assassination. >> nick, the marine, a tough vet-turned-target. >> somebody hated nick so much that they shot through his window. >> then came in through the window and shot him some more. >> yes. >> angry colleagues at work. >> people complained of how nick talked to them. >> which was, let's go. >> get the job done. >> and some angry exes too. >> i know he was cheating on me. >> he's dated a number of women. >> maybe he made the wrong one angry? >> that's what we thought. >> bullet casings, carpet fibers, bloody clothes. who was the killer? >> it's somebody full of hatred. >> we wanted answers. >> there needs to be justice. >> people are no good at getting away with murder. ♪♪ >> hello and welcome to "dateline." kristy said she waited 40 years for nick morelos to come into her life. the happy couple were engaged to be married when suddenly her world crumbled. she found nick gunned down in his own home. detectives went through a pool of suspects, from spurned lovers to office enemies before a boost from nick's brother helped reveal the true killer. here is josh mankiewicz with "stone-cold." >> reporter: put people together in a workplace and things can develop. friendships, rivalries, sometimes even love. most of the time it's not a problem. but in this case, it was deadly. >> 911. do you have an emergency? >> he's just laying there, and he has a bullet hole in his head. >> this is a stone-cold assassination. >> it was like our house was turned into a shooting gallery. >> reporter: one man's militant style of doing business that left a trail of bruised egos in his professional life. >> if you're not doing what your job requires, he's going to let you have it. >> reporter: and a trail of broken hearts in his personal life. >> at work i could tell that he was probably a pretty good womanizer. >> reporter: by the end of it, investigators would discover a world of grudges and a hotbed of affairs and messy love triangles. and it all began with this man, nicolas morelos. >> we were constantly teasing and messing with each other. >> reporter: john morelos and his brother nick grew up outside tucson, arizona. what was he like as a little brother? >> a prankster. he was either going to get in trouble or he had already done something that would've gotten him in trouble. >> or he was going to get you in trouble. >> absolutely. >> reporter: just 18 months apart, john and nick were close, partners in crime, brothers who had each other's backs. and just like his brother, nick served in the military. at 18 he enlisted in the marines. in 1990, he fought in operation desert storm. >> he came back a changed person, very motivated, very dedicated. >> maybe he was a little less of a jokester and a little more of a straight arrow? >> very much so. definitely more -- more serious. >> reporter: after the war, nick returned to tucson and settled down. he married and had a son, nicolas jr. and while nick loved being a father, the marriage didn't last. >> it really hurt him for many years. he told me that he would never get married again. >> reporter: actually he did, but that marriage didn't work out either, and nick focused on work. starting as an aircraft mechanic, he quickly rose to director of maintenance at what was then marana aerospace. >> that's the fastest i've seen anybody move up through the ranks. >> reporter: bob welsh was a client who brought aircraft to marana for service. >> he was not a, per se, people person. >> reporter: within the walls of marana aerospace, nick was tougher than an irs audit and every bit as unforgiving. but at the same time, he wasn't devious or sneaky. nick morelos would stab you in the front. >> he didn't know how to approach people and just have a conversation about, hey, maybe you should do it this way rather than this way. >> it was, you're doing it wrong. start doing it right. >> and if you don't do it this way, go home. >> reporter: john, a lieutenant colonel in the army, worked at the same air park as nick. what would people say about him? >> he was -- he was tough. he was, excuse the language, a hard ass. very vocal, intimidating to some. >> reporter: there was one area where nick seemed quite popular -- with women. and conveniently marana aerospace employed some. do you have any idea how many women at marana he dated, how many of his co-workers? >> he only admitted to me two. there was a lot of rumors, but he told me of two. >> reporter: and one of them changed everything. in 2016, nick met kristy. >> i liked that he was such a hard worker, and he was so smart. >> reporter: no immediate fireworks, but as kristy and nick got to know each other, they realized they both loved books, dogs, and plants. >> he was the tough guy at work, and here he is, you know, tending to these delicate plants and talked about how much he loved his dog. >> reporter: his dog smokey, an american pit bull terrier. >> to look at smokey, you would think, oh, my goodness, there's this big, scary dog. and this is the most gentle dog you'll ever know in