tonight -- >> there's no such thing as a perfect marriage, and we had our share of issues. >> one woman, two dead husbands under suspicious circumstances. >> i can tell you right now, very rarely does anybody commit suicide naked. >> the unusual clue linking the two deaths. >> underneath the bed there was a bottle of anti-freeze that was on its side. >> and the daughter she tried to poison and frame. >> i hate my mother for ruining so many people's lives. what gave her the right to play god with people? >> this special edition of "nightline," "black widow," will be right back.

that leave therea lasting impression. like the feeling of movement as a new journey begins, or the sight of soft fur, warmed by the morning sun.

you might remember new flavours, the sound of an old friend's laugh, or a view that defies all expectations. these are the memories that stay with you, long after the moments have passed. this special edition of "nightline," "black widow," continues. here now, david . police communications, can i help to work this morning, i don't know what's going on. i'm getting a little concerned because me out of the bedroom. >> reporter: this story begins with a call to 911. it's a call involving a husband. on that phone is a frantic wife.

her name is stacy caston. >> one of the things stacy was concerned about was david had a shotgun under his bed. she was worried that he might have committed suicide. >> i bang on the door. don't get any response. >> i kick the door in. >> walked into the bedroom. and i observed david lying on his stomach across the bed. >> it was really an incredible scene. they find david caston, the husband, on the bed. no clothes on. and he's dead. >> stacy was just crying a lot. i mean, distraught. physically upset. you could see that she was struggling with her emotions. >> david castor was stacy castor's second husband, her knight in shining armor. >> she has two daughters, ashley and brie, who are teenagers, from a previous marriage. and he was married once before, too. and has a grown son.

david jr. >> for both david and stacy, this was their second chance at happiness. and their friends were really rooting for them. >> david and i had a very good relationship. >> there wasn't fighting? >> there's no such thing as a perfect marriage, and we had our share of issues that we dealt with. and obviously being a blended family, it made that much more to have to deal with. >> reporter: august 2005. david plans an anniversary trip but stacy says she didn't want to leave her daughters behind. >> david got upset, took the bottle of southern comfort, went into the bedroom and locked himself in, and reportedly got drunk. wouldn't come out. >> he wasn't sleeping. he was actually in the process of dying that weekend. >> on the night stand next to the bed was a short glass half full of a green liquid. another glass that had some remnants of some juice. an apricot brandy bottle. there was a cranberry juice bottle there too. >> then underneath the bed there

was a bottle of antifreeze that was on its side with the top off. >> i remember standing in the kitchen and speaking with one of the members of the sheriff's office. had observed a turkey baster lying in the garbage can. >> and i noticed that it's got droplets inside it. so i pick it up. and i pull the rubber ball off it and i smell it. i can smell alcohol in it. i know he's been drinking. i know alcohol's involved. i know antifreeze was involved. >> people have committed suicide in the past by drinking antifreeze. it's not a pleasant way to go. >> stacy had told me that david had been depressed because he had recently lost his father and that possibly his drinking and suicide that weekend was as a result of him being depressed about his father's death. >> this case could very well have closed and ended and everyone would have thought that

david castor killed himself. this was a suicide. but for people who knew david castor, suicide, it just didn't make sense. >> i can tell you right now, ra suicide naked. when you find a body naked, oh, no, start running the lab tests. >> we started sending in the physical evidence, the antifreeze bottle, the apricot brandy bottle, the glasses, to see if there was any fingerprints or dna evidence on those items. >> the glass actually had three fingerprints on it. they were all stacy castor's. >> one of the things that jumped out at us was the turkey baster. it turns out that there was antifreeze inside that turkey baster. one of the other puzzling things was david's dna was on the tip of that turkey baster. >> they're starting to get even more and more suspicious of what stacy's motives are. the investigators now start to focus in on, how did david

really die? and if it wasn't a suicide, then somebody must have killed david. >> so it all starts unfolding. and it all starts to even raise more questions for this detective. he wants to interview stacy castor's first husband. >> has anybody interviewed that guy? no, we haven't tracked him down. well, it turns out we can't talk to him because he's dead. >> michael wallace was buried in a cemetery, and in that cemetery it was his headstone. she had a headstone that would be for her someday. and right next to them was david's headstone. it was very odd and very peculiar. exhuming a body years later is very unusual. it's not like investigators go around to graveyards every day and dig bodies up.

>> not many judges are going to let you dig up a decease you ha. but we were able to convince the district attorney that this was indeed a homicide of david castor, and we believed that michael wallace met the same demise. >> a few days later i was walking through the criminal investigations division when i received a phone call from the medical examiner. and he said, hey, we just got done with the autopsy, have the results for you. >> said, guess what i found? he's loaded with crystals. when you are poisoned with antifreeze, crystals form in your organs. and they don't ever go away. and that was one of the reasons why we exhumed him was so we could find out if those crystals were still there. >> i knew at that point we had a double homicide. stacy castor probably killed both her husbands. that's when we said, we need to bring her here for a second interview.

