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what did you write in that note? >> was it a confession or a setup to frame her? >> i would have done anything for her. but she tried to kill me instead. >> who will the jury believe? >> the wrong person is sitting in that chair. >> my god! you lost two husbands! to poisoning. my god. is this your testimony? >> david muir, two years on the trail. two women, two suspects. who did it? >> i'm not the person to ask that question. >> who do you think i should be asking? >> black widow. here now david muir and elizabeth vargas. >> good evening and welcome to "20/20" saturday. for the next two hours, a mystery about a mother and daughter. one of them is in prison but which one. >> our team spent two years reporting on this story from the emergency room to the medical examiner's office and right there in the courtroom to find

out which one is the real black widow. >> reporter: a late summer day here in the rolling hills of upstate new york. a quiet, serene afternoon was about to change with one worried phone call to police. a wife's voice filled with concern about what might have happened to her husband. >> my husband has locked himself in our bedroom for the last day. he didn't show up for work this morning. >> reporter: 38-year-old stacie castor can't understand why her husband would do this. sergeant robert willoughby answers the call. >> she called home several times, can't get him to answer the phone. she says she knocks on the door, he doesn't answer. >> reporter: as he enters the house, stacie says her husband has been depressed and worried what he might have done with the shotgun he keeps under his bed. >> i bang on the door. don't get any response. i kick the door in, and david was laying naked across the bed. she asked me if he's okay. all i said was "no he's not." the paramedics go in the room, they leave, and at this point, she's screaming.

have him come back. he's not dead, he's not dead. >> she was just hysterical. >> reporter: stacie so distraught, she tells her friend lynn to make the paramedics come back. >> make them go back and get him and put him in the ambulance. she kept saying that over and over and over. >> reporter: she tries to calm stacie. >> i just finally said, stacey, it's over. there's nothing they can do. it's over. >> stacy's husband was dead. she described to us her loss. >> david was support and strength and security to me. >> reporter: do you find yourself asking why, even today? >> oh, absolutely. especially today. >> reporter: david castor was stacey's second husband. the successful businessman. he owned his own heating company, where she worked, too. husband and wife, going to the office together. married just two years, at first, he doted on stacey. >> she felt like a princess. she felt this was a fairy tale. she was loved.

she was treated like a lady. >> reporter: both married before, this was their second chance at happiness. she embraced his hobbies, his snowmobiling, his motorcycle. >> kind of like cinderella and live happily ever after. it seemed to be perfect. >> reporter: but after they got married in 2003, things began to change. stacey's two daughters, ashley and bree, missed the way it used to be, just the three of them. they missed having their mother to themselves. >> we all used to eat dinner together, like, laugh and joke around. just used to be me, her and my sister. all of us girls and we did a lot of things together. >> take us on trips. make us laugh. >> reporter: and stacey's mother, judie eaton, says from the very start, david castor did not like his new role as step-father. >> after they got married, he did not like having the daughters. things got very strained with the girls.

>> david was difficult with the kids. he expected them to do everything that he said without question. and being my children, they questioned everything. and that created a lot of problems. >> reporter: it was the oldest, 17-year-old ashley, with whom he fought the most. and that relationship would only grow more difficult. what would he say about ashley? >> selfish, disrespectable. >> reporter: dani and mike colman have been friends with stacey for many years. >> he didn't like the girls. didn't like the girls. >> at first, we really didn't like him. >> reporter: what didn't you like about him? >> just his attitude, like, he said he didn't want to be our father, but then, he was trying to be. >> reporter: it all seemed to reach a breaking point, the weekend of david castor's death. stacey says the couple was supposed to go away. her husband grew angry when she didn't want to leave bree alone.

her husband grew angry. >> he wanted to go on an extensive trip. ashley was an adult that could stay home by herself, but i didn't want to leave bree home alone for two weeks, and yes, there was an argument about that. >> he blew right up and said, we're going alone. she's 15 years old, she can stay home alone. >> and the way she explained it to me, he got so mad, his head split open and an alien came out. >> reporter: instead of the getaway, stacey got out of the house, alone, staying with friends. >> i encouraged her to come over, because she was just, you know, so distraught the entire weekend. >> reporter: her husband, she says, drank and slept away the weekend. she would go back to the house just to check on him. >> she said, she put her ear up to the door, she said, he heard him snoring snored like a mac truck. she knew he was in there sleeping. >> reporter: but he wasn't sleeping.

he was slowly dying, violently sick to his stomach. and as soon as detective dominick spinelli walked into the bedroom, he thought he knew why. >> next to the bed, i saw an anti-freeze container on the floor. empty bottle. a bottle of apricot brandy and two glasses. one of the glasses was half full of anti freeze. so thought he may have gotten in an argument and went through a depression and may have conducted suicide. >> reporter: detectives conduct a routine interview with stacey. she tells them of her husband's depression since his father's death. she said he was worried about his business, as well. >> the business was a strain on him. he was under a lot of stress to get things done. i think that maybe he, for whatever reason himself didn't feel happy. >> reporter: detectives looked around the house, taking items from the bedroom, the glasses, the anti-freeze container. in the kitchen garbage, they discover something else.

>> after pulling a few pieces of paper out, i find a turkey baster. when i picked it up, i saw droplets inside it. i pulled the rubber ball off the end of it, and it smelled like alcohol. i found that very odd. no food around, no dirty dishes, no indication that anybody had been cooking or baking or -- i know he's been drinking. alcohol is involved. i know anti-freeze was involved. i don't know which is in this at the time, but one of the two is in there. >> reporter: and as detectives collect those items in the house, at the morgue, the medical examiner is conducting an autopsy. >> there were crystals, and the presence of those crystals in the kidney confirmed that he died of ethylene glycol toxicity. >> reporter: in other words, he

died from anti-freeze. even a small amount causes the organs to slowly shut down. the coroner's conclusion, suicide. david castor had taken his own life. stacey breaks the news to ashley. and what did you think of that? >> why would he kill himself? like, i didn't know, really, that he was hurting like that. i was crushed. >> reporter: one family's tragic suicide. but there was that detective with gnawing questions still unanswered about the drinking glasses on the night stand, that turkey baster. and why anti-freeze to kill himself? when we come back, the autopsy may be in, but the forensics were not. if you struggle with type 2 diabetes, you're certainly not alone. fortunately, many have found a different kind of medicine that lowers blood sugar. imagine what it would be like to love your numbers. discover once-daily invokana®.

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september 2005. the evidence gathered from 48-year-old david castor's suicide is taken to the county's forensics lab in syracuse. david's widow stacey, the case is closed. to david's step-daughters ashley and bree, there is just shock and sadness. their own father had died five years earlier, and now their step-father, too. >> just me and bree and my mom again. you lose your father and now you lose your step-father, like, what is going on? i thought maybe she just got dealt a bad hand in relationships. >> reporter: you felt sad for your mom?

>> right. >> reporter: but david castor's suicide just didn't make sense to his sister linda. >> david worked in heating and air conditioning. he worked on vehicles. he knew what anti-freeze could do to him. and how painful a death that would have been. he never would have done something like that. i remember walking up to the casket and looking at david laying there and i just thinking in my head, you know, why are you laying here? what happened? >> reporter: others wondered, as well. david's first wife, janice, and their son together, david jr. >> he would never commit suicide. never. he loved life. he loved his toys. he would never do it. >> mom knew right from -- she's like, this didn't happen. she kept after the detectives and really kept the case going.