your life. >> reporter: kristy fell not just for smokey but for nick too, and hard. you sound kind of swept off your feet. >> i was. absolutely. never -- never knew a man like that in my life. he was -- he was my superman. he was always my protector. >> you could see it in his eyes. he was happy. his heart was full. he spoke to my parents about things that we'd never thought he'd talk about. >> like what? >> a marriage. >> serial monogamist. >> yes. >> finally settling down. >> yes. >> reporter: before that, nick and kristy came to an agreement, that the past was the past. he dated a lot of women in that same company, some of your co-workers. that give you any pause at all? >> oh, absolutely. you know, my outlook was, look, we both have a history, you know. you're single. he's allowed to date who he wanted to. >> reporter: nick and kristy got engaged. by july 2016, they were making plans to move in together. >> he just looks right at me, and he just said, i just want you to know how much i love you and appreciate everything you do for me. i just remember walking in the kitchen and thinking, god, i am so lucky. i am so lucky. >> reporter: 24 hours after that moment came this call. >> my fiance, i think he's been killed. i think he's been shot. >> coming up, what had happened to nick? >> i zeroed in on him, and he was just laying there. >> curious clues in the garage. >> immediately i noticed a bucket full of water and some carpet fibers. >> and blood in the bedroom. >> the floor was very sticky, and it smelled very heavily of mouthwash. we felt that whoever did this tried to clean up whatever tracks they left. >> this is the man i'm supposed to marry. this was just not -- not possible. >> when "dateline" continues. there's an invisible threat in your backyard that could cause deadly heartworm disease for your dog. but not if you protect him every month with heartgard plus, the #1 choice of dogs. digestive and neurological side effects have rarely been reported. ask your vet for heartgard plus. i'll be observing your safe-driving abilities. play your cards right, and you could be in for a tasty discount. 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[ tires screech ] well, that came out of nowhere. what is humana doing sending me a diy test kit? old health insurance reminds you to schedule a screening, say, for colon cancer. humana does you one better and sends you an at-home test kit, when it's overdue. huh! one of those tests could save your life, or at least a little hassle. or both. yeah! you get it, you do it, you send it back. i get it, i do it, i send it back. you get it, you do it, you send it back. yeah, i got it. you got it! ♪ ♪ humana. a more human way to healthcare. i just felt like i can't believe i get to be his bride. i was just -- i was excited. i waited 40 years for him. >> reporter: kristy and nick were engaged to be married. >> every morning started with either a text or a call. good morning, i love you. have a great day. every night, same thing. >> reporter: so when kristy awoke monday, july 18th, 2016, and saw that nick, an early riser, had not called, she was immediately concerned. >> of course i'm rationalizing. oh, maybe he got stuck on a call with his boss, or maybe he slept in a little bit, you know. >> reporter: a few hours later, still no word from nick. so kristy drove to nick's house and went up the stairs to the master bedroom. the door was barely open. >> i zeroed in on him. he was just laying there, and he was just -- just full of bullet holes. >> he's just laying there, and he looks like he has a bullet hole in his head. >> this is the man i'm supposed to marry. this was just not -- not possible. and the police arrived, and the nightmare began. >> we received a message advising that there was a homicide on the north side and that the whole unit needed to respond. >> reporter: pima county sheriff's detective jennifer garcia had been in the homicide unit for all of seven months. this was a call she'd prepared for ever since she was a little girl and saw her grandfather in uniform. >> it was just something that i've always wanted to do, you know, sort of my dream job. >> reporter: and now here she was, lead detective in the biggest murder investigation in tucson. she began by methodically walking through the scene, nick's house, starting in the garage. >> immediately i noticed a bucket full of water and some carpet fibers, which at the time i thought was odd. >> reporter: inside the cabinet under the kitchen sink was open. in the living room, cleaning products left out. and in the backyard was a large pit bull. presumably whoever lived there had let the dog out? >> possibly, yes. >> or the killer had. >> yes. >> reporter: as detective garcia went up the stairs, she saw bullet holes in the wall. at the top, the master bedroom door was ajar. >> i immediately saw a bloody foot of nick morelos. i opened the door and saw his naked body laying there riddled with bullets. >> reporter: a lot of people will tell you that