Knox Trial: Window Broken from Outside

US murder suspect Amanda Knox is escorted by a penitentiary police officer as she arrives for a hearing in the Meredith Kercher murder trial, in Perugia, Italy, Saturday, June 6, 2009. Knox and her former Italian boyfriend, Raffaele Sollecito, are on trial for the murder of Knox's British roommate, student Meredith Kercher, found dead in the house they shared in Nov. 2007. (AP Photo/Stefano Medici)
AP Photo/Stefano Medici
News reports say a police official and defense consultant has testified in the murder trial of a U.S. student in Italy that no break-in was staged in the apartment where a Briton was slain in 2007.

The testimony casts doubt on a key prosecution argument.

Prosecutors say Amanda Knox and co-defendant Raffaele Sollecito killed Knox's roommate, Meredith Kercher, and then broke one of the apartment's windows from the inside to stage a burglary.

A stone was found in one of the bedrooms, with shattered glass on the floor.

The ANSA news agency said Francesco Pasquali testified Friday in Perugia, central Italy that the window was broken from the outside.

ANSA said Pasquali used a video to reconstruct how the stone was thrown.

Knox and Sollecito deny wrongdoing.