had deliberately gone out of her way to frame Patrick".
He added: "It was a ruthless defamation that destroyed Patrick as a man, husband and father. By naming him she hoodwinked the officer in charge of the investigation."
Mr Lumumba spent two weeks in custody before being completely cleared by several witnesses who saw him at his bar on the night of the murder.
None of this, prosecutors argued, was the behaviour of an innocent woman.
As Mr Lumumba's lawyer said: "Who is the real Amanda Knox? Is it the one we see before us here, simple water and soap?
"Or is she really a she-devil, a diabolical person focused on sex, drugs and alcohol; living life to the extreme and borderline?"
When Knox was arrested she was thrown into the spotlight already shining on Perugia, and every detail about her life was seized on by those fascinated with this young, female murder suspect.
Her good looks and the lurid headlines about her sex life splashed across newspapers made her a transatlantic object of fascination.
Her nickname Foxy Knoxy on social networking site MySpace was seen as a reference to her looks and was adopted by the press.
Her family and friends insisted it was a nickname she had gained due to her football skills, but the name stuck.
Originally from Seattle, Knox was a University of Washington student who went to Perugia to study.
She described herself on her MySpace page as a lover of "good wine, rock climbing, backpacking long distances with people I love, yoga on a rainy day, making coffee and lots of languages".
Not long after arriving in Perugia, she developed the relationship with Italian IT graduate Sollecito.
She claimed that the night Miss Kercher was murdered, she was at Sollecito's house, smoking marijuana and making love.
It was not a version of events that the judge and jury chose to believe.