Arias and an ex-boyfriend had been expected to speak to jurors before the panel begins deliberating whether to sentence the 32-year-old Arias to life in prison or execution for murdering her lover in 2008.
Arias was convicted of first-degree murder earlier this month in the death of Travis Alexander. Last week, jurors heard tearful comments from Alexander's brother and sister as they described how his killing has torn their lives apart.
Judge Sherry Stephens instructed jurors they could consider a handful of factors when deciding what sentence to impose, including Arias' lack of a prior criminal record and assertions that she was a good friend, had an abusive childhood and is a talented artist.
In opening statements, prosecutor Juan Martinez told the panel none of those factors should cause the jury to even consider a sentence other than death, given the brutal nature of the killing.
Defense attorney Kirk Nurmi explained to jurors that Arias herself would testify this week.
"When you understand who Ms. Arias is, you will understand that life is the appropriate sentence," Nurmi said.
Arias, 32, acknowledged killing Alexander at his suburban Phoenix home on June 4, 2008. She initially denied any involvement and later blamed the attack on masked intruders. Two years after her arrest, Arias said she killed Alexander in self-defense.
The victim suffered nearly 30 knife wounds, had his throat slit from ear to ear and was shot in the forehead. Prosecutors say the attack was fueled by jealous rage after Alexander wanted to end his affair with Arias and prepared to take a trip to Mexico with another woman.
Jurors convicted Arias on May 8 of first-degree murder, with all 12 unanimously agreeing it was premeditated, after about 15 hours of deliberations over four days.
The panel later took less than three hours to determine the killing was especially cruel, meaning the death penalty would be a consideration for sentencing.
The ongoing penalty proceedings will be the final phase of the trial. Jurors are expected to begin deliberating Arias' ultimate fate this week.
The proceedings will play out like a mini-trial as the prosecutor will be allowed to cross-examine each witness, and both sides will offer closing arguments before the jury begins deliberations.
Under Arizona law, if the jury cannot reach a unanimous decision on sentencing, the panel will be dismissed and jury selection will begin anew. Another panel would then be seated to hear arguments in only the penalty phase to determine a sentence. If the second panel cannot reach a unanimous agreement, the judge will then sentence Arias to either her entire life in prison or life in prison with the possibility of release after 25 years.
The most anticipated part of the penalty phase will be when Arias takes the witness stand, though exactly what she will say remains a mystery. Within minutes of her murder conviction, Arias complicated efforts for her defense when she gave an interview to Fox affiliate KSAZ, saying she preferred death over life in prison.
It wasn't clear whether the prosecutor would use those words against her in court, given some experts say it might not work in his favor aimed at securing a death sentence.
"Jodi Arias has proven herself to be a conniving manipulator so she may be saying something like this to get a reaction from the jury," said San Francisco criminal defense lawyer Michael Cardoza. "She may be hoping the jury says, 'We won't give her what she wants, and if she wants death, we're giving her life.'"
Cardoza noted that in Arias' case, with so much evidence against her, the defense can still claim some level of satisfaction is they can just keep her off death row.
Arizona defense attorney Thomas Gorman, who has handled dozens of death penalty cases, said Martinez may not need to mention Arias' comments in the television interview to jurors given they haven't been sequestered throughout the trial.
"They just can't avoid it," Gorman said. "If they're at a bar or a restaurant, they're going to see and hear things."
Arias also cannot choose the death penalty. It's up to the jury to determine a sentence. And while death penalty appeals are automatic in Arizona, she could choose not to pursue additional appeals if she indeed wanted to die for her crime.
Earlier this week, after Arias' was interviewed post-conviction, her attorneys asked to be allowed to step down from the case, but a judge denied the request. Legal experts say the decision was not a surprising one because the attorneys have a conflict of interest with their own efforts to try and save her life while Arias has said she'd rather die.
The motion to withdraw will have no impact on the penalty phase of the trial given jurors are not privy to the filing.
- AP