This is a special room. I'm Michelle Franzen in New York with his ABC news digital special report. In her own defense Kerry Kennedy took the stand today to testified in the -- driving trial. The... See More
This is a special room. I'm Michelle Franzen in New York with his ABC news digital special report. In her own defense Kerry Kennedy took the stand today to testified in the -- driving trial. The daughter of Robert F Kennedy an ex wife of New York governor Andrew Cuomo sought to convince the jury that it was all a mistake. When she got behind the wheel to taking a sleeping pill Ambien crashed into a tractor trailer and kept driving. Here you see her departing for today's lunch break Kennedy says she didn't remember -- thing. Prosecution says if she knew she was -- Kennedy should have pulled over for more on what Kerry Kennedy said on the stand today -- want to bring in ABC's. -- her -- from outside the courthouse in White Plains, New York Aaron thanks for joining us you were just in the courtroom. What was -- Kennedy saying in her defense. Well mainly that she did not realize she was coming under the effects. Of Ambien and despite the prosecutors' best efforts to portray her under cross examination as a frequent and being user for the last decade. Familiar with what -- would have done. Kerry Kennedy said she simply didn't really think about how she feels when she pops one of the Ambien pills instead she just goes to sleep. And there and we also heard a little bit from Kerry Kennedy invoking her dad's name on the stand when she took the stand saying quote. Daddy was the attorney general during the civil rights movement and I have ten Brothers and sisters my mother raised us because my father died when I was eight. He was killed while running for president. -- when she asked about it father how that they play that board. Kerry Kennedy's lineage has been part of this case from the beginning Michelle and in case jurors didn't get it with -- Ethel Kennedy sitting right there Robert Kennedy's widow and other members of the famous Stanley in court in the spectators gallery. -- Kerry Kennedy's attorney. -- right off the bat -- to describe herself and -- -- grew up in Virginia and that's when she talked about growing up in McLean Virginia. Because her father had been the attorney general and then senator from New York. And when she said that her father died when she was safe that's why her mother had raced here. -- a defense attorney asked and how did your father died she said simply he was killed. While running for president so Kerry Kennedy's lineage has been well established during this entire trial and it's impossible to know. How that plays for jurors are they impressed -- they truly believe that she would do anything intentionally to two. Further tarnish that that the Kennedy name. -- Do they find attacking that. That this has to be brought up in the court it's impossible to read those jurors. But there have been a few lighthearted moments where the jury didn't seem to connect with -- Kerry Kennedy. At one point she talked about the thyroid medication she was supposed to take instead of the NBA and and Michelle she was asked why do you take thyroid medication what would happen if he didn't take it she said well my hands would field Cole. That's one of the symptoms and she said I've been feeling cold a lot lately in this courtroom. And the jurors laughed because -- -- you can see from this kind of they were having it's a little bit -- -- you know. Nicole thanks for taking us inside of the courtroom just another question which the jurors are made up -- four men and two women. You mentioned it's hard to say how she came across jurors but how does she come across. On the stand -- she -- honest in her testimony that she appeared nervous. She doesn't appear nervous on the stand but as other character witnesses -- testifying today Kerry Kennedy had her left arm draped over the arm of the chair and with her right handed appeared to shake a little bit perhaps in anticipation of her testimony -- she was fiddling with a -- And she clearly wants to try and and impressed this jury she looked them straight in the -- as she was testifying. And she did try to have somewhat of a report she talked about traveling to Italy that's where she was about to go on a on a business trip. On July 13 of 2012 and and she talked about getting ready in. He wouldn't be excited getting ready for for Italy and she -- -- to draw the jurors. Into her world a little bit it is a rarefied world but she's doing her best to to come across as a normal person who. Lived in an apartment above her garage during the Summers while she -- out her house. Calling a neighbor for help the night of the accident trying to I think connect with the jury on just -- -- one to one type level. But substantively. She is certain that she had no memory. Of what had happened when she got on -- highway six city for a local highways here in Westchester County. And that's when she said that the drug must've taken over her hijacked her as her defense attorney has said. Prosecutors suggested she would have felt the on -- effects of -- but she said she simply does not remember. And