(CNN) Jodi Arias and her legal team will begin fighting for her life this week when a new jury hears opening arguments on whether she should receive a life or death sentence for her murder conviction.

It's been a long legal journey for Arias, 34, whom a jury found guilty last year of first-degree murder in the gruesome killing of ex-boyfriend Travis Alexander, 30.

This week's court proceeding in Arizona is a retrial of the penalty phase. In 2013, the same jury that convicted her became deadlocked later on whether she should be executed for the 2008 murder of Alexander, who was stabbed 29 times, shot in the face and had his neck slit from ear to ear.

The impasse came when the jury voted 8-4 in favor of the death penalty for Arias, a source with knowledge of the jury's vote said at the time.

A death penalty requires a unanimous vote by the 12 jurors, and during the penalty retrial, a similar 12-0 vote will be required if Arias is to die by lethal injection, said Jerry Cobb, spokesman for the Maricopa County Attorney's Office.

Photos: The Jodi Arias trial Photos: The Jodi Arias trial Jodi Arias reacts on May 8, 2013, after an Arizona jury found her guilty of first-degree murder for killing Travis Alexander in June 2008. In 2015, Arias was sentenced to life in prison. Her trial took many turns and revealed a story of sex and violence. Hide Caption 1 of 15 Photos: The Jodi Arias trial Arias and Alexander met in 2006 at a business convention in Las Vegas. Arias became his girlfriend two months later, she testified. Alexander's bloodied body was found in his Mesa, Arizona, home in June 2008. Hide Caption 2 of 15 Photos: The Jodi Arias trial Faith was an integral part of Alexander's life. The professed son of methamphetamine addicts, Alexander was raised in Riverside, California, with three brothers and four sisters. His grandmother introduced him to Mormonism as a child. Soon after their first meeting, Alexander baptized Arias into the Mormon faith, a ceremony that was followed by anal sex, according to Arias' testimony. Hide Caption 3 of 15 Photos: The Jodi Arias trial Arias says that the pair broke up in 2007, and Alexander began seeing other women. There were claims that Arias would stalk him, peering in his windows at times. Still, he and Arias continued to hang out on several occasions until -- disenchanted Arias says -- she moved back to Northern California. They continued to communicate. Hide Caption 4 of 15 Photos: The Jodi Arias trial Alexander's naked body was found crammed in a stand-up shower after he missed two appointments, prompting friends to go to his house. Arias was charged with murder, at first denying the claims and later admitting she killed him in self-defense. Alexander's body was found with 27 stab wounds in the back and torso, a shot in the head, and his throat slit from ear to ear. Hide Caption 5 of 15 Photos: The Jodi Arias trial Arias spent 18 days on the witness stand recalling the minutiae of her allegedly abusive relationship with Alexander but claimed to have no recollection of the actual attack. Hide Caption 6 of 15 Photos: The Jodi Arias trial On February 28, 2013, prosecutor Juan Martinez asks Arias about a photograph she took of Alexander in the shower moments before he was killed. Prior to Alexander's killing, Martinez said, Arias stole her grandparents' .25-caliber pistol, rented a car in Redding, California, turned off her cell phone and brought along cans of gas so there would be no record that she was in Arizona. Hide Caption 7 of 15 Photos: The Jodi Arias trial Arias breaks down on February 28 after being asked by Martinez if she was crying when she stabbed Alexander and slit his throat. Hide Caption 8 of 15 Photos: The Jodi Arias trial Arias puts her arm around defense attorney Jennifer Willmott after being asked to demonstrate how she had her arm around her sister in a photograph that had been admitted into evidence. Willmott has said Arias was the victim of a controlling, psychologically abusive relationship and that Alexander considered Arias "his dirty little secret." Hide Caption 9 of 15 Photos: The Jodi Arias trial Arias talks to defense attorneys Willmott, left, and Kirk Nurmi during her trial on April 3, 2013. Arguing the prosecution's position that Arias was obsessed with Alexander and stalking him, Nurmi said it didn't add up because Arias was active on a Mormon dating site. "Jodi ... wasn't so locked in on Travis that she wasn't looking for other men," Nurmi said. Hide Caption 10 of 15 Photos: The Jodi Arias trial Prosecutor Juan Martinez makes closing arguments on May 2. Throughout the trial, prosecutors said Arias manipulated people as well as the evidence. Hide Caption 11 of 15 Photos: The Jodi Arias trial Mitigation specialist Maria DeLaRosa whispers to Arias during closing arguments. Arias' defense team denied that she went on a meticulously planned "covert mission" to Arizona to kill her ex-boyfriend and then hide her tracks. Hide Caption 12 of 15 Photos: The Jodi Arias trial Arias listens to defense attorney Kirk Nurmi make his closing arguments on May 3. Her case drew worldwide attention. Hide Caption 13 of 15 Photos: The Jodi Arias trial Alexander's family and friends react after Arias was found guilty of first-degree murder. Hide Caption 14 of 15 Photos: The Jodi Arias trial Judge Sherry Stephens receives the jury's decision in May. The jury had been in court since January 2. Jurors deliberated for 15 hours and five minutes before finding her guilty of first-degree murder. Hide Caption 15 of 15

