huktd the girl most likely to brighten your day encourage her boyfriend to take his life? >> tonight, breaking news in the suicide texting trial. >> reviewing the evidence -- >> a young woman's future now set. in the bizarre case still making headlines. >> he got out of the truck, said i can't do this, i'm not going to do this. she said, get back in the truck. suck it up. >> was it to end his suffering, or to become more popular and famous herself? >> if you really look at it, your honor, she's really desperate for attention. her boyfriend died, and she's the grieving girlfriend. >> tonight, we're going back with his family to the place where it happened. >> the idea that this is the spot that he was in -- >> it shouldn't be. in a parking lot.

>> his grieving aunt speaking out to "20/20." >> how do you even wrap your mind around that? >> he was a kid. he was ours. he was our kid. >> the private video diaries. >> i feel, what's the word -- >> recorded just weeks before his death. >> i'm definitely wired from everyone else, like there's something wrong with me. >> her secret cell phone text messages, goading him on. >> okay, so you want to kill yourself? when are you going to do it? >> that doesn't make her behavior okay or good. but the question is, is it criminal? >> you said you don't want to take your life. you don't want to. she said this to him for two years. >> until she eventually says do it. >> can words kill? good evening. welcome to "20/20 saturday." i'm elizabeth vargas. >> and i'm david muir. this question tonight -- can words kill? that was the question at the heart of a courtroom drama that captivated the country in the so-called suicide texter case. two sets of parents stunned as

they saw what their kids were doing and saying on their cell phones. >> all culminating in a groundbreaking conviction, which essentially concluded that text messages and phone cats can lead to suicide. words can indeed kill. but was that the motive? deborah roberts has that tragic teenage love story with a very modern twist. >> buzz answered's bay on the south coast of massachusetts. good sailing weather. striped bass are biting. and in matapoisett, the views from the historic light at whale's point built to guide ships to safe harbor as spectacular as ever. it's the kind of summer conrad roy would have loved. conr conrad's aunt kim. >> tell us about him as he was growing up. >> he was kind of like the instigator in our family. he's the kid that never got in trouble.

he'd start the trouble but he somehow got away with it. >> reporter: athletic? >> oh, yeah. he played baseball. he loved baseball. >> reporter: conrad, whose family calls him coco, excels, at least academically, in high school. he graduates in 2014 with good grades and test scores high enough to win him a free ride at a state college, but he's unsure whether to go off to school or join the family tugboat business. and did conrad like it? >> yeah. he loved it. he loved being on the water. he got his captain's license at the age of 18 which is pretty awesome. >> reporter: a life by the sea, with so much promise. but conrad is adrift. >> hi, this is conrad henry roy iii, reporting to you about what's going on through my mind, what's going on through my head the last few days. >> reporter: confiding deep emotional distress in private video diaries. >> i've created a monster out of

myself the past few years. because of my depression. racing thoughts. suicidal thoughts. >> it is a hard video to watch. i think we see a very troubled teenager who's obviously going through a multitude of emotions and issues. >> the hardest thing for me is to be comfortable in my own skin. >> reporter: after his parents' divorce in 2011, he begins a downward spiral. depression, a stay in a psychiatric facility, and several attempts at suicide. >> i feel -- what's the word? i feel like i'm differently wired from everyone else. >> reporter: but this story really begins with his chance encounter with a girl. conrad meets michelle carter while both are visiting relatives in florida. she's a year younger and lives

in plainville, an hour north of conrad's hometown. like conrad, she's athletic, a softball player. coach ed mcfarland says she was a decent shortstop, and a nice girl. >> quiet kid, never known her to do a mean thing. would do whatever she could to help you in the process. >> reporter: classmates would later vote michelle most likely to brighten your day. but sera congi, a reporter for abc boston affiliate wcvb, says michelle was also struggling. >> she suffered from depression, and she had an eating disorder. we know she took antidepressants. >> reporter: something that seemed to bother michelle most -- making and keeping friends. but michelle's new friend conrad apparently fills the void. they fall into an intense facebook, texting, all hours of the day and night, on again, off again, virtual romance. one even conrad's mother knew very little about. does she know who she is?

