Is abuse a defense that can be measured?

>>> sex, lies and murder. the jodi arias trial is in black until wednesday. this means they're not in progress until wednesday. sorry for the -- to the headline news network for that but everyone is talking. well, almost everyone is still asking about the past two weeks of jodi on the stand. nbc's katy tur covering the story. you are back in l.a. while the trial's break and seen jodi on the stand for 17 days , what's the defense strategy here?

>> reporter: well, all the jury knew about her is changing the story three times. she wasn't there the night that alexander was killed and then she was there finding pictures there on travis alexander 's camera. she said masked intruders came in and now self defense . she had to take the stand to explain why she thinks it was self defense . how he was abusing her. much of that she claims was sexually. her attorneys want her to -- want her to seem as sympathetic as possible, to know her. they need to convince them that she was scared for her life. that travis alexander really was as she claims a sexual deviant and he was abusing her.

>> you initially testified that sex was a way for travis to relieve stress. and later testified it was a way for him to relieve anger. which is correct?

>> both are correct. anger was stressful and he had the term destress and sex was a way to destress and it seemed like after he climaxed that he felt a lot more calm.

>> how do you know that?

>> based on his demeanor and conversations we have had regarding that and requests that he's made. specifically to that -- of that nature and the term destress.

>> reporter: they're back in court on wednesday. the defense has a lot more to do. they have to call the expert witnesses still. they need to prove that she was scared for her life. that he was abusing her. it's hard to do, i imagine, because she admits to killing him and shooting him in the face, stabbing him 27 times and slitting his throat from ear to ear. that's hard to prove that it was self defense but she claims it was self defense . the prosecution says she was jealous that he was dating other women and that this was premeditated murder . of course, again, if convicted, she does face the death penalty. steve?

>> all right. nbc's katy tur.

>>> the bulk of the jodi arias defense base odd an claim she was a victim of domestic violence . cdc estimates 1.3 million american women are victims of physical assault by an intimate partner each year. while she never reported the supposed violence to police, she wouldn't be alone. it's within of the most chronically underreported crimes in the country but arias changed the story three times before settling on the self defense claim so will the jury believe she is the victim here? want to bring in psychiatrist dr. joshua winer. i guess that's an interesting question to me because we understand that a woman stepping forward to claim she's a victim of a domestic abuse isn't always going to have evidence and seems like relying on sort of her trustworthiness here and looking at changing the story, the grisly nature of the scene and kept a diary and never anything she told anybody. if somebody in general were to come to you and say i'm a victim of domestic violence what would you look for besides their word that you could verify it with?

>> i'd be wanting to find out about the details. i'd want to make sure what they're telling me seems to make sense and recalled with specifics. you can just tell sometimes talking with somebody whether their story just doesn't really make sense or whether it does make sense. oftentimes some people by the time they see a psychiatrist maybe they had a track record and started the process of making notes in a notebook or taking photographs or calling the police. you want to do background search to find out whether what they're telling you is backed up. but quite honestly, most of the time when somebody comes in to see a psychiatrist i have no reason but to believe them. a criminal case is different so here you have to wonder whether what she's saying is the truth or a good excuse for trying to get out of the murder charge but coming in to see a psychiatrist, most often talking about this, they're telling the truth.

>> jodi 's story, i mean, there's good reason to believe skeptical of what she is saying, having changed the story a number of times, the 27 stab wounds, the slitting of throat ear to ear, et cetera , but for women out there who are really victims of domestic abuse and watching the trial and the fact she's sort of presumed guilty and is being ridiculed in a way, does that have a chilling affect on the legitimate victims thinking about coming forward?

>> well, i think it has the potential to do that. i think probably people are realistic, though, and recognize their situation cannot be compared to this woman. they might be victims of domestic abuse but they haven't gone out and done the things that she's done. they haven't killed somebody. so i think that most people are going to be reasonable. they understand that necessarily what she's doing isn't a representation of what they might be experiencing in their own lives. but i do think there is that fine line where people have to be cautious because it is possible that even though she didn't tell other people or write it down in a diary, there is no -- there are no pictures of this, it is still possible that what she's saying is the truth. the problem in her case is that she's juster have hard to believe because of the fact she's admitted to lying several other times.

>> doctor, hearing about somebody committing this level of violence toward another person, an absurd number of stab wounds, shooting in the face, and neck and violence to the head area, trying to sort of mutilate or obliterate this body that they once very recently claimed to have loved, what does that say to you?

>> love and hate are not that far apart in some cases, right? when from's a lot of love, passion and if something triggers that passion to turn to intense anger, hatred and fear, i don't think it's terribly unreasonable to assume there's physical damage that can be done to somebody else. i think it would be unreasonable to make any mass speculations about what it means for the fact that she did so much damage to him. clearly, when somebody is enraged, you don't know ma they're going to do. some people are just going to shoot somebody once. some people stab them multiple times. i think that you have to be cautious reading too much in to that. i don't really know what to make of it myself.

>> do you read anything in to the gigantic transformation that i don't di has undergone. used to be a vivacious-looking blond. wearing the glasses, not blond. trying to look mousey.

>> not that there's anything wrong with dark hair.

>> but adding the bangs, looking more mousey. you are laughing. you read something in to that.

>> i absolutely do, yes. i think a defense tactic. right? i mean, you see the pictures posted on facebook. you see the way she would carry herself previously. this is not the woman who's on the stand. i think she's clearly trying to look like the girl next door who's very innocent, who's very simple and who would never really do something like this unless you were pushed to the absolute brink and fearful for safety. i think that was one of the first things that stood out to me. see the pictures on facebook and then the woman on the stand. they look like two different people.

>> people more likely to convict a blond perhaps.

>> i don't know. i wouldn't go that long.

>> someone made that judgment on her team somewhere. thank you, doctor.

>>> a lawyer tasked with arguing one of the most important civil rights supreme court cases of all time will join