>> reporter: dominick spinelli was already suspicious and had quietly refused to close the case. >> a sixth sense is something you develop throughout your career. it tells you something isn't right. >> reporter: he was particularly bothered by something stacey said to detectives, on how she said he got the idea on how to poison himself. >> she said she watched a show in which a woman had killed two husbands by giving lethal doses of anti-freeze, that maybe david got the idea there, to kill himself that way. >> reporter: and when she told you this, what were you thinking? >> odd. something strange about it. >> reporter: in fact, when the detective examined the phone records from the day her husband lay dying, the records revealed she called only once. not the several times she first claimed. and when she made that call to police after spending the night at a friend's house, it was not from home beside her sick husband when investigators

believed she had been checking in. instead, she went to work. >> my husband has locked himself in our bedroom for the last day he didn't show up to work this morning. >> reporter: the first officer on the scene, sergeant robert willoughby found that odd. >> supposed to show up at work at 7:30 and this call is almost 2:00 in the afternoon. why are we waiting five hours after he's supposed to show up for work before you call? >> if you are so concerned about somebody, you leave the residence to go back to the business to make the telephone call? you don't call from the house? you don't call from your cell phone. >> reporter: didn't add up? >> no. >> reporter: and it turns out, it would not add up at the forensics lab, either. >> the print on the left-hand side is the print that was developed from the drinking glass. >> reporter: only three fingerprints were found on that glass on the bed stand, and they matched not david castor but his wife, stacey.

and strangely, there were no fingerprints at all on that container of anti-freeze. >> if david poured a glass of anti-freeze, then, why isn't there one fingerprint on that container? why, if he drank out of that glass, isn't there any other smudges or prints on that glass? >> reporter: which would lead to one of the central questions. why was that glass on the bedstand, if it didn't have his fingerprints on it at all? >> the glass, i think that was just a prop. appears as though david really never drank it out of that glass. >> reporter: and then that turkey baster found in the bottom of the garbage can in the kitchen. with drops inside. a lab found the drops inside were anti-freeze, and there was more. you found his dna on the tip. >> his dna is on the tip of the baster. >> reporter: to bill fitzpatrick, the district attorney, the evidence was now

no longer pointing to suicide, it was pointing to homicide. >> why does a guy kill himself over the course of three days in a horrific manner such as anti-freeze poisoning, when he's got a shotgun under his bed? and can end it all in a fraction of a second? and why is there anti-freeze in a turkey baster? >> reporter: do you believe as he was lying in that bed she was feeding him out of the turkey baster? >> absolutely. no other explanation for it. >> reporter: because fitzpatrick asks, if you're really going to kill yourself with anti-freeze, would you do it one drop at a time? >> suicide by turkey baster is not something i have ever heard of in my career. >> reporter: so now, a big turn in the case. the detective no longer alone in his questions. d.a. fitzpatrick quietly opened a criminal investigation with stacey castor, the wife, the prime suspect. and while she didn't know they were investigating her, she does admit for people on the outside, it didn't add up.

do you understand how people could look at this and think, there's something not right here? >> sure. i can see that. >> reporter: how do you explain it? >> i'm not the person you have to ask that question to, because i can't explain that. >> reporter: who do you think i should be asking? she wouldn't answer the question. but in the police report on castor's death, there were family members who told detectives to question somebody else about it. stacey's older daughter ashley. it was well known ashley and her step-father didn't get along, and it was becoming clear among family and friends that everyone was beginning to take sides. as investigators quietly continued their work, here on the outskirts of town in this small cemetery, david castor is laid to rest. but right beside his grave is someone else who will also play a part in this unraveling mystery. stacey castor's first husband, who died at just 38.

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it was here stacey castor, still a young woman, would experience her first great love. and her first great loss. when stacey was just 17, she met the man who would become her first husband, michael wallace. >> mike was the love of my life. i knew five minutes after i met him that i was going to marry him. >> they went together about three years before they got married. and she was as happy as she had ever been. >> mike was the life of the party. mike was larger than life. and when michael was good, michael was very, very good. and when michael was bad, he was very, very bad. >> reporr: what do you mean by bad? talking about drugs? >> yes. >> reporter: alcohol? >> yes. he had a problem with both. for a long time in his life. >> reporter: but mike adored stacey, and in 1988, they had their first daughter ashley. >> right. >> reporter: what was that like for you? >> i was in love.

i knew from that minute on, my whole reason for being here was to take care of her. i would say that ashley and i were best friends. we did everything together. >> reporter: three years later, stacey gave birth to their second daughter, bree. michael was instantly taken with her. he would soon call her the princess. >> bree was daddy's little angel. bree could do no wrong in michael's eye. bree could walk on water. >> reporter: what about ashley? >> there was no talk of any relationship with ashley and michael. ever. all stacey ever talked about, mike and bree, mike and bree. >> and i think on some levels, definitely that hurt her. >> reporter: could you see it as a mom? >> yeah. everybody around could tell that. could see that. >> reporter: ashley was not daddy's little girl, it was the other daughter? >> yeah. >> reporter: though michael and

stacey sometimes argued, they seemed to love each other and were getting by. stacey worked at an ambulance dispatch company. mike was a mechanic. but as time wore on, the luster wore off. a decade into the marriage there was talk both husband and wife had begun to stray. stacey confided in her friend kim she was considering divorce. >> she then came back to me and said, you know, it's almost christmas time, i don't want to rock the boat. i don't want to upset the household before the holidays. >> reporter: there was no divorce. and not long after, michael started to get sick. >> it was on and off, it was a yo yo. a roller coaster ride for like six weeks. >> reporter: mel ann, who was married to michael's brother, said michael's family was worried. no one knew what was making him sick. >> and i remember him acting like he was drunk. he was very unsteady and he was just saying, mel, i'm

really tired of feeling this way. it's been going on for so long and i don't know why. >> he did not look good. he was coughing. he said his shoulder ached. he said, i think if i just rest for awhile. i said, i think you better go to the doctor tomorrow. >> reporter: but he never made it to that doctor. a few days later, ashley was home alone with her father, and noticed he was behaving oddly. >> he was laying on the couch and he was making what i thought were funny faces. and all of a sudden he just sticks his arm up in the air and, like, puts his arm on his side and the arm just fell down and by that time, i had to go get my sister from school. >> reporter: she left to get her sister, her father laying on that cough. it was the last time she would see him alive. >> when my mom got home, she told us to go next door. we stayed over there until my grandmother came back and told us that he had passed away. >> reporter: and what was that all like? >> it was scary.

i've relived this day over and over again in my head because, what if there was something that i could have done. i should have known. but i didn't. i was 11. >> reporter: how did ashley react to her father's death? >> she blamed herself for a long time. said that it was her fault that her father died. >> reporter: why would she say that? >> i don't know. >> reporter: she used to say, it's my fault? >> yes. yes. >> reporter: doctors believed that first husband, a 38-year-old who drank and smoked, died of a heart attack. but there was only one way to know for sure, an autopsy. stacey told the doctors it wasn't needed. if he was the love of your life, why wouldn't you want to know what was truly behind his death? >> because when his doctors told me that they believed he died of a heart attack, i believed that. there was no reason for me to question that. if the doctor had said, do it, it would have been done. but he didn't.

