© AP Photo/The Arizona Republic, David Wallace
Defendant, Jodi Arias, right, talks with her defense team during the prosecution's opening statements in the trial of Arias in Maricopa County court in Phoenix on Wednesday, Jan. 2, 2013. Arias is charged in the murder of her boyfriend, Travis Alexander.
The photographs present a chilling portrait of sex and death.

A nude Jodi Arias on Travis Alexander's bed. A naked Alexander in the shower. Then minutes later, an image of Alexander stabbed and slashed nearly 30 times in the heart, back, hands and torso, shot in the head, his throat slit from ear to ear.

Other evidence has stacked up since the June 2008 attack in Mesa, a suburb of Phoenix. A bloody palm print; wildly conflicting stories; and, finally, a confession.

The evidence - including time-stamped photos from the day police say Alexander died - is being presented at a trial in Phoenix that's been dominated by the torrid affair, sex, jealousy and a defendant whose only chance at acquittal is to convince a jury she's the victim.

There's no question who killed the 30-year-old businessman and motivational speaker. Arias admits she stabbed and shot him, but claims she was defending herself against an abusive lover.

Alexander "lunged at Jodi in anger," her attorney, Jennifer Willmott, told jurors.

"Jodi's life was in danger. He knocked her to the ground in the bathroom where there was a struggle," Willmott said. "If she did not have to defend herself, she would not be here."

Prosecutors say the 32-year-old came prepared to kill, packing a .25-caliber handgun and knife, neglecting to call police and leaving behind a crime scene that investigators described as among the most gruesome they'd ever seen.

"This is not a case of whodunit," prosecutor Juan Martinez said in his opening statement. "The person who committed this killing sits in court today."

Arias repeatedly changed her stories about the killing that could land her on death row if convicted. She first denied any involvement, then blamed it on masked intruders before finally confessing.

The case now rests largely on intent. Her attorneys are trying to convince jurors she was an abused woman defending herself from an enraged ex-boyfriend - something experts say will be difficult given the evidence.

"Why did she bring a gun to a love fest for one?" said San Francisco criminal defense lawyer Michael Cardoza. "This is about damage control now. No jury is going to let this lady walk. It's just about trying saving her life."

The story began in fall 2007, when Alexander met Arias, an aspiring photographer, at a Las Vegas convention. The two began dating, and the stormy relationship went on for about five months. At the time, Arias was living in Southern California and would visit Alexander at his Mesa home.

Friends of the man say she practically lived there from time to time, and that Alexander became bothered with her possessiveness and jealousy. They say he broke it off and that she stalked him for months, slashing his tires and hacking into his Facebook account.

She claims she ended the relationship after catching him in too many lies. But she says it was at his urging that she moved to Mesa from California for a time after their breakup.

He started dating other women, yet the two continued to have sex up until the day of his death.

They exchanged thousands of emails and text messages. He sent her photos of his genitalia and requested she wear a French maid outfit while cleaning his house. She sent explicit messages; he told her it appeared he was nothing more than a sex toy "with a heartbeat."

The profile of Alexander is in sharp contrast to what some friends and family knew. Many believed him to be a devout Mormon who was saving sex for marriage. Friends said Arias also converted to Mormonism after they started dating.

"This year will be the best year of my life. ... I will earn more, learn more, travel more, serve more, love more, give more and be more than all the other years of my life combined. ... And how will I do this? By strict obedience to the commandments of God," Alexander wrote in a blog post before his death.

Arias' challenges are formidable. Police say her bloody palm print and hair were found at the crime scene, along with the photographs on a camera inside Alexander's washing machine. In addition, authorities say Arias' grandparents reported a .25 caliber gun - the same caliber used in the slaying - stolen from their Northern California home about a week before the killing. Arias was staying with them at the time.

No weapons were found at the crime scene. Arias' attorneys have yet to explain why she washed Alexander's bedding and put the camera in the washing machine, why she left his body in the shower without reporting anything to authorities, and why she lied repeatedly to investigators.

All of this, combined with the sheer brutality of the attack, makes it more difficult for a defense attorney to do anything but attempt to spare her the death penalty, experts say.

"Her changing stories, the confession, the forensic evidence, it's just a very difficult case to defend," said California criminal defense lawyer Mark Geragos.

Geragos said her only hope is if defense attorneys can convince jurors Alexander was abusive, and that he attacked her on the day he was killed.

"They're going to need expert witnesses to clean up her mess," Geragos said. "The biggest problem is, she's given all these different stories that don't comport with the facts, and now she's admitted doing it."

As she sat in jail just three months after her arrest, Arias was adamant - at this point sticking with her second story about the intruders - that she was innocent of the crime.

In an interview with "Inside Edition," she was certain jurors would believe her.

"No jury is going to convict me," she said. "I am innocent and you can mark my words on that."