Jodi Arias Trial: Prosecutor challenges murder defendant's PTSD diagnosis

(AP) PHOENIX - A prosecutor in Jodi Arias' murder trial is targeting a defense expert's credibility and the psychologist's diagnosis that she suffers from post-traumatic stress disorder.

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Prosecutor Juan Martinez questioned psychologist Richard Samuels' credibility during a heated exchange Monday, leading to repeated objections from defense attorneys.

Samuels has spent two days on the witness stand describing how Arias suffers from amnesia and PTSD. He said it was the reason why she can't remember much from the day she says she killed her lover in self-defense.

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"Amnesia is not necessarily a fake or made-up kind of occurrence," Samuels told jurors. "It is not as if amnesia can only be made up to cover up something."

Samuels said he met with Arias a dozen times for more than 30 hours over three years before eventually diagnosing her with PTSD and amnesia. He was set to resume his testimony Tuesday.

Arias faces the death penalty if convicted of first-degree murder in the June 2008 death of Travis Alexander in his suburban Phoenix home.

Authorities say she planned the attack in a jealous rage. Arias initially told authorities she had nothing to do with it, then blamed it on masked intruders. Two years after her arrest, she said it was self-defense.

Arias spent 18 days on the witness stand during which she described her abusive childhood, cheating boyfriends, dead-end jobs, a shocking sexual relationship with Alexander, and her contention that he was physically abusive in the months leading to his death.

She said she recalls little from the day of the attack.

But as Martinez began his bullish cross-examination, Samuels stammered to explain his techniques and relationship with Arias.

Martinez showed jurors a written test administered by Samuels to Arias as he worked toward a diagnosis.

Samuels acknowledged that he knew Arias lied when answering some questions, such as one where she said she had suffered a life-threatening traumatic event at the hands of a stranger.

"Knowing that this was a lie, you used it and then concluded that those scores ... confirm the presence of PTSD even though you just now told us this is a lie?" Martinez snapped.

"Perhaps I should have re-administered that test," Samuels replied.

Martinez also noted that Arias testified that on the day of Alexander's death, before she killed him, the victim had tied her wrists to his bed as they had sex. He then pointed out how Samuels noted she had both her wrists and ankles tied.

"Well, that's what I had in my notes," Samuels said. "I don't remember what she told me."

Under questioning by defense attorneys, Samuels explained how he was once reprimanded in New Jersey in the mid-1990s when he was serving as an objective evaluator in a child custody case. He said he found both parents to be fit, then later began seeing the man, who was a dentist, as a patient.

Samuels said the man couldn't afford to pay him, so he traded his services for dental work, only to later find out it was not permitted under New Jersey law.

Martinez seized on the revelation, accusing Samuels of blurring the line between being an objective observer and a therapist offering treatment.

Samuels said that during his time evaluating Arias while she was jailed, he bought her a self-help book about getting over depression.

"That creates an issue of your objectivity in this case doesn't it?" Martinez asked loudly, saying Samuels had then created a doctor-patient relationship.

"I don't think so," Samuels said.

"You can see there is an appearance here that you're trying to help her, right?" Martinez responded.

"From your perspective," Samuels said.

Alexander suffered nearly 30 knife wounds, was shot in the head and had his throat slit before Arias dragged his body into his shower. She said she recalls Alexander attacking her in a fury and said she ran into his closet to retrieve a gun he kept on a shelf and fired in self-defense but has no memory of stabbing him.

She has acknowledged trying to clean the scene of the killing, dumping the gun in the desert and leaving the victim a voicemail on his cellphone hours later in an attempt to avoid suspicion. She says she was too scared and ashamed to tell the truth.

Samuels attempted to explain the call as part of the acute stress she was suffering.

"By creating an alternative reality, it's as if it didn't happen and it reduces the level of stress," he said.

Samuels also explained how when a person finds themselves in a stressful situation, the body releases hormones and adrenaline that block the brain's ability to retain memory.

The judge had been prepared to hear arguments from attorneys before deciding if she would allow Samuels to offer his opinion on whether he believed the killing appeared planned. The prosecution had objected, and the defense inexplicably withdrew its motion.

Since the trial began, none of Arias' allegations of Alexander's violence, that he owned a gun and had sexual desires for young boys, has been corroborated by witnesses or evidence. She has acknowledged lying repeatedly but insists she is telling the truth now.

Complete coverage of Jodi Arias on Crimesider