lighting every soccer match at shell energy stadium. we're moving forward with the houston dash. because we're moving forward with everybody. shell. powering progress. i don't want you to move. i'm gonna miss you so much. you realize we'll have internet waiting for us at the new place, right? oh, we know. we just like making a scene. transferring your services has never been easier. get connected on the day of your move with the xfinity app. can i sleep over at your new place? can katie sleep over tonight? sure, honey! this generation is so dramatic! move with xfinity. [music playing] hellduring the middlening, and tof the night,ine." i heard this loud noise. it sounded like someone was in the house. this is dateline.

i heard a noise. it sounded like someone was in the house. i opened up her door to her bedroom and i thought, i am hearing things. >> your instincts were right. something happened in the middle of the night. >> you think your child is safe in your home sleeping. she was just 16. emma, the honor student, cheerleader, volunteer. >> she could get along with anybody. >> always so like kindhearted and sweet. >> she wanted to be a nurse and she had a plan. >> reporter: she went to sleep one sunday night and never woke up. >> i saw a 16-year-old female laying in her bed. >> there was a bullet hole in the wall. >> she has been shot? >> someone fired a shot from outside of the residence. >> was emma a target? that weekend she seen a mysterious figure in black. >> she was shaking. >> reporter: now, two brave friends set out on a secret

mission. could they help catch her killer? >> you are trying to bring down a murder suspect. >> i just knew it was something that had to be done. >> this is insane. >> everybody put your hands out the of the vehicle now. >> it all became a lot more real. >> reporter: hello, welcome to "dateline." emma walker was a spirited teenager with a nack of stirring up fun. pretty and smart. but after her death the police had a tough investigation. whoever shot her it would take a bold plan to catch her killer. here is "noises in the night." >> when the ought imchill seeps into the community north of knoxville, tennessee, hundreds of school students are drawn to the blaze of friday night-

lights to cheer on their hometown heroes, the bobcats. she was the friday night-light that shown brightest of them all. emma walker, a bobcats cheerleader since her freshman year. >> she was a really good cheerleader. some would go through the motions and but emma put her own sparkle. >> they said their friend could be sassy. >> she would say, i am kind of a big deal. >> i am saying she said it with a hint of sarcastic. >> she is a super pretty cheerleader, but then meet her, she is the nicest person. >> reporter: they were her long time school friends >> once you got to know her she

is a down-to-earth person and sweet. >> she had a smile that could light up a room. a big beautiful smile. >> emma's parents say that smile was the hallmark her playful personality. >> she liked to play jokes on me. grabbing my iphone and taking self-ees selfie. >> reporter: she wanted to be a nurse. >> when we would talk about the different professions and get to the ones about babies, she would say that is what i want to do. >> reporter: no surprise she was noticed by boys at school. one boy she definitely noticed back. >> that is really all she liked talk about at first. just like, he is super cute. >> reporter: he, was riley. two years older than emma, popular, too. a stand out wide receiver on

the bobcats football team. >> did you think riley would make it to the nfl. >> if there was anybody to do it was going to be riley. >> reporter: he was not just a high school jock. he was active at church and loved "star wars" movies. >> started out as a nerdy guy, that is how we met, obviously. >> obviously [ laughter ] >> and then later in high school he got more into football but he kept with his nerd roots. >> he was really funny. i think that is why emma fell for him in the first place. they were both super goofy. >> she had a big crush on him. >> she did. >> reporter: just one problem. riley already had a girlfriend but he broke up with her to date emma. >> things got serious between the two of them? >> dwrai. >> reporter: but as the months went by, it became clear riley the star football player was also, well, a player. it turned out his ex was not

really an ex after all. >> he promised his ex- girlfriend he would take her to prom that year and she would go to prom the next year. >> she let it go? >> yeah. >> i guy with two girls on the go that is not cool. >> no t is not cool and she was young and, had a mind of her own and did not want us to voice our opinion about our concerns. >> reporter: emma's determination caused a lot of tension between her and her parents >> how does it work when you are trying to be good parents and your daughter has that strong personality. >> it is difficult. >> very difficult. [ laughter ] >> she just was stubborn and thought her way was the right way. she wanted to learn for herself. >> reporter: emma and riley dated on and off for two years, riley graduated and went to

college half an hour away. they tried to keep it going but emma saw snap chats of riley with other girls on camp us and she broke up with him for good. the tension at home evaporated. >> it must of felt so good to be the happy family again? >> it is. the whole household was different. the household was not calm for very long. on november 20th, 2016, a sunday, emma went for ice cream with her dad and planned to get up early for school the next morning. >> i told her, good night, love you. going to bed. during the middle of the night i, i heard a loud noise. >> what kind of noise was it? >> it sounded like someone was in the house and opened the door and slammed it. and i heard it again. >> mark jumped out of bed to check on emma and her brother. >> i opened up her door to her bedroom and i stared at her for

