"This has been a real tragedy," he said. "I'm not a criminal."
Sollecito's new defense strategy comes as their legal teams prepare to appeal the couple's murder convictions in the death of Knox's former roommate Meredith Kercher before Italy's Supreme Court next year.
It's a dramatic departure from the past seven years, where the tactic has been to "stick together" and be "tried" together.
Sollecito attorney Giulia Bongiorno said that approach no longer works.
"They are not Siamese twins -- one body with two heads," she said.
The old approach began to change shortly after an Italian appeals court sentenced Sollecito to 25 years in prison and Knox to 28 years in January, and that change continued Tuesday.
Sollecito's lawyer John Kelly started laying the groundwork in February.
"It's imperative that the Italian courts consider Raffaele's case separate from Amanda's case," he said. "By necessity, he has to distance himself and his case from Amanda and her case."
In a CNN interview at the time, Sollecito followed his attorney's lead.
Though he said that the evidence clears them both, he used more selective language.
"There is nothing against me and nothing very strong against Amanda," Sollecito said. "And in my case, I really did nothing wrong, and I don't want to pay for someone else's peculiar behavior."
In a note on her Facebook page in February, Knox acknowledged Sollecito's new stance and appeared to back it up.
She said he's a scapegoat.
"The only reason he has been dragged into this is because he happens to be my alibi," she wrote.
Knox's behavior on the morning Kercher was found stabbed to death in the apartment she and Knox shared seems to be a new wrinkle in the Sollecito defense.
That was early November 2007, and he and Knox had been dating for only a week.
Sollecito expanded on his doubts in an interview with Italian television that also aired on NBC.
Knox had spent the night with him but went back to her place to shower, he said. When she returned, she was "very agitated," he said.
She told him that it looked like someone had broken in and that there was blood in the bathroom, Sollecito said. But rather than call police, she showered and returned to his place.
He finds it odd, he said.
"Certainly I asked her questions," he said. "Why did you take a shower? Why did she spend so much time there?"
He didn't get any real answers from her, he said in the interview.
"I'm not saying that Amanda is responsible for all this situation, but they focus on her and they accuse her all the time, but I have nothing to do with all these circumstances and all these accusations," Sollecito said.
Tuesday's news conference in Rome was a profile in contrasts.
At one point, Sollecito called into question Knox's version of events on the morning Kercher was found stabbed to death, saying it was "imagination and hallucination."
Yet, a few minutes later, he added, "Amanda and I still believe she is innocent."
There are some anomalies, Bongiorno said, but the legal team hopes that Italy's high court will rule in their favor by "annulling the sentence in full."
Since Kercher's death, Knox and Sollecito have gone through a legal odyssey that led to a conviction in 2009 that was overturned, followed by a second conviction in January.
Knox is now living in the United States. Sollecito lives in Italy.
Another man, drifter and drug dealer Rudy Guede from the Ivory Coast, is serving 16 years for Kercher's murder. He was tried separately from Knox and Sollecito.
He admitted having sex with the young British woman but said someone else killed her while he was in the bathroom.
CNN's Deborah Feyerick and Ben Brumfield contributed to this report.