ROME — Lawyers for Amanda Knox’s ex-boyfriend made a final appeal to Italy’s top criminal court Friday, urging it to overturn the pair’s murder conviction for the 2007 slaying of Knox’s roommate, saying there were errors of “colossal proportions” in the guilty verdicts.

Attorney Giulia Bongiorno dissected the 2014 Florence appeals court decision to show what she said were numerous errors of fact and logic that resulted in prison sentences of 28 1/2 years for Knox and 25 years for Raffaele Sollecito in the death of student Meredith Kercher.

Judges at the high Court of Cassation began deliberating shortly after noon, and a decision could come late Friday. A decision to confirm the convictions could result in an extradition request from Italy for Knox, who is currently free in the United States. Knox has vowed never to willingly return to Italy.

In her closing arguments, Bongiorno said even Knox’s original statement to police — which was never entered as evidence and was later changed — exonerated her client.

Knox, who along with Kercher had been studying in the university town of Perugia, had initially accused a Congolese bar owner of the murder. She also told investigators that she was home the night that Kercher was killed and had to cover her ears to drown out her screams.

Bongiorno said she believed Knox’s statement was coerced — but that even if the high court chooses to consider it, Sollecito figures nowhere in her story.

“My heart is crying because I think she was pressured by an intermediary,” Bongiorno said, apparently referring to the person who served as Knox’s unofficial translator during police questioning. But within that statement, Bongiorno added, Knox “rules out Sollecito.”

Kercher, a 21-year-old student from Britain, was found dead Nov. 2, 2007, in the apartment that she shared with Knox and two other students. Her throat was slashed and she had been sexually assaulted.

Knox and Sollecito were arrested a few days later. They both have maintained their innocence.

Initially Sollecito said he was working on his computer all night, and that he couldn’t remember if Knox had stayed the whole night with him. Police said there was no sign he used the computer that night.