probably 15 or 20 seconds and, she was just lying asleep. in her bed. and, i shut the door and went to my son's bedroom and he was in the bed asleep. so i thought, i am hearing things. so, i checked the doors around the house and went back to bed. >> reporter: in the morning, emma's mom woke up early. i went in to wake her up and i could not wake her up. >> what was going on in your mind. i can not recall a lot of it. i just know that i checked for a pulse. >> and there was no pulse? >> no pulse. >> no. >> emma's younger brother evan rushed in. >> poor evan i am sure that is something. >> i wish he never had to experience it. it is like a nightmare. [crying] >> reporter: jill calmed 911.

i just tried to wake up my daughter for school and she has no pulse. >> she is nonresponsive? >> what had happened to emma walker? [crying] coming up. the investigation begins. >> i saw a 16-year-old female laying in her bed with a small amount of blood in her pillow. >> people thought she might of overdosed on something. >> they thought she ingested poison or whatever >> this is a mystery right now. >> it is all a mystery. >> when "dateline" continues a >> when "dateline" continues copd hasn't been pretty. it's tough to breathe and tough to keep wondering if this is as good as it gets. but trelegy has shown me that there's still beauty and breath to be had. because with three medicines in one inhaler, trelegy keeps my airways open and prevents future flare-ups. and with one dose a day, trelegy improves lung function

so i can breathe more freely all day and night. trelegy won't replace a rescue inhaler for sudden breathing problems. tell your doctor if you have a heart condition or high blood pressure before taking it. do not take trelegy more than prescribed. trelegy may increase your risk of thrush, pneumonia, and osteoporosis. call your doctor if worsened breathing, chest pain, mouth or tongue swelling, problems urinating, vision changes, or eye pain occur. ♪ what a wonderful world ♪ ask your doctor about once-daily trelegy for copd because breathing should be beautiful. everybody wants super straight, super white teeth. they want that hollywood white smile. new sensodyne clinical white provides 2 shades whiter teeth and 24/7 sensitivity protection. i think it's a great product. it's going to help a lot of patients.

scout is protected by simparica trio and he's in it to win it! simparica trio is the first chew with triple protection. whoa fleas! and ticks! (♪♪) intestinal worms! whoa! heartworm disease! no problem with simparica trio! this drug class has been associated with neurologic adverse reactions including seizures. use with caution in dogs with a history of these disorders. for winning protection— go with simparica trio. breathing claritin clear is like... is he? claritin clear? yeah. fast relief of your worst allergy symptoms, like nasal congestion. live claritin clear® (vo) if you have graves' disease, your eye symptoms could mean something more. that gritty feeling can't be brushed away. even a little blurry vision can distort things. and something serious may be behind those itchy eyes.

up to 50% of people with graves' could develop a different condition called thyroid eye disease, which should be treated by a different doctor. see an expert. find a t-e-d eye specialist at isitted.com ♪you're the one that i want!♪ nexgard® plus helps you protect your dog from fleas, ticks, heartworm disease and more... all in one delicious, monthly soft chew. use with caution in dogs with a history of seizures or neurologic disorders. nexgard® plus. the one you want for one-and-done protection. nothing dims my light like a migraine. with nurtec odt, i found relief. the only migraine medication that helps treat and prevent, all in one. to those with migraine, i see you. for the acute treatment of migraine with or without aura and the preventive treatment of episodic migraine in adults. don't take if allergic to nurtec odt. allergic reactions can occur, even days after using. most common side effects were nausea, indigestion, and stomach pain. it's time we all shine. talk to a healthcare provider about nurtec odt from pfizer.

talk to a healthcare provider monday, november 21, 2016 was supposed to be a regular school morning. instead, first responders were arriving at the walker family . monday, november 21st, 2016, was supposed to be a regular school morning, instead, first responders were arriving at the walker family home and word that something horrible had happened to emma was tearing through town. friends calling friends. >> she was just balling. i was like, okay. you need to breathe, you need to calm down, what is wrong. she said emma is dead. >> what are you talking about? >> it did not register in my mind like . >> not our emma, no. >> reporter: did not seem real to nathan, either >> i was like, yeah, that is my best friend but she did not pass away. it just hit me. i started balling.