>> reporter: was it strange to you that nobody asked for an autopsy, no one wanted a definitive answer? >> no, i was working for a physician that was there in the er at the time, and he told me, he said, i don't see a need for it. when you have physicians tell you that, you figure, okay, there's no need. it was a heart attack. >> reporter: and as the entire family grieved, to friends and relatives, stacey put on a stoic front. >> i didn't see her cry at all. even in the hospital, she wasn't crying when i saw her there. i wouldn't classify her as the grieving widow. >> she didn't really cry at the funeral. i thought she was sad and i thought she was trying not to cry because me and my sister were there and she didn't want us to see her sad. >> she said, i need to get back to normal. i can't lay in my bed. the girls need to know that i'm okay. i thought it was amazing that she was able to kind of pull

herself together in a fairly short span of time. >> reporter: with michael's $50,000 life insurance policy, stacey paid for the funeral and paid off some of the family debt. she took the girls to disney world, their first real vacation. a mother, now left to raise her two daughters alone, was looking to the future. in the months after your dad passed away, you moved on. >> you got to move on, yeah. >> reporter: so life went on as normal after. >> basically, yes. it was just me and my mom and my sister. and that's how it was for awhile. everybody liked it that way. or so we seemed to think. and then she met david. >> reporter: david castor, the man who would become stacey's second husband, the man who would become step-father to her two girls. but just two years into the marriage, he was dead, too. >> i just remember thinking, how can this be happening? it seems so surreal.

how can any one person have such incredibly bad luck? >> reporter: but was it really bad luck that claimed both of stacey castor's husbands? beneath the grave stone, her first husband michael wallace, dead for five years. he might be the only one with the answer to that question. and there is just one way to find out. when we come back. (sniffing) new phone smell. jump on a video chat with my friend. he's a real fan boy, so i can't wait to show this off. picture is perfect. i got mine at verizon. i... didn't. it's buffering, right out of the box he was impressed. i couldn't be happier. couldn't see him, but i could hear him making fun of me. vo: you waited this long for the s6, so why settle for anything less than verizon. [announcer:] what if one protect you from cancer? what if one push up could prevent heart disease? [man grunts] one

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now that her two husbands are dead and buried, stacey castor is moving forward with her own life, pursuing a new career. >> i thought about becoming a lawyer, but didn't go to college. so, when i had the opportunity to work at legal aid, i was thrilled. >> reporter: she would become a legal assistant, working at an agency that offered legal help to those who couldn't afford it. >> when they had a position that was available and they asked me if i was interested in the job. >> reporter: they were convinced you were a good worker? >> apparently, because they gave me the job. >> reporter: but what that new legal assistant didn't know was that she may need legal help of her own. investigators were quietly growing more suspicious that david castor didn't kill himself, but was poisoned with that antifreeze. there was that drinking glass

beside his bed with only his wife's fingerprints. the turkey baster with antifreeze in it, a poison that mimics alcohol, making you feel and act like you are drunk. it is a slow and easily hidden murder weapon, and a disturbingly common one. >> there are dozens of cases across the country of people using antifreeze for murders. virtually every home has some, and it's almost impossible to detect if you disguise it in some other liquid. >> reporter: and there was about to be something else. the will. david castor's will left almost everything to stacey, and nearly nothing to his own son, david castor jr. now with his own little boy. >> she gave me my father's bracelet and gold chain and cross. a handprint from when i was about five. >> reporter: what did you think? >> i was hurt. a lot. that you would write off your only kid. >> reporter: when you heard the

will was rewritten and your son wasn't included, what did you think? >> something is very wrong. david didn't do that. >> reporter: and she was right. it was stacey who oversaw the will. and it wasn't signed until after david's death, witnessed by stacey's friend lynn, who thought she was just helping a grieving friend. >> she had been through so much and i just felt that if this would help to make that smoother, why not? i never in my wildest imagination ever thought that it would turn out to be what it was. >> reporter: what it was to district attorney bill fitzpatrick was just another piece in a mounting case he was building against stacey castor. does it prove anything? >> well, it proves that she's deceitful, and it proves that it certainly was some financial motive.

>> reporter: and she monkeyed with the will after his death? >> we believe that to be true, yes. >> reporter: investigators say stacey collected more than $50,000. david jr. would get that cross, that handprint he made, and his father's restored dodge. the cash? nearly all of it went to stacey. the evidence was beginning to add up, and by the summer of 2007, investigators were suspicious enough to take the next step, ordering wiretaps on stacey's phone, and mounted cameras, one outside stacey's home. they also put surveillance some place else, right here in the graveyard where stacey castor's husbands are buried side-by-side. a plot for stacey herself right in the middle. investigators were watching here, too. after all, only two years had passed since the loss of her second husband, the pain still so fresh. you might expect she'd visit the grave.

but that second anniversary would come and go. did she pay her respects? >> not that i know of. there were no new flowers on the gravesite. that bothered me. why hadn't stacey been there to visit him? >> reporter: and while stacey may not have been there to pay her respects, detective spinelli was, determined to figure out, was david castor's death really a suicide, and how could he seemingly healthy first husband die of a heart attack of just 38. >> we found there was no history of heart disease, heart problems with michael wallace. there didn't seem to be anything that should have caused his death. >> reporter: nothing that would have caused a heart attack? >> no. >> reporter: so spinelli was ready to take a huge gamble. highly unorthodox, and one that would weigh heavily on the detective's own see key. >> the last thing i want to do is to disturb someone who is at peace. especially with nothing showing up in the system.

>> reporter: september 5th, 2007, detectives gather at that cemetery outside syracuse with a solemn purpose. they were about to exhume that first husband's body. >> heavy equipment is doing their work. i remember thinking, michael wallace came out of the ground, i wonder if he's saying -- it's about time you guys are looking at this. because i didn't just die on my own. >> reporter: his body was off to the county morgue, where the autopsy he never had. we'll be back.

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just one day after the body of michael wallace was exhumed from the grave, the medical examiner was already studying a piece of tissue from wallace's body, now seven years after he had been laid to rest. dr. robert stoppacher has a clear picture.

>> you're looking at the slide of michael wallace's kidney. >> reporter: though so much time had passed, doctors say in cases like these, bodies can hold clues. and there in that image, the answer detectives were looking for. the tell-tale crystals. antifreeze. >> yes. >> reporter: when the m.e. told you what he found, what did you think? >> stacey castor killed him. >> the fatal dose would be two to three ounces. which is not an awful lot. eventually it forms the crystals and they're carried by the bloodstream to your kidneys and your brain. and your kidneys shutting down and failing will be the first step before ultimate death. it's an extreextremely unpleasao die. >> reporter: now knowing the first husband died from antifreeze, they believed it impossible that her second husband, david castor, chose to drink that antifreeze himself, that he committed suicide. it had become clear he'd be murdered.

the medical examiner showed us slides of castor's kidneys. >> this is his kid any. >> look at the two images side by side. the first and second husband. they died five years apart, and both lie in their graves with antifreeze in their kidneys. the next morning, detective spinelli and valerie brogan come to the house. >> she said, i can't believe this. i got the letter from the office that said that david's death was a suicide. i thought this was done and over. she made the comment that she was tired of being controlled by someone from the grave. and i kind of remember shooting a look to spinelli, thinking, that's an odd thing to say. >> reporter: they bring stacey downtown, where for nearly three hours, spinelli interrogates her in this small room. detective brogan watching through a two-way mirror. they probe asking questions about the most recent death.