when their time comes, they want to die at home. very few will say they want to go the way nick morelos did, in his bedroom, alone with his killer, in a hail of bullets. nick had been shot eight times, including once in the middle of his forehead. >> they shot through his window and assassinated him. >> then came in through the window and shot him some more? >> yes, until he was finally dead. >> reporter: detective garcia believed the killer climbed onto the roof outside nick's bedroom. that's where she found blood on broken panes of glass and on the stucco. so maybe the killer cut him or herself coming in through that window? >> yes. >> reporter: there was blood throughout nick's bedroom, in his closet, and on a mouthwash cap in his bathroom. >> the floor was very sticky, and it smelled very heavily of mouthwash. so we felt at the time that whoever did this tried to clean up whatever tracks they left. >> reporter: in the bedroom, more evidence the killer tried to clean up. >> it appeared that the rug under the bed was cut. like half of the rug was gone. >> reporter: detective garcia believed the killer bled so heavily on the rug that he or she cut the rug and took it right out of nick's house. there was also evidence the killer failed to get rid of. garcia's team recovered 11 shell casings, each with a unique five-star stamp. and this was odd. 11 shots, yet none of the neighbors called 911. >> very early on, the detectives that i was working with, who have done previous homicides, they believe that a silencer was used. >> reporter: one neighbor said she heard a noise around 4:00 a.m. but wasn't sure what it was. investigators thought that could well be nick's time of death. while detective garcia worked the scene, two other detectives went to john morelos' office to tell him what had happened. then john had to break the news to his mother. a tough conversation to have. >> oh, most definitely. that was probably one of the toughest things i've ever done in my life. >> reporter: kristy also wrestled with her new reality, a life without nick. >> i went from this amazing life to just, you know, being traumatized and just complete disbelief. >> reporter: while nick's family faced the loss of a man they loved, investigators began to learn what nick's co-workers and exes already knew. he was not beloved by everyone, not by a long shot. >> coming up, angry colleagues on the job. >> people complained of how nick talked to them. >> except the way nick talked to them was kind of what nick was being paid for. >> correct. >> which was, let's go. >> were any angry enough to kill? >> feels to me like maybe there are a lot of people you might want to be talking to at the office. >> yes. the list was very long. >> when "dateline" continues. s l natural fragrances, inspiring air wick to create our new spring collection. so we're partnering with world wildlife fund to reseed native wildflowers and grasslands. learn more at airwick.us (man) i'm a verizon engineer, part of the team that built 5g right, the only one from america's most reliable network. we designed our 5g to make the things you do every day better. with 5g nationwide, millions of people can now work, listen, and stream in verizon 5g quality. and in parts of many cities where people can use massive capacity, we have ultra wideband, the fastest 5g in the world. this is the 5g that's built for you. this is 5g built right. only from verizon. 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(deborah) when i finally had miracle-ear and i could hear for the first time, i started crying. i could hear everything. new miracle-earmini. so small and comfortable that no one will see them, but you'll notice the difference. call today to start your 30-day risk-free trial at your local miracle-ear. ♪♪ >> reporter: often at "dateline" we tell you the stories of murder victims who lit up the room or who didn't have an enemy in the world. well, not so much with nick morelos. he definitely knew how to light up a room, but depending on which room it was, there might have been people in it who actively wished him ill. that was true in his personal life, and it was true here at work. the question for investigators, which side of nick's life had caught up with him? detective garcia quickly began to find out how much nick's leatherneck exterior had rubbed people the wrong way. jeff johnson was h.r. director at marana aerospace. >> i did have some exit interviews that people complained of how nick talked to them. >> except the way nick talked to them was kind of what nick was being paid for. >> correct. >> which was, let's go. >> get the job done and get it done on time and on budget. >> he was brought in to sort of be the hammer. >> exactly right. >> reporter: but when you're hired to be a hammer, sometimes everything and everyone starts looking like a nail. feels to me like maybe there are a lot of people you might want to be talking to at the office. >> yes. the list was very long. >> reporter: a lot of them had petty