>> reporter: emma's ex- boyfriend was in college. he grieved on social media >> how much he loved her and will misher. she does not deserve this. she is in a better place now. tell god about your verse. >> did their hearts go out to riley, he lost -- a lot of people commented i am so sorry. prayers for you. >> still, no one knew, yet, how emma died. >> what are some of the rumors now floating around on social media? about what happened to emma. >> people had thought she might of overdosed on something. >> people said brain bleed. >> reporter: the biggest one that upset us the most were people who did not know her saying she killed herself. >> reporter: was there and part of you that was confused and thinking, maybe it is possible. >> you know that she has not

survived whatever has happened but you don't know what. >> it is all a mystery.. >> investigators arrive with sketchy details from first responders >> they thought, originally, it was a suicide, she ingested something. a poison or whatever. >> reporter: knox county major was assigned to investigate the case with major climb detective merit. >> i saw a 16-year-old teenager liing in her bed with a small amount of blood on her pillow. some people confused that with that she gotten sick or had ingested something and caused her to vomit. >> when the detective looked closer he saw something unusual. >> first responders did not immediately see the hole in the wall. >> reporter: there was a hole in the wall next to emma's bed. a bullet hole. only a little blood visible on the pillow, when the investigators investigated her head there was a small entry

wound. >> so she has been shot? >> yes, ma'am >> in her own bed. >> the bullet struck her just left and above the ear. it was a fatal wound. >> reporter: she had to have been shot then through the wall? >> yes. it was obvious someone had fired a shot from outside of the residence into the residents striking her in the head. >> reporter: this is not the kind of neighborhood with drive- by shootings, right? >> yes, ma'am, it is a low- crime rate area. >> reporter: as the detectives processed what is now a crime scene, they found more clues as to what might of happened >> we go outside of the residence. that is where we determined that there was a second shot that had been fired through the inwall part of the house and there in the walker's yard. >> we find a shell casing, a spent casing that had been fired and then as we again work around we find a spent casing

and a live round. >> reporter: when emma's parents learned what happened they barely had been taken it? >> they told us she had been shot. >> it is unthinkable. >> reporter: emma's father recalled the noises that he hard during the poit >> knowing those noises that i heard were gunshots and they sounded nothing like gunshots. >> but your instincts were right. something happened in the middle of night. >> you think your child is safe in your home, sleeping. >> reporter: but who would want to kill this sweet popular girl whose goal in life with to care for newborn babies? it turned out the last few days of emma's walker's life was anything but normal and might be key to the unraveling the mystery. >> coming up. >> she sees a person dressed

all in black.. >> a mysterious figure at emma's door >> this person comes to the front door and starts to try to get in the house. turning the doorknob, she is in fear. in panic. >> i would have been terrified. >> absolutely. >> when dateline continues ter >> absolutely. >> when dateline continues 3 out of 4 people achieved 90% clearer skin at 4 months. and skyrizi is just 4 doses a year after 2 starter doses. serious allergic reactions and an increased risk of infections or a lower ability to fight them may occur. tell your doctor if you have an infection or symptoms, had a vaccine, or plan to. with skyrizi, nothing on my skin means everything! ♪ nothing is everything ♪ ask your dermatologist about skyrizi. learn how abbvie could help you save. some people just know that the best rate for you is a rate based on you, with allstate. because there are people out there who aren't you. a lot of them. and you don't drive like... whoa. i don't want my child being raised by a robot! other drivers are not you.

yes, thank you so much to all 50 of my subscribers. nope, definitely not you. save with drivewise and get a rate based on you. you're in good hands with allstate. shingles. the rash can feel like an intense burning sensation, and last for weeks. shingles could make it hard to be there for your loved ones. over 50? the virus that causes shingles is likely already inside you. don't wait. ask your doctor about shingles. students...

students of any age, from anywhere. using our technology to power different ways of learning. so when minds grow, opportunities follow. ♪ lighting every soccer match at shell energy stadium. we're moving forward with the houston dash. because we're moving forward with everybody. shell. powering progress. shell renewable race fuel. reducing emissions by 60%. ♪♪ we're moving forward with indycar. because we're moving forward with everybody. shell. powering progress. business. it's not a nine-to-five proposition. it's all day and into the night. it's all the things that keep this world turning. the go-tos that keep us going. the places we cheer. and check in. they all choose the advanced network solutions

and round the clock partnership from comcast business. see why comcast business powers more small businesses than anyone else. get started for $49.99 a month plus ask how to get up to an $800 prepaid card. don't wait- call today. emma walker was shot dead in her own bed. at 16 years old, she had her whole life ahead of her. . emma walker was shot dead in her own bed. at 16 years old she had her

whole life ahead of her. >> all of the great things she would have done. >> yeah. >> proms, graduations and things that we never get to see, you know. getting married, having kids. >> reporter: as emma's family began imagining life without her the police were focused on finding her killer. they were talking to her family and friends about the days before the shooting. >> that is a lot of activity in a period of two days unexplained. >> reporter: it was the weekend before thanksgiving. friday night emma and her group were celebrating a football win at a friend's house. emma received a message from an unknown number. the message said something about riley, he had been taken. >> someone has riley? >> yes. someone kidnapped him. >> reporter: riley, kidnapped? the strange messages kept coming. then, emma's phone rang and riley was on the line