>> a detective spinelli and i drove out to speak to stacy. >> i said, stacy, there were two glasses sitting on the night stand. you say that you poured him some cranberry juice at one point, right? she said, yes. i said, i'm going to show you a picture of those two glasses. i asked stacy, do you remember which glass it was that you poured the cranberry juice in? and she looked at it and said, well, when i poured the anti-free -- then she stopped and said, i mean the cranberry juice. >> like she realizes what she's just said. >> i said, you said anti-free. she said, you know, i don't like this, you're trying to frame me, you're trying to pin this on me, i'm done. and she stopped the interview. we decided the next step would be to obtain a wiretap on stacy's phones. >> and it scares the living

[ bleep ] out of me, because i didn't do this. >> stacy in that week making a lot of calls. she was in distress. they think i did this. >> and i don't believe for one second that they found antifreeze in michael's body, i don't believe it. >> she tells me, they exhumed your father's body. and i didn't believe it. so i went out and checked. i started crying. i got upset. like, he was resting peacefully, and they just dug him up. why would they dig up daddy? >> ashley has just graduated from high school, and she's just entering college when she gets this news. >> two investigators show up and deliver her the news that her father didn't die of a heart attack, he died of antifreeze poisoning. >> hello? >> mommy, they came to my freaking school. >> they came to your school? are you okay? >> i'm going to be okay, but i'm really freaking out right now. >> and you can hear it in her mother's voice too, this

disbelief that they've come to the school and that they've told her daughter this. and then stacy castor, the mom, has this suggestion. you know what? this is all too heavy, why don't we drink, why don't we have a drink? >> stacy mixes this probably 12-ounce plastic cup. ashley, caught up in the moment, this is so cool, this is neat, i want to make my mom happy. she drinks it. and becomes lethargic. and eventually passes out. and winds up in her bedroom. >> she wakes up, got a little hangover, goes back to school, comes back, mom again says, let's drink. this time, let's get really drunk. >> and this time ashley says, mom, it's not even noon yet. she says, it will be noon by the time we're drinking. but this wasn't just a second day of mother and daughter drinking. this was actually the scene that would now lead to the second phone call to 911 from stacy castor about an emergency playing out in her home.

>> i need an ambulance at wetzer road. she's having trouble, i think. it sounds like there's something in her throat. ashley? oh my god, oh my god, oh my god. this is not happening. touch shows how we really feel. but does psoriasis ever get in the way? embrace the chance of 100% clear skin with taltz... the first and only treatment of its kind offering people with moderate to severe psoriasis a chance at 100% clear skin. with taltz, up to 90% of people quickly saw a significant improvement of their psoriasis plaques. don't use if you're allergic to taltz. before starting, you should be checked for tuberculosis. taltz may increase risk of infections and lower your ability to fight them. tell your doctor if you have an infection, symptoms, or received a vaccine or plan to.

inflammatory bowel disease can happen with taltz, including worsening of symptoms. serious allergic reactions can occur. ready for a chance at 100% clear skin? ask your doctor about taltz. (thunderclap) if your day doesn't unfold as predicted. unfold this. new neutrogena® makeup remover single. and remove 99% of makeup. 100% rain or shine. neutrogena®. and i don't add 10trup the years.s. but what i do count on... is boost® delicious boost® high protein nutritional drink has 20 grams of protein, along with 26 essential vitamins and minerals. boost® high protein. be up for life. this is charlie not coughing because he took delsym 12-hour.

and this is charlie still not coughing while trying his hardest not to wake zeus. delsym 12-hour. nothing lasts longer for powerful cough relief.

shshow me homecoming. baby sloth videos on youtube. amy, do you uh mind giving someone else a turn? oh yeah i made myself a little comfortable here. i got a pizza for amy! yes, that's me! xfinity lets you search netflix, prime video, and youtube with the sound of your voice. and i don't have my wallet, so. that's simple. easy. awesome. get started with xfinity internet and tv for $40 each a month for 12 months when you bundle both. click, call or visit a store today. (music throughout)

this special edition of "nightline" continues. here again david muir. >> reporter: stacey castor's two husbands have mysteriously died.

now her oldest daughter ashley to work through whatever she had ingested and start to come out of it. >> it's blurry. i can't really see anybody's face. tunnel vision. all i could see is this big guy in this red shirt. he's yelling at me, how many pills did you take? >> she starts to respond. and i flat-out ask her, did you try to kill yourself? and she looks a the me and she had no clue that any of this had taken place. >> he told her that there was a suicide note indicating that she had killed her father and her stepfather. she looked at me really wide-eyed and flat-out says, i did not try to kill myself, nor did i leave a suicide note. >> i didn't know what they were talking about, because i didn't do anything. >> you didn't write the note? >> i didn't write the note.

