been replaying in my head, over and over. it was, all, very unbelievable. >> it happened on thanksgiving. two teenagers, missing. >> i just buried my head into my hands, and i started to cry. >> where they were, and what they did would launch a terrifying case. >> why did have to happen here? >> with a deadly end. >> nobody's leaving until we figure out what happened. >> a man at home, alone, and afraid. what would you do, if you felt in danger? >> they were really attacking his home. >> you have a right to protect your home, and to protect yourself. >> he planned. he prepared. and he was determined to kill. >> the most chilling detail of all. what you'll hear on tape. ♪ ♪ ♪ hello and welcome to "dateline. " growing up, cousins nick brady and haile kifer were close. nick loved to joke, and haile loved to laugh. the teenagers were together that cold, november day, when tragedy struck. the horrible incident was all there for police to hear, on a perfectly-clear recording. so, why was what happened so unclear? a mystery that would divide a community, and spark a national debate. here's kate snow with "12 minutes on elm street. " >> 12 minutes. not a long time. but for three people, whose paths collided on thanksgiving day, 12 minutes was all it took for their lives to explode, in a flash. >> i refuse to live in fear. >> 12 minutes, that would haunt their families. >> i dropped to my knees, and i was like, this can't be happening. >> basically, why? >> every second of those terrifying minutes would be fiercely debated. >> your natural instinct is to save yourself, however you need to do it. >> a town divided over what happened inside this house, on elm street. >> got a lot of weird things happen in trial. i've never, in my life, had evidence such as this. >> this might be more than what we're, initially, being told. >> but before all the fear and the finger pointing, it was just another thanksgiving weekend in november, 2012, in the small town of little falls, minnesota. >> everybody knows everybody and everything about everybody. >> 18-year-old, rachel brady, was spending the holiday with her 17-year-old brother, nick, and their 18-year-old cousin, haile kifer. >> we were always together. we would go camping. we were always in the water. always doing something. me and haile were always together. >> nick was the fun-loving one in the group. kimberly is his mom. >> he found joy in everything, and he would make sure to find something to make you smile. >> he'd just sit there and hug me. and be like, oh, rachel, rachel, my big sister. and then, make me laugh every single time. >> like all kids, they liked to tease each other. like, when rachel called nick the nickname he had when he was a little boy. "nickel baby." >> nobody else called him that? just the family? >> oh, no, like his really good friends would call him it, after they heard me call him it. he would get so mad at me for saying it in front of his friends. >> growing up, nick was into sports and loved the outdoors. so did his cousin haile, who was as bright and active as he was. >> she was vivacious, bubbly, and funny. >> she was very athletic in high school. she was in gymnastics and softball and track. >> the close-knit cousins spent the wednesday before thanksgiving together. rachel says, there isn't all that much for teens to do in little falls so they would drive around town in the red mitsubishi nick rebuilt, himself. >> did you cruise right down the main drag here? >> pretty much, everywhere. >> so, just spending the day, with -- with no cares. >> yeah. >> they all spent the night together at a friend's apartment. on thanksgiving morning, nick and haile left around 11:00 a. m. >> they said they were going to go to my mom and dad's house. >> the plan was to meet later at grandma's house but nick and haile never showed up. kimberly and rachel tried calling them. >> is it strange for nick not to answer his phone? >> absolutely. even if i would have called over and over again, he would have called or answered and been like, what do you want? >> strange for haile to not answer her phone? >> extremely. she would have never not answered my phone call. >> adding to their worry was the weather. it had started snowing. >> so i'm thinking, okay, the weather. maybe, he got stranded somewhere. and i was hoping that he was just staying overnight in a -- >> safe place. >> yeah, in a safe place. >> are you worried about a car accident? >> i was very worried. >> sure enough, on friday morning, there was frightening news. >> we heard about a car accident that had a red car. and we thought it was him, right away. and so, we went and looked and it ended up being car pieces for a different car. and so, then, when that wasn't him either, we started to get extremely worried. after that. >> we drove up and down the back roads, though. >> we looked. >> up and down the highway. any way i could think of that might lead -- >> through town, anywhere. >> rachel posted messages on facebook. has anyone heard from haile or nick? still, nothing. by friday afternoon, they were out of their minds with worry. >> i mean, we called and called and called. no answers. no nothing. we kept getting the voicemails. and i was like, nick, this is getting serious. you know, we -- >> i started crying, on one of 'em. and i was like, you better not be making fun of me. >> this better not be a joke. >> yeah. >> before the day