>> she just thought she was an acquaintance of conrad's, nothing more. >> reporter: in fact, we can't find a single photo of the teens together. they meet in person only two or three times, the relationship almost entirely electronic. >> they were intimate with each other over text message, because they talked so much about their personal feelings. but were they a traditional boyfriend and girlfriend? it's hard to say. >> reporter: but the relationship is clearly intense. conrad sends michelle this selfie. >> if you only knew what's inside my head. >> reporter: in a facebook exchange, early on, conrad tells michelle about his brush with death. >> i tried to kill myself. >> how did you try to kill yourself? do you still want to? >> no, i'm going to. just letting you know. the voices in my head tell me to. >> reporter: later, he confides he's planning to try again. >> i want to die. >> i know you want to and you research it and everything, but are you actually really gonna do it? >> yeah. if i can find a way to 100% work. >> he tells her pretty

definitively early on that he wants to die, and that he has a plan to die, and that he's going to do it. >> reporter: by the summer of 2014, conrad on his own combs the internet hundreds of times, searching terms such as "cyanide," "death by cop," and "easy ways to find poisons." he sends michelle a photo of a rifle, and a noose hanging from a tree. then conrad hints they should do something together. >> we should be like romeo and juliet at the end. >> ha ha, i'd love to be your juliet. >> but do you know what happens at the end? >> oh, yeah, [ bleep ] no! we are not dying. >> reporter: dan glaun is a reporter for mass live, a digital news outlet. >> there's these weeks and weeks of messages where conrad roy is saying, "i'm depressed. i want to die." he says this to her over and over. >> she's overwhelmed by this caretaker role she has with her boyfriend. she can't handle it. >> reporter: michelle, also

emotionally fragile, repeatedly tries to talk him out of it. >> conrad, stop. you're not gonna do it. i know you won't. i don't want you to. >> no, i actually am. >> you have so much to live for. please don't. >> reporter: for two years the relationship builds, the star-crossed teens discussing all kinds of things online. but conrad's obsession with suicide runs through it like a sinister thread, and for most of that time, michelle consistently encouraging him to get help. >> i'm never gonna be better. i have to accept that. >> you're in a dark tunnel but it's not gonna last forever. you'll find the light someday. >> she's encouraging him to stay alive, she's trying to pull him away from that darkness. >> reporter: when she's hospitalized for an eating disorder, she asks conrad to join her. >> you aren't gonna get better on your own, you need professional help like me, people who know how to treat it and fix it. >> reporter: conrad warns michelle not to tell anyone who could stop him -- and she doesn't.

>> and the only way i'd hate you is if you told people about this. you hear me? >> i'm not gonna tell anyone. because if i did then you'd have to go to a hospital and i know that's not what you want. >> reporter: on the fourth of july, 2014, conrad is talking more and more about ending his life. >> i wish i had a gun. >> would you use it? >> yes. >> reporter: his family says they know nothing about these messages, and think he's feeling better emotionally. the morning of july 12th seems to begin as a typical summer day for conrad roy. he goes to horseneck beach with his mom and younger sisters. >> they walk on the beach, and his mother talks about how he seemed more optimistic. she kind of felt a little more encouraged that maybe he was moving forward and that it was a good day. >> reporter: ominously, though, instead of swimming or sunbathing, conrad spends most of the afternoon in the car, feverishly texting with someone.

that evening, conrad tells his mom he's going to see a friend. >> his mother asks, "will you be home for dinner?" and he says he doesn't know, he doesn't think so. and that's the last thing he says to his mother. >> reporter: her son drives off in his black pickup truck, and disappears into the summer night. >> and that was the last time anyone in his family saw him alive. >> reporter: when we come back, searching for conrad, and the haunting messages on his cell phone that will shatter two families. stay with us. jimmy's gotten used to his whole room smelling like sweaty odors. yup, he's gone noseblind. he thinks it smells fine, but his mom smells this... luckily for all your hard-to-wash fabrics... ...there's febreze fabric refresher. febreze doesn't just mask, it eliminates odors you've... ...gone noseblind to. and try febreze unstopables for fabric. with up to twice the fresh scent power, you'll want to try it... ...again and again and maybe just one more time. indulge in irresistible freshness.