grievances, like a safety inspector named james lapan. >> it's just we never got along is the thing. >> reporter: lapan told investigators nick had given him a hard time for parking his car in a restricted area and had accused him of using a personal tablet computer during working hours. >> anybody you know that wants to kick his ass? >> kick his ass? no. >> reporter: maybe not over a parking spot, but then detective garcia started learning for herself about the other part of nick's life. this was a guy who made a lot of women angry. >> yes. >> reporter: his second ex-wife once threatened to kill him. an ex-girlfriend slipped into his house, and nick woke up to find her watching him and a new girlfriend while they slept. and then there were nick's romantic entanglements at work. >> we did not have a fraternization policy. >> and nick, i think, took advantage of that. >> i think so, from what i heard. anytime i questioned nick on it, he would deny it to me, for good reason, i'm sure. >> because you were the h.r. director, i'm thinking that might be the reason. >> correct. >> reporter: long before nick met kristy, he was involved in a relationship that now caught detective garcia's attention. >> he was a really, really, really hard worker. >> reporter: claudia banks worked in administration at marana aerospace. she and nick dated for six months. >> he was awesome. he really was. >> reporter: claudia told detective garcia she'd had a good relationship with nick. however, that came at the expense of someone else, her ex-boyfriend, justin skinner. claudia moved in with nick and broke up with justin almost in the same breath. >> yes, that's right. >> reporter: claudia told detective garcia she tried to cut off all contact with justin. >> and shortly after the breakup, it was reported that he had followed claudia while she was driving her vehicle, and nick was in the vehicle. >> reporter: claudia also said justin unexpectedly came by her home a couple of times. then the day nick's body was discovered, claudia said she went out with her mom. >> me and her went to circle s. >> reporter: the circle s saloon, the proverbial bar on the outskirts of town, where she saw justin. >> did he have any marks on him at all? >> i saw him and pretty much walked -- just walked right by. >> reporter: the next day claudia said justin left a note on her front gate about her ex-boyfriend, nick. >> saying, hey, i heard what happened, and i'm really sorry. if you need anything, let me know. >> reporter: and claudia directed detective garcia's attention to yet another ex-girlfriend from nick's past. >> before me, he was dating a girl, um, jessica. i don't know if you've spoken to her yet. >> reporter: jessica stillwell, another of nick's girlfriends from marana aerospace. she and nick dated for about six months, even lived together for a while. >> she seemed nice. never saw them argue. they always seemed happy and giggling together. >> reporter: detective garcia learned that didn't last. nick abruptly kicked jessica out of his house and his life and moved claudia into both. and then garcia heard about something that happened shortly after claudia and nick started dating. >> claudia was at his house, and jessica showed up, seeing her vehicle in the driveway area and was very upset, banging on the door, saying, i know she's in there. let me in. >> reporter: nick had told his brother, john, about the dustup with jessica. and he thought that was, what, amusing, alarming? >> he's like, man, it's going to be drama. i can already tell. >> reporter: and then a day after nick's murder, john's kids snapped these pictures of a woman poking around nick's house. >> my children were adamant that it was jessica. >> does it seem at all significant to you that nick was murdered like almost exactly a year from the time of his breakup with jessica. >> i found it very odd. >> or very coincidental. >> correct. >> reporter: the number of scorned lovers in nick's past was enough to warrant a scorecard, and investigators weren't even done counting. there were more answers to be discovered in the place where so much of nick's social life was centered, marana aerospace. >> that mystery woman at nick's house, was it an angry ex? coming up -- >> some of the family identifies you as being the one that was at the house. >> it wasn't me. >> a lover's triangle and a tightening circle of suspects when "dateline" continues. these are real people, not actors, who've got their eczema under control. with less eczema, you can show more skin. so roll up those sleeves. and help heal your skin from within with dupixent. dupixent is the first treatment of its kind that continuously treats moderate-to-severe eczema, or atopic dermatitis, even between flare ups. dupixent is a biologic, and not a cream or steroid. many people taking dupixent saw clear or almost clear skin, and, had significantly less itch. don't use if you're allergic to dupixent. serious allergic reactions can occur, including anaphylaxis, which is severe. tell your doctor about new or worsening eye problems, such as eye pain or vision changes, or a parasitic infection. if you take asthma medicines, don't change or stop them without talking to your doctor. so help heal your skin from within, and talk to your eczema specialist about dupixent. if your financial situation has changed, we may be able to help. hey shaq. oh what up fellas? 