MILAN — The Italian appeals court that reinstated the conviction against Amanda Knox in her roommate’s 2007 murder said in a lengthy reasoning made public Tuesday that Knox delivered the fatal blow, and overwhelming physical evidence precluded a need to determine a clear motive.
Presiding Judge Alessandro Nencini concluded in a 337-page document that the evidence ‘‘leads to the upholding of the criminal responsibility’’ against Knox and her former boyfriend Raffaele Sollecito for the murder of 21-year-old Meredith Kercher in a hillside villa occupied by students in the university town of Perugia.
The judge said the nature of Kercher’s wounds inflicted by two knives and the absence of defensive wounds indicated multiple aggressors were to blame, including Rudy Hermann Guede, an Ivorian man convicted separately and serving a 16-year sentence.
Nencini presided over the panel that reinstated the guilty verdicts against Knox and Sollecito in January, handing Knox a 28½-year sentence including the additional conviction on a slander charge for wrongly accusing a Congolese bar owner. Sollecito faces 25 years.
The release of the court’s reasoning opens the verdict to an appeal to the supreme Court of Cassation. If it confirms the convictions, a long extradition fight for Knox is expected.
She has been in the United States since 2011, when her earlier conviction was overturned. Knox has vowed to fight the conviction, saying she would ‘‘never go willingly’’ to Italy to face her judicial fate.
Sollecito’s lawyer, Giulia Bongiorno, tore apart the reasoning, saying ‘‘from the motive, to weapon, to the DNA, it is a string of errors.’’
‘‘I can’t wait until they fix a day to hear us for the appeal, because honestly the verdict is so full of errors, illogical elements, and contradictions, that I strongly believe it will be overturned,’’ Bongiorno said.
The judge said relations between Knox and Kercher were strained, despite Knox’s attempts to downplay tensions during the trial, and that the two had argued over housekeeping and visitors.
He also cited as credible Guede’s statements that the British student had accused Knox that evening of stealing rent money from her room, though none of the defendants was convicted of the theft.
According to Nencini, Knox and Sollecito on the night of the murder arrived at the house sometime after Kercher, and Knox let Guede inside — dismissing defense arguments that Guede had broken in.
‘‘It is a matter of fact that at a certain point in the evening events escalated; the English girl was attacked by Amanda Marie Knox, by Raffaele Sollecito, who was backing up his girlfriend, and by Rudy Hermann Guede, and constrained within her own room,’’ the document said.