During the retrial, if all 12 jurors can't vote for death, then Arias will be eligible for one of two life sentences: life without the possibility of release or life with the possibility of release after 25 calendar years, Cobb said.

That means Arias and her legal team will need to persuade only one of the 12 jurors to vote against the death penalty for her to be spared from execution, Cobb said.

Graphic testimony expected

The 12 jurors and eight alternates are expected to hear evidence for three to six weeks, Cobb said.

That testimony won't rehash whether Arias committed murder. That's already been decided.

Rather, the jury will hear evidence from the prosecution on why a death sentence is warranted and from the defense on how Arias' background and relationship with Alexander pose mitigations favoring a life sentence, Cobb said.

Nevertheless, the testimony is expected to be gruesome and grisly because prosecutors must show the murder was done in a "cruel, depraved or heinous" manner, among other factors, Cobb said.

"The state will be arguing and building on that theme," Cobb said.

JUST WATCHED 2013: Arias jurors: Jodi deserved death Replay More Videos ... MUST WATCH 2013: Arias jurors: Jodi deserved death 02:36

Arias' legal team is arguing that life is "the appropriate penalty" for the convicted murderer for a number of reasons, according to court papers they filed this month.

Her legal team notes that Arias has no prior criminal history. She was only 27 when she killed Alexander and has since been remorseful, according to court papers. She also has a psychological makeup that "impaired her ability to cope with the tumultuous relationship she had with Mr. Alexander," court papers said.

No live telecast until verdict

Unlike the 2013 trial, the penalty retrial won't be televised live.

Rather, Judge Sherry Stephens, who will preside over the retrial as she did in the 2013 trial, has ruled that while TV cameras will be permitted in the retrial, no video can be aired until a verdict has been rendered.

The judge's decision came after the defense argued that live TV coverage would keep their witnesses from testifying.

The 2013 trial was sensational, attracting a media circus and a national audience riveted by themes of sex, violence and 18 days of testimony by Arias, who detailed what she called an abusive relationship with Alexander but claimed she remembered nothing of his killing.

Public fascination

The trial also featured phone sex conversations between Arias and her boyfriend as well as video of her interrogation by police.

The public also became fascinated with Arias because she took the stand in her defense. More recently, she sought to act as her own attorney in the penalty phase retrial and was initially granted permission in August. But Arias changed her mind in September.

During last year's trial, jurors and the public saw Arias on video making a number of declarations to police investigating the murder.

"I'm not a murderer," she told detectives. "If I killed Travis, I would beg for the death penalty."

The police video also showed her doing bizarre behavior when left alone in a police room: she began stretching and doing handstands.

In another police interview, Arias blamed Alexander's killing on intruders.

"They didn't discuss much, they just argued," Arias told a detective.

"About what?" the detective said.

"About whether or not to kill me."

"For what reason?"

"Because I'm a witness," Arias said on video.

Then came a moment of high courtroom drama: the packed gallery sat in stunned disbelief when Arias took the stand in her defense.

"Did you kill Travis Alexander on June 4th, 2008?" the attorney asked her.

"Yes, I did," she said.

"Why?"

"Um, the simple answer is that he attacked me, and I defended myself," Arias said.

But the jury didn't buy it and convicted her of first-degree murder.