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the search is on for a missing teenager, conrad roy. he had driven off from his mother's house in fairhaven, massachusetts, on a saturday evening, supposedly to visit a friend. but by sunday morning he still wasn't home. >> you could tell she was worried. and i said, "well, you really need to call the authorities and see if they can start searching for him." >> reporter: with no word from her son, a frantic lynn roy contacted the fairhaven police department. an officer was soon on the case and began searching. he wound up in this kmart parking lot. >> and i saw out of the corner of my eye, a black f-250 parked over there. >> reporter: parked right over here. >> right over there. >> reporter: fairhaven officer dave correia finds the black pickup truck, conrad's lifeless body behind the wheel. he's gone. his life over at age 18. >> i'd seen enough people that were gone to realize just by looking at him that he was gone, that there was nothing that

anybody was going to be able to do for him. >> reporter: in the back seat, this portable water pump, powered by a gasoline engine. running that engine with the windows closed filled the truck with a lethal cloud of carbon monoxide gas, enough to kill anyone inside in 20 minutes flat. deadly as a loaded gun. >> it's immediately clear that it's a suicide. they contact his parents and lynn roy learns that her son has died. >> and i just grabbed my sister and hugged her as tight as i could, and she -- >> reporter: how did you even wrap your mind around that? >> you can't. there's no way. he was a kid. he was ours. he was our kid. >> reporter: conrad had left notes at home for his family, and michelle carter. >> he thanks her for being there for him, for supporting him, for sticking with him as he went through all of these struggles and mental health problems. >> reporter: immediately conrad's grieving family is comforted by a friend of his they had scarcely known

existed -- michelle. >> she begins trying to establish a relationship with conrad roy's family. with his mother, lynn, and his younger sister, camdyn, telling them that conrad would have wanted them to stay strong and to not break down over him. >> reporter: she begins texting, calling, e-mailing. >> i am so sorry i didn't do enough to save him. i have never tried harder in my life to help fix someone. >> reporter: michelle, who most of conrad's family and friends had never met, also attends his wake and his funeral. and michelle carter was showing up at these various times. >> yeah. >> reporter: and even asked for part of his ashes? >> yeah, yeah. she wanted to go through his room and take some of his belongings. >> reporter: what did you all make of that? >> that's when things started to get a little weird. it was like, hmm. yeah, you don't do that. >> one thing that she does, is

she begins organizing a charity baseball tournament for conrad. >> reporter: on a facebook page she says she wants to be an anti-suicide activist. >> even though i could not save my boyfriend's life, i want to put myself out there to try to save as many other lives as possible. >> reporter: and something else a little spooky. even after his death, michelle continues texting conrad. >> today it has been one month since you passed. it was a hard day for all of us. i hope you were looking down with a smile. >> reporter: meantime, fairhaven police are working what seems to be an open and shut-case of teen suicide. until a detective thinks to check conrad's cell phone. >> i got the call the next day from detective gordon, he wanted to know where the phone was. he had gotten the code from the family. i told him where it was, and of course the rest is history. >> reporter: on that phone, some very strange text messages with michelle carter.

>> i don't get why you don't just overdose again, but go somewhere in private. you already know it works. >> she actually begins to almost agree with him. like, okay, so you want to kill yourself? when are you going to do it? how are you going to do it? >> you're really gonna do this? >> yeah. >> okay, there's no turning back now. >> starting about on july 2nd she starts saying, "are you serious? like, you should just do it." >> reporter: in early july, after conrad apparently fails to go through with an overdose of sleeping pills, police say michelle seems not relieved, but irritated. >> i knew you weren't gonna try hard. i feel like such an idiot. >> why? >> because you didn't even do anything! and i poured my heart out to you thinking this was gonna be the last time i talked to you. i thought you really wanted to die, but apparently you don't. i feel played and just stupid. >> she's almost bullying him about it. >> tonight? >> eventually.

>> see, that's what i mean. you keep pushing it off! >> reporter: authorities are stunned to find that in the last week of his life, michelle asks conrad when he was going to kill himself more than 40 times. >> when are you gonna do it? >> i'll let you know when. >> well, is it gonna be soon? >> whenever he had doubts, she'd diminish them. whenever he had guilt about leaving his family, she assured him that she would comfort them. >> everyone will be sad for a while, but they will get over it and move on. >> reporter: still ahead -- >> we're talking to michelle carter. >> reporter: detectives go to school. michelle carter's school. >> michelle, the reason we came out here is because we were looking into conrad's unfortunate passing. >> reporter: how will the senior most likely to brighten your day explain all those text messages? >> they read my messages with

him. i'm done. his family will hate me and i could go to jail. >> reporter: stay with us.

