Transcript for Woman goes on trial for murdering second husband, attempting to kill daughter: Part 8
is now underway. Castor faces 25 years to life. The witness list could be as many as 160 people. The first witnesses will take the stand tomorrow. January of 2009. The dead of winter. I remember it being brutally cold. Meanwhile, you have this really surreal and almost unbelievable story of a mom who may have tried to kill her daughter to Ver up killing two of her husbands. You have something that is very, very rare -- a mother versus her own blood daughter. You're going to have a grandmother who believes granddaughter did it. You also had David castor, Jr., who has lost his father, and David jr.'s mom, David's first wife. All rise. County court judge, the honorable Joseph Fahey presiding. Court is now in session. Please be seated. We had really three cases that we were presenting to a jury. We had the death of David castor. We had the attempted murder of Ashley Wallace. And we were allowed to present evidence about the death of Michael Wallace as well. You will have no choice but to stand up and shout, "Mrs. Castor, you are a murderer, and for that, you will pay." D.A. Bill Fitzpatrick is a bulldog. Once he sinks his teeth into something, he doesn't let go. Chuck Keller is trying his first murder case, and he's going to have to deal with the cross-examination of his client's daughter, who's gonna sit there and say, "She did this to me." That's not an easy spot fo defense lawyer to be in. You will decide that the wrong person is sitting in that chair. So the begins, and the D.A. Has taken the move, the bold move, to put the daughter Ashley on the stand as the first witness. Put your left hand on the bible, raise your right hand. E starts off by establishing her as somebody the jury likes, as really a tender-hearted teen girl. I want to about the day your dad died. Here's this 20-year-old remembering what it was like to see her father lying on the couch, and essentiallyying in front of her eyes. I saw him take and lift his arm up and then he made a breath and then he didn't move again after that. So I thought he was just sleeping. As she tells her story, he slowly leads her to the moment she takes a swallow of the drink offered to her by her mother. She came home and she was like, "Let's get drunk. Let's get just totally drunk." Police believe that the first round of drinking was a test run to just see how it goes, sort it out. But that the second time that Stacey actually puts pills into the drink. And she handed me the cup and she had a cup, and she told me to keep stirring the cup. Okay. What happened next? I took a drink of it. And? And it tasted horrible. What did you say? And I was like, "Mom, this doesn't taste good." She's like, "Probably -- there's probably too much vodka in there." And so she took it and went back in the kitchen, and she brought it back and the cup was full. Did you continue to drink it? Yes. Now, Ashley, I want you to explain to the jury, if the cup tasted bad and you didn't enjoy it, why would you ? Because I trusted her. I think any daughter trusts your mother. You're my mom. You love me. Why would you hurt me? Next, Mr. Fitzpatrick moves onto the suicide note. Stacey castor clearly hoped her daughter would be dead. This, in her mind was her way out, and she was trying to use the death of her daughter and a fake suicide note to basically clear herself from the investigation. What's the next thing you remember? Waking up in the hospital tive asking me what I did. "What did you drink? What did you do? What did you take? What did you write in that note?" But I didn't know what he was talking about because I didn't write a note and I didn't take anything. Have you set before, in my office? Never. Have you ever read this note? No. Did you write this note? No. You're absolutely certain. I'm 100% positive that I did not write that note. Did you poison your father with antifreeze? No, I did not. And did you poison your stepfather with antifreeze in 2005? No, I did not. Everybody in that courtroom was looking to see would there would be any kind of exchange between mother and daughter and we really never saw Stacey castor make eye contact with her daughter. She sat there stoically, without emotion. I can't imagine my own flesh and blood is 50 feet away from me, sang that "You tried to kill me," and not having a reaction to that. All right, chuck. Cross examination. Thank you, your honor. Now it's our turn. We get a chance to finally ask questions of this person. So the next thing you know, you wake up in the hospital the next day, right? Right. Chuck Keller's in a tough spot. Ashley's young. It's been emotional, and yet, his job is to show she's lying. So he's got to go after her to some degree, but without alienating the jury. We want to know questions about what happened with David. We want to know about with Michael. Whether or not the fact that Michael Wallace considered bree to be his princess with this name and this way of treating her bothered her. Did it bother you at all that your sister had a nickname from your father, this princess, and you didn't? No. You didn't think that was a little bit unfair? No. The defense is presenting a motive for Ashley to have done this. Angry at her father for not being the favorite child and the way she was treated growing up, angry at stepfather for disrupting the life that mom and two sisters had developed together, and then he moves on to that suicide note. We asked her, I mean point blank. Did you write the note? Is it possible you wrote this note? You wrote a suicide note before, didn't you? I had wrote a note to an exboyfriend. And inside this note you discussed two prior suicide attempts, right? Yes. When she wakes up in the hospital and she's asked, "Did you try to kill yourself?" "No." "Have you ever tried to kill yourself?" "No." Well, that's a lie. The biggest bombshell today was a letter that he says Ashley Wallace wrote to a prior boyfriend describing two prior suicide attempts. Keller in hisiant defense of Stacey castor questioned Ashley repeatedly about motive for murder. But Ashley was ready for him and it all fell flat. He's having real trouble portraying her as someone who wanted to kill her father and then her stepfather and then herself. Four weeks of the trial. Over 50 witnesses in the case. Clues at the crime scene worthy of Sherlock Holmes. The Turkey baster that had David castor's DNA on it. The suicide note, the autopsy results for David castor and Michael Wallace. Interesting testimony with one remaining question -- will Stacey castor testify in her own defense? If she did testify, was she going to break? Was she going to admit it or was she going to keep up that steel exterior of a cold, calculating killer ???
This transcript has been automatically generated and may not be 100% accurate.