was over, the family would find out, this was no joke. something terrible had happened to nick and haile but it wasn't a car crash or an accident. it was something, no one in little falls, could have seen coming. >> i tried to be a good person. >> across town, police gather at a crime scene. and concerned neighbors fear the worst. coming up -- >> just worry and panic like something's wrong. >> someone else had, also, met with trouble that-thanksgiving day. the deadly kind. when "dateline" continues. but with my moderate-to-severe eczema, it hasn't been easy. now, i'm staying ahead of it. dupixent helps heal your skin from within. so, you can clearer skin and noticeably less itch serious allergic reactions can occur, that can be severe. tell your doctor about new or worsening eye problems, such as eye pain or vision changes, including blurred vision, joint aches and pains, or a parasitic infection. don't change or stop asthma medicines without talking to your doctor. ask your doctor about dupixent [coughing] when caroline has a cough she takes robitussin. so, she can have those one on ones again. hey jim! hey! can we talk about your yoga breaks? sure. get fast, powerful cough relief with robitussin, and find your voice. ♪ robitussin ♪ mom! i got the job! yeah, i feel like its all coming together. introducing the all-new 2024 chevy trax. with all the tech. here we go. we're going home monty. and all the room... for all of life's firsts. your first new car is here. the all-new chevy trax starting under $22,000. rsv can severely affect the lungs and lower airways. but i'm protected with arexvy. arexvy is a vaccine used to prevent lower respiratory disease from rsv in people 60 years and older. rsv can be serious for those over 60, including those with asthma, diabetes, copd, and certain other conditions. but i'm protected. arexvy is proven to be over 82% effective in preventing lower respiratory disease from rsv and over 94% effective in those with these health conditions. arexvy does not protect everyone and is not for those with severe allergic reactions to its ingredients. those with weakened immune systems may have a lower response to the vaccine. the most common side effects are injection site pain, fatigue, muscle pain, headache, and joint pain. i chose arexvy. rsv? make it arexvy. >> the friday after thanksgiving, 2012, kimberly brady was worried sick that her son nick and her niece, haile, never showed up for thanksgiving dinner. they had been missing for more-than-24 hours. by friday afternoon, the family was frantic. >> so you decided to call the police? >> we went into the sheriff's department. >> right away. >> and filled out missing-person's reports for both of them. >> as authorities processed those reports, three other sheriff's deputies were over on elm street, investigating something, so troubling, they later called in a crime-scene van. that got the attention of john and kathy lange, who saw the van go straight towards the house of their good friend, byron smith, a 64-year-old, retired man, living on his own. >> i was decorating the christmas tree. i saw a big, huge truck go down his road. called the crime-scene unit. and i shouted for john. i think you were in the kitchen. and i said, call byron's cell. something has happened. >> what did you worry, kathy? what did you think had happened? >> i thought he was dead. >> kathy and john feared the worst for their friend, who had seemed out of sorts, in recent months. everything was fine when byron, first, moved back to his hometown of little falls about-five years earlier, after a career that took him all over the world with the u. s. state department. >> he was talking about living in moscow and cairo and dakar. and it's amazing. >> a worldly guy. >> very much, so. a great conversationalist and -- and fun to talk with. >> but recently, byron wasn't himself. his house had been broken into a few times. the thieves taking everything, from money to precious, family heirlooms. the langes say their friend who had mentored boy scouts and let teens jam in his garage become afraid. >> he was acting real quiet, real scared. >> and then, that crime-scene van showed up outside byron's home, and kathy was sure her friend was in trouble. >> just worry and panic. it's like, something's wrong. >> she was right. something was wrong. burglars had struck, again. this time, byron was home, and he had a gun. he had managed to defend himself, and survived the break-in. >> if you break into somebody's home, you better not have an expectation you're going to walk out alive, because the law permits them to shoot you. >> nickel wetzel was the sheriff. when two intruders broke into his house and crept downstairs, byron shot both of them, dead. >> minnesota law is clear on, this thing. you have the right to use deadly force against another person, if you believe your life or the life of another is in immediate jeopardy. >> as investigators continued to secure the scene at byron's house, the sheriff's office was calling another family. kimberly brady had been frantically trying to find her son nick and her niece haile. now, investigators knew what had happened to them. they drove out to speak with kimberly, and they brought a chaplain. >> as soon as i saw them turn the corner, the -- something -- i knew he was gone. i didn't know how or why. and then, all of a sudden, i remember the door opened and the