there's a lot of deceives in the world. >> with this type of crime scene the way it was laid out and amount of evidence that was left for us, it was a home run. you couldn't ask for anything better. up next -- >> my husband has locked himself in our bedroom. >> the death certificate came back as a suicide. >> or was it murder? >> what in the name of heaven is he doing committing suicide by a turkey baster. >> the evidence at the scene confounds investigators. >> there's something more going on with this. it just wasn't right. >> it's creepy, it's chilling. >> and it would take years before the forensics could figure it all out. >> this case was a forensic bonanza for me. the heating and air conditioning business was a lucrative one for david castor. his perfectionism and attention

to detail were well-suited to the job. >> my dad was a very particular guy. he liked everything a certain way. whenever we worked on something, if something was like a quarter inch off or wasn't perfectly level, we'd start right from scratch, do it again. >> things were going well for david castor until his father died. the two had been very close and david was having a hard time dealing with the loss. >> he was very depressed. i really felt for him. i just couldn't imagine what was going through his head. >> david's wife stacey told friends he began to drink

heavily and his behavior became erratic. when he locked himself in the bedroom and wouldn't come out, stacey called police. >> my husband has locked himself in our bedroom for the last day. friday night, we got into an argument. he was aggressive but he wasn't violent. >> okay, don't cry. we're going to check on him and make sure he is okay. are you going through something right now? >> his father died a month ago and he's been kind of weird acting the last month. >> david, are you inside? >> a sheriff's deputy arrived at the house, found the master bedroom door locked and with stacey's permission broke the door down. >> this is a terrible scene.

the guy is found sprawled naked on the bed. he is face down but his head is in the corner against the wall. there is a tremendous amount of vomitus and other biological material on the bed. >> emergency medical personnel pronounced david dead at the scene. >> for lack of a better word, i felt kind of raped, like a relationship was stolen from me, like it was just taken away. >> on the nightstand next to the bed were two glasses. >> one was half full of a green liquid. another clear glass had some remnants of something in it. you could see it on the bottom. >> the green liquid was sent to the lab for testing. >> we were able to identify ethylene glycol, the main component of antifreeze.

>> ethylene glycol is toxic in large quantities. the autopsy confirmed david castor ingested a lethal dose. >> the death certificate came back as a suicide. >> under the bed, emergency personnel found a shotgun and a container of antifreeze. investigators wondered if david castor had a gun, why would he use antifreeze to kill himself? >> maybe he didn't use the shotgun under his bed because he wanted to kill himself over 72 hours as opposed to 0.72 of a second. >> another item confiscated during the initial search also raised questions. >> one of the deputies looked in the trash basket in the kitchen area and found a turkey baster. the turkey baster had traces of green liquid in it. >> again, tests showed the green liquid was antifreeze. and scientists found dna on the tip of the turkey baster. >> the only dna on the turkey baster is at the tip and it belongs to david castor. what in the name of heaven is he doing committing suicide by turkey baster? i've never heard of such a thing. >> so investigators now wondered if they were dealing with a murder. the official ruling of suicide in david castor's death was a hard sell for the investigators who were at the scene. they hadn't seen many suicide cases where ethylene glycol was used, and there were several contradictions. >> my gut was telling me there was something more going on with

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the official ruling of suicide in david castor's death was a hard sell for the investigators who were at the scene. they hadn't seen many suicide cases where ethylene glycol was

used, and there were several contradictions. >> my gut was telling me there was something more going on with this. it just wasn't right. >> for one thing, the victim's wife, stacey castor, told the 911 operator things that were contra ticketing. >> friday night he got heavily intoxicated and slept through the day on saturday. >> yet the toxicology report showed no alcohol in his system. >> that caused us to raise our eyebrows again. >> there were two glasses found on david's nightstand. on the rims of both glasses was david's dna. david's fingerprints were on the glass with the small amount of alcohol residue, but only stacey's fingerprints were on the glass that held the antifreeze. >> if david had been drinking out of that glass and poured the antifreeze itself and committed suicide, why didn't it contain at least one fingerprint of his? >> the location of the antifreeze bottle on the side of the bed told the story. >> there's vomitus dripping on the bed and you can see there is

vomitus under the antifreeze jug, but there's no vomitus on the antifreeze jug itself. >> proof, investigators say, that the antifreeze bottle was placed there after david consumed the antifreeze and got sick, and investigators found several things very odd about stacey. >> when i interviewed stacey, i asked her if she knew what the substance was in antifreeze that can kill you, and she said to me, ethylene glycol. i found it very strange because most people wouldn't know that but off the top of her head, she knew that when i asked her. >> at the same time, stacey would routinely mispronounce the word antifreeze.

