The defense for U.S. student Amanda Knox says female police officers investigating the murder of British student Meredith Kercher "had it in" for Knox because of a sex toy found in the home both women shared, Sky News reported.

SLIDESHOW: Amanda Knox on Trial for Murder

In closing arguments, Knox's lawyer Luciano Ghirga described a "clash between women from the Perugia flying squad" and his client.

"They had it in for her just because she had condoms and a vibrator in her beauty case," said Ghirga, according to Sky News.

LIVESHOTS: Amanda Knox’s Verdict: Life Or Walk Free?

Knox "had suffered as a result of this antagonism," Ghirga told the murder trial, being held in Perugia.

Knox, 22, and her former boyfriend Raffaele Sollecito, 25, are jointly charged in Kercher's murder in Perugia, Italy. Prosecutors claim she was killed after refusing to take part in a drug-fueled sex game.

Ghirga wrapped up his closing arguments Wednesday, breaking down after he urged the court to give his client back her life.

He insisted that Knox was the victim of a "mechanism that crushed her."

"Amanda is asking to have her life back. Give Amanda her life back by clearing her of all charges," Ghirga said, raising his voice and fighting back tears at the end of his three-hour long remarks.

A verdict by the eight-member jury is expected by the end of the week.

Ghirga challenged evidence in the case, including a knife that prosecutors say could be the murder weapon. The 6 1/2-inch blade that prosecutors say had Kercher's DNA on the blade and Knox's on the handle was found at Sollecito's house. According to Ghirga, wounds and cuts on the Kercher's body indicate that a smaller knife might have been used in the attack.

He charged that prosecutors had changed their minds about the alleged motive for the attack.

"Initially, it was a sexual motive, now it's hate," Ghirga said. "But that's just another non-existing motive."

In his closing remarks, lead prosecutor Giuliano Mignini contended that Knox "harbored hatred" for Kercher and wanted to get back at her for saying she was not clean and was promiscuous. Knox has denied having problems with Kercher and has said she was shocked by her friend's death.

In an apparent acknowledgment of the enormous pressure the high-profile case has created, Ghirga appeared to weep as he thanked the jury and colleagues at the end of his arguments.

"I broke down at the end, as soon as I stopped talking. I even feel a bit embarrassed about it," he said as he left the courtroom.

Prosecutors requested life terms for Knox and Sollecito, who maintain they were at Sollecito's apartment the night of the slaying, watching a movie on his computer and smoking pot. Defense lawyers for Knox and Sollecito are working on the theory that Guede was the sole attacker.

Knox's sister, Deanna Knox, said she was nervous about the outcome but hopeful things would go well.

"I know she is innocent and she'll be home any time now," she said.

Knox is also being tried on charges of defamation for allegedly accusing Diya "Patrick" Lumumba — a Congolese man who owns a pub in Perugia where she worked — of being the killer. Because of her accusation, Lumumba was briefly jailed. He was later cleared and is seeking damages from Knox. The American testified last June that she was beaten by police and confused when she was questioned and that the pressure led her to accuse Lumumba.

Police have denied any misconduct.

Knox is expected to speak for the last time at the trial later.

An indication of what she might say emerged from a piece of paper she had been making notes on, as she sat in court on Tuesday, Sky News reported.

Written in perfect Italian under the heading "Things I want to say," it read: "I am scared that I am going to be convicted for something that I didn't do," the Web site reported.

"I would like to thank the judges and say that I am scared of losing my chain of thought because what I am being accused of is just not me."

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The Associated Press contributed to this report.