the second husband and the supposed suicide. stacey claims she kept checking in on her husband that weekend, fft, calling him several times the morning he lay dying. but spinelli challenges her with phone records that show she made only one call to david castor that day. >> at that point, she just -- she shut down, she said, that's it, i want an attorney. >> reporter: when she gets home, stacey tells her daughter ashley, police are zeroing in on mom, that police suspect that she's killed ashley's father and step-daughter, too. >> i said, that can't be right. you couldn't have murdered him. they issued a death certificate that he died of suicide and daddy had a heart attack. >> reporter: and she said? >> she said, i know. i didn't do this. >> reporter: in the days ahead, events start to move very quickly. detectives say phone calls to stacey's friends grow more alarmed. >> it scares me because i didn't do this. and i don't believe for one second that they found antifreeze in michael's body. i don't believe it. >> stacy was treejsly nervous

and scared. why are the police after me? i didn't do anything. michael died of a heart attack. >> reporter: stacey hires a lawyer, and she goes to that cemetery to see for herself. did they really exhume her first husband? and when he daughter finds out -- >> i started crying. i got upset. like, why would they dig up daddy? he was resting peacefully. i thought it was inhumane and i didn't like it whatsoever. >> reporter: none of it made sense? >> not at all. >> reporter: it was an overwhelming week for ashley. she had her first day of college where she was studying to be an accountant. >> i was excited, in class, signing the attendance sheet for my first class and the lady from the office comes down and she goes, i need you to come with me. >> reporter: two detectives are waiting to tell ashley that, yes, they had dug up her father's body, and that there was no heart attack. he had been murdered with antifreeze. >> i got upset. i was -- i was like -- you're lying. because i knew that my dad had a heart attack. that's how it was. he had a heart attack.

>> reporter: upset, ashley calls her mother. >> 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. >> reporter: stacey rushes to pick up ashley from school, and under the crush of suspicion and growing evidence, a mother is about to offer her underage daughter something very unusual. >> she's like, well, we've had a hard day. we had a hard week, let's drink. she let me drink. >> reporter: had she ever said that before? >> not really, no. occasionally she would let me have one beer, but she would stand there and watch me drink it. this time, she bought me a whole six-pack of smirnoffs and said, let's get drunk. >> reporter: and you thought? >> i was like, cool. what kind of teenager wouldn't think that was awesome? parents just gave you permission to drink. sweet. you know? so -- i drank with her.

>> reporter: first, she says, she drinks what her mother gives her in a glass, and the daughter starts drinking straight from the bottles. she gets sick. ashley says her mother gives her a pill to help her sleep it off. she goes to bed. the next morning, she pulls herself out of bed, goes to school. when she comes home, mom is waiting with another unlikely offer. let's drink again. >> i'm like, mom, it's 12:00 -- it's not even noon. she's like, that's okay, by the time we get off the stuff it will be noon. so i'm like, okay, you know, whatever. but i still do it because i trust her, you know? she's my mom. >> reporter: a security camera captures stacey buying drinks for her daughter. and when they come home, ashley says her mother comes out of the kitchen carrying a large cup. >> she's stirring the cup. i thought it looked funny. she told me to keep stirring it. and i was like, well, that's kind of weird.

she goes because the sprite is in there, you need to keep stirring it. i took the spoon out and took a sip and it tasted really gross. >> reporter: what did it taste like? >> i can't even explain it. like, it made me gag. because it tasted so bad. and she's like, oh, just take another sip. and i was like, okay, and i'm drinking it, and i'm like, mom, i can't drink this. she's like, well, let me show you a trick that i learned when i was a kid. put the straw in the back of your throat and count to ten while you're drinking it. so, i did what she said. >> reporter: and you drank it? >> i drank more, yep. >> reporter: a lot of people will say, if it tasted that bad -- >> why did you do it. >> reporter: why did you drink it? >> because i trusted her. >> reporter: soon after, ashley says she went into her room and laid down to take a nap. and what was about to happen in that house on wetzel road, would lead to stacey castor's third call to 911. >> i need an ambulance. she's having trouble, i think.

it sounds like there's something in her throat. ashley? oh my god! oh my god! >> reporter: when "20/20" continues. [narration throughout] i started my camry. ran a race most wouldn't dream of starting. chose to take down a monster. and realized when it's dark enough...

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the quiet of a small town, clay, new york, is shattered in early september. >> i need an ambulance. >> and what's the problem? >> my daughter has taken some pills. >> reporter: a distraught mother, stacey castor, for the third time in eight years, calls police. an ambulance rushes to her house. this time, it is her 20-year-old daughter ashley gasping for life. >> it sounds like there's something in her throat. ashley? oh my god. oh my god. oh my god. >> i was in complete shock and panic at that point. this is my baby. what's going on? is she okay? >> her mouth was open and her eyes were wide open. they were all glassy. >> reporter: ashley's younger sister, bree, was the one who discovered her. >> i tried to call her name and she didn't answer me.

and so i screamed for her again. and she still didn't answer me. that's when i went and yelled for my mom. came flying out of her room. >> reporter: stacey tells the 911 dispatcher that ashley swallowed pills and vodka. >> can you try to determine what she took? >> ambien. >> do you know how many? >> no, i don't. the prescription was just done. >> she drank an entire bottle of vodka. >> her head was, like, tilted back and she just -- it was like a blank stare, but she looked scared. >> reporter: did you think you were losing her? >> i did. >> probably one of the hardest things i've ever seen in my life was seeing her laying there like that. >> reporter: detectives have already been watching the house. suspecting stacey of poisoning her two husbands. now they're being called to the scene again, this time, her daughter is dying. could it really be happening again? could a third member of this family be dying? the next discovery could turn

the entire case upside down. the younger sister bree goes back into ashley's bedroom and makes a discovery. a note. >> i was really scared, so i went back and as soon as i got there, in her room, i saw it. it was at the head of her bed behind her head. >> was it there before? >> i didn't see it before. but i saw it right away when i went back. >> reporter: did you read it? >> i started to, but my mom ended up taking it away from me. >> reporter: stacey is still on with 911. >> she left a letter. >> she left a letter? >> left a note. oh my god, this is not happening. >> reporter: the note, a 750-word type-written letter, is a shocking confession. ashley, the daughter, admitting she killed her father, and then her step-father, and was not crumbling under the pressure. trying to kill herself. and the note contains details of the poisoning that only the killer could know. at the end, ashley says good-bye to her boyfriend, good-bye to

her sister, and farewell to her mother. please don't hate me. remember, i love you. ashley's name typed at the bottom. >> and it said, i'm sorry that i had to do this, but now everyone will know the truth and they won't blame you, they'll blame me. >> reporter: so, at that point, you thought this was a suicide note. you're thinking -- ashley tried to kill herself. >> yeah. >> reporter: ashley is rushed to the hospital, her blood alcohol level spiking. >> they wheeled her in. she was unresponsive. they were running around like crazy trying to save this girl's life. >> her heart was beating 170, 190 times a minute, and was very erratic. >> if they didn't figure out what she had ingested, there was a possibility she wasn't going to make it. >> reporter: not knowing ashley would survive, stacey stands beside her daughter in that room. >> i told her that i loved her. that was the last thing i got to say to her. >> reporter: the last thing she

would say to her daughter, after that letter, revealing that ashley was the killer all along. but ashley would wake up. the second hour of this special "20/20" starts right now. tonight, as "20/20" continues -- >> oh my god. >> one woman, her two husbands dead. poisoned. >> next to the bed i see an antifreeze container on the floor. >> but who killed them? wife or daughter? a mountain of evidence, prints, pictures, cemetery secrets and now a suicide note from the daughter. is it a confession? >> my daughter has taken some pills. she left a letter. >> she left a letter? >> oh, my god. this is not happening. >> did the daughter really write it, or was the mother out to set her up and pin both murders on her? from the emergency room to the autopsy room to the courtroom. >> my god!

