(CNN) -- The jury in the Jodi Arias trial has one decision left to make: Should she live or die?
After months of dramatic testimony full of so many twists and turns that people lined up for seats in the Phoenix courtroom, jurors began deliberations Tuesday to decide whether Arias should get the death penalty or life in prison for murdering her ex-boyfriend.
Earlier this month, jurors convicted Arias of first-degree murder and found that she was "exceptionally cruel" when she killed Travis Alexander in 2008. She stabbed him 29 times, slit his neck from ear to ear and shot him in the face.
On Tuesday, the same jury that found Arias guilty of murder deliberated for about an hour and a half before adjourning for the day. They are scheduled to come back to court and continue weighing her fate Wednesday at 10 a.m. (1 p.m. ET).
Arias pleaded for her life to be spared, telling jurors Tuesday that she could teach people to read in prison and make a positive impact on inmates.
She also called the murder of Alexander "the worst mistake" she'd ever made, "the worst thing I've ever done." She couldn't have imagined herself capable of such a grizzly crime. "But I know that I was," she said. "And for that I'm going to be sorry for the rest of my life -- probably longer."
She told jurors that she had been a victim of abuse as an adult and as a child. She showed several family photos from holidays and vacations. She claimed she was a gentle person who caught spiders in cups and took them outside rather than kill them. And she showed the jurors several pieces of her artwork.
"I'm not going to become a mother because of my own terrible choices," she said, adding that she would no longer be able to paint with oil, either.
It was a drastic change in tone from less than two weeks ago, when a tearful Arias, minutes after her murder conviction, told a local television station that she wanted to be sentenced to death.
Explaining her decision not to request the death penalty, Arias said Tuesday that her family -- to whom she pointed in the courtroom -- gave her the strength to continue living.
Her previous comments about her desire to die were sincere when she expressed them, Arias said.
"Each time I said that, though I meant it," she said, "I lacked perspective."
She noted she could bring "people together in a constructive and positive way" by participating in various programs, including prisoner literacy initiatives, her "Survivor" T-shirts, which would benefit victims of domestic violence, and by donating her hair so it could be used to make wigs for sick children.
Beginning about 90 minutes later than scheduled, Arias, 32, said she never wanted the "graphic, mortifying, horrific details (of her and Alexander's relationship) paraded out into the public arena."
"It's never been an intention of mine to malign his name or character," she said.
Defense attorney Jennifer Willmott argued Tuesday that Arias' life should be spared.
"We're not talking about whether or not to convict. We're talking about whether or not to kill. And so when we talk about that, it matters that she was 27 years old and she had no criminal history," she said. "It matters that she hadn't done anything wrong in her life befo re that."
Prosecutor Juan Martinez said pointing to Arias' artwork as evidence that her life should be spared wasn't a valid defense.
"It's an entitlement road that they want you to travel when they talk to you about the fact that she's a good artist," he said. "It doesn't mean anything. All it means is, give her special or preferential treatment."
He argued that jurors should sentence Arias to death.
"You have a duty, and that duty really means that you actually do the honest, right thing, even though it may be difficult," he said. "And in this case ... the only thing you can do based on the mitigating circumstances and their lack of, is to return a verdict of death."
During the trial, Arias claimed she killed Alexander in self-defense after he attacked her. After the guilty verdict, she told a local television station that she had no interest in life in prison.
"I said years ago that I'd rather get death than life, and that still is true today," she told Phoenix television station KSAZ. "I believe death is the ultimate freedom, so I'd rather just have my freedom as soon as I can get it."
The penalty phase of the trial took a sudden break Monday, when the judge said that proceedings could not continue and that Arias would make the statement to the jury.
The adjournment followed Judge Sherry Stephens' dismissal of a defense motion for a mistrial and ended a session in which the defense called no witnesses on Arias' behalf. Also denied was a second request by Arias' lawyers to withdraw from the case.
Arias, who testified for 18 days during the trial, was not cross-examined after her Tuesday statement, which Stephens said was not under oath.
For Arias to be sentenced to death, the jury's decision must be unanimous. In the case of a deadlock, a new jury would be chosen for this phase only.
If Arias is given a sentence of death, she would be the fourth woman on death row in the state.
HLN's Graham Winch contributed to this report.