>> help me, help me, help me, emma >> you can hear riley on the call, calling for help? >> yes. emma and her friends rushed out of the house and there was riley. he had his hands on his head, he looked confused. i saw her yelling at him. she was really angry. >> reporter: emma was furious, she and her friends thought the whole thing was some kind of prank. >> we were all, oh, it is far- fetched for him to be kidnapped. we did not think twice about it. if the kidnapping was a joke what happened the next morning was no laughing matter. friends said that saturday she drove herself home from her friend's house. >> as she was pulling in approaching her residence she sees a person dressed all in black and as she gets closer, you know, he gets his hood up and puts the glasses on. >> emma was texting her friends

>> as she gets in the residence this person comes to the front door and starts trying to get in the house, turning the door knob. she is in a fear, she is in a panic. she reaches out to the one person that she thinks can help her that was riley. >> emma just broken up with riley and angry about what she thought was that strange kidnapping stunt the night before. still, she texted him this. i hate you but i need you right now. she face time called him and asked him to come over. >> why do you think she reached out to him given that they had just broken up? >> i think he was a sense of security to her. he was a protector. from other things. >> reporter: riley searched the house and neighborhood. saw no signs of anyone. neither called the police. but, now, the detectives were investigating emma's murder. they discovered surveillance footage from a neighbor's house

and there he was. >> so, this is the mysterious man in black? >> at that point it is. >> were you able to see a face? >> no. >> a possible intruder? an attempted kidnap something what was going on? the police needed to talk to riley right away. they asked him for details about the kidnapping and he insisted it really happened. >> it was traumatizing. i did not know what to make of it. i went up to my step dad's house. i pulled into the driveway and a van pulled in the semicircle. and these two guys were, like, walking across the street and next thing i know, one of them grabbed my bag and the other one is around the corner and they just like, put their hand over my face and just took me to their van or whatever. >> why would someone do that to you? >> i genuinely have no idea. >> they did ask me, they were

like, um, you know, like, who would you want to talk to for the last time, i started freaking out and i said emma. they made me call emma. she thought i was playing a crank on her. >> emma did not buy the story. she was genuinely terrified when she called him the next day about the plan in black. >> she face time called me. crying, freaking out. okay, give me a minute i will check it out. >> that is the only person riley could think of who would want to harm emma. >> the only thing that i thought of who was at her house, that was the first thing that i thought of. >> reporter: riley told the police even though they were broken up he still cared for her. in fact, they spoke on the phone sunday night. in the hours before emma was shot. >> i just told her how much i loved her and, and that i was sorry that she did not want

what we had anymore. she did not care about the relationship, she cared about me, she loved me but did not want to be with me anymore. >> reporter: he spent the rest of the night on campus 25 miles away crying about the break up. >> i sat in the parking lot looking at the pictures of us. >> he woke up to people texting and calling with their condolences. >> i was like what are you talking about? did you not hear what happened. no, what are you talking about? >> riley, the heartbroken ex, now lost the love of his life for good. but, this pair of seasoned investigators had their radar up. >> did you start seeing more of his personality you can see he had to have her. >> coming up. a closer look at that mysterious man in black. >> she had actually seen the man in black. she recognized him by his build, by his gait, the way he walked, carried himself. >> who was he? >> when "dateline" continues el. >> who was he?

>> when "dateline" continues even a little blurry vision can distort things. and something serious may be behind those itchy eyes. up to 50% of people with graves' could develop a different condition called thyroid eye disease, which should be treated by a different doctor. see an expert. find a t-e-d eye specialist at isitted.com [♪♪] your skin is ever-changing, take care of it with gold bond's age renew formulations of 7 moisturizers and 3 vitamins. for all your skins, gold bond. sup? -who are you? ofi'm your inners achild. get in.

listen, what you really need in life is some freakin' torque. what? horsepower keeps you going, but torque gets you going. what happened to my inner child craving love and acceptance? how about you love and accept this? p-p-p-p-powershot! when can i drive? you already are! the dodge hornet r/t... the totally torqued-out crossover. (woman) ugh, of course it stops loading at the best part. (tony hale) you need verizon. get their crazy powerful network out here, and get six months of disney bundle on them! (vo) stream with six months of disney bundle on us. and watch it all on the new samsung galaxy s24+, also on us. only on verizon. this charmin ultra soft smooth tear is soooo soft and soo smooth. charmin ultra soft smooth tear has wavy perforations that tear so much better for a smooth more enjoyable go. charmin, enjoy the go.