chaplain came out. all i said was, no. i don't really remember if i said anything else. he's like, your son is dead. >> nick and haile were both dead. kimberly fell to her knees. and then, the chaplain told her, it was no accident. >> he's like, your son was shot. and i was like -- and then, i mean, shot? that just wasn't -- >> doesn't fit. >> i just remember feeling, like, i said what do you mean, shot to death? when i could finally get something out. and he said, well, he was shot three times. i was like, shot? what do you mean shot three times? and that -- that was -- i couldn't function. i couldn't really hear, after that. >> were you there, rachel, during that? >> i walked in. and then, my dad said that somebody -- somebody shot nickel baby. and i remember, i just went right outside, and i sat in the snow. i just buried my head into my hands, and i started to cry. and then, he tapped me on the shoulder, and told me, haile's gone, too. >> that's your brother and your best friend. do you remember what was racing through your head, rachel? >> basically, why? i guess, we all just couldn't believe it was both, at one time, so suddenly. >> even harder to absorb? how and where nick and haile were shot. they were the intruders byron smith killed. >> it was all very unbelievable. >> so, what happened in that basement, on elm street? the answer to that would lead to a heated debate. how far is too far, when it comes to defending your home? when do you cross the line, between victim and criminal? >> coming up -- a grainy image captures a clue. is that nick? >> you see him, on different cameras, different angles, walking around the house. >> is that haile? when "dateline" continues. >> the story of what happened on elm street spread, quickly, around little falls, minnesota. that two teenagers had broken into byron smith's house. leaving the terrified homeowner no choice but to shoot them, in self-defense. his friends and neighbors, john and kathy lange, had no trouble believing it. >> what was scary, it was very personal to him because they were really attacking his home. >> but the family of those intruders. they were in shock. >> i didn't believe it. i thought it was completely not right or untrue. >> teenage cousins, nick brady and haile kifer had gone missing the day before, thanksgiving. now, as she learned the circumstances of her son's death, nick's mother had so many questions. >> how do you reconcile, in your head, your beautiful boy, who loves the outdoors, and what they're telling you, that he broke into somebody's house? >> i just, i couldn't imagine it. it just was so not him. >> so you just couldn't reconcile? >> yeah. i had a lot of trouble. >> kimberly had never heard the name byron smith, but rachel had. >> i knew that my brother had worked for him, in the summer. but i didn't know him at all. >> nick had once done yard work at byron smith's house. now, the sheriff had evidence of what he was doing there again. byron had set up surveillance cameras at his home. frightened, after a string of break-ins. those cameras proved there was no mistake about the break-in. just after 12:30, the cameras pick up a man approaching the house. the hooded figure is nick. he looks through several windows, as if checking to see if someone's home. he clutches his hood, closely, concealing his face. jeremy luberts is an investigative sergeant with the morrison county sheriff's department. >> you could see that there had been what appeared to be a little bit of casing done on -- on nicholas brady's part. >> he even heads toward one of the cameras and tries to dismantle it. then, he walks out of camera range, shatters a window and enters the house. minutes later, the camera shows another hooded figure. this one, carrying a purse and a cellphone. it's haile. >> on the video, it shows that the female had come walking through the yard, up toward the house. >> all on tape, clear as daylight. but why? what were nick and haile up to that day? >> they both went to my school, at one time. >> dylan lange is the son of byron's friends, john and kathy. >> in little falls. you know, you have your regular, high school crowds. like, the jocks and the goth kids. then, you have a group that is misguided. >> dylan didn't know haile well, but says, at school, nick was no angel. >> what did you know about those two teenagers? >> i knew that nick was aggressive. he would be the kid, who would push up against the locker. >> kind of a bully? >> right. he was a bully. >> and as it turned out, a thief. after the shootings, authorities determined that nick had been behind one of those previous burglaries at byron's house. just a month earlier, he and a friend broke through this door and stole thousands of dollars in cash and priceless-family heirlooms. and more disturbingly, two guns. >> they took things that were really important to him, personally. >> yes. and then, when he took the guns, he thought he was going to get shot by his own guns. he was extremely afraid. >> to sergeant luberts, it all looked like a classic case of trouble-making kids crossing a line into dangerous, criminal behavior. >> you have two teenagers that seem to be running kind of rampant. you can, obviously, see that they had a change in their lives. >> and in fact, when investigators located nick's car parked on a secluded road near byron smith's home. they found items stolen from another house. >> maybe, it