Jodi Arias Trial Update: Defense Files Motion to Allow One More Expert Witness on the jodi arias trial. Her defense seen two new twists to the judge on monday. Ryan owens has the details. Reporter: Is it starting to feel like the jodi arias murder trial may never end? Wait until you hear this. Only days after the defense rested its 38-day-long case, arias' attorneys decided they're not done after all. They're asking the judge to allow one more expert witness, this san diego psychologist. Nothing but the truth, so help you god? Reporter: They hope he can reverse some of the damage done by dr. Jean demarte, who diagnosed arias with personality disorder. People with this profile, display defensiveness. Reporter: She was the first witness of the prosecution rebuttal case. She spent 12 hours interviewing arias behind bars and says she's a manipulative liar. Arias sa she killed her boyfriend, travis alexander, in self-defense. There did not appear to be significant abuse. Reporter: It's not clear whether the judge will allow the defense to reopen its case four months into the trial. But it's possible because this is a death penalty case. It's rare for a defense team to ask for a sur rebuttal. And get a sur rebuttal. But this is the jodi arias case. And everything is different. Reporter: Arias' attorneys also filed a second motion. This one asking the jury be allowed to consider a lesser charge than murder. The defense opens manslaughter by sudden quarrel or heat of passion will be added to the jury instructions. If the judge allows that and the jury finds arias guilty of a lesser charge, she could face only a few more years behind bars for shooting and repeatedly stabbing her ex-boyfriend. For "good morning america," ryan owens, abc news, san francisco. Let's bring in "gma" legal analyst, dan abrams for more on this. The lesser charge, manslaughter for sudden quarrel. The prosecutors will say, where's evidence of that? She's saying self-defense. Who is saying heat of passion? It is possible that the judge will say that a reasonable jury could conclude that based on the evidence, this is manslaughter. Let's be clear, that would be a huge win for jodi arias. If she were to get convicted of manslaughter, it would mean they actually believed a good amount of her story, about why she did this and how she did this, just in terms of her reaction. Again, she's claiming self-defense. But to be able to say it was in the heat of passion. They would believe she had motivation. But there's no motivation for manslaughter. That's the thing. When it comes to murder, it would have to be a level of intent. Manslaughter could be in the heat of the moment, I just kind of lost it. Again, the problem is that no evidence has been presented specifically targeting that. But I wouldn't be surprised if the judge errs on the side of caution. And the jury will see a list of things. And sometimes jurors are inclined to compromise. With a difference. That's where the concern is. How about this call for a new witness? This is not that unusual to ask for. It would be unusual to grant it. What the defense is saying, the prosecution presented new evidence in its rebuttal case. The rebuttal case is supposed to be, we are responding to what they presented. And what the defense is saying, in their response, they presented new evidence that we now want to respond to. At some point, you have to end the trial, right? At some point, you have to say enough of the responding to the responding to the responding. I have seen high-profile cases when you have a sur rebuttal case. When talking about a death penalty case, the judge may say I will allow limited testimony on this, that's going to be quick. Every chance.