Italian prosecutors Saturday requested life in prison for Amanda Knox and her ex-boyfriend accused in the fatal stabbing of her British roommate during a drug-fueled sex game.

In their closing arguments, prosecutors said Knox and Italian Raffaele Sollecito should be convicted on charges of murder and sexual violence for the 2007 slaying of Meredith Kercher. Knox and Sollecito deny wrongdoing.

Reporters said the 22-year-old Knox took a deep breath when Prosecutor Giuliano Mignini requested life imprisonment -- Italy's stiffest punishment. Knox then told the court the accusations against her were not true and that, contrary to what the prosecution has said, she did not hate Kercher and called her a friend.

Knox's stepfather, Chris Mellas, was in the courtroom and later called the prosecution's story of the killing a "fantasy."

Knox has been jailed for more than two years since her arrest shortly after the slaying.

Defense lawyers begin their closing arguments late next week.

On Friday, lead prosecutor Giuliano Mignini claimed Knox of fatally stabbing Kercher because of a growing hatred for the victim and killed her in retaliation during a drug-fueled sex game. Knox appeared to be weeping as Mignini described the wounds on Kercher's body. Her lawyer, Luciano Ghirga, sitting next to her, at one point held her hand. Looking discouraged and keeping her head down, she was hugged and comforted by lawyers during breaks.

Mignini recalled previous testimony by Kercher's friends, in which the Briton reportedly expressed surprise and irritation at Knox's behavior. Knox has denied having major problems with Kercher and has said in the past she was shocked at the death of a woman she considered a friend.

Ivory Coast citizen Rudy Hermann Guede is appealing his conviction and 30-year sentence handed down after the fast-track trial he requested.

According to prosecutors, a knife with a 6 1/2-inch blade with Kercher's DNA on the blade and Knox's on the handle was found at Sollecito's house.

"That is the weapon with which Amanda inflicted the deadly blow," Mignini said. Defense lawyers argue that the knife is too big to match Kercher's wounds and the amount of what prosecutors say is Kercher's DNA is too low to be attributed with certainty.

Prosecutors also maintain Sollecito's DNA was found on the clasp of Kercher's bra, although his defense team contends that the evidence might have been inadvertently contaminated during the investigation.

Also on Friday, Mignini said that Knox and Sollecito staged a burglary in the apartment by breaking a window in a bedroom in an attempt to sidetrack the investigation.

A rock was found in a bedroom, and witnesses testified that shattered glass was found all over clothes on the floor, suggesting the window was broken after the room was put into disarray.

"The key to the mystery is in that room," Mignini said, adding that it would be nearly impossible to climb through the window without getting cut and leaving blood on the shattered glass.

Also, he argued, that window, the most exposed of the apartment, was an unlikely choice for a burglar. Nothing in the room with the broken glass, which belonged to a roommate of Knox and Kercher, was reported missing, Mignini noted.

"All of this was done to channel suspicions on a stranger, and divert them from those who had the apartment keys," he said. Knox's defense lawyer Carlo Dalla Vedova said Mignini's reconstruction was "suggestive," but it failed to present solid evidence.

Defense lawyers for Knox and Sollecito are working on the theory that Guede was the sole attacker.