(ABC NEWS) -- Prosecutors in Arizona will begin arguing today that 32-year-old Jodi Arias should die for the especially brutal murder of her one-time boyfriend, Travis Alexander, who was found dead in his shower over four years ago.
Investigators say Arias stabbed Alexander 27 times, slit his throat and shot him in the head at his Mesa, Ariz., home in June of 2008. Arias, who has been locked up since her arrest, has pleaded not guilty to first-degree murder.
"I didn't hurt Travis. I would never hurt Travis," Arias said in a jailhouse interview after she was arrested in July 2008. "I would be shaking in my boots right now if I had to answer to God for such a heinous crime."
Arias and Alexander met at a work conference six years ago. Arias says they fell in love, traveled the country together, and to strengthen her ties to the devout Mormon, she even converted to his religion. But Alexander's friends say after dating a few months he tried to break it off.
"There's nothing about her that I see in marriage material -- or wife material," Alexander said, according to his friend, Dave Hall. "But it's hard to say no to a woman that sneaks into your house, crawls in your bed and tries to, you know, seduce you."
Alexander's family and friends say Arias was stalking him in the months before the murder -- something she denies.
At first she also denied being at his house in the night of the murder. Then police found a camera in Alexander's washing machine containing pictures of the two having sex that day. There were also pictures of Alexander after he was killed.
Faced with that evidence, Arias then told the television show "Inside Edition" that she was there, but didn't kill Alexander.
"I witnessed Travis being attacked by two other individuals," she said on "Inside Edition." "Who were they? I don't know. I couldn't pick them up in a police lineup."
Now the accused killer is admitting to the court that she did kill Alexander, but that it was in self-defense. She claims he was sexually and physically abusive throughout their relationship.
Steven Alexander, Travis Alexander's brother, said that he can see Arias' true colors.
"It makes me sick because I know her true side," he told ABC News. "And I ask people to please not buy into this sweet innocent personality that she puts on."
Arias told "Inside Edition" that she believes she will walk away from the trial a free woman.
"No jury is going to convict me," she said. "Why not? Because I'm innocent. You can mark my words on that. No jury will convict me."