PERUGIA, Italy – A police officer dealt an apparent blow to the alibi of a young Italian man on trial for the murder of a British student when he testified Saturday that there was no sign of the defendant using his computer during the hours the woman was stabbed to death.

Tests on student Raffaele Sollecito’s computer found that nobody had worked on it in some eight hours spanning the night when Meredith Kercher was stabbed to death in her bedroom, prosecution witness Marco Trotta told an Italian court.

Sollecito, 24, and Amanda Knox, his 21-year-old former American girlfriend, are on trial accused of murdering Kercher in 2007 in the Umbrian university town of Perugia. Both defendants deny any wrongdoing.

Sollecito has maintained he was at his own apartment the night of the murder, working on his computer.

Kercher’s body, stabbed in the neck and lying in a pool of blood in a bedroom of the apartment she shared with Knox, was found in the late morning of Nov. 2.

Knox, a University of Washington student, was on an exchange program in Italy and sharing a flat in a rented house with Kercher, a 21-year-old student from Leeds University in England.