>> at what point did you think, my mother tried to kill me? >> from the moment i woke up and everybody was asking me questions. i just knew. >> we finally decided that we have a woman who has killed two people and tried to kill a third walking around in public. we can't let her act again. >> i gave the direction that she be placed under arrest for the murder of david castor, the attempted murder of ashley wallace. >> stacey castor charged with poisoning one husband to death, trying to do the same with her daughter, will be tried for murder. >> january 2009. the dead of winter. meanwhile, you have this really surreal and almost unbelievable story of a mom who may have tried to kill her daughter to cover up killing two of her husbands. >> the trial of stacey castor is now under way. >> castor faces 25 years to life -- >> all rise.

>> 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. >> so the trial begins, and the d.a. has taken the move, the bold move, to put the daughter, ashley, on the stand as the first witness. >> place your left hand on the bible, raise your right hand. >> she came home and she was like, let's get drunk. let's get just totally drunk. and she handed me a cup, and she had a cup. she told me to keep stirring the cup. 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 said probably there's too much vodka in there. she took and it went back in the kitchen. she brought it back in, the cup was full. >> did you continue to drink it? >> yes. >> explain to the jury, if the cup tasted bad and you didn't enjoy it, why would you drink

it? >> because i trusted her. >> what's the next thing you remember? >> waking up in the hospital with a detective 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. >> four weeks of the trial. >> over 50 witnesses in the case. >> judge, we have one more witness. the defense calls stacey castor. >> all right. >> do you solemnly swear to tell the truth, the whole truth, and nothing but the truth, so help you, god? >> i do. >> chuck lays out his case with stacey and comes to the end and has to ask the critical question. >> did you kill david castor by poisoning him with antifreeze? >> no, i did not. >> did you try to murder your daughter and try to frame her

for the murders of david castor and michael wallace? >> absolutely no, i did not. >> the next morning, it was bill fitzpatrick's turn to cross examine stacey castor. >> fitzpatrick clearly made a decision here that the way to go after stacey castor is to talk to her as if she's a murderer who tried to frame and kill her own daughter. and that's exactly the tone that he used. >> you don't remember stati that? ashley poisoned him? >> i didn't poison him. >> when did ashley poison him? >> i don't know. >> despite raising his voice and making accusations -- >> you were typing the suicide note to frame your daughter, weren't you? >> no, sir. >> objection. >> overruled. we caught you, didn't we? >> no, you didn't. >> stacey castor remains cool, calm, collected.

question's going to be, does that make her seem more guilty or less guilty? >> the case is now in the hands of the jury in the stacey castor murder trial. >> finally you get that call that the jury's got a verdict. >> morning. >> good morning. >> as to count number one, murder in the second degree, what is the verdict? >> guilty. >> on count two, attempted murder in the second degree, what's the verdict? >> guilty. >> when you heard guilty? >> it can't be happening. it's got to be wrong. i didn't look around. i just sat there and waited for it to be done and left the courtroom. >> honestly, that was the best

day of my life. because i knew that people knew that i didn't do it. >> so we're sitting back down. and you're a convicted murderer. >> that's what they say. >> can you sit here across from me again and tell me that you're not a killer? >> no, i'm not. no, i'm not. i will never say i did something i didn't do. i will maintain my innocence until the day that i die. lobsterfest is on at red lobster. with the most lobster dishes of the year, what'll you choose? how 'bout lobster lover's dream? more like a lobster dream come true. a butter-poached maine tail, roasted rock tail and creamy lobster linguine. or try new lobster in paradise. it's a crispy coconutty, vacation on a plate. new ultimate lobsterfest surf & turf is here, too. 'cause what's better than steak and lobster?

steak and lots of lobster. breast cancer. we thought that we would travel to cancer treatment centers of america. we left on day one feeling like we're gonna beat this and that feeling is priceless... visit cancercenter.com. gonna beat this and that feeling is priceless... with advil liqui-gels, what stiff joints? what bad back? advil is... relief that's fast. strength that lasts. you'll ask... what pain? with advil liqui-gels. this is charlie not coughing because he took delsym 12-hour. and this is charlie still not coughing while trying his hardest not to wake zeus. delsym 12-hour. nothing lasts longer for powerful cough relief.

as to count number one, murder in the second degree, what is the verdict? >> guilty. >> on count two, attempted murder in the second degree, what's the verdict? >> guilty. >> the end for her came in prison. she died. she was 48 years old. natural causes. and she never saw her daughters again.

[ music playing ] ♪ heyou, all of you. how you live. what you love. [ laughter ] that's what inspired us to create america's most advanced internet. internet that puts you in charge. [ chattering ] that protects what's important. that handles everything [ group cheering ] and reaches everywhere. this is beyond wifi.