. news update. benjamin netanyahu reiterating his position invades rafah. benjamin netanyahu showed no signs of backing off the ground offensive. five people are dead after an outbreak of tornadoes hit oklahoma saturday night. it was part of a weekend storm system that saw over 100 tornadoes touched down across the midwest. for now, back to "dateline." welcome back to "dateline." who shot emma walker the day before she died a menissing man dressed in black showed up at her house triggering a panicked phone call to her ex-boyfriend. riley told the police by the time he got there the man was

gone. now, the detectives are about to discover something that riley did not tell them and it will send the investigation into overdrive. once again, here is "noises in the night." emma walker had been murdered. all over twitter, riley was the grieving ex. >> what did he change the bio to? >> living every day through emma walker. >> now, her friends were looking back. they remembered a high school boyfriend who was jealous, possessive, even obsessed. >> he started to get very kind of controlling of her, like where she was, what she did, if she wanted to hang out with our friend who is like, you are not going. >> he did not want her to hang out with people. it was just him and her. >> and if emma went somewhere without him . >> he would text her 40 to 100 times.

he was just blowing up her phone, emma, talk to me, text me back, call me. >> yes. call her 20 or 30 times. >> emma's parents throughout the relationship was toxic. they had seen their daughter change. >> the new personality with riley in the picture was not one that you recognized >> no, her fun loving self-was no longer, very closed off. more in her room. >> angry. >> angry at us. >> was it like her spark had been extinguished? >> yes. her parents said riley seemed intent on driving a wedge between emma and her family. >> he could tell her she really didn't have parents, barely had a brother. i think he just wanted her to think that was, he was all she had. >> a nightmare situation for a parent >> yes. >> reporter: jill and mark had always been involved parents. monitoring their kid's social media and cell phones. even had a tracker on emma's

car. when things got bad with riley they tried to limit emma's contact with him. but he always seemed to find a way around their rules. >> he would show up to our church because they could not tell him to leave or a basketball game because it is public event going on. so they can not tell him he should not be there. >> reporter: and when emma finally broke up with him a few weeks before she died. even his close friends seemed like it was like he was unraveling. >> were you worried about him? >> yeah, very, very. >> i think this is when we started to see like, if he wanted to do something like, he could. >> he seemed unstable to you? >> yeah. >> reporter: now that emma was dead her friends were not buying his sad messages on social media. >> what are you thinking when you are reading riley's post. >> he is trying to cover up.. >> did you think he did it or something else? >> i thought he had something to do with it. >> the police were thinking the same thing as they listened to

stories about emma and riley. >> based on my experience as a detective it was abusive, not physically but emotional and psychological abuse.. >> the police were skeptical of everything riley said. did not believe the kidnapping story. they talked to one of emma's friend they were more suspicious. the friend was certain that riley was the man in black. >> she had actually seen the man in black and believe today to be riley and recognized him by his build, his gait, the way he walked and carried himself. >> during the interview the police were closely watching riley. they noted how they referred to emma in the strangest way. >> the girl, she, she texted me. >> which girl? >> the one that passed away. >> what is her name? >> emma >> now this is someone he professed his love to and gone

on social media and spoke out about how she is his everything and all of that. but yet when he goes to talk to me in the interview, he refers to her as the girl. >> how did you get from there . >> as the interview progressed the police tried to nail down riley's whereabouts, he stuck to the same story, he was at his college. half an hour away. >> i remember getting back in my dorm at 4:30 and my roommate being awake because he asked me i didn't was getting in so late. >> as they saw riley they were more and more skeptical. >> i hope to god i am not a suspect in her death. >> based on my experience it was phony. >> i would hurt myself

>> did you shoot into emma's house? >> no, sir. >> riley was now the prime suspect but they had to let him go. they did not have enough evidence. and there was a missing piece to the muzzle. where puzzle. >> riley is about to become the target of a secret operation. coming up. >> they set up a listening device in the car >> the police could hear you but you could not hear them? >> this is insane. >> could these two friends find that missing gun and the killer? >> this potentially can be very dangerous. >> absolutely. you will have two boys in a car with a guy that is believed to have already killed one person with a murder weapon. this is a huge dangerous thing. >> when date line continues da >> when date line continues symptoms can sometimes take you out of the moment. now there's skyrizi, so you can show up with clearer skin...