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>> no, and nick was my protector above all else. so i don't know that he would have said anything to me, not wanting to worry me. >> reporter: but perhaps there had been reason to be worried. detective garcia now spent some time charting the romantic geometry of nick's love life pre-kristy. >> it all comes back to their employment. they all worked at the same place, marana aerospace. nick had been dating jessica, very quickly began to date claudia. >> reporter: bob welsh, nick's friend and a client of marana aerospace, remembers how jessica reacted to the breakup. >> whenever nick was in the same room, there was no smiles out of her. i could tell it was not a -- not a good atmosphere between the two. >> nick ever say why they broke up? >> no. no, and i -- it's none of my business. >> reporter: it was detective garcia's business. she eventually interviewed jessica on tape. >> i know he was cheating on me with claudia. when he got caught with her, um, and then he kicked me out and then moved her in. >> that's the kind of speed that's going to make people feel bruised and angry. >> yes. >> and maybe vengeful? >> yes. >> he kept denying it. so i drove by his house, and i took a picture of her truck parked outside and confronted him with it. >> reporter: was the morelos family right? was she the woman they saw poking around nick's house just after the murder? >> some of the family identifies you as being the one that was at the house. >> it wasn't me. >> why are they saying it was you? >> i have no idea. i haven't been to his house in almost a year. >> reporter: it turned out she was telling the truth. detective garcia ran the mystery woman's license plate and found it belonged to a mother who was looking for her missing son, not jessica. >> do you think that this should have happened to nick? >> no, this shouldn't happen to anybody. nobody deserves that. >> reporter: jessica told detectives she was home with her young daughter at the time nick was killed, which was not exactly an airtight alibi. detectives also needed to speak with the other scorned lover in this story, claudia's ex-boyfriend, justin skinner. in the nick/jessica/claudia triangle, he was the square who didn't fit. >> so you were in a relationship with claudia? when was that? >> she left almost on the day a year ago. >> reporter: detective garcia and her colleagues spoke with justin at his home. justin told them he loved claudia, had plans to marry her, and then she ended things. >> i never really expected it to go as south as it did, so i was -- i was really -- you know, i was really hurt by it. >> he's certainly showing all the earmarks of somebody that you might want to be wary of. >> yes. >> reporter: justin's alibi the night nick was killed? the circle s saloon, the same bar where claudia saw him the night after nick was murdered. >> i got to circle s at 6:00, and then at midnight i ended up leaving. >> when you left, where did you go? >> home. >> reporter: video from the circle s confirmed justin's presence until midnight. however, his story that he'd then gone home was somewhat harder to prove. >> his roommate stated that he wasn't quite sure if he was actually in his room or not. >> reporter: and then there was this. >> i'm seeing a few scratches on your arm. how did those happen? >> landscaping. >> reporter: when she asked to photograph those scratches and take a dna sample, justin said no. that had to make you sit up a little straighter. >> yes. >> coming up -- >> your loved one had just been murdered. we wanted answers, and we just weren't getting them, not quickly enough for us anyways. >> nick's brother is about to turn detective. could he give the true detectives the lead they need? >> he said, johnny, you're not going to believe this. i just dealt with that guy a few months ago. >> when "dateline" continues. you said you'd never get a dog. you said you'd never do a lot of things. but you never knew all the things a dog could do for you. and with resolve you never have to worry about the mess. love the love, resolve the mess. for skin that never holds you back don't settle for silver #1 for diabetic dry skin* #1 for psoriasis symptom relief* and #1 for eczema symptom relief* gold bond champion your skin pima county sheriff's detective jennifer garcia was suspicious of nick's ex's ex, justin skinner. he seemed to have both opportunity and motive to kill nick. so when justin didn't want to give a dna sample -- >> i thought that he -- he might be the guy. >> reporter: but then after a little persuasion -- >> yeah, that's fine. collect dna. let's do