Now a psychologist and expert witness is coming under fire for backing up that story by diagnosing 32-year-old Arias with post-traumatic stress disorder (PTSD) and amnesia.
Psychologist Richard Samuels, an expert witness for Arias' defense, was grilled on the stand Wednesday by prosecutor Juan Martinez, Fox News Latino reports.
Martinez wanted to know how Samuels could diagnose Arias accurately when she was lying to him repeatedly. He also suggested the psychologist was not exactly an "objective observer" since he'd bought Arias a self-help book, according to Fox.
The defense is largely relying on Samuels' "dissociative amnesia" diagnosis to explain why Arias claims to remember little from the day she killed Alexander, ABC News reports.
That day, she appeared to methodically cover up the killing — dragging Alexander's body into a shower, cleaning up blood in his Mesa, Ariz. house, and trying to destroy one of his cameras that had naked pictures of her.
When Samuels diagnosed her with PTSD and dissociate amnesia after the June 2008 killing, he was taking her lies at face value, forensic psychiatrist Steven Pitt told ABC.
"This guy, he got bamboozled by Jodi Arias," Pitt told ABC. "He drank her Kool-Aid and now he is finding out that it is a toxic mix of 'BS.'"
To be sure, Arias isn't the most credible defendant. She initially told investigators she had no idea what happened to Alexander before telling them he was killed by masked intruders.
The 32-year-old aspiring photographer finally settled on self-defense. Her lies have earned her the nickname "Mormon Casey Anthony."