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save 50% on the ultimate limited edition bed with adjustable comfort on both sides. ends soon. visit sleepnumber.com for a store near you. >> reporter: it seems everyone's talking about teen suicide. the tony award winning musical, "dear evan hansen," taking on that difficult subject. ♪ can anybody see is anybody waiting ♪ ♪ is anybody waiting >> reporter: from broadway to netflix, and the tv show "13 reasons why," about a teenage girl who takes her life. >> i'm about to tell you the story of my life. more specifically, why my life ended. and if you're listening to this tape, you're one of the reasons why.

>> reporter: but for conrad roy, the angst was not entertainment, it was all too real. >> hi. this is conrad roy, and i'm going to talk to you about social anxiety. >> reporter: the 18-year-old documents his despair in secret video diaries just weeks before his death. >> what i am doing is i'm looking at myself so negatively. i'm looking at myself, minuscule little particle on the face of this earth that's no good, trash, will never be successful. never have a wife, never have kids, never learn. >> reporter: now police investigating his suicide are searching through his phone and all his electronic exchanges with michelle carter. they're beginning to suspect her role in his death was not as innocent as it first appeared. mostly because of messages like this one. >> hanging is painless and takes

like a second if you do it right. >> reporter: michelle, police say, is actively helping conrad plan his death. >> carbon monoxide poisoning is the best option. if you fall asleep in your car while it's running in a garage, it will kill you and there's no pain. >> portable generator that's it. >> do you have one of those? >> there's one at work. i was thinking turning it on in my truck and passing out asleep you're a genius. >> he gets a gas generator but it breaks down. >> go to sears. >> google it, hold on, i'll do it for you, and i'll tell you exactly how to kill yourself hopefully. >> reporter: instead, conrad takes a gas powered water pump from a relative. but as with previous attempts, he seems to waver. >> i'm scared babe. >> it's okay to be scared and it's normal. i mean, you're about to die. >> reporter: but the next morning, conrad, as authorities will later put it, has the

audacity to still be alive. >> hike why am i so hesitant lately? >> you're so hesitant because you keep overthinking it and pushing it off. you just need to do it conrad. it's time to do it today. >> reporter: that evening, conrad still procrastinating, michelle still pushing. >> are you going to do it now? >> leaving now. >> okay, you can do this. >> reporter: five minutes later, conrad fires off another text. >> okay, i'm almost there. >> that last text message is before he drives to the kmart parking lot where he turns the water pump on, in the cabin of his truck. and then he's gone. >> reporter: months after conrad's death, a detective goes to king phillip high school, to have a talk with michelle carter. >> we were talking, and then the phone hung up but i didn't really think anything of it. >> reporter: didn't think anything of it, she tells police, but that's not what she

told her friends. a search of her phone reveals michelle sent a series of stunning text messages to classmate, samantha boardman, after conrad's death. when michelle hears detectives are searching conrad's phone, she sends samantha a frantic message. >> sam, they read my messages with him, i'm done. his family will hate me and i could go to jail. >> reporter: but it gets worse. two months after conrad's death, michelle sends samantha this jaw-dropping admission. >> sam, his death is my fault. like honestly, i could have stopped him. i was on the phone with him and he got out of the car because it was working and he got scared [ bleep ] and i told him to get back in. >> when he got out of the truck and said, "i can't do this. i'm not gonna do this," she said, "get back in the truck. suck it up." >> that is the saddest part of this whole story, the truck is filling up with carbon monoxide, and he gets out. and she tells her friend sam that she told conrad to get back

in the truck. >> she did not call police. she did not call her parents, his parents, nobody. she sat there, waited for him to die and then texted her friends, "omg, i think my friend just committed suicide." >> reporter: michelle goes on to tell samantha -- >> i couldn't have him live the way he was living anymore. i couldn't do it. i wouldn't let him. i could of stopped him but i [ bleep ] didn't. >> reporter: we asked former prosecutor nancy grace and abc chief legal analyst dan abrams to discuss the case. is the question whether words can kill? is that what it is? >> oh, this was more than words. much more than words. she researched modes of death. she said, "you could hang yourself. you could put a plastic bag over your head. you could shoot yourself in the head." >> and the reason that she did that is because he asked her for help. he's the one who drew her into this thing from the beginning. >> reporter: how would you describe this relationship between these two young people? >> tragic.

that's how i would describe it. it was conrad roy laying a lot of his baggage on michelle carter, he consistently bombarded her with his suicidal thinking. >> i don't think that she helped him kill himself. i think she forced him to kill himself. >> reporter: you think she is the cause of his death? >> mm-hmm. yeah. i think if it wasn't for her, he'd still be here. >> reporter: the text messages may sound horrible, but are they a crime? prosecutors say yes. and six months after conrad roy's death, a grand jury agrees that michelle carter's words are a weapon. indicting her on a charge of involuntary manslaughter. >> that trial making national headlines. >> the teenage girl is facing charges in another teen's suicide. >> the young woman is now charged with manslaughter after her then boyfriend killed himself. >> we had never heard of a story like that before, a charge like that before, a case like that before.