it. >> reporter: his cooperation plus statements from people at the bar and claudia were enough for detective garcia. >> we were able to rule him out pretty quickly as a suspect. >> reporter: the morelos family was waiting impatiently for an arrest. >> your loved one had just been murdered. we wanted answers, and we just weren't getting them, not quickly for us anyways. >> reporter: too small tucson is how some refer to this city. it's a place where everyone seems to know everyone else. while detectives were examining nick's romantic past, brother john started doing a little detective work of his own, by talking with nick's co-workers. he told h.r. director jeff johnson how the suspect had apparently been cut while going through nick's window. >> jeff johnson called me and said, hey, you're not going to believe it, but this guy that i've had concerns about and who had filed a grievance against nick has bandages on his left arm. >> what's his name? >> james lapan. >> reporter: james lapan, one of nick's co-workers police had already spoken with. >> it's just we don't -- we never got along. >> reporter: jeff johnson said just 11 days before the murder, lapan had come to him with a complaint about nick and with it, a warning. >> he said that if i don't handle it, he has his own way of handling things and just bolted right out of my office. >> you knew the name james lapan. >> i did. >> nick had talked about him as somebody he'd had problems with. >> yes. >> but not being afraid of. >> no. >> reporter: detective garcia now interviewed lapan again at marana aerospace. he told her he spent the sunday before the murder with his family and said he and his wife went to bed around 9:00 and got up around 5:00 a.m., which would have been an hour after nick's murder. >> if i contact your wife, she's going to tell me this is where you were on sunday? >> i would hope so. >> okay. >> he pretty much answered all the questions that we had. the interview ends. >> reporter: but then maybe two minutes later, there was a knock on her door. >> and it's james. he came back, and he tells us, i basically need to tell you the truth. >> reporter: the truth? like a confession? well, yes, but not to murder. james lapan owned up to slipping. >> what was the part you were not forthcoming? >> jessica and i have slipped. >> reporter: slipped, as is had an affair with number's ex-girlfriend, jessica stillwell. >> she broke it off pretty quickly because she did not want to be the other person, and he didn't want to leave his family. >> reporter: now detective garcia had someone new she wanted to talk with, james lapan's wife, serena. >> i know he's been, um -- fell off the marital bandwagon, so to speak. >> reporter: serena said james had told her about the affair weeks earlier. they were going through counseling, she said, and working on the marriage. and when detective garcia asked her about the night of nick's murder -- >> her statement was exactly the same as james'. >> they hung out together during the day. they went to bed together. they woke up together. >> yes. >> so she alibis him. >> yes. >> you wouldn't try to be covering up for him for anything? >> no. >> okay. >> reporter: if serena was telling the truth, james could not be the killer. as detective garcia pondered that, nick's brother john kept up his own investigation. he mentioned lapan's name to a childhood friend. remember how tucson can be a big small town? >> he said, johnny, you're not going to believe this. i just dealt with that guy a few months ago. >> reporter: john's friend owned a machine and fabrication shop. he said james lapan had come in looking for a tool, one he could use to fix a silencer. he's repairing a silencer. >> correct. >> just a couple of months before your brother's murdered with perhaps a silencer. >> correct. so i contact the detectives, gave them the information. >> reporter: detective garcia obtained a search warrant for james lapan's home. in his garage, her team found 18 boxes of .45 caliber ammo, all with the distinctive five-star stamp. they also found two spent shell casings that matched the ones found at nick's house. so the same gun fired the bullets at the crime scene and a couple of casings that you found in lapan's garage? >> yes. >> reporter: inside the house, investigators didn't find the gun itself, but they did find this empty box for a para-ordnance black ops combat .45, which they believed was the murder weapon. the search warrant also turned up an empty box for a silencer that would fit on that gun. what's more, investigators found carpet fibers in the back of the lapan family vehicle that matched both fibers found in nick's garage and the cut-up rug in nick's bedroom. and there was this. >> in the master bedroom closet on a very, very top shelf, detectives noticed a pair of work pants that looked like they had blood on them. >> reporter: that same day, james lapan was arrested while carpooling to work. in the driver's seat was, of all people, jessica stillwell. she said