was the motivation of money and having material items. maybe, it was the motivation of having friends. and wanting to please friends. >> the evidence appeared to, all, be there. clearly, captured on that surveillance video. nick and haile had broken in, and byron smith seemed to have every reason to be afraid. >> the impression that he kind of left on me was that he was living in fear. he was not sleeping. it was, obviously, bothering him, physically and -- and emotionally. >> at first, even nick's mom, while she didn't want to believe much of what she was learning about her son, tried to imagine herself, in byron's shoes. >> i don't believe that breaking and entering is right. and i don't -- wouldn't have expected it out of my son. >> it looked like a tragedy, all around. two intruders and a fearful homeowner, with no choice but to shoot them. >> we know you have a right to protect your home, and to protect yourself. >> but a quick survey of the scene told sheriff wetzel that the teenagers were unarmed. as with any shooting, it would require more investigation. >> it would be ordinary, with two people dead in a home, that nobody's leaving until we figure out what happened. >> beginning with one question. smith's house, friday afternoon, only to learn that the break-in and shootings, happened thursday, on thanksgiving day. >> i asked him. i said, why didn't you call law enforcement? and he tells me, i didn't want to bother you guys on thanksgiving day. >> that struck the sheriff as extremely odd. >> nobody worries about wrecking our thanksgiving. they don't worry about wrecking our day. >> so, the intruders had been dead, for 24 hours, when byron called a neighbor for help. and asked him to call the sheriff's office. >> when you found out that byron smith had waited 24 hours. >> my mind was then, why? if he was so scared, wouldn't you be on the phone? i mean, because those kids had families, too, that were waiting. >> and then, for him to say he didn't want to bother anybody on thanksgiving. really? >> it became clearer and clearer and clearer that there were some things that were strange about this case. >> investigators were about to learn a lot more about that shooting in the house on elm street. and what happened next would tear this town apart. >> coming up -- >> i was no longer willing to live in fear. >> byron smith's story. was it all adding up? when "dateline" continues. teeth sensitivity is so common. it immediately feels like somebody's poking directly on the nerve. i recommend sensodyne. sensodyne toothpaste goes inside the tooth and calms the nerve down. and my patents say: “you know doc, it really works." ♪ it's the most wonderful time of the year ♪ ♪ non-drowsy claritin knocks out symptoms from over 200 allergens. without knocking you out. feel the clarity and make today the most wonderful time of the year. live claritin clear. >> i'm jessica layton, with the hours top stories. senator bob menendez as a primary challenger amid mounting calls for him to resign. new jersey congressman, andy kim, says he plans to run against menendez who was recently indicted on bribery charges. and the third republican presidential debate is set for november 8th in miami. with the strictest qualifications yet. candidates will have to secure 4% of the vote and multiple polls, and connect a milam of 7000 unique donors to earn a spot on that stage. and now back to dateline! now back to da teline ♪ ♪ ♪ >> welcome back to "dateline. " i'm craig melvin. was byron smith justified, in killing two teenaged intruders? nick brady and haile kifer were both unarmed when he shot them. also, troubling to police. the 64-year-old waited a full day, to call for help. now, smith was about to give detectives a chilling account of what happened in his basement. and it would turn this case on its head. here, again, is kate snow with "12 minutes on elm street." >> nick brady and haile kifer had broken into byron smith's house. the frightened homeowner said he had shot them in a moment of self-defense. but investigators had questions for byron. so, sergeant luberts escorted him down to headquarters right away that friday. >> can you tell me your full name, please? >> byron david smith. >> i just wanted his story. i wanted to find out the rest of the facts of what happened at the house. >> whoever it was, who was breaking into my home, had been doing it for so long, that i was no longer willing to live in fear. >> byron explained how he'd been terrified, ever since that break-in, a month earlier, when two of his guns were stolen. >> these are people, who have stolen my guns. i figure they're willing to use those, if they steal guns. >> byron wasn't home during those other break-ins. but this time, he was. as seen on this home-security camera. he said he had moved his truck a few blocks away, that morning, so he could clean his garage. the teens must have thought he wasn't there. >> i needed to clean out the garage, and i wanted it out of the way for a while. >> byron told him how he was in the basement when he heard the first intruder break in, upstairs, and head down toward him. >> you heard footsteps coming down the stairs, is that correct? >> yes, and then i saw his feet. and then, i saw his legs. and when i saw his hips, i shot. >> it was nick. byron shot him three times. >> i was reacting. >> okay. >> what were you reacting to? is what i'm asking. >> the threat, the previous losses. i spent 20 years overseas. a couple years in bangkok. several years in cairo. 