Jodi Arias stepped down from the witness stand today after mounting an emotional effort to save herself from death row, insisting to the Arizona jury that an explosive fight with ex-boyfriend Travis Alexander led to his death, and that her lies about killing him masked deep regret and plans to commit suicide.
Arias, 32, will now face what is expected to be a withering cross-examination beginning Thursday from prosecutor Juan Martinez, who has been aggressive to many witnesses throughout the trial and who is expected to go after Arias' claim that she was forced to kill Alexander or be killed herself.
She is charged with murder for her ex-boyfriend's death and could face the death penalty if convicted.
Catching Up on the Trial? Check Out ABC News' Jodi Arias Trial Coverage
The day's dramatic testimony started with Arias describing the beginning of the fight on June 4, 2008 when she and Alexander were taking nude photos in his shower and she claims she accidentally dropped his new camera, causing Alexander to lose his temper. Enraged, he picked her up and body slammed her onto the tile floor, screaming at her, she told the jury.
Arias said she ran to his closet to get away from him, but could hear Alexander's footsteps coming after her down the hall. She grabbed a gun from his shelf and tried to keep running, but Alexander came after her, she said.
"I pointed it at him with both of my hands. I thought that would stop him, but he just kept running. He got like a linebacker. He got low and grabbed my waist, and as he was lunging at me the gun went off. I didn't mean to shoot. I didn't even think I was holding the trigger," she said.
"But he lunged at me and we fell really hard toward the tile wall, so at this point I didn't even know if he had been shot. I didn't see anything different. We were struggling, wrestling, he's a wrestler.
"So he's grabbing at my clothes and I got up, and he's screaming angry, and after I broke away from him. He said 'f***ing kill you bitch,'" she testified.
Asked by her lawyer whether she was convinced Alexander intended to kill her, Arias answered, "For sure. He'd almost killed me once before and now he's saying he was going to." Arias had earlier testified that Alexander had once choked her.
Timeline of the Jodi Arias Trial
Arias on Ex-Boyfriend's Death: 'I Don't Remember' Watch Video
Jodi Arias Describes Violent Sex Before Shooting Watch Video
Jodi Arias Testifies Ex Assaulted Her, Broke Her Fingers Watch Video
But Arias' story of the death struggle ended there as she told the court that she has no memory of stabbing or slashing Alexander whose body was later found with 27 stab wounds, a slit throat and two bullets in his head. She said she only remembered standing in the bathroom, dropping the knife on the tile floor, realizing the "horror" of what had happened, and screaming.
"I have no memory of stabbing him," she said. "There's a huge gap. I don't know if I blacked out or what, but there's a huge gap. The most clear memory I have after that point is driving in the desert."
Arias said that she decided in the desert not to admit to killing Alexander, a decision that would last for two years as Arias lied to friends, family, investigators and reporters about what really happened in Alexander's bathroom.
During that time she initially claimed she got lost that night while driving to a friend's house and never went to Alexander's home in Mesa,Ariz. She later changed her story and said two masked people, a man and a woman, burst into the home and killed Alexander and threatened to kill her family if she told anyone what happened.
She eventually confessed to killing her ex-boyfriend, but insisted it was self defense.
"The main reason (for lying) is because I was very ashamed of what happened. It's not something I ever imagined doing. It's not the kind of person I was. It was just shameful," she said. "I was also very scared of what might happen. I didn't want my family to know that I had done that, and I just couldn't bring myself to say that I did that."
"From day one there was a part of me that always wanted to (tell the truth) but didn't dare do that. I would rather have gone to my grave than admit I had done something like that," she said.
Arias said that she continued to lie because she figured she would never get caught; she was planning to kill herself before trial.
"I was concerned with how it would affect my family. I wanted to die. I was going to definitely kill myself," she said. "That was my plan. You can purchase different things in jail and I bought a bunch of Advil... and took it all in the next few days so it was in my system. They have razors for shaving, so I got one and took it apart one night with intentions to slit my wrists."
Arias said she balked at slitting her wrists after accidentally cutting herself, but that she still planned to commit suicide sometime in the future. When she told news reporters that "no jury would convict her," she claims she said it believing that she would be dead before they'd have a chance to put her on trial, Arias testified.
Arias said support from the public and her family eventually led her to change her mind.
"My family remained very supportive, and told me 'it doesn't matter what happens, we love you anyway.' I realized even if I told the truth they would still be there and wouldn't walk away," she testified.
"By the time spring, 2010, rolled around, I confessed. I basically told everyone what I could remember of the day and that the intruder story was all BS pretty much."
She said that her testimony today, a third version of events, was the truth.
Arias was arrested a month after Alexander's death, and prosecutors have argued that her behavior during those weeks showed a lack of remorse for the killing and an attempt to get away with murder.
Arias said today that after she killed Alexander and drove away from his Mesa, Ariz., home in a panic, it dawned on her that police would soon be looking for Alexander's killer, and she decided that she would pretend the bloody confrontation had never happened.
"I knew that it was really bad, that my life was probably done now. I wished it was just a nightmare I could wake up from, but I knew I had messed up pretty badly and the inevitable was going to be something I could not really run from," she testified.
"I didn't want anyone to know that that had happened or that I did it, so I started taking steps in the aftermath to cover it up. I did a whole bunch of things to try to make it seem like I was never there," she said.