Peter Popham: Italians have already passed judgment on Foxy Knoxy

The trial of Amanda Knox and her Italian ex-boyfriend has begun , with a media frenzy erupting amid the studied indifference – revulsion might be a better word – of the city of Perugia. After a wait of 15 months, during which she flashed before the cameras for only a few seconds between police van and courtroom, finally the world was able to gaze on "Foxy Knoxy".

What did we see? A fairly nice-looking, preppy American student, transparently delighted that the long wait is over and that at last she is facing the judge and six jurors.

Knox, 21, and Raffaele Sollecito, 24, who sat a few feet from her throughout the occasionally impassioned, frequently tedious, seven-hour hearing on the first day of the trial, are accused of murdering Amanda's English flatmate, Meredith Kercher, in the flat they shared in central Perugia. Kercher's death is alleged to have been the culmination of an orgy that went horribly wrong.

But although the murder and the subsequent investigation have been headline news in Italy for more than a year, the public seating remained all but empty on Friday. The appetite for titillating gossip about the vivacious young American is clearly huge, but the city where the terrible events of the night of 1 November 2007 unfolded does not want to know.

Perugia's mayor, Renato Locchi, claimed the lack of interest was a measure of his citizens' maturity. "After hearing about the murder for more than a year, they can't take any more," he said. "They can't wait for justice to be done and the whole thing to be over. And in this respect I feel fully in harmony with them."

The deeper reason is that this is not an Italian crime but a foreign one. The victim and two of the three alleged killers are foreign, and the context is Perugia's University for Foreigners, which has little connection with the city. By staying away, citizens are saying: "This has nothing to do with us."

The only spectator on the first day of the trial was retired schoolteacher Teresa Marcucci, 63. "This crime has upset me so much," she told La Stampa, the Italian daily. "I feel a sense of pain for the poor victim, and an enormous pity for the young people in the dock." And what of them? "It seems to me that Raffaele was chased into trouble by Amanda," she said. And Amanda? "To see her laughing that way – even if she didn't commit the murder, she's not behaving well. It's very sad."

In Italy's eyes, Amanda Knox can do nothing right. She is so open and spontaneous that Italians are convinced she must have something to hide. On Friday she sauntered into court as if it was her first day back in class after Christmas, wreathed in smiles. The obvious explanation – that she was at last out of her cell and on her way – was too simple for Italy. Either she was concealing her guilt beneath that happy face, or (or in addition) she was exposing herself as the reckless voluptuary described by the prosecution. And in any case, as the sole spectator said, a person accused of murder should not put on such a happy face at her trial. It's unseemly.

It's an indication of how much work the defence will have to do to convince the poker-faced jury that Knox and Sollecito are innocent. The judge in the fast-track trial of the third accused, Rudy Guede, who last year sentenced him to 30 years' jail for his role, rejected out of hand the prosecution's garish description of how Amanda had presided at a satanic Halloween orgy in which she wielded the knife. But he was sufficiently convinced by the evidence investigators amassed to send the pair for trial.

Where did they actually pass the night, and doing what? Why did they make a start on cleaning up the murder scene next morning, and why didn't they call the police? Amanda Knox will have to do a lot more than smile if she wants to go home.