20 years overseas. not one problem. and i retire to my peaceful hometown. >> while byron's voice broke a few times during his account of the shooting, sergeant luberts was surprised at how calm and matter of fact he was for most of the interview. >> you would think, after such a horrific event, shooting and killing two people that broke into your house. that he would be very emotional. maybe, crying, at times. i didn't notice any of that, from byron smith. he just maintained his composure, which was rather odd. >> much stranger, still, the investigator thought, was byron's account of what happened a few-minutes after he shot nick. haile entered the house and byron fired, again. >> it jammed. trigger clicked and she laughed at me. i just pulled out the. 22 and shot her. if you are trying to shoot somebody and they laugh at you, you go again. >> was haile really laughing, as he shot her? to the sergeant, it seemed like such a bizarre detail. and then, byron told them this. >> i thought she was dead, and it turned out she wasn't. so, i did a good, clean, finishing shot. >> he shot haile six times, in all. and with that, the investigators came to believe this was something, other than a simple case of self-defense. >> my question, byron, is why did you shoot, again? she didn't have a weapon in her hand. >> actually, i don't know if she had a weapon in her hand, until later. >> okay. >> i wasn't looking at her hands. >> but did -- she was laying there, hurt. did she -- she wasn't threatening you. i'm just asking. >> there was, certainly, a continuation of the use of deadly force, after it appeared to us the threat had stopped. and that made us believe that this needs to be looked at by the prosecuting attorney. >> byron smith was arrested that day. but later, released on bond. a grand jury was convened to look at the case. in little falls, his friends were shocked that authorities could believe byron was anything but an innocent victim. >> it was ridiculous, that he would be this cold-blooded killer. like, really? he's a quiet, soft-spoken person. it -- i just didn't fathom it. >> while byron was free on bond, his friends, the langes, say he can't bear to go back to his own home. so they took him in. >> i could hear him in his room, many, many nights. i'm so sorry. i feel so bad. i didn't want to hurt anybody. i could hear him in there, crying. >> the case, quickly, became a big controversy in little falls, minnesota. >> did people take sides? >> absolutely. people became more opinionated about what happened. >> some people would come up to me. he's going to prison. he shouldn't have done that. and i said, well, you haven't heard the whole story. >> i think that byron's got a lot of support, in this area. >> bill anderson was byron's neighbor. the same one, who called authorities the day after the shootings. >> myself? would i have done the same thing that mr. smith did? no doubt in my mind. no doubt in my mind. >> it seemed like a big box of puzzle pieces. >> prosecutors, pete -- and brent -- were in charge of evaluating the case against byron. and they knew it was controversial, from the start. >> when brent and i got involved in it, the e-mails started. the phone calls. castigating us for taking this. after all, doesn't a homeowner have a right to defend his dwelling? i didn't argue with people. i just said, well, just stay open and let the evidence come out. and then, let's see if you hold that same view. >> after looking at all the evidence, the prosecutors believed there was a strong case. >> the moment nick broke the window and entered into that house, didn't byron smith, then have the right to defend himself? >> yes. yes, he did. but that's not what he did. he went way, way beyond defending himself. >> that grand jury in minnesota agreed. in april of 2013, five months after the shootings, byron smith was indicted on two counts of first-degree murder. now, there would be a trial, in the case everyone in town was talking about. with revelations from both sides. >> coming up -- murder? or self-defense? >> why did he wait so long, before calling authorities? >> fear. >> the explosive debate heads into court. when "dateline" continues. running is awesome. but her moderate to severe eczema would make her skin so uncomfortable. now i'm staying ahead of it. dupixent helps heal your skin from within. so, they can have clearer skin and less itch. serious allergic reactions can occur that can be severe. tell your doctor about new or worsening eye problems such as eye pain or vision changes including blurred vision, joint aches and pain, or a parasitic infection. don't change or stop asthma medicines without talking to your doctor. ask your doctor about dupixent. type 2 diabetes? discover the ozempic® tri-zone. ♪ ♪ i got the power of 3. i lowered my a1c, cv risk, and lost some weight. in studies, the majority of people reached an a1c under 7 and maintained it. i'm under 7. ozempic® lowers the risk of major cardiovascular events such as stroke, heart attack, or death in adults also with known heart disease. i'm lowering my risk. adults lost up to 14 pounds. i lost some weight. ozempic® isn't for people with type 1 diabetes. don't share needles or pens, or reuse needles. don't take ozempic® if you or your family ever had medullary thyroid