PERUGIA, Italy (AP) — A defense lawyer for Amanda Knox, accused in the 2007 slaying of her British roommate in Italy, argued Tuesday that evidence in the case isn’t sufficient to convict the American exchange student.

In his closing arguments, lawyer Carlo Dalla Vedova charged that key DNA evidence in the case cannot be attributed “beyond any doubt.”

“There are still many doubts in this trial, and there’s a young girl waiting to be judged,” he told the eight-member jury, which is expected to issue a verdict this week.

The Seattle-born Knox and her former boyfriend Raffaele Sollecito are being tried in Perugia, central Italy, for the 2007 slaying of Meredith Kercher. They deny wrongdoing.

Kercher’s body, her throat slit, was found in a pool of blood on Nov. 2, 2007, in the apartment she shared with Knox. Prosecutors argued that Knox resented her British roommate and killed her, together with Sollecito and Rudy Hermann Guede, of Ivory Coast, under “the fumes of drugs and possibly alcohol.”

Prosecutors say a knife with a 6 1/2-inch (16.5-centimeter) blade, with Kercher’s DNA on the blade and Knox’s on the handle, was found at Sollecito’s house. Defense lawyers have argued that the knife is too big to match Kercher’s wounds. They say the amount of what prosecutors say is Kercher’s DNA is too low to be attributed with certainty.

Knox, 22, and Sollecito, 25, have been jailed for more than two years since being arrested shortly after the slaying. They are being tried on charges of murder and sexual violence and prosecutors have requested life imprisonment for them.

Guede was sentenced to 30 years in prison last year after a fast-track trial he had requested. He also denies wrongdoing and is appealing his conviction.