...and show it off. ♪ nothing is everything ♪ with skyrizi, you could take each step with 90% clearer skin. and if you have psoriatic arthritis, skyrizi can help you get moving with less joint pain, stiffness, swelling, and fatigue. and skyrizi is just 4 doses a year, after 2 starter doses. serious allergic reactions and an increased risk of infections or a lower ability to fight them may occur. tell your doctor if you have an infection or symptoms, had a vaccine, or plan to. thanks to skyrizi, there's nothing like clearer skin and less joint pain, and that means everything. ♪ nothing is everything ♪ ask your doctor about how skyrizi could help with your skin or joint symptoms. learn how abbvie could help you save. icy hot. ice works fast. ♪♪ heat makes it last. feel the power of contrast therapy. ♪♪ so you can rise from pain. icy hot.

an alternative to pills, voltaren is a clinically proven arthritis pain relief gel, which penetrates deep to target the source of pain with nonsteroidal anti-inflammatory medicine directly at the source. voltaren, the joy of movement. feeling claritin clear is like... ♪♪ [cat meow] —is she? letting her imagination run wild even though she has allergies. yeah. with the freestyle libre 3 system know your glucose levels. no fingersticks needed. all with the world's smallest and thinnest sensor. manage your diabetes with more confidence and lower your a1c. try it for free at freestylelibre.us ♪ you're the one that i want ♪ nexgard® combo is the only monthly topical that protects against fleas, ticks, tapeworms, and more. use with caution in cats with a history of seizures or neurologic disorders. nexgard combo,... ♪ you're the one that i want ♪ ...the monthly one-and-done you want.

nexium 24hr prevents heartburn acid for twice as long as pepcid. get all-day and all-night heartburn acid prevention with just one pill a day. choose acid prevention. choose nexium. it's started. it's... the side hug. tween milestones like this may start at age 9. hpv vaccination—a type of cancer prevention against certain hpv-related cancers, can start then too. for most, hpv clears on its own. but for others, it can cause certain cancers later in life. you're welcome! now, as the “dad cab”, it's my cue to help protect them. embrace this phase. help protect them in the next. ask their doctor today about hpv vaccination.

the day before emma help pwalker was killed, next. riley gaul's grandfather called police about a handgun he owned. . the esday before emma walke was killed, riley's grandfather called the police about a handgun he owned. >> he files a report that the gun was stolen. >> that missing gun was a problem for riley, too. he lived with his grandpa and the gun was the same caliber as the one used to kill emma. the police did not think that was a coincidence. >> did he express that he knew where the gun was? or did he completely deny? >> he completely denied everything relevant to the gun.

>> reporter: and after his denials to the police, riley reached out to his close friends, alex and noah. since his break up with emma, riley was leaning on them for support. >> what did he day? >> he was torn up, i tried to spend time with him, be there if he needed. >> he would never hurt emma is what he said, had nothing to do with the shooting but he did have his grandpa's gun. >> they will find a way to put this on me if they find the gun. can you guys help me get rid of this? >> the boys were willing to comfort riley but not help get rid of evidence in a murder investigation. instead, they called the lieutenant. >> it is amazing they called. >> absolutely, absolutely. >> they could of went on living their lives, minding their business. >> reporter: riley told his friends he planned to go to the

bluffs, high above the tennessee river ands to the gun into the water. the police hatched a plan. a bold and risky sting operation. have alex and noah go with riley and the moment they see the gun signal to the detectives and they would scoop in. >> it could potentially be dangerous? >> absolutely. two boys in a car with a guy believed to have already killed a person with a murder weapon and this is a huge dangerous thing. >> reporter: dangerous? for sure. and then, the detectives played it more complicated. they decided to secretly record the whole thing. >> theyet up a listening device in the car itself. my car. had a little bit in the cut of my jacket which sucked because i could not take off my jacket the whole time. >> then you got the key fob as well. >> the police could hear you but you could not hear them? >> yeah. >> everything came together with lightning speed.

just hours after calling the police. 18-year-olds alex and noah were wired up. >> what did your parents think about this? you are vulnerable. >> my parents had just moved. to north carolina. i was living in tennessee on my own. i did not . >> you did not tell your parents. >> i didn't. [ laughter ] >> the plan hinged on the boys texting a secret word without tipping off riley. the pressure was intense. >> [beep] >> this is insane. >> riley came over to noah's house. the mission was underway. >> i know that she really loved and cared about me a lot. >> we spent two years another. >> the police were nearby. listening in. as instructed. the boys tried to be natural. >> i am sorry about emma my want to be so upset but i can't because i am more worry about being arrested for a murder

that i never commit >> never in my life would i kill somebody that i love that much. >> love you, bro. it sucks you have to deal with all of this, man. >> riley had no clue about the sting. he had faith in his friends >> i am trusting you guys with my life. there is 70 years in jail if i get convicted of something that i did not do. >> why can't you just give them the gun? >> just, it just needs to be gone for whatever reason it just needs to be gone. >> you don't have to come with me if you don't want to. >> i mean, i got you back >> if it is in the tennessee river they will never find it. >> the boys headed out. >> the first stop, riley's stepfather's house where he hidden the gun. he came out holding a plastic garbage bag. the detectives were still tracking the boys closely or trying to. >> it was kind of a crazy part here. we have detectives watching them, they leave out from the step dads and at some point we