you lost two husbands to poisoning! >> two women, two different versions of the truth. >> i wonder how you try to kill your own child. >> i did not try to kill my daughter. period. >> reporter: you think she's the black widow? >> here now david muir and elizabeth vargas. >> wael back to our second hour of "20/20" saturday. a young woman lies in a hospital bed, almost killed by an overdose. but did she poison herself or was he poisoned. >> as a mystery unfolds of what happened to this young woman's father or stepfather. >> i couldn't really see. it was blurry. i can't really see anybody's faces. tunnel vision. i realized that i'm in the hospital because my arms are tied down. >> reporter: in that hospital room, 20-year-old ashley wallace is waking up. emerging from a near deadly haze

of vodka and sleeping pills. doctors say she's lucky to have made it. >> if she had not been found, i think it's unlikely she would have lived past 10:30, 10:45. i think her heart would have gotten to erratic. she would have expired at home. >> all i could see was this big guy, and he's yelling at me, how many pills did you take? what did you do? what did you take? what did you drink. >> i'm not real sure that she understood what was going on. i told her that there was a suicide note indicating that she had killed her father and her step-father. >> and i'm like, what you are talking about? i didn't do any of these things. that you're saying that i did. >> she looked at me like i was out of my mind. >> what did you write in that note? >> all of a sudden, everyone is asking who is telling the truth? who really wrote that note? some side with the daughter. >> there's no way she tried to kill herself. >> some siding with the mother. >> stacey did not do this. i don't know who did it, but stacey didn't do it. >> reporter: it was all coming down to this.

did ashley kill her father and step-father, or, did a mother who had killed her two husbands, now try to kill her own daughter to save herself? >> i think she began to panic. >> stacey knew that our grip was getting a lot tighter on her, and there was no way out of it. besides trying to use her daughter as a scapegoat. >> reporter: framing her daughter? >> yes. >> reporter: as family members stood outside that hospital room, ashley's younger sister bree says her mother desperately wanted to go back in. >> she was shaking, like, like her whole body was just shaking. she's just like, i don't understand why they won't let me see her, and i'm her mother, i should be in there. >> there were police all over the place and they wouldn't let me in the room with her. >> reporter: 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.

>> reporter: it all came together? >> when the detective asked me what happened, what i did, i just knew i didn't do anything, so somebody had to have done it. >> reporter: detectives were convinced of that, too, and they moved in for the arrest. >> told her to turn around, put her hands behind her back, she was under arrest. for the murder of her husband. >> i couldn't believe what i was hearing. i couldn't believe that this man had just said they were arresting me. >> reporter: they thought you poisoned your daughter. >> i had a speeding ticket when i was 18 years old. that's the closest i've come to a brush with the law. so, to be arrested and handcuffed, i was terrified. i was devastated. i just couldn't believe that that was happening. >> reporter: stacey castor is charged with murder, and charged with attempted murder of her own daughter. and while she was sitting behind bars, that mother says all she could think about was that daughter. >> i still didn't know if she was already.

>> reporter: prosecutors say you're the one who did that to her. >> no. anybody that truly knows me and knows how i feel about my kids could never believe that. i would have died for my kids. i could never hurt them like that. ever. my kids were my whole life. >> reporter: and you realize, when you say that you didn't do it, that can only mean somebody else was responsible. >> yes. >> reporter: your daughter. for the first time, stacey castor makes it clear, she's calling her daughter the killer. it is mother versus daughter, but to believe stacey castor, you would also have to believe that ashley began killing at just 11 years old. in order to believe you, people would have to believe that your daughter would have killed her father. >> it may be easier for people to decide that i did it because i'm the mother and i'm 40 years old. but kids do things like that.

all you have to do is turn on the news or read the paper. there are children that kill children and other people every single day. it happens. >> reporter: the idea that your daughter would think of antifreeze, would come up with this plan? >> but it does happen. >> reporter: antifreeze? >> the truth will come out. >> reporter: and you're convinced of that? >> absolutely. >> how can you sit there and blame your own child for something that you know you did? that's just what i don't get. >> reporter: the daughter is outraged her own mother could suggest it was her. >> i didn't try to kill anybody and i would never kill anybody. >> reporter: did you murder your husbands? >> no. i did not. i loved both of them very much. >> reporter: did you give your daughter that drink? >> no, i did not. >> reporter: did you write that suicide note? >> no, i did not. >> reporter: you're convinced that she did write it? >> i know that i didn't. i know that i didn't.

we're going to prove that i didn't do it and that the truth is going to come out. i know. i'm very confident of that. >> reporter: as we sat across from stacey castor in jail, she told us that she often thinks of her two late husbands there are tattoos for each of them on her shoulders. she had not spoken to either of her daughters since that arrest at the hospital. months had passed. no phone calls, no letter from either daughters. they had chosen their side. as time goes by, do you wonder when the next time you will talk with them? >> yeah. yeah. >> reporter: or if you'll talk with them. >> yeah. and i worry about, you know, if they're okay and if they're safe and what they're doing and all the mom stuff. >> reporter: your mother told me that you were her best friend.

>> she was my best friend, too. she was. and she took that all away. i would have done anything for her. but she tried to kill me instead. >> reporter: someone is not telling the truth. mother and daughter will now face off in court, and the grandmother has made her choice. and the hardest part of it all must be knowing that it was one of them. >> true. >> reporter: she is convinced she knows who really did this. when "20/20" continues. introducing new flonase allergy relief nasal spray. this changes everything. new flonase outperforms a leading allergy pill, so you will inhale life. when we breathe in allergens, our bodies react by over-producing six key inflammatory substances that cause our symptoms. most allergy pills only control one substance, flonase controls six. and six is greater than one. so roll down your windows, hug your pet, dust off some memories, make new ones.

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40-year-old stacey castor is suspected of the unthinkable. not only murdering her two husbands, but then poisoning her own daughter to frame her for the crimes. >> i have woke up in the middle of the night and you just lay there and you think, how did this happen? >> reporter: for stacey's mother, judie eaton, grandmother to ashley, the one day a week she can visit the county jail in syracuse has become a painful ritual. what is that like, visiting your daughter? >> it kills me. it's very difficult. she doesn't deserve this. >> reporter: doesn't deserve this, because judie believes her daughter stacey castor is innocent. she says she is convinced that the suicide note from ashley was

real, and because it contained information only the killer could know, the grandmother believes the killer is ashley. you are convinced it was your granddaughter? >> i am. ashley had ample time, ample opportunity, and i don't like to say that, because i love her as much as anybody else in the family. >> reporter: the grandmother says there had long been warning signs. her granddaughter, who wasn't daddy's favorite, and one who famously fought with her step-father. >> reporter: some people watching might say, this is a grandmother who is saying it could be her granddaughter who did this. >> i've seen her temper. yes. i think she probably could have. >> reporter: is it hard though to think that your mother has had to put her daughter before he granddaughter? >> i asked her about that myself, and she said, yes, she loves ashley, but i'm her daughter. >> reporter: and stacey castor has someone else on her side, chuck keller, defense attorney. >> the mother and daughter are the only two people that know

the truth. it's a tragedy for everybody. there is no happy ending. >> reporter: this is keller's first murder trial. >> lab reports. >> reporter: he's facing a mountain of evidence. but it's his mission and his mission alone to create reasonable doubt in the mindsle of those jurors. >> hardly a person i can talk to who doesn't already feel based upon what they've heard that stacey's absolutely guilty and that we should just throw her away for good. but they can't take someone's life away when there is a chance that they've got the wrong person. >> reporter: just a chance? >> just a chance. >> reporter: and she walks? >> she walks. >> reporter: we spent nearly two years following keller an his team as they worked day and night, looking for clues that could clear the client. chuck's investigator begins looking for evidence that the daughter, ashley, could, in fact, be the killer. >> hi. >> hi, come on in. >> reporter: one of his first stops, dani and mike colman. stacy's closest friends.