>> maybe that's why the anti-free idea. >> stacey castor used the word anti-free in the interview. a very odd way of saying antifreeze. >> stacey also admitted she knew that antifreeze could be used in a homicide. >> she said, oh, by the way, david and i had watched a true crime show where a woman killed her husbands, plural, with antifreeze by putting it in their jell-o. >> this was an interesting comment since david castor wasn't stacey's first husband to die under suspicious circumstances. five years earlier stacey's first husband, mike wallace, died unexpectedly at the age of 38. >> nobody did an autopsy. there is stacey castor at the hospital saying, no, no, he had a bad heart, and the physician comes in and from a visual examination looks at him and says, well, this is a heart

attack. >> mike's family had wanted an autopsy, but stacey said no. >> the family was very upset about there not being an autopsy and wanted to know what legally is the next of kin that makes that decision. >> a look at mike wallace's medical records showed no signs of heart problems before his death. even more bizarre, stacey had both husbands mike wallace and david castor buried next to one another. in between the two was where stacey planned to be buried when she died. investigators petitioned the court for permission to exhume michael wallace's body to see if there was any connection between his death and the death of stacey's second husband david castor. a judge approved the order. >> the doctor was going to be conducting the autopsy, felt

very strongly if there was some type of poisoning in his system, that it would still be there. >> why? because the active ingredient in antifreeze, ethylene glycol, in lethal amounts causes the body to create something it normally doesn't. >> ethylene glycol formed crystals which will affect the kidneys of an individual, eventually leading to death. >> those crystals remain intact for years after death, and the medical examiner found them during michael wallace's autopsy. >> upon getting the results back from the medical examiner's office, there was absolutely no doubt in my mind that stacey had killed both of her husbands. >> but just as prosecutors prepared to arrest stacey castor for the murder of her two husbands, stacey made another call to 911. >> my daughter, i believe, has taken some kills. >> is she conscious? >> yes. i'm leaning over her. she's having trouble, i think.

it sounds like there's something in her throat. ashley, ashley. >> paramedics arrived to find stacey's daughter ashley close to death. next to her was a suicide note along with an empty bottle of sleeping pills and an empty bottle of vodka. >> there is a suicide note in which she claims responsibility not only for the death of david castor but also for the death of her own father, michael wallace. >> mommy, i did this because i love you. i couldn't let daddy be mean to you and me anymore. once i put the anti-free in daddy's gatorade, it took only a day or so, and when they dug daddy up, i knew what was going to happen. they think you did it, but you didn't. it was me. >> but investigators were now

faced with a dilemma. was ashley truly capable of a double homicide? >> if ashley wallace killed michael wallace, she would have only been 12 years old at the time and could a 12-year-old really formulate such an elaborate murder scheme? >> and if ashley didn't survive, they might never know. >> my biggest fear was that ashley was going to die because her vitals would crash and then they would spike back up and that's one thing i don't think i would have ever gotten past, was if ashley died. latte or au lait?

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ashley wallace's younger sister brie found ashley unconscious one morning and urged her mother to call 911. >> the doctors said she was probably ten minutes from death. >> thanks to brie's quick action and excellent medical treatment, ashley survived. >> i actually woke up in the hospital and i had no idea what day it was. i had no idea where i was. one of the detectives was asking me questions like, what was in that note that you wrote? i was like what letter, what pills are you talking about? all i remember was having a drink with my mom. that's all i knew. >> ashley denied writing any

suicide note and denied any involvement in killing her father mike wallace and stepfather david castor. >> i was always skeptical. i didn't know exactly what happened. i didn't know what to believe really. >> prosecutors felt that whoever typed the note was also the person that poisoned the two husbands. >> to find out who typed the suicide note, investigators confiscated the castor family's computer and sent it to computer evidence specialist francis bracken. the first thing he noticed was that the document was created in microsoft word which has a feature most people don't know about. . >> if you 0 open a document, type in it, even if you don't save it as a document, the program itself auto saves it for you in the background and it gives it an unusual name that you would never recognize. >> interestingly only one person in the family used microsoft word. >> microsoft word had never been used on the ashley wallace

