Knox, 24, appeared tense during the session. Her mother, Edda Mellas, said it was hard for her "as she has to listen to people saying horrible and untrue things about her."
Costagliola pointed to what he said were the clues that point to the defendants: bloody footprints found in the house that are compatible with those of the defendants, cell phone activity and witness testimony that appear to contradict the defendant's alibi that they spent the night at Sollecito's house and stayed there until about 10 a.m. the day after the murder, a staged burglary at the house of the murder aimed at sidetracking the investigation.
All clues converge toward the only possible result of finding the defendants guilty," he said.
Knox and her former boyfriend are hoping a recent review of DNA evidence will help to get their convictions overturned in the 2007 murder of Meredith Kercher.
Next week, a lawyer representing the Kercher family and then the defense lawyers will make their closing arguments. Knox herself is expected to address the court in a final appeal to proclaim her innocence.
A verdict is expected by early next month.
The Associated Press contributed to this report.