A judge has ruled the trial of two suspects for the murder of Meredith Kercher will be heard in public.
American Amanda Knox, 21, and Italian Raffaele Sollecito, 24, appeared in front of an eight-member jury in a courthouse in Perugia, Italy.
A lawyer for the Kercher family, who are from south London, had tried to bar the press and public to stop some evidence being made public.
Judge Paolo Micheli reserved the right to hold some sessions in private.
He said the court would decide on a case-by-case basis when to do this.
As the trial began the defendants were seated next to their lawyers and guarded by prison officers.
Miss Knox wore jeans and a striped top.
During proceedings, she smiled and chatted with an interpreter, while Mr Sollecito, wearing beige trousers and a bright green sweater, looked tense.
Both deny the murder of 21-year-old Meredith, found stabbed to death in November 2007 in the apartment she shared with Knox.
Meredith Kercher's partially-clothed body was found locked in her bedroom
A third suspect - 21-year-old Rudy Hermann Guede, born in Ivory Coast - was jailed last October for 30 years.
Prosecutors claim the Leeds University student was killed as part of a bungled sex game involving Guede, her housemate Miss Knox, from Seattle, and the American's ex-boyfriend Mr Sollecito, from Bari in southern Italy.
Miss Kercher had been studying in Perugia as part of the Erasmus student exchange programme.
Miss Knox's family are trying to block the publication of a book about the murder case written by an Italian journalist.
Before the trial started, Miss Knox's lawyer, Luciano Ghirga, confirmed that his client was seeking 500,000 euros (£450,046) in compensation for damage allegedly already caused by the book and articles published in an Italian daily newspaper.
He said too much "sensitive information" about the sex life of the Seattle-born foreign exchange student had been published.
Mr Ghirga said: "She is not a victim, but the media has created a false picture of Amanda.
"We still hope she will get a fair trial though."
A large number of journalists from the national and international press have descended on Perugia for the beginning of the trial, which could last up to a year.
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