>> what's novel about it is the technology that we don't have to be at the crime scene, that we can still be present when somebody's committing a crime because we're on the phone with them, we're talking to them, we're in their head. she was virtually present. >> reporter: the trial, up next. and look who takes the stand. michelle carter, but not for the reason you might think. stay with us.

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we return now to a pretty shocking story playing out in court right now. >> she faces up to 20 years if convicted. >> prosecutors say because of what was written in those texts. >> reporter: the case some are calling death by text captures the full attention of the country. >> the defense claims that roy had planned that suicide and that carter's words did not

alter his plans. >> reporter: michelle carter, charged with involuntary manslaughter for allegedly causing the death of conrad roy, a boyfriend she had only seen in person three times. it's a controversial accusation. >> this is new legal territory. this was potentially precedent setting in the state of massachusetts. that someone could be held accountable for involuntary manslaughter based on their words. or in this case, their texts. >> reporter: can you be responsible for killing someone from miles away, with words alone? >> what she said is reprehensible and it is just bone-chilling. but that's a separate question from, is it criminal? >> reporter: on the day of jury selection in michelle carter's manslaughter trial in taunton, massachusetts, the case takes a whiplash turn. >> today was supposed to be the day that they would begin the process of selecting 16 jurors for this trial, but in a relatively surprise move, first

thing this morning michelle carter chooses not to have a jury decide her fate. >> has anyone promised you anything or threatened you in any way to make you forego your right to a jury trial? >> no. >> reporter: carter puts her fate in the hands of one man, judge lawrence moniz. mistake? >> big mistake. >> reporter: what might the defense have hoped to gain by going for a bench trial? >> i think the defense was afraid of the response that a jury would have to these texts. they're terrible. >> they're very incendiary. >> and so i think that you are hoping that a judge will be able to view it in a more rational -- >> like calmer heads prevail. >> and maybe focus on issues like causation and the definition of the statute, as opposed to how horrible the texts are. >> reporter: and so the trial begins. >> she assisted and devised and advised and planned his suicide. she pushed him to kill himself

sooner rather than later, and she mocked him when he chose to delay his death. >> reporter: prosecutors mary clare flynn and katie rayburn laying out the case and a motive. >> if you really look at it, your honor, she's really desperate for attention. look at me, i lost my boyfriend. >> you presented her as a girl who was manipulating, who was looking for attention. >> she wanted him to die. it appears to gain attention or to gain friendships or get girls to like her more. >> she used him as a pawn in her sick game. >> reporter: the prosecution's first witness, conrad's mom, lynn roy. >> so you said that you brought him to either a hospital in october of 2012? >> october 3rd. >> and what was the reason for that? >> because he was having suicidal thoughts. >> reporter: prosecutors call 14 witnesses. the officer who found conrad in the parking lot -- >> appears to be mr. conrad roy. >> reporter: the medical examiner who determined it was carbon monoxide that killed him. and most important, michelle carter's classmates, those girls she so desperately wanted to befriend.

>> 8:25, does michelle carter now send you another text that you receive later on that night? >> yes. >> and what does she tell you? >> i think he just killed himself. >> reporter: she testifies about that incriminating text from michelle. >> i was on the phone with him and he got out of the car because it was working and he got scared. and i [ bleep ] told him to get back in. >> reporter: isn't that pretty incriminating stuff? >> yeah. >> yes. and she goes on to say, i could have called police. i could have called his family. but she didn't. what she did do with him, three minutes, is start texting the guy she was trying to date and her other friend, sam boardman, and talking to them about, oh, it's all about me, what am i going to do now? >> she essentially put him back into a gas chamber, she listened to him gasp for air, take his last breath, and die, and she did nothing. >> reporter: michelle's defense resting nearly entirely on one witness, psychiatrist peter breggin. how could the girl who's most likely to brighten your day encourage her boyfriend to take

