PHOENIX -- The sensational murder case against Jodi Arias in the death of her onetime boyfriend has gone to the jury, which is weighing weeks of evidence and the defendant's ever-changing version of events.

The trial has become a tabloid and cable TV sensation and has attracted spectators from around the country who have been lining up as early as 2 a.m. for a chance to score a few open seats in the courtroom.

After closing arguments, the panel deliberated for just about an hour Friday before concluding for the day. Deliberations resume Monday.

Arias says she killed Travis Alexander in self-defence, but prosecutors say it was an act of premeditated first-degree murder that could carry a death sentence or life in prison.

The eight men and four women on the jury have the option of finding Arias guilty of second-degree murder, too, if they don't believe she planned the attack but think it occurred in the heat of the moment. If convicted on that charge, she could face up to 25 years in prison. A manslaughter conviction carries a sentence of seven to 21 years.

Authorities say Arias, 32, planned the attack on Alexander in June 2008 at his suburban Phoenix home. They say she was enraged because he wanted to end their affair and was preparing for a trip to Mexico with another woman.

Arias initially denied any involvement and later blamed it on masked intruders. Two years after her arrest, she said she killed Alexander in self-defence when he attacked her after a day of sex.

The closing arguments wrapped up with Arias' lawyer imploring jurors to take an impartial view of his client, even if they don't like her, and prosecutors describing the defendant as a manipulative liar who meticulously planned the attack and is still lying.

"It's not about whether or not you like Jodi Arias. Nine days out of 10, I don't like Jodi Arias. ... But that doesn't matter," defence attorney Kirk Nurmi told jurors. Arias smiled as he made the remark, then returned to an unemotional gaze.

Nurmi told jurors the entire case was about "fear, love, sex, lies and dirty little secrets" and repeated over and over that the prosecution's theory of a planned attack "doesn't make any sense."

On Thursday, prosecutor Juan Martinez delivered the state's closing arguments, displaying autopsy photos of Alexander's body covered in stab wounds and bruises, a bullet wound to his forehead.

He described Arias as a liar who planned the savage attack. Martinez said Arias lied from the start and is still lying.

Alexander suffered nearly 30 knife wounds, was shot in the head, and had his throat slit. Arias' palm print was found in blood at the scene.

Arias said Alexander grew physically abusive in the months before she killed him, but there was no evidence or testimony during the trial to corroborate her allegations.

The defence has portrayed Alexander as a womanizer who used Arias for sex and abused her physically and emotionally. Prosecutors depicted Arias as an obsessed ex-girlfriend.

Martinez told jurors that Arias had been stalking Alexander and arrived armed and unannounced on the day she killed him, sneaking into his home at about 4 a.m. The two went to sleep together, then awoke and had sex.

At some point, Martinez said, Arias decided it was time to carry out her plan.

Nurmi told jurors on Friday that the state's theory is "nonsensical."

He pondered out loud: If Arias had planned the attack in advance, why not kill him right when she arrived at Alexander's home? Why leave a paper trail, starting with the police report from the burglary? Why rent a car instead of borrowing one from friends or family? Why use her debit card for gas and other purchases instead of cash?

"It doesn't make sense if you're on a covert mission," Nurmi said, adding Arias had numerous other opportunities to kill Alexander, but she didn't.

Nurmi acknowledged his client is a liar. But he explained she isn't on trial for lying.

Arizona criminal defence lawyer Benjamin Taylor, who sat in on closing arguments, said the defence did a good job at raising reasonable doubt about premeditation.

"Nurmi showed she had plenty of time if she really wanted to kill him," Taylor said. "After today, it's going to be hard to get 12 jurors to agree unanimously on premeditation."