that's of course where this case how it hinges on this. And in addition to Carrie Kennedy's testimony defense attorneys also showed pictures of the two pills the Ambien and the thyroid medication. How did they look to use similar easily mistaken. Very similar in fact there apparently different colors different shades of the pastel but to tip my eyes from the photos you really couldn't tell the difference there. The same shape both kind of -- dealer. And they both are about the same size and the pill bottles -- your standard issue. Prescription pill bottles from CVS pharmacy where she filled the prescriptions and Kerry Kennedy said she wishes that day she had looked at the label but she didn't. And she said as she had we wouldn't be here today -- and she. Tried to bolster the defense's contention from the beginning the -- that this was all a mistake. She thought she was taking her thyroid medication instead she ends up taking Ambien. Now we saw pictures of Carrie Kennedy also joined alongside her attorneys as well as her sister today Rory Kennedy. Will she be cross examined by the prosecution when she comes back this afternoon. It -- the cross -- began before the lunch break and it will pick up again after the lunch but lunch break and it looks like the prosecutor has a ways to go. She's really trying to establish that for the last decade or so. Kerry Kennedy has been a frequent user. Ambien and by that I think the prosecution wants to show that she would know. What the drugs guns and therefore would be responsible. For driving while under its influence. Kerry Kennedy's resisting she say she doesn't really think about what Ambien does when she takes it she just goes to sleep. In this particular case he said she remembers driving. And getting in her car because she remembers thinking how nice the light looked as it was filtering through the trees that July morning back and -- twelve. But once she goes a couple of miles on her route that's when her memory fails and she says it was like a state of -- consciousness. Now of course jurors hearing all the details of this from both sides Aaron what's at stake here for -- Kerry Kennedy if prosecutors are able to prove their case. Well -- she could lose her license -- did the penalty is -- at maximum is a year in jail but since Kerry Kennedy has no record it's unlikely. She would ever be sent him to prison for this but she could lose her license and that's why the defense has been fighting this case so hard. Kerry Kennedy believes if she does lose her license even for a period of a few months. That would really curtail her human rights work with the Robert F Kennedy Foundation she doesn't want that to happen of course. And and the key here seems to be. How the judge is going to instruct the jury once the testimony is over the facts of the case -- are not in dispute. She took Ambien both sides concede she took it by accident there's a dispute over whether she would have felt its effects since it was. But what really matters according to the prosecutors is simply that she drove under its influence was impaired by the -- -- the defense contends but that's not the law the defense says that the prosecutors have to prove she knowingly and intentionally took the drug which she said she did not. How the judge instructs the jury. To read the testimony I think is going to be key. General quickly Aaron we're hearing term that the defense is using its -- sleep driving have you heard that as well being -- this morning for. It hasn't come up this morning that's been a defense term of art but it's one of the side effects that that -- that is recognized in and -- defense expert will take the stand later to talk a little bit more about it. Effectively what the defense is saying is that Kerry Kennedy's body was hijacked by Ambien without warning that that the drug. It didn't fifteen -- thirty minutes after she took it. And at that point instantly. She had a form of amnesia and was sleep driving in other words driving but she didn't know she was driving in and Kennedy has testified to that effect without using the term sleep driving. But I think we may hear more of that when an expert takes the stand later for the defense. And Aaron as you mentioned of course prosecutors also called their own witnesses including their own expert so jurors will hear from two experts on that. What's next for the trial -- -- -- three we've heard about a week do you think -- could go. Less -- more. Well it seems as -- did the defense really only has that one other expert witness once Kerry Kennedy -- the stand and so it's possible that by the end of today perhaps. The jury would get the case if not it could go into into tomorrow or even Friday but the judge has said that he wants this case over by the end of the week and he's made that. Assurance to the jury as well. ABC's Aaron Rodgers -- White Plains, New York thanks for braving the elements you give -- that he. What's going on in the court. You can of course get a complete recap right here on abcnews.com. I'm Michelle Franzen in New York -- has been an ABC news digital special report.
This transcript has been automatically generated and may not be 100% accurate.