cancer, or have multiple endocrine neoplasia syndrome type 2, or if allergic to it. stop ozempic® and get medical help right away if you get a lump or swelling in your neck, severe stomach pain, or an allergic reaction. serious side effects may include pancreatitis. gallbladder problems may occur. tell your provider about vision problems or changes. taking ozempic® with a sulfonylurea or insulin may increase low blood sugar risk. side effects like nausea, vomiting, and diarrhea may lead to dehydration, which may worsen kidney problems. living with type 2 diabetes? ask about the power of 3 with ozempic®. [coughing] when caroline has a cough she takes robitussin. so, she can have those one on ones again. hey jim! hey! can we talk about your yoga breaks? sure. get fast, powerful cough relief with robitussin, and find your voice. ♪ robitussin ♪ holy cannoli. look at this. it's like a science project. ordering lunch -- easy for you and me but can be so difficult for a young homeowner turning into their parents. are those all different lettuces? uh, yes, sir. brown rice, white rice, or quinoa? -[ groans ] -we're gonna need a minute. do you have any food allergies? -well, my teeth are sensitive to cold. progressive can't protect you from becoming your parents, but we can protect your home and auto when you bundle with us. that'll be $19.45. oh, i'm just paying for my own salad. >> byron smith's first-degree that'll be $19.45. kate snow: byron smith's first-degree murder trial murder trial got under way in april, 2014. and just like the town, itself, carved in two by the mighty, mississippi river. the people of little falls, minnesota, found themselves divided. on one bank stood those who saw byron as a cold-blooded killer, who fired nine shots at two unarmed teenagers. >> when you are talking about multiple shots, down on the ground. right away, jumps out at you. you know, hey, this is premeditated murder. >> on the other bank, were those who viewed smith as a man with every right to defend himself and his home against intruders. >> they weren't invited for thanksgiving dinner. there wasn't a table set for them. they didn't come through the door. but they, certainly, found a window to come in. >> but nick's mother, kimberly brady, was determined, even through her own grief, not to make up her mind, until she'd heard all the facts. >> i kept an open mind, because if he was fearful for his life, i couldn't fault him for defending himself. i waited, until i heard all the evidence. >> the evidence said byron smith's defense attorney would show his client had done nothing wrong. >> this is a case about big misunderstanding. this is about byron smith being accused of a crime, he did not commit. >> did you believe that byron smith was justified in shooting nick brady and haile kifer? >> yes. it's not something he wanted to do, but he didn't ask them to burglarize his home, in a violent way, on thanksgiving. they chose to do that, and he reacted. >> so the defense came to court, confident a jury would see it that way. >> in minnesota, as i understand it, you have the right to protect your life. you have the right to protect your home, your property, as long as it's reasonable. >> if somebody breaks into your home and commits a -- a felony offense, in your home. you can kill that threat. >> meshbesher said that everything byron did that thanksgiving day and the next was evidence that he was truly terrified inside his own home. >> why did he wait so long before calling authorities? >> fear. he was afraid there was a third or fourth or fifth person. so, he's afraid of the backyard, the front yard, the stairway, the door. he's just in utter fear, and he goes into a closet and hides. in his own house. until the fear subsides. >> as for smith's calm demeanor and the matter-of-fact way, in which he described the killings? >> i just pulled out the. 22 and shot her. >> the defense said, he was just a man trying to help the authorities, any way he could. >> on the exterior, he appears to be calm. but he's talking about how frightened he is, internally. he is trying to explain, to the police, what happened. he is trying to help them solve what occurred. >> but would the defense be able to convince the jury that byron smith's own account of the shootings, how he gave haile a self-described, finishing shot was really justified? >> i did a good, clean, finishing shot. >> from a human standpoint, it just sounds so cold blooded. >> it does, and i had to deal with the way it sounded. but it's not evidence of what he is thinking. it's evidence of emotion. it's not evidence of murder. >> he thought his strongest evidence to justify the shootings was the fact that nick brady had broken into byron smith's house, before. had even stolen guns. so, byron had every reason to fear for his life. >> you wanted to show them that these were kids that were up to no good? >> no, that's not what i wanted to do. i wanted the jury to see the truth, rather than just see a painted picture that the media was playing of their high school photographs. >> but the judge said, testimony about nick's involvement in that previous break-in was irrelevant and inadmissible. meshbesher, also, couldn't say in court that there was evidence that nick and haile, together, had robbed another house, too. >> unfortunately, the judge would not allow that evidence to come in. and i thought he was making a