lose them. we lose sight of the vehicle, we lost the wire. >> is that a heart-beating moment. >> . >> yes. we want to track them realtime, keep up with them. >> the police did find them again. in time to see the boys make an odd detour. on the way to the river they stopped for drive-thru fast food. >> yeah, i need a cajun chick wean two sides of hush puppies with chili and cheese on it and a large dr. pepper. >> no. >> oh, my god, try it . >> you are in the middle of the operation you go for chili cheese fries, why? >> the whole time we were saying good-bye to one of my best friends. it was almost like comforting to kind of have it be like it was before. >> they got to the bluffs

around 11:00 and pulled into the complex parking lot. alex knew the security code for the gate. he used to make deliveries there. then, the big moment, alex and noah will never forget it. riley pulled the gun out of the bag. >> oh, my going. >> noah texted the detectives, they were supposed to pounce. but 30 seconds passed and then a minute. no police. alex saw their suvs outside of the gate. what was the delay? two minutes, still, no police. the tension was unbearable. then, alex did something, he took the gun out of riley's hand. >> this is a real gun. >> alex, why did you take the gun from riley? that was kind of a bold move >> it really was. >> i was watching from the backseat. i was like, no >> it was this thing and riley grabs it back out of my hands.

that was scary. >> and that is when the police got through the gate. and made their move. >> what the -- [beep] >> everybody put your hands out of the vehicle now. >> riley was cuffed and taken away the gun was still in the car. >> just pull that back. >> just to see the serial number. >> the mission was a success. alex and noah was safe. riley was charged with the murder of emma walker and taken to jail. it was the end of a long crazy day. a popular football hero was behind bars. how did it all come to this? >> he was controlling and obsessive but you never thought like a murder >> in a case already full of surprises the biggest one was still to come. >> coming up, a sudden change in riley's story. and it is a stunner. >> as crazy as it is and as

bizarre as it is, he was hoping that he could come to her rescue. >> what riley is saying is that i am not a cold blooded killer. >> would the jury believe it? >> count one, charging the defendant with first-degree murder, did the jury reach a verdict? >> when "dateline" continues jua verdict? >> when "dateline" continues

choose advil liqui-gels for faster, stronger and longer-lasting relief than tylenol rapid release gels because advil targets pain at the source of inflammation. so for faster pain relief, advil the pain away. (vo) if you have graves' disease, your eye symptoms could mean something more. because advil targets pain at the source of inflammation. that gritty feeling can't be brushed away. even a little blurry vision can distort things. and something serious may be behind those itchy eyes. up to 50% of people with graves' could develop a different condition called thyroid eye disease, which should be treated by a different doctor. see an expert. find a t-e-d eye specialist at isitted.com dad, i got a huge barbeque wing stain. this bottle says i need to pretreat. that stuff has way more water. a little bit of tide goes a long way, so you can save your shirt and maybe even a little money. nice! more money for nights at the...library. right... for a better clean with less... it's got to be tide.

nothing dims my light like a migraine. with nurtec odt, i found relief. the only migraine medication that helps treat and prevent, all in one. to those with migraine, i see you. for the acute treatment of migraine with or without aura and the preventive treatment of episodic migraine in adults. don't take if allergic to nurtec odt. allergic reactions can occur, even days after using. most common side effects were nausea, indigestion, and stomach pain. it's time we all shine. talk to a healthcare provider about nurtec odt from pfizer. if you spit blood when you brush, it could be the start of a domino effect. new parodontax active gum repair breath freshener. clinically proven to help reverse the four signs of early gum disease. a new toothpaste from parodontax, the gum experts. norman, bad news... i never graduated a from med school.rom what? but the good news is... xfinity mobile just got even better! now, you can automatically connect to wifi speeds up to a gig on the go. plus, buy one unlimited line and get one free for a year.

i gotta get this deal... that's like $20 a month per unlimited line... i don't want to miss that. that's amazing doc. mobile savings are calling. visit xfinitymobile.com to learn more. doc? when others divide. we unite. with real solutions to help our kids. like community schools. neighborhood hubs that provide everything from mental health services to food pantries. academic tutoring to prom dresses. healthcare to after care. community schools can wrap so much around public schools. ...and through meaningful partnerships with families, they become centers of their communities. real solutions for kids and communities at aft.org they become centers of their communities. [dramatic music] andrea canning: almost a year and a half had passed since emma walker was shot and killed through the wall of her bedroom.