they've known stacey for 20 years and among the few friends convinced that stacey is innocent, and that the daughter ashley was not only capable of killing, but that she did it. >> i think that because i could see how evil and jealous one of the kids can be, and how she can flip her temper very quickly. >> in my mind, in my gut, it makes more sense that she could have done it opposed to stacey. >> reporter: and so we sat down with them, too, because to believe ashley could have been the killer, you'd have to believe she began killing at a very early age. do you believe ashley was capable of killing her father? >> absolutely. 100%. >> yes. >> reporter: and a few years later, killed her step-father? >> she got away it with once. >> reporter: you think a child could keep that secret? >> she was a very dark person. >> reporter: but dark doesn't mean deadly. chuck keller knew he needed more than that, scouring the family home. >> you never know what you're going to find. >> reporter: they were looking for writing samples that would match the writing in the

type-written suicide note left on the bed next to ashley. >> you can compare the style of writing, the way they spell certain words or misspell certain words. >> reporter: they also begin to explore ashley's past as they build their case, looking for evidence that ashley was jealous of her father's relationship with her sister. and looking for proof that ashley often fought with her stepfather. and more importantly, could show have really written that suicide note? had she spoken of suicide before? they track down an exboyfriend and a letter she wrote to him, and in it, exactly what they were looking for? ashley writing about killing herself. >> after my dad died, i used to think about what would happen if i died. i almost tried to do it twice. >> and that is crucial to this case, because somebody who has contemplated suicide now actually makes the attempt? that's absolutely consistent.

>> reporter: and as sure as he is that the daughter was capable of this, the prosecutor, william fitzpatrick, is even more confident that the mother, stacey castor, was the killer. >> when somebody gets tired of some person in a marriage, they might go see a lawyer or try to see a counselor. stacey just pours them a drink. >> reporter: for nearly two years, we were given exclusive access to the prosecutor and his war room. a rare look as they dissected every detail of this case, the kind of cold-blooded calculation that surprised even this veteran prosecutor. >> what kind of mother will try to kill her daughter to protect herself? >> there isn't an answer to that question. there just isn't. you could bring on somebody with more degrees than a thermometer and tell you, you know, in my professional opinion, this woman suffers from this -- it's just bald-faced evil. >> reporter: you think she's the black widow? >> absolutely. >> let's cokeep going.

>> one of the toughest prosecutors in new york state. his ammunition will be the evidence his team has gathered. first and foremost the suicide note found on the bed next to ashley. >> there was no signature or personal tough. >> nothing handwritten at all. nothing, not a word. >> you have seen suicide notes before. >> sure. >> have you ever seen one like this. >> no. absolutely not. >> the forensics lab searched for fingerprints and the only ones they found were the mothers's. >> were her fingerprints found on my of these eemt? >> ashley's are nowhere to be seen on any of the items tested. >> the typewritten suicide note, when the county's expert examened the hard drive of the family computer he discovered two previous drafts of the note. it had been a work in progress. >> i don't think there could be a more damning piece of evidence

against her than those two practice notes and the final note. >> reporter: and beyond the note, they have something else. something they believe is even more convincing. their star witness, the daughter herself. >> the beauty of it is for the jury, there's only two people you have to focus on here as the murderers. stacey castor or her daughter ashley wallace. and when they see ashley they're going to know she had nothing to do with it. >> reporter: but across town, defense attorney chuck keller is certain proof of the daughter's poisonous relationships make it plausible she could be the killer. >> we have found some things to believe there's a hole in the daughter's story. the entire thing falls apart. >> reporter: and the mother goes free? >> if the daughter is not to be believed, there's only one explanation, and that's that she's responsible. and the mother is not. >> reporter: as the months wore on with stacey castor in jail, she knew that this had become mother against daughter, and that she could face life behind bars.

>> reporter: have you thought about the possibility that you might never be free again? >> i know that the truth is going to come out of this. the evidence will show that i am innocent. and i will go home. >> reporter: but there is someone else determined to keep that from happening. her daughter. who is about to be the first witness at the trial. when we come back. headache? motrin helps you be an unstoppable, let's-rock-this-concert- like-it's-1999 kind of mom. back pain? motrin helps you be the side-planking, keeping-up-with- your-girlfriend- even-though-you'll-feel-it- later kind of woman you are. body pain? motrin helps you be an unstoppable, i-can-totally-do-this- all-in-one-trip kind of woman. when pain tries to stop you, there's motrin. motrin works fast to stop pain where it starts. make it happen with new motrin liquid gels.

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a bitter cold winter day at the county courthouse in syracuse. after nearly a year and a half in jail, stacey castor's fate is now on the line. will she walk free or will she spend the rest of her life in prison? >> all rise. court is now in session. please be seated. >> reporter: stacey castor is charged with murdering her second husband, suspected of murdering her first. she's also charged with trying to murder her own daughter, ashley, to frame her. two dead men, two versions of the truth, from the mother and the daughter.

the trial begins. >> you will decide that the wrong person is sitting in that chair. >> you will have no choice but to stand up and shout, mrs. castor, you are a murderer and for that, you will pay. >> reporter: a mother and daughter, once best friends, now separated by the truth. now facing each other for the first time in more than a year. >> place your left hand on the bible, raise your right hand. >> reporter: the prosecutor calls his star witness first. the daughter who recounts at the tender age of 11, watching her father slowly dying on the couch in the family's living room. >> i saw him take and lift his arm up and then he made a breathe and he didn't move again after that, so i thought he was just sleeping. >> reporter: the first husband's body had been ex-assume and the autopsy showed anty freeze.

>> let's get something to drink because we have had a hard day. >> did you have anything to drink. >> yes. >> did it taste normal? >> no. i said mom this doesn't taste right. >> what did she say? >> she goes it's probably just the watermelon flavoring in it. >> reporter: ashley says she then passed out, and prosecutors are convinced that first round of drinks was just a trial run. because the next day, after school, ashley says her mother offers to drink with her daughter again. >> she came home and she was like, let's get drunk. let's just get totally drunk. >> did she say why? >> she was, like, let's celebrate your 21st birthday because i might not be around for it. >> reporter: and remember that security camera that captured stacey castor buying her daughter drinks? the prosecutor believes the mother was about to mix a deadly cocktail of crushed pills and vodka. >> she told me to keep stirring the cup. >> did you? >> yes.

