PERUGIA, Italy Dec. 2, 2009— -- A lawyer for Amanda Knox wrapped up her defense in the Italian murder trial today with an emotional, at times tearful, appeal to the court to acquit her of charges that she murdered roommate Meredith Kercher.
The dramatic plea by attorney Luciano Ghirga came on the final day of summations in the nine-month long murder trial which is expected to produce a verdict by the end of this week.
Ghirga railed against what he said were investigative mistakes, an abusive interrogation that produced screams from Knox, and to faulty evidence by the prosecution. He turned frequently towards the 22-year-old Knox as he portrayed her as a victim of a justice system that had gone awry.
"Amanda was a victim of a mechanism that crushed her," he said.
The lawyer appealed for sympathy for Kercher, but also for Knox.
"We suffer for what happened to Meredith," Ghirga told the jurors, referring to the murder victim, "but also for the future of Amanda."
Ghirga teared up at the end of his summation and apologized for a little "emotion." Turning to Knox's parents, he told the court, "Amanda's parents ask you for her acquittal. There is no Knox clan, just two desperate parents."
"The prosecutor is right about one thing, you should not forget the victim, Meredith," he said. "And there is one thing the prosecution should have done for Meredith, and that is an investigation done well from the beginning, with rigor."
Ghirga concluded by saying, "Amanda asks you for her life. Give Amanda her life back, by acqutting her."
The court took a break after his appeal and as Knox was led out of the court, she looked back at her family and smiled. They were also in tears.
Seated in the courtroom was Knox's father Curt Knox and her mother, Edda Mellas. Joining them today from their home in Seattle were Knox's younger sister Deanna, 20. Not allowed in court were her two youngest sisters Ashley, 14, and Delaney, 11.
Kercher's family is expected to arrive in time for the verdict.
The last word in the trial belongs to the defendants, and Knox may make a final appeal in the closing minutes of the trial on Thursday
Knox has been in jail for two years since her arrest for the Nov. 1, 2007 murder of Kercher, a 21-year-old British student whose semi-nude body was found in the cottage they shared with her throat cut. On trial with Knox is her ex-boyfriend Raffaele Sollecito. A third man, Ivory Coast native Rudy Guede, who has already been convicted of taking part in the crime and sentenced to 30 years in prison.
Amanda Knox Could Be Sentenced to Life in Prison
During the prosecutor's summation, he claimed that Knox led an attack on Kercher who criticized her for her cleaning habits, for bringing boys back to the cottage late at night, and accused her of stealing money from her.
If convicted, Knox could be sentenced to life in prison.
During his assault on the evidence, Ghirga said that his client was roughly grilled without the presence of an attorney. During the trial Knox testified that the officers yelled at her, called her a liar and hit her in the head.
"This is a privation of the right to defense of a person who was at that moment effectively a suspect, and," he said with his voice rising to a shout, "we will not accept it. It is a very serious omission that we cannot bear - something we did not know how to explain to her and her parents."
Ghirga said prosecutors leaked investigative documents that were to be kept secret, and he repeated charges that the blade of the alleged murder weapon did not match the cuts on Kercher's throat.
Besides facing murder charges, Knox is simultaneously being tried for slander since at one point she implicated Patrick Lumumba, a bar owner who she worked for at the time.
She mentioned Lumumba's name during her interrogation when she gave an odd confession, telling police that she had a vision of being at the murder scene the night Kercher was killed. She told police that Lumumba was also there.
Lumumba was later cleared of any involvement in Kercher's death and is suing Knox. Conviction of slander could result in a six year prison sentence.
Ghirga spent a considerable amount of time defending Knox against the slander charge.
Addressing the jury, he said that they have to decide whether "what Amanda said that night, her implosion, was the collapse of her alibi or evidence of utmost stress."
He cited a police offical who was in the building that night who heard Knox's screams down the hall. "How can someone give a serene statement" if she was yelling, he asked.
Ghirga said police were aggressive and critical of Knox until she signed her statements, and only later were they nice to her and took her for coffee.
Amanda Knox Jury To Deliberate on Friday
Turning to Knox, Ghirga asked, "And then what happens Amanda? What do they do? Handcuff you?"
Prosecutors ended their case later in the day with a rebuttal statement, particularly attacking the defense's claim that they had presented little in the way of a motive to explain Knox's vicious attack on her roommate.
Prosecutor Giuliano Mignini called Knox a "coiled spring that was unleashed that night."
"Meredith accused Amanda of a series of things, that Meredith must have considered unbearable: she brought boys home, she had a vibrator and condoms, she didn't flush the toilet," Mignini told the court.
The two men were willing to help her because "Raffaele always followed Amanda, and Rudy also tried to please her. The three of them were full of drugs and alcohol and things degenerate quickly in those conditions."
Her confession of having a vision of being at the murder scene was not coerced and it was not improper that a lawyer wasn't present, the prosecutor said.
"I asked Amanda if she wanted to make a spontaneous statement, and she said yes. In that situation the presence of a lawyer is not necessary. If a prosecutor questions a person, then a lawyer must be present," he said.
That statement was signed at 5:45 a.m.
Lawyers for the defense will get one last chance to rebut the prosecution and the jury is expected to begin deliberations by Friday.
ABC News' Nikki Battiste contributed to this report