The trial will resume Nov. 25, with a verdict expected in January.
Sollecito asked the court in Florence to find him innocent and restore normality to his life, the British newspaper The Guardian reported. Knox remained at home in the United States and did not attend the trial.
"I was already imprisoned as an innocent person in Italy, and I can't reconcile the choice to go back with that experience," she told NBC's "Today" show.
Police experts testified a knife thought to be the murder weapon had DNA from Knox but not from the victim, Meredith Kercher, a British exchange student and Knox' roommate, Gazetta del Sud reported. The knife was from Sollecito's kitchen.
Attorneys for Sollecito and Knox say the lack of DNA guts the prosecution case.
In a 15-minute address to the court, Sollecito, 29, said he had been described as "a ruthless killer" in the 2007 death of Kercher, "but I am nothing of the sort."
"I would like to make you understand that these charges against me are absurd," he said. "There was not a basis to charge me, to put me in jail. I don't wish anybody on Earth to go through what I went through. This was something that was so bad," CNN reported.
He and Knox, a U.S. student studying in Italy, were convicted in 2009 of killing Kercher in a group orgy gone bad. They served four years in prison before their convictions were overturned in 2011. Italy's Supreme Court decided to retry the case in 2012.
Knox, 26, chose not to return to Italy for the retrial. She and Sollecito maintain they are innocent
Luca Maori, Sollecito's lawyer, said before the hearing her client had returned to Italy from the Dominican Republic "to show that he is not running away."
Sollecito said Knox was his "first true love" and they were living a "little fairy tale" at the time of Kercher's murder. Their only crime, he said, was that they initially failed to take the charges against them seriously.
The retrial began Sept. 30 without either of them in the courtroom. Knox returned to her hometown of Seattle and has said she won't return to Italy.