his life? >> the short explanation is, she thought that was the only way to help him. she had had a drastic change in medication three months earlier. >> reporter: dr. breggin testifies michelle was under the influence of involuntary intoxication caused by her antidepressants and she was overwhelmed by what he calls conrad's abusive talk of suicide. >> she didn't want him to take his life. she said, "you don't want to take your life. you don't want to." she said this to him for two years. >> reporter: until she eventually says, "do it." >> she said if that's what you want, do it. she breaks. she breaks under his pressure, under the drugs. >> reporter: what did you make of the psychiatrist saying that she was involuntarily intoxicated. >> i couldn't believe that they even tried that. >> reporter: but she's a teenager, she's got emotional troubles and she's taking medication. >> yes, she's evil. that is her trouble. >> reporter: what doesn't the world understand about michelle carter? >> that she loved conrad roy. she really cared for conrad roy.

she thought she was supporting what he wanted. and she even talks about it in her texting. "you're going to go to heaven," as he talked about. "you're gonna be a great angel." >> reporter: after six days of testimony, the fast-moving trial wraps up with closing arguments. >> it's a new day and age, your honor, and the phones that we have now allow you to be virtually present with somebody. people fall in love on the internet and via text, people bully via text and the internet, and you can encourage someone to die via text, and you can commit a crime via text. >> you can look at the various text messages, as well as the psychological records. you will see that mr. roy himself stated to michelle carter, "i want to die." straight up, those words. i want to die. this is not a homicide. michelle carter did not kill conrad roy. it's sad. it's tragic, but it's just not a homicide.

>> she absolutely knew it was wrong, and she absolutely caused the death of this 18-year-old boy. and i ask you to find her guilty. >> ms. carter, please stand. >> reporter: the judge's verdict. where will michelle carter spend the best years of her life? when we come back. >> i think a lot of people were a little surprised that that's what actually happened. >> reporter: stay with us.

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♪ ♪ the gig-speed network that powers the dreams of america's businesses is now doing the same for america's olympic and paralympic athletes. dream gig. comcast business. june 16th, 2017. decision day at the usually quiet courthouse in historic downtown taunton, massachusetts. the press out in full force, anticipating judgment day for michelle carter. she strides into court escorted

by court officers and her defense team. then upstairs to hear the judge's decision on whether she caused the death by suicide of boyfriend conrad roy. >> it was a packed courtroom and many relatives of conrad roy were filling the first couple of rows. >> reporter: more than a half dozen white-shirted court officers stand guard near the carter and roy families. >> the right side, the first few rows, filled with conrad roy's relatives. the left side, michelle carter's parents. >> reporter: judge lawrence moniz is ready to deliver a verdict in the involuntary manslaughter trial of michelle carter. she's opted against a jury. >> we obviously expect him to say guilty or not guilty, but he chooses to give an explanation to his verdict. >> to provide some context for the decisions that have been made. >> reporter: as the judge begins to read, michelle appears shaken, displaying the most emotion she's shown during the entire trial, her attorney taking her hand. >> this court first finds that

the actions taken by miss carter -- >> are you going to do it tonight? >> -- constituted wanton and reckless conduct by her. the commonwealth has not proven that said behavior caused the death of mr. roy. >> reporter: hearing that, michelle lets out a sob. >> he starts off by saying that it was not reasonable behavior. but that didn't make him kill himself. >> reporter: conrad's aunt kim bozzi sits in the tense courtroom. so when judge moniz starts offering his verdict, it sounds at one point that maybe she's going to be acquitted. >> yeah, i was kind of like a roller coaster of emotions. all i could think about was conrad and how she has to be held accountable. she has to be. there's no way we went through all of this. you know? >> i thought it was going very well. it sounded like he was going to acquit her. >> reporter: but the judge goes on. >> however, his court finds that instructing mr. roy to get back in the truck constituted wanton and reckless conduct by miss

carter, creating a situation where there is a high degree of likelihood that substantial harm would result to mr. roy. >> if the judge had written this for maximum dramatic tension, i don't think he could've done a better job. for 15 minutes, this courtroom was dead silent. i could hear my pen scratching on my notepad when i was taking notes. >> she called no one. and finally, she did not issue a simple additional instruction, "get out of the truck." ms. carter, please stand. this court, having reviewed the evidence and applied the law thereto, now finds you guilty. >> reporter: michelle carter, now 20 years old, guilty of involuntary manslaughter. when you heard guilty? >> oh, my god. three years of going through this. i felt good.

