Perugia, Italy (CNN) -- A defense lawyer for Amanda Knox made an impassioned plea to the jury Wednesday as the high-profile case neared its conclusion. Knox is the American student accused of killing her British roommate, Meredith Kercher, at the villa they shared in Italy.
"We suffer at the memory of Meredith. But we look at the future of Amanda," Luciano Ghirga said in his defense summation.
"Meredith was my friend," he quoted Knox as saying, rejecting the notion that she hated her roommate, who was fatally stabbed in November 2007.
Prosecutors say Kercher died during a twisted sex game in which Knox taunted Kercher, and two men -- Knox's then-boyfriend Raffaele Sollecito, 26, and acquaintance Rudy Guede -- sexually assaulted her.
The prosecution says a knife found in Sollecito's house had Knox's DNA on the handle and Kercher's on the blade, among other pieces of evidence.
But Ghirga rejected the accusations against Knox on Wednesday.
He attacked the way police and prosecutors had treated the defendant, giving them a symbolic "red card" -- a referee's sign in soccer that a player is being expelled from the game for breaking the rules.
Ghirga concluded an emotional oration -- sobbing as he came to the end -- by asking the judge and jury to acquit Knox, because her mother asked him to request it, because her family asked it.
Knox's father, Curt, said Wednesday she had been a victim of "character assassination," and expressed hope she would be found not guilty.
Members of Kercher's family have declined repeated CNN requests for comment on the case.
But prosecutor Giuliano Mignini accused the defense of "lynching" the Italian police who worked on the case.
He defended the work of the police and the credibility of the prosecution witnesses as he responded to Ghirga's arguments Wednesday.
And he called again for life sentences for Knox and Sollecito if they are found guilty. Italy does not have the death penalty.
The jury is expected to begin deliberations on Friday, after the prosecution completes its summary.
Another Knox attorney on Tuesday said the prosecution's theory doesn't fit the facts of the case and there is not sufficient evidence to find her guilty.
Calling Knox a victim herself, Carlo della Vedova said the police had rushed to judgment following the murder, leaving Knox to fend off a myriad of false media reports regarding the crime.
The lawyer showed photos published in the media, purportedly showing the crime scene, that weren't authentic -- including a photo of the bathroom -- and said false allegations and rumors about Knox's character created a bias from the start.
Della Vedova also questioned the change in what prosecutor Mignini said was the motive for the murder.
In preliminary hearings, Mignini argued Knox, Sollecito and Guede slashed Kercher's throat during a sexual misadventure as the two men vied for Knox's attention. In recent days, Mignini has focused more on what he says was a hatred between the two roommates.
Defense lawyers have staunchly disagreed, claiming the two women were friends.
Ghirga on Wednesday said the two had gone to a chocolate festival together days before Kercher was killed.
The defense has argued that Guede, who was convicted in a separate fast-track trial and is currently appealing his conviction, was the sole killer. The defense has said there is no evidence tying the three suspects together or proving they planned Kercher's murder.
Della Vedova also focused during closing arguments on the lack of evidence tying Knox to the crime scene.
As defense lawyers have throughout the entire trial, he cast doubt on DNA evidence that prosecutors claim shows Knox's DNA on the handle of the alleged murder weapon. The defense has said the knife doesn't match Kercher's wounds or an imprint of the knife left on a bedsheet, and the DNA sample is too small to be conclusive.
During the first day of closing arguments for Knox's lawyers, della Vedova stressed to the eight-member jury that they should also keep church law in mind as they decide whether to find Knox and Sollecito guilty or not guilty.
He told the jury they needed to be "morally certain of their decision."
"If you have the minimum of doubts, you must absolve this young girl -- a girl that is merely 22 years old," he said.
Knox and Sollecito, who both deny any role in the murder, have been jailed for more than two years since they were arrested on charges of murder and sexual violence.
Their trial began in January.
CNN's Mallory Simon contributed to this report.