>> what happened next? >> i took a drink of it. and it tasted horrible. >> what did you say? >> i was like, mom, this doesn't taste good. she's like, 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. >> did you finish everything in the cup? >> yes. >> now, ashley, i want you to explain to the jury why you drank it? >> because i trusted her. >> reporter: watching the trial unfold, ashley's grandmother, judie eaton, who isn't buying any of it. >> i do not believe that stacey put anything in a drink and gave it to ashley. >> reporter: you think that was all made up? >> i do. i don't care if you're a 20-year-old and your mother says drink it. you're not going to drink it. ashley wouldn't have drank it if it tasted that bad. >> reporter: on the stand, ashley recounts waking up the next day in the hospital. a detective questioning her about a suicide note found on

her bed, confessing that killing her father and her step-father, and now trying to kill herself. >> 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. >> reporter: and then the prosecutor pulls out the note. >> have you seen that before? >> never. i'm 100% positive that i did not write that note. >> reporter: and finally, the biggest question of all. >> did you poison your father with antifreeze -- >> no, i did not. >> and did you poison your step-father with antifreeze in 2005? >> no, i did not. >> reporter: for three hours, with her tearful daughter on the stand, the mother, stacey castor, has not made eye contact with ashley. >> so, the next thing you know, you wake up in the hospital the next day, right? >> right. >> reporter: then, it's chuck

keller's turn, his cross examination. his turn at ashley. >> someone from the district attorney's office, did they ask you if you tried to harm yourself before? >> yes. >> reporter: he tries to poke holes in her story. >> you told them? >> i told them there might be a note. >> reporter: first he tackles the suicide note. saying it is possible she wrote it. after all, she had written about suicide before. >> i had wrote a note to an ex-boyfriend. >> and inside this note you discussed two prior suicide attempts, right? >> yes. >> reporter: keller moves onto ashley's relationships. did she fight with her step-father? and was she jealous because her father considered her younger sister his princess? >> that was his nickname, right? >> right. >> did you have a nickname? >> not that i can recall. >> did it bother you at all that your sister had a nickname from your father, princess, and you didn't? >> no. >> reporter: four intense weeks, a legal back and forth.

dozens of witnesses, and now a mountain of damning evidence. >> the right middle finger. >> reporter: the drinking glass with the mother's fingerprints. the turkey baster with the antifreeze. the computer with the multiple drafts of that suicide note. so far, stacey castor hasn't said a word. until now. >> defense calls stacey castor. >> reporter: when we come back, the mother takes the stand and takes on her daughter. today something entirely new is being built into bounty. dawn. new bounty with dawn. what a novel idea! just rinse and wring, so you can blast right through tough messes and pick up more. huh aren't we clever.... thanks m'aam. look how much easier new bounty with dawn cleans this gooey mess versus soap and a sponge. thank you! new bounty with dawn. available in the paper towel aisle. obviously! let's save on every let's dblooming thing. friday.

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. inside the county jail. stacy cast to, the mother suspected of flaming her own daughter is preparing for her last chance to convince the jury it wasn't her. still not certain whether it's the right move. she's up all night with her attorney. explains it would be a gamble but it would be her only chance to offer her version of the story. when morning comes just three minutes before court begins, she tells him she's going to do it. >> do you swear to tell the truth? >> i do. >> be seated. >> her attorney begins with the

first husband, michael wallace. >> stacy, did you kill michael. >> no, i did not. >> did you love michael? >> with all my heart. i still do. >> reporter: her defense attorney moves five years later. stacey car or the married to husband number two. he asks about that weekend fight with david castor, the last weekend he was alive. what did she see when she went to check on her husband, who she said was angry with her and drinking his way through that weekend? >> when i opened the door, david looked at me and he said get away from me and leave me alone. >> and what happened next? >> i backed out of the bedroom and closed the door behind me. >> reporter: she says it was the last time she saw him alive. this was the first time stacey was offering any details about that final weekend. and her attorney is about to point out that she wasn't the only one with access to her husband that weekend. that her daughter ashley was in the house, too. and that ashley was home alone with him while her mother ran to the post office.

>> how long had you been gone from the time you left to the time you got back? >> i would say about an hour. >> reporter: and what about the will? witnessed and signed after her husband died. for the first time, stacey's explanation. >> i needed to be able to take care of david's things. i never anticipated that i would be a widow after two years of marriage. >> reporter: he then turns to the cocktail of crushed pills and vodka. ashley says her mother made secretly trying to kill her daughter. >> did you give her a drink like that? >> no i did not. >> you said ashley went to her room at 1:30? >> yes. >> and did you see her come out of her room the rest of that afternoon? >> no. >> was that unusual, was that strange? >> no. >> why not? >> ashley could come home at 9:00 on a friday night and sleep until 4:00 on a saturday afternoon if she didn't have to get up. >> the mother says she awoke the next morning to her younger daughter's screams. >> i heard bree scream, mommy,

there's something wrong with sissy. i got up and went into ashley's room. i called her name. i tried to shake her, and she didn't give any response. i immediately went to get the phone to call 911. >> i need an ambulance. >> and what's the problem? >> my daughter has taken some pills. >> did you try to murder your daughter and try to frame her for the murders of david castor and michael wallace? >> absolutely no. >> did you kill david castor by poisoning him with antifreeze. >> no, i did not. >> reporter: the next morning it's the prosecutor's turn asking the mother a question. why would her daughter want to kill her own father at just 11 years old? >> i can't give you a reason why she would do it.

>> you think she killed michael, correct? >> yes. >> then the prosecutor turns to those critical few days when detectives were turning up the heat on stacy. they exhumed the first husband and found antifreeze in his kidneys. two men, two kidneys, two sets of anti-freeze crystals side by side. >> it's going to be what it's going to be. >> investigators hear stacy talking and very faintly typing. >> so? what were you doing? >> reporter: the prosecutor grills her. >> i remember it wasn't typing. >> you just remember that you weren't typing, right? >> yes. >> reporter: fitzpatrick erupts. >> because you were typing the suicide note to frame your daughter, weren't you? >> no, sir. >> and we caught you, didn't we, mrs. castor. >> no, you didn't. >> just with that little phone call with the little click click click. mommy. please don't hate me. right? >> no.

>> reporter: stacey castor doesn't flinch. and so then the d.a. turns to that deadly drink that investigators say stacey gave her daughter. the prosecutor presses her on the 17 hours that her daughter was napping in her bedroom. >> and the next time that you saw your daughter conscious was when she was being carted out by ambulance attendants on friday morning. >> yes. >> and this is normal, right mrs. castor? >> objection, judge. screaming at the witness. >> overruled. >> this is normal? >> for ashley to be in her bedroom, sure it is. >> sure it is. sure it is. it's normal. and she was drooling, wasn't she? was she drooling normally? >> objection, judge. >> i've overruled it. >> was she? >> i don't know. my god! you lost two husbands to poisoning. your daughter had just learned that her father was dug out of his grave. she's drooling normally in the

bedroom. my god, is this your testimony? >> reporter: stacey castor is still not rattled. and after four weeks and more than 50 witnesses, the trial is nearing an end. >> i'm pretty nervous. >> an agonizing wait. the prosecutor is waiting, too. >> she's guilty as hell. juries generally do the right thing. >> reporter: as the hours turn to days with no verdict, it became clear there would be no quick decision. in jail, stacey castor was waiting, too. along with thoughts of the daughters who haven't spoken to her in a year and a half. and reminders of her two dead husbands the tattoos for each of them on her shoulders. and finally, after three days, a verdict. >> the people of the state of new york versus stacey r. castor