she was giving him a ride. four days after nick's murder, newly minted homicide detective jennifer garcia, had made an arrest. how did that feel? >> pretty good. pretty good that i had gotten the right person for this crime. >> reporter: maybe. but this case still had to go to trial, and james lapan still had an alibi, that is, until a lifetime movie changed everything. >> coming up -- >> she calls and says, i've got a new story to tell. >> a lie told in fear. >> you didn't want to tell that lie, did you? >> no, i did not want to tell that lie. >> but you did? >> out of fear, yes. >> and the courage to reveal the truth. >> i actually slept all night without nightmares. >> when "dateline" continues. i'm a performer. always have been. and always will be. never letting anything get in my way. not the doubts, distractions, or voice in my head. and certainly not arthritis. voltaren provides powerful arthritis pain relief to help me keep moving. and it can help you too. feel the joy of movement with voltaren. dad! no shoes in the house. our son says, since tide antibacterial fabric spray kills 99.9% of bacteria. just to be sure. he wants us to spray everything every time we walk into the door. it's just to be sure. just to be sure! i thought you just sprayed those. ma, it's just to be sure. see, he takes after my side of the family. for every just to be sure, it's got to be tide antibacterial fabric spray. sure, your health insurance tells you to see a doctor but, um, look around. these days it's not that easy. you're telling me. but humana helps make it easy. human care gives you tons of ways to talk to your doctor: phone, computer, in person, or tablet. hey jean! hi! this is just a quick follow up. your numbers are looking great. you don't even have to put on shoes. ooo! easy peasy. you like that, huh? mhm. humana. a more human way to healthcare. welcome back. james lapan was under arrest for the murder of nick morelos. a search of his property revealed a mountain of evidence, including bloody pants and rug fibers matching nick's carpet. but james did have an alibi. his wife serena said he was with her the night of the murder. could a tv movie get serena to flip her script? the real story was about to be revealed. here's josh mankiewicz with the conclusion of "stone-cold." >> i assumed he was a marine because he carried himself with such confidence and attitude. >> serena met her future husband james lapan at a weekly dance class. >> every single time i came in, he'd come sliding up again, and he's like, so, when do i get to throw my name in the hat? and i'm like, maybe never, you know? there's the door. go away. >> but he wouldn't go away? >> no. >> reporter: serena, a sergeant first class in the army and a self-described alpha female, was happy to have met a man who wasn't a pushover. >> with james and his strong personality and my strong personality, we were on the same page, and we got -- things were going amazing. >> reporter: in 2010 at james' request, they entered into a covenant marriage. what's a covenant marriage? >> covenant marriage is recognized before god and state, and quite frankly it's a lot harder to get divorced. >> reporter: less than a year into their marriage, james' father died, and serena says something in her husband changed. he became, she said, controlling and frightening. serena recalled a disagreement in which she wanted to step away from him to check on their children. >> he was physically holding onto my biceps at that point in time. he was just like, we're going to finish this discussion. immediately following that, he said, the children are replaceable. we can make more. i'm not. and at that, i'm like, oh, you're replaceable, but not like i -- it's not like i can say it, you know, because at that point -- >> and if you had said it, what would have happened? >> i don't want to know. so i don't know want to know what would have happened. so then it became an issue of pick your battle. and the battle i picked was protect the children. >> reporter: which is why, she says, she turned a blind eye to her husband's affair with jessica, even when james invited jessica home for dinner. what kind of hostess did your husband expect you to be for jessica? >> the same hostess as anybody else. if they're invited over to dinner, i'm going to be cook -- i'm going to be the one cleaning up the kitchen. >> for your husband's mistress? >> yep. >> you get some sense that james enjoyed humiliating you like that? >> absolutely. i think it was a power thing. >> serena cooked dinner for her husband and his lover and listened to james and jessica talk about nick morelos. >> it was all demeaning and hateful stuff. james used to pick on her and poke at her about why don't you go back to your -- go back to nick? you guys were such a couple and a thing. go back to nick. >> so there was some jealousy there? >> definitely. >> now james lapan's only possible hope at trial was serena and her statement to police that her husband was asleep next to her