. almost 1 1/2 years have passed since emma walker was slot and killed through her bedroom. her expled not guilty to murder. knox county attorney general prepared for a high profile trial >> why do you think this case captured so much a sneens people can relate to a teenage couple in love, people can relate to break ups, and the one thing that really scared people in our community was that emma was asleep in her own home in her own bed. >> was it stressful as the trial approached? >> yes. >> very. >> just the worries. >> reporter: the prosecutors would have to prove to a jury that it was riley who pulled the trigger. >> what was your strategy going into this trial? >> i think the main thing we needed to focus on in the beginning was putting him there that night.

so, i think the cell phone records and the gps locations were very important up until that moment. >> they placed him around emma's house >> he placed himself in maryville and the phone records placed him in knockville. >> he clearly told a lie about where he was when emma was shot. >> yes, yes, yes. >> the picture that we painted was someone who was phony. you could not get the truth out of him if you tried. >> reporter: but, on the first day of trial riley's defense attorney, wesley stone, upended the state's case with an admission. riley was there, did fire the gun but it was not murder. >> that was a fairly stunning claim. from the gallery, veteran crime reporter saw jaws drop. >> what he said was, riley never intended to kill her. and in fact assumed he would

not kill her if he shot through a wall. >> we will ask you to find mr. gaul guilty of reckless homicide >> not premeditated murder >> right. in tennessee that is 2-4 years. >> that would be a huge difference >> yes. >> all of the state's preparation went out the window. >> the case went from a whodunit to a state of mind defense.. >> the defense said riley was not a crazy killer just crazy in love with emma with a bizarre plan to win her back >> when riley gaul fired that shot in the backyard, as crazy as it is, bizarre as it is, he was hoping he could come to her rescue. >> reporter: the defense told the jury that riley only meant to scare emma with the gunshots, then, with emma needing comfort he would swoop in. his attorney argued that riley had no idea the bullets would pass through the house

>> for some of us to know about firearms may know if you shoot into a house that it will go through the wall. some of us may not. and i submit to you, riley gaul did not. >> the defense denied riley was the man in black. but, admitted the kidnapping story was a ruse. it showed how desperate his client was to be with her. >> what riley was trying to do is to get an opportunity to see emma. that is what he was trying to do >> they would be a theme of his defense that rather than killing emma what he intended to do was play her rescuer >> it sounds like he was just trying to scare her when you first heard it. >> i would think the same thing then i looked at the scene and looked at where he would be standing and it is what five feet away from the house the measurements were. and, it is, me pointing a gun right at you right now and

pulling the trigger. it was that close.. >> so close, prosecutors said it was . >> shoot up in the air, shoot anywhere than where you shot. he was desperate to be with emma but that desperation was dangerous. of course he was the man in black. after that and the kidnapping stunt failed they said riley gave up on winning her back. instead, he snuck into her backyard, stood outside of her window firing into the wall knowing exactly where she left on the other side. >> i think this is a case about revenge. i think that he sought to get back at her for the hurt that he perceived that she was purposely putting on him by breaking up with him. >> and after he killed her the prosecutor said he went to

great lengths to cover his tracks. >> and he was going to throw the gun off of bluff? >> yes, sir >> and how riley tried to manipulate his friends >> i am trusting you guys like, with my life. >> his plan was to get away with this. his plan was never to be caught. >> which theory would the jury believe? a reckless act or premeditated murder? they went off to dell iberate and dell . >> went off and came back four hours later. >> we the jury find riley gaul guilty. >> guilty. >> he will number his 70s by the time he is eligible for parole. >> we are very proud of all of the investigators and all of

the work that, we are almost more proud of noah and alex. >> are they the heros in this? >> i think they are, i do. >> lieutenant merit, the walkers, they call you the heros >> we just did what we got to do >> it took a lot of guts to do what you guys did. >> as for emma that used to joke that she was kind of a big deal she has become one with tributes to her all over time. a scholarship in her name and a dog park dedicated to the animal lover. >> a happy place to remember her and for other people to remember her. >> and here at the east tennessee children's hospital, a nicu exam room named her memory. emma's parents believe the best way to honor their daughter is to learn from what happened. detective merit says it is important to understand what teenage drama turns into dangerous behavior. >> we need to educate our young

people better about relationships and what a healthy relationship is and what is psychological abuse healthy relationship is and what is psychological abuse >> that's what we hope someone gets out of this story. >> know what's healthy for you. >>, may be gone but for those who loved her, the young girl still sparkles. >> she would want to be out there. she would want us to be laughing and having fun. you can't cry all day. you still have to live life. >> that's all for this edition of dateline. i am andrea canning. thank you isfor watching. . hello, i'm andrea canning, and this is "dateline."r les in the middle of a hurricane. hello, i am andrea canning, wais dateline.