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a month and lock in your rate for 2 years. plus save up to 20% on your home owners insurance. call 1-800-xfinity today. the jury deliberates for three agonizing days, while the families huddle anxiously outside courtroom 310, waiting for word of the verdict. and then, in his office, stacey castor's attorney chuck keller gets the call. >> just got a call from the court. there's a verdict. >> reporter: the two daughters, ashley and bree, have been waiting for days now outside the courtroom. >> ashley was standing in the hallway, and someone had said we had a verdict and she just dropped to her knees on the ground. >> reporter: stacey castor is brought into the courtroom. is she a murdering mother and wife, or was she wrongly accused? the foreperson reads the verdict

to the judge. >> as to count number one, murder in the second degree, what is the verdict? >> guilty. >> reporter: stacey castor, guilty of the murder of her husband david. >> attempted murder in the second degree, what is the verdict? >> guilty. >> reporter: guilty of trying to murder her own daughter. she looks stoic just as she was described after the deaths of her two husbands. ashley and bree are overcome. when the jurors said your mother was guilty? >> that was the best day of my life because i knew they knew i didn't do it. >> reporter: the mother who tried to frame her own daughter is led out of the courtroom in handcuffs. >> it was sad to see her leave that way, but i didn't feel bad for her because i was happy that that was what they said. we all knew that she was guilty. >> oh, my god. >> reporter: for the relatives of the two dead husbands, it was justice. michael wallace's sister, rosemary. >> just glad it's over. and i believe that my brother was there by their sides.

all the way. >> reporter: david castor's son, david jr. >> does not deserve to see the light of day. >> reporter: after three days of deliberations, the jurors said it came down to two things. was stacey castor believable, and who had the most access to those two men? the time to methodically poison both of them. >> some of the things she said were believable but the biggest things weren't. >> i, for one, did not think she was believable on the stand. i definitely did not. >> reporter: upstairs in his office, the tough prosecutor and the tearful families, grateful their nightmare was over. grateful ashley didn't become victim number three. she almost died. >> she almost died. she probably came within a couple of doses of lexapro of dying. no one that i've prosecuted was so cold-blooded and heartless as this woman was. so unemotional about it.

>> well, that's that, i guess. >> yep. >> at least for now. >> reporter: chuck keller takes the long walk back to his office, where he worked tirelessly, trying to find clues that he believed created reasonable doubt. >> they considered ashley's motives versus stacey's motives, and really what it came down to was opportunity. stacey had more opportunity. >> reporter: some would say, the jury decided. she's a killer, not only of her two husbands, but she tried to frame her own daughter. >> well, that's exactly what the jury did decide. >> reporter: one month later, the sentencing. and ashley, the daughter whose mother tried to kill her, now stands before the court, her sister beside her. ashley, with one last message for her mother. >> i hate my mother for ruining so many people's lives. what gave her the right to play god with people? i never knew what hate was until now, even though i do hate her,

i still love her at the same time. that bothers me. it's so confusing. she was my best friend, and she took that all away just because she got scared. well, i was scared, too, when i was in the hospital by myself and i wanted my mom. when she was the one that did this. i didn't get a chance to say goodbye and this will be the last time i get a chance. as horrible as it makes me feel, this is good-bye, mom. as hard as you tried, i survived, and i will survive because now i'm surrounded by people that love me. i'm going to do good things in this world despite making me in every sense of the word an orphan. >> reporter: giving that statement helped? >> absolutely. because i didn't get to say what i wanted to say when i was giving my testimony. >> reporter: you said a number of times you hated your mother. >> i do hate her. but hate isn't a nice thing to

have, so, i try really hard to not hate her, but i can't. she killed two people, and then she tried to kill me, and i don't know how that can ever be forgiven. >> reporter: back in court, the sentence now from the judge, who tells stacey castor she is alone in her evil. >> in my 34 years in the criminal justice system, i've seen murders of every variety, but i have to say, mrs. castor, you are in a class by yourself. what you did to david castor can only be described as premeditative torture. as bad and as evil as that is, what you tried to do ashley is simply something that i find i almost can't comprehend. i've seen a lot of defendants come through this court system, including some whose parents tried to take the blame for what they did. but i have never seen one who was prepared to sacrifice their child to shift the blame away from themselves.

>> reporter: the judge's sentence, the maximum. more than 50 years in prison. and still not an ounce of emotion from the killer. >> she didn't show much or blink. >> reporter: what were you hoping for? >> i was honestly hoping that she would justpologize. she didn't have to say anything else except those three words. i'm sorry, i'm sorry. >> reporter: on the other side, the grandmother who put her own daughter before her granddaughter. >> i'm not going to give up on her. i'm going to stand behind her until the day i die. i do not believe stacey did this. >> reporter: and the daughter who now says she moves forward with one unanswered question. do you wonder how she could have done this? >> every day of my life, i wonder how she did it. i don't understand how you can try to kill your own daughter. >> reporter: a question we would get to ask one more time, because inside that jail, stacey castor has said nothing about the trial or the verdict until

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stacey castor is now a wife convicted of murder, and a mother convicted of trying to kill her own daughter. she left that courtroom without a word, sentenced to life in

prison. but agreed to talk to us one more time. >> reporter: you sit here across from me a year later and tell me that you're not a killer? >> 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. i did not kill michael wallace. i did not kill david castor. and i did not try to kill my daughter. period. and i will never say that i did. ever. >> reporter: you're still telling me that your daughter killed your two husbands? >> i'm telling you i did not. >> reporter: and if she didn't do it, who did? do you believe that police never considered your daughter fully enough as a suspect? >> absolutely. absolutely. >> reporter: you think the outcome would have been different? >> sure. i wouldn't be the one sitting here. >> reporter: stacey castor is working on an appeal. she says she didn't get a fair trial. what was unfair about it? what was the main thing that you think people did not hear? >> a defense.

we weren't allowed to put on a defense. period. >> reporter: you can say to me right now anything you would like. what do you want people to know that would have changed those jurors' minds? >> anything that made me look bad or could point a finger at me was allowed. anything else was shut down. and was not allowed to be presented. >> reporter: you say there were questions they weren't allowed to ask you. >> correct. >> reporter: allow me to ask them. what do you want me to ask you that would change the jurors' minds? >> i can't -- i wasn't in that juryroom. >> reporter: though we asked her, stacey could not come up with the questions, the evidence, or which witnesses she could bring forward that would change her fortune. but she was still adamant she did not try to poison her own daughter. >> she's 20 years old, and i gave her a vile, disgusting drink, told her to drink it. if my mother gave me at the age of 20 a drink that was that horrible to my taste, and told

me to drink it, i would tell her, sorry, mom, i'm not drinking that. >> reporter: she said she trusted you. >> what does trusting me have to do with drinking something that tastes so horrible? >> reporter: and when she asked her about something else, something she told a detective almost two years ago. when this investigation began telling them that one of her husbands might have gotten the idea to kill himself with antifreeze from an old program they'd watched together on tv. >> reporter: two husbands. have you thought about the irony here that this program is going to be about a woman who killed two of her husbands with antifreeze? >> no, this is going to be a program about a woman who has been accused of -- >> reporter: and convicted. >> doesn't mean i did it. >> reporter: as for ashley and bree, they've been living with ashley's boyfriend, matt, and his parents. they now call them mom and dad. bree, now 18, says she wants to go to college, possibly to become a teacher. and ashley is getting near perfect grades, expecting to graduate next year. the two sisters have no intention of ever speaking to their mother again.

it really is the two of you now. >> it has always been the two of us. i don't know how life would be without the two of us. >> reporter: and though there remains great pain, ashley says there is one question finally answered. the question she used to ask herself. >> she lost my father, who she said was the love of her life. and then she lost david, who she said she loved very much. it was confusing. why does god keep doing this? now i know it wasn't god that did it, it was her. >> reporter: is it hard to believe even now? >> it's just like a bad dream. >> that's our program for tonight. thank you very much for watching. >> for all of us here thanks for watching on a saturday night.

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