grave error. >> how many witnesses did you have lined up, who weren't allowed to speak? >> about half a dozen. >> and so, byron smith's friends, watching in court, could only hope that the jury would see things, as they did. that he was a scared man, who defended his life and property. >> we knew him as our friend byron. so, it was ridiculous, to us, for authorities calling him a cold-blooded killer. >> it would be an uphill battle in the court of public opinion, thought prosecutors. they knew they had the burden of proof. >> i have tried a lot of murder cases. and this one, in particular, seemed like a real challenge. >> why? >> because a lot of people thought we'd lose it. >> a lot of people saw this, as a referendum on whether it's okay to protect your property, and protect your life. you don't see it that way? >> not this case, not these facts. >> but to prove murder, in the first degree, the state would have to show that byron acted, not just with excessive, unreasonable force but, also, with premeditation. and while the defense may have had a lot of townspeople on its side, the prosecution had something else. a piece of evidence, they felt, would sway any juror to see byron smith, not as a fearful victim but, as a calculating killer. >> did byron tell investigators that he had made audiotapes? >> no, he did not. >> coming up -- < < you're dead! >> the revelation that stopped everyone, cold. >> can you ever erase that from your memory? >> not ever. >> no. >> when "dateline" continues. my a1c was up here; now, it's down with rybelsus®. his a1c? it's down with rybelsus®. my doctor told me rybelsus® lowered a1c better than a leading branded pill and that people taking rybelsus® lost more weight. i got to my a1c goal and lost some weight too. rybelsus® isn't for people with type 1 diabetes. don't take rybelsus® if you or your family ever had medullary thyroid cancer, or have multiple endocrine neoplasia syndrome type 2, or if allergic to it. stop rybelsus® and get medical help right away if you get a lump or swelling in your neck, severe stomach pain, or an allergic reaction. serious side effects may include pancreatitis. gallbladder problems may occur. tell your provider about vision problems or changes. taking rybelsus® with a sulfonylurea or insulin increases low blood sugar risk. side effects like nausea, vomiting, and diarrhea may lead to dehydration, which may worsen kidney problems. need to get your a1c down? you may pay as little as $10 per prescription. some luxury creams just sit on top of skin. but olay goes 10 surface layers deep. our clinically proven hydration beats the $500 cream. to strengthen my skin for smoother, brighter results. your best skin yet. olay. ♪ it's the most wonderful time of the year ♪ ♪ non-drowsy claritin knocks out symptoms from over 200 allergens. without knocking you out. feel the clarity and make today the most wonderful time of the year. live claritin clear. >> there are people who think byron smith is a hero. what do you say to them? >> i say he is a murderer, and murderers can't be heros. >> in a sharply-divided, minnesota courtroom, the prosecution argued that byron smith was no fearful, innocent victim. but, an angry man, bent on violent confrontation. he told investigators, from the beginning, that he was sitting, reading a book, in the basement. that he was caught, unaware. you don't buy any of that? >> no. not at all. >> the prosecutors said they had evidence that it was premeditated murder. they told the jury, byron had set a trap for the burglars. remember the story about moving his truck to clean the garage? the prosecutor said that was a lie. that byron had, in fact, moved the truck to make it look like he wasn't home. >> you think byron wanted to catch the people who had been breaking into his house? >> clearly. he planned. he prepared. and he was determined to kill whoever's breaking into his house, and stealing his property. >> the prosecution said byron was in the basement, not to read a book but, to wait, like a hunter. >> it just seemed like byron smith was deer hunting. like a lot of folks do in minnesota. where you get in your stand, and you wait and you wait. and when a deer comes by, you shoot and kill it. and it just seemed like that's what he did with these kids. >> but could they prove it? turns out, the prosecutors had something they'd never encountered, in nearly-half a century of combined-trial work. >> do you remember when you first listened to it? >> i do and it knocked me out. i've never been able to hear a murder actually occurring. >> byron smith had recorded the break-in and the shootings. investigators found this digital-audio recorder on a bookshelf in the basement. it had captured more-than-six hours worth of audio, that day. >> you ended up with a trove of information. his own words, on tape. >> indeed, we did. >> here is byron smith, shortly before the break-in, talking to himself. >> in your left eye. >> in your left eye. why would he say that, a half-hour before anyone came over? well, when you go through the autopsy photographs, you see that he shot haile kifer in her left eye. >> he was planning where he was going to shoot an intruder. >> not just shooting them, but where. where, in the face, is he going to shoot'em? >> then, it sounds like byron is planning not just the shooting but, also, his defense. he practices contacting a lawyer. >> i realize i don't