i know that may seem odd, and i know it's a situation where there are no winners, but i felt like we won. >> the fact that we got a guilty conviction was a victory. the world would know that conrad roy did not commit suicide, that he was a victim of a homicide. >> i was very surprised. i support the judge's decision, but i really did not think the judge would have the backbone to do it. and he did. >> reporter: do you regret not seating a jury? >> if i had to do it over again, i might pick 12 people in the box. >> reporter: outside, the media pouring out of the courthouse. >> out of the way, guys. >> reporter: defense attorney joseph cataldo runs a gauntlet of cameras and microphones. >> i'm very disappointed with the outcome, with the verdict. >> reporter: conrad roy's father speaking to reporters after the verdict. >> this has been a very tough time for our family and we would like to just process this

verdict that we're happy with. >> reporter: prosecutor katie rayburn reminds everyone that, in the end, this case was about an 18-year-old boy, conrad roy. >> i know we all wish he had the opportunity to grow up, into adulthood, to become a tugboat captain and to enjoy his future. >> reporter: as she speaks, conrad's father overcome with emotion. >> given the nature of this case, i would like to conclude by reminding everyone that if you have a loved one in need, or you know someone in need of help please tell someone. >> reporter: a court has decided that words can kill. >> are you going to do it now? >> yes, she was guilty of involuntary manslaughter, but does she deserve to be in jail? >> reporter: now words will also dictate the fate of michelle carter. will her words send her to prison for 20 years?

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>> reporter: the courthouse in taunton, massachusetts, where michelle carter's future will be decided is a modern building. a fitting location for this most modern of crimes. committed amidst a tangled web of thousands of text messages. from her arrest in 2015, through her trial, michelle carter has not spent a day in jail. >> michelle carter continues to live her life in those three years, despite all of this going on, she's been free on bail and has continued to do all the things that 17, 18, 19-year-olds have done. >> reporter: but that could all change. just hours ago, michelle carter back in court for sentencing on the involuntary manslaughter

conviction in the death of conrad roy. >> what a travesty. there is no earthly reason why conrad henry roy should not be here today. her actions killed conrad roy. >> ms. carter does not pose a danger to the public. i suggest that this sad, tragic manslaughter was a very unusual set of circumstances unique to these two individuals. >> reporter: conrad's sister fighting back tears, telling the judge how much she misses her big brother. >> not a day goes by without him being my first thought waking up, or my last thought going to bed. >> reporter: and his dad grappling for answers. >> where was her humanity? in what world was this behavior okay and acceptable? >> reporter: judge lawrence

moniz addresses the hushed courtroom. >> this is a tragedy for two families. everyone is entitled to a decision devoid of any emotion with respect to this case. >> reporter: the judge has the option of just sentencing her to probation, no jail time, or a maximum of 20 years in prison. >> i think any time is too much. i think the fact that they found her guilty is too much. >> reporter: but judge moniz decides that michelle carter was aware of her actions and should go to prison for her crime. >> i have not found that ms. carter's age, or level of maturity, or even her mental illness, have any significant impact on her actions. >> reporter: michelle standing stone-faced as the judge sentences her to 15 months in jail followed by 15 months of probation. and in a surprise move, allowing her to remain free pending appeal. when you heard that michelle carter was going home instead of going to prison after this sentencing, your reaction? >> that was awful.

this was the second time that michelle walked out of the courtroom. we certainly felt the family's outrage that she walked out when they don't have their son. >> to just have her go home tonight. you know, what kind of justice is that? >> reporter: what can you tell us about michelle's feelings about what happened? >> she regrets it. she is remorseful over the situation, but she is a far different person today than she was then. >> she has to live the rest of her life in her skin, as her. one of the most hated people in the country, so good luck with that. >> reporter: conrad roy, so young when he died. now he will be forever 18. as for michelle carter, the young woman convicted and sentenced for his death, a week from tonight, she will celebrate her 21st birthday. a milestone conrad's family says they will never see.

>> as of now mark she will carter is still at home, not behind bars, while the appeals process of her defense now plays out. >> if you or someone you know is having suicidal thoughts, find resources for help at abcnews.com. and that is our program for tonight. i'm elizabeth vargas. >> i'm david muir. from all of us here at "20/20" and abc news, we hope you enjoy the rest of your weekend. good night. taking a live look outside from our emeryville camera

tonight, warm evening out there an