account, but it had been used on the stacey castor account. >> bracken found evidence there were numerous drafts of the suicide note which the writer made a point of not saving, but fragments of the final note still on the computer's hard drive were timestamped. the timestamps automatically registered by the computer showed ashley could not be the writer. >> i was able to determine that microsoft word was not used after 2:27 p.m. on 9/12, the very same day which, therefore, shows that ashley wallace couldn't have written the notes, because she was in school the entire day. >> the final clue was in the note. stacey let something slip. >> the cops said there was

anti-free in daddy's body. >> there was always the word anti-free in the suicide note. >> it hit me like a ton of bricks. my first reaction was, oh, my god, anti-free, what stacey said in the interview is exactly what was in the note. it wasn't a note. it was a confession. and it was stacey castor who confessed in the note. >> but stacey denied involvement in the two deaths and continued to maintain her daughter ashley killed both men. it would be up to a jury to decide. do you solemnly swear to tell the truth, the whole truth,

do you solemnly swear to tell the truth, the whole truth, and nothing but the truth so help you god? >> i do. >> be seated. >> as stacey castor is about to go on trial for the murder of her husband, david castor and the attempted murder of her daughter, ashley, the question on everyone's mind was motive. >> i'll say that she is completely amoral, she is completely self-absorbed. everything in life revolves around her. she's narcissistic to the extreme. she is troubled only by the inconvenience of other people. mike wallace becomes an inconvenience, i'll get rid of

him. david castor's an inconvenience, i'll get rid of him. pick up some cash on the side. parting gifts from don pardo as i leave this stage of life. my daughter, i've got to frame her. >> financially, stacey got a $50,000 insurance payout after her first husband's death. there was even more money after the death of stacey's second husband. >> our best estimate is that she probably pocketed with the house, the business, the cars, the life insurance, close to $200,000 for david castor. >> investigators believe since stacey got away with her first husband's murder, why not try it again? prosecutors say stacey put antifreeze in one of david's drinks sometime on friday night. by the next day, david was unconscious but still breathing. the evidence shows stacey tried

to get david to drink more, but that didn't work. that's why only stacey's fingerprints were on that glass. so stacey used the turkey baster to force more antifreeze into david's mouth. that's how david's dna was on the tip. once stacey realized she was about to be charged with david's murder and the murder of her first husband michael, stacey came up with a plan to pin the murders on her daughter. stacey created the suicide note on the family computer, using phonetic spellings to words she routinely mispronounced and typed the document around 2:30 in the afternoon when ashley was in school. later that night stacey mixed sleeping pills and other drugs into ashley's drink and left her to die. if ashley's younger sister hadn't found her unconscious in bed the next day and demanded her mother call 911, ashley

would most likely be dead too. >> mom, mom. >> she killed two husbands. then she tried to kill her own flesh and blood. there are no words that i'm familiar with in the english language that adequately convey that type of person. >> on the witness stand, stacey insisted ashley was the killer. >> you referred to her very negatively, didn't you? >> i'm sure i did. >> because she killed, after all, your two husbands. didn't she? >> yes, she did. i can't give you a reason why she did it. >> the jury didn't buy it. stacey castor was convicted of murder and the attempted murder of her own daughter.

she was sentenced to a minimum of 50 years in prison. >> you're not just a danger to the general public. you're a danger to the people who love you and are closest to you. >> prosecutors could still charge stacey for the murder of her first husband michael wallace, but with stacey serving a 50-year prison term, there doesn't seem to be much need. ashley wallace has no contact with her mother. >> i hate her. i hate her. i don't understand. i don't get it. i don't think i ever will understand why she did what she did. >> without the forensics, this case would have ended in 2005 with the death of david castor being ruled a simple suicide as it was. and stacey castor would still be walking the streets today. >> and everything that she said

and everything that she did just backfired on her right in her face. >> because you're a killer. bottom line, look at yourself in the mirror. you know what you did and you know what you tried to do to your daughter up next -- >> a serial killer was on the loose in new york city. >> these people were chopped up. it's just a savage way to die. >> you found you pissed somebody office. >> the media called him the last call killer. >> last call for drinks. that's the last everybody had seen of him. >> nearly a decade later the police still have no suspects until advances in forensic sciences finally help pinpoint the killer. >> it's the most bizarre case i've ever been involved with. for sanitation workers collecting trash along the new jersey turnpike in 1991, it was a day like any other until they found a plastic bag so heavy the men deci