have an appointment. but i would like to see one of the lawyers here. >> ten minutes later, the practicing is over. the recorder captures something real. >> how quickly did everything go down, that day? >> 12 minutes. >> 12 minutes, from the first shot fired, at nick brady, to the ninth-and-final one fired at haile kifer. >> it was frightening. >> the prosecutors played all-12 minutes, in court. but first, warned nick and haile's families, who sat through every day of the trial, that they may not want to hear it. >> he actually suggested you probably shouldn't be there that day. >> he did, more than once. >> why did you want to be there? >> i needed to know. i mean, i -- you -- you need to hear the whole story. to understand it, i think, in this case. you can't just make a snap judgment. >> this is the sound of nick entering the home. walking down the stairs, to the basement. >> and as he is going down the stairs, you can hear him get shot. >> we won't play that part of the recording. but listen to what byron says, after shooting nick, three times. >> you're dead. >> then, there's a rustling sound that the prosecution says is byron unfolding a tarp, that he uses to move nick's body. you can, then hear byron reload his gun. ten minutes go by then the recording picks up a whisper. it's haile, coming into the house, looking for her cousin. >> so, she comes in, and goes right to the basement. starts walking down. and that's when he shoots her. >> here, on the recording, is what the prosecution says is a pivotal moment. in his interview with investigators, byron had said he felt threatened by haile. and that she had been laughing at him, when he fired. >> she laughed at me. >> but on that audio recording of the shooting, which again, we have edited, the prosecution says haile clearly sounds terrified. >> oh, my god. >> she's screaming, in a high pitch. saying, oh, my god, oh, my god. >> and after he is done shooting, this is what byron says. >> bitch. >> those, in court, saw byron smith wipe away tears as the audio played. there was stunned silence save for the quiet sobs from nick and haile's families. >> can you ever erase that from your memory? >> not ever. >> like, ever since i heard it, it's been replaying in my head, over and over. i feel like anytime i hear somebody say, oh, my god, that's what i think of. >> but the prosecution wasn't done with that recording. >> cute. i'm sure she thought she was a real pro. >> because byron continued to talk to himself, after the teens were dead. >> i felt like i was cleaning up a mess. i don't see them as human. i see them as vermin. >> by now, kimberly had heard all the facts she needed. >> what do you hear, when you hear those words? >> pure evil. i don't know how you can say that about anybody, let alone two precious kids. and i -- i don't believe he was scared. i -- i believe it was premeditated murder. >> but in court, the defense said, that recording, as disturbing as it is, proves no-such thing. >> i tried to be a good person. >> rather, it shows a man, quite possibly, driven mad with fear. >> i feel a little bit safer. not totally safe. i'm still shaking a bit. >> he's talking to himself, mumbling things. a lot of things didn't make sense. >> he sounds, frankly, like someone who is maybe losing his mind. someone who is -- >> or lost their mind. he simply had no ability to deal with reality, at that time. >> after a week of testimony, the case went to the jury. it was anyone's guess which portrait of byron smith those 12 people would believe. the cold-blooded killer, lying in wait? or the terrified man, under siege, in his own home? >> what were you thinking, as the jury went out to deliberate? >> i gave it all to god. i was pretty peaceful. >> just put your faith in him? >> i did. >> and waited? >> and waited. >> it wasn't a long wait. the jury was back, in less than four hours. the verdict? guilty of first-degree murder for killing both nick brady and haile kifer. >> i waited. i heard. and i believed. and then, it was said. >> i was very happy to see him taken away. but there was no winners. >> doesn't give you your brother and your best friend back. >> exactly. >> i put my head in my hands, and went, thank god for them. you know? that they got that. >> the families? >> yes. >> but byron's supporters felt the opposite of relief. >> shocked. stunned. >> it was such a one-sided trial. it was so unfair. >> kathy said there's so much more to her friend the jury never learned. >> he just came here to retire, and want a quiet life. this should have never happened. >> this was just pure, utter sadness. >> it was just-12 minutes that changed so many lives, in so many tragic ways. byron smith will live out his retirement, in prison, having received an automatic-life sentence. and nick brady and haile kifer, two young cousins, who made a terrible decision to enter that home, paid for it with their lives. and their loved ones are left to mourn a future that will never be. >> you had a little, baby girl, not too long ago. and nick and haile weren't here to see that. >> i think that's probably one of the hardest parts about all of it. i would have loved to see my brother hold her. >> he would have been uncle nick. >> uncle nickel baby. >> that's all for this edition of "dateline. " i'm craig melvin. thank you for watching. >> i'm craig melvin. >> and i'm natalie morales. >> and this is "dateline. "