Expert: Knife didn't kill British co-ed

PERUGIA, Italy, July 6 (UPI) -- A defense witness says a knife identified as the murder weapon of a British co-ed in Italy isn't compatible with wounds suffered by Meredith Kercher.

Attorneys for Amanda Knox, an American college student accused of killing roommate Kercher in 2007, called on medical consultant Dr. Carlo Torre to testify for Knox's defense Monday at her trial in Perugia, Italy, the news agency ANSA reported.

ANSA said Torre disputed the prosecution's identification of the knife as the weapon that killed Kercher, saying instead the 22-year-old student had been attacked with a smaller blade. The distinction is important because prosecutors say police found traces of DNA belonging to Knox and co-defendant Raffaele Sollecito on the weapon's handle.

Kercher was found semi-naked and with her throat slit on Nov. 2, 2007, in the house she shared with Knox, 21, and two Italian women. Prosecutors say Knox, her then-boyfriend Sollecito and another man killed Kercher when she refused to participate in a sex game.

Torre testified Kercher's killer stabbed her from the front as she was lying down, adding evidence indicated that she "was not wearing a bra" when her throat was cut, ANSA reported.