when nick was killed. >> you wouldn't try to be covering up for him for anything? >> no. >> but now a little bit of drama was about to spawn a lot more. in december 2017, as james lapan sat in a pima county jail cell, his wife of seven years sat in a hotel room during a work trip, watching a lifetime movie about an abusive, controlling husband. >> seeing that made me fully realize the fact that it's a pattern that's going to continue to get worse. and if he had not been arrested, this would probably be a direction in which my life would be going. >> it took months, but eventually, serena found the courage to pick up the phone. >> she calls and says, i've got a new story to tell. >> pima county chief trial counsel jonathan mosier. >> we bring her in for an interview with recorders running. >> when you talked to police previously -- >> i lied. >> okay. what did you lie about? >> the fact that he had left the house because he did. >> serena told prosecutors what really happened the night nick morelos was killed. she said she and james went to bed about 9:00. >> and then he got up, and he had left the house. >> and later that night, serena said she rolled over and saw james in bed. then when she woke up in the morning, he was gone again. >> while i was in the shower, he had come in. and when he had come in, his arm was bloody, and he just looked at me, and he said, i was home all night. we worked out this morning. >> he didn't tell you why he needed that alibi? >> no. >> and when james ordered her to lie to investigators -- >> you didn't want to tell that lie, did you? >> no, i did not want to tell that lie. >> but you did? >> out of fear, yes. >> until that movie made her want to tell the truth. how did that feel? >> for the first time in a long time, i actually slept all night without nightmares. so it was terrifying and relieving at the same time. >> after james was arrested for nick's murder, the case against him only got stronger. his dna was found all over nick's bedroom, and nick's blood was on the pants recovered at the lapan home. with the overwhelming dna evidence plus serena's testimony and the firearms analysis evidence, jurors didn't need much time to reach a verdict. >> we, the jury, do find the defendant james lapan guilty of the offense first-degree murder. >> you're not required to offer a motive, but what do you think the motive was here? >> obsession and hatred. that's all tied up around nick and jessica. >> jessica stillwell, james lapan's mistress and nick's former girlfriend. prosecutor mosier called her as a witness, but his interest in her was not so much about what she said as what she might have done. >> i can't prove that she had involvement, but i can't rule it out either. we have these texts from the evening of the murder that are really pretty disturbing. >> at 6:36 p.m., james lapan sent this text to jessica. "pitbull." to which jessica replied, his dog. his name is smokey. and then james instructed jessica to delete all their texts. >> why are you talking about nick's pit bull the night he's murdered? >> jessica testified she and james had talked about her getting a dog like smokey for her daughter. that said, investigators still wonder if jessica was feeding james information about nick. remember, after the murder, smokey was found in the backyard. did james put him there, and was he able to pacify the dog based on help jessica provided? we wanted to ask jessica about all of that. she declined to be interviewed. if she committed a murder or played a part in committing a murder, she's getting away with it. >> we cannot find any evidence. >> or -- >> yeah. >> -- she's not guilty? >> correct. >> as for serena and james and their covenant marriage, it's over now. they divorced in 2019. but serena still worries about what effect james might still have on her and her children's lives. you ever going to be free of this guy? >> when god hits his off switch. >> james lapan will most likely be in prison when that happens. he was sentenced to life. kristy, who says she waited 40 years to meet nick, now faces the rest of her life without him. >> he'll always be my superman. i'll always love him. that will -- that doesn't change. >> and even in the midst of mourning his brother, john morelos takes some comfort in how he helped solve nick's murder. you've still got his back, don't you? >> absolutely. >> i guess that never ends. >> no. >> that's all for this edition of "dateline." i'm natalie morales. thank you for watching. breaking news right now on msnbc. on the way, those $1,400 stimulus checks now making their way into americans' bank accounts. some could see deposits as soon as today. president biden taking his victory lap while setting a new timeline for vaccines. mounting pressure. new york's two senators now the latest to call for governor andrew cuomo's resignation, adding to a growing tide of fellow democrats urging him to step down. but he remains defiant. >> let the review proceed. i'm not going to resign. i was not elected