(PHOENIX) -- Jodi Arias' defense team put Dr. Richard Samuels on the stand this week to convince an Arizona jury that Arias was so traumatized by the violence in killing ex-boyfriend Travis Alexander that she developed dissociative amnesia from the stabbing frenzy.
Jurors will have the opportunity to ask questions of Samuels Thursday, but Samuels has failed to convince at least one legal and mental health expert who has monitored the trial.
"Saying Jodi Arias has dissociative amnesia is like saying Casey Anthony would make a great babysitter," said Dr. Steven Pitt, referring to the Florida woman who was acquitted of murdering her daughter after claiming that the girl had been stolen by a babysitter.
"This guy, he got bamboozled by Jodi Arias," said Pitt, a forensic psychiatrist from the Phoenix area who has testified and consulted on several high profile cases across the nation. "He drank her Kool-Aid and now he is finding out that it is a toxic mix of 'BS.'"
Arias, 32, is accused of murdering Alexander in 2008 with 27 stab wounds, a slit throat and two bullets in the head. She could face the death penalty if convicted in the marathon murder trial that has captivated a national audience and inspired a Lifetime movie.
Samuels testified that he believed Arias suffered from PTSD, that the killing -- which she claims was in self defense -- was so traumatic for her that she developed the amnesia, preventing her from remembering what took place.
During her 18 days on the witness stand, Arias told the jury that she could not recall grabbing a knife and stabbing Alexander, putting his body in the shower, cleaning up the blood-soaked floors, or putting his camera -- which contained graphic photos of the couple -- in the washer and turning on the rinse cycle.
Juan Martinez, the animated and fiery prosecutor, challenged the validity of those tests, which he says were based on lies.
Pitt said Samuels played right into the veteran prosecutor's hands.
"Martinez had Jodi Arias for dinner and he ate this guy for dessert. It is as if Jodi Arias was Bernie Madoff and [Samuels] would have invested his life savings in what she is telling him. That's where he made his mistake," he said. "What a good expert would do is say, 'Look, I know I am dealing with a bald-faced liar. The last thing I am going to do is ride that horse as the basis of my opinions. I'll consider what she has to say, but I recognize that this woman is an admitted liar."
Arias initially denied killing Alexander or being at home and then changed her story to claim that a pair of masked intruders enter the house and killed Alexander. While on the stand Arias also admitted telling other lies which she claimed were partly out of shame for the killing and partly to avoid being caught.
On the stand, Samuels tried to defend the tests, "I'd like to make it clear to you that she's responding to some trauma ...Granted she told me one story. And we found out later that there was another story, but both would have been perceived as traumas, so it's possible -- and I'm not saying that it is for sure -- it's possible that the trauma she was referring to was actually due to the killing."
Samuels also made it clear Wednesday on re-direct that he did not rely solely on the PTSD tests to render his opinion.
"No one test and certainly no one scale on a test, should ever be used to make a diagnosis... It should be used in conjunction with other available information, which is how I used it in this particular case," he said.
Pitt emphasized the importance of "collateral sources," interviewing people who knew both the victim and the defendant who can offer a fuller picture and a better understanding of their relationship. Samuels said he did not conduct interviews outside of his 25 to 30 hours with Arias, although he testified to having access to interviews with family members.
Fundamentally, Pitt said, what Samuels has testified to is possible, but warns, "It is not enough for an expert to come into court and say, 'Take my word for it because of these initials after my name,'" Pitt said. "The jury is not going to find Dr. Samuels' testimony credible. I predict they will find his testimony incredible."
Another critical misstep, Pitt believes, was Samuels' decision to send Arias a self-help book in jail.
"I think at best it was poor judgment and at worst it was an ethical breach of conduct. In a forensic context, when you are evaluating someone regardless of which side retains you, this is not a 'Kumbaya' experience. You are there as an independent expert to render diagnostic opinions that will help educate the jury. Your job is not to become buddies with the person you are examining."
On Wednesday during re-direct questioning by defense attorneys, Samuels insisted that he had not blurred any ethical boundaries and that the book was not meant as a form of therapy.
Another critical defense expert, Alyce LaViolette, is expected to take the stand next week and testify on issues of domestic violence, to give context to Arias' testimony about the alleged emotional and physical abuse that she says she endured with Alexander.
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