her life was just beginning. no one deserves this. >> reporter: posters, searches, heartache. >> she had a heart of gold. she was there for everybody! >> reporter: her name was carrie. and one monday morning, she went >> i saw the tattoo. cephaland . >> someone is in her car. someone is at her bank. but most jaw dropping of all, someone is up on stage with a song turned sinister. >> i couldn't believe what i was hearing. >> my hard was pounding. we need to figure this out fast. >> here is andrea with without a trace. >> a sad fact of life, gone

where was carrie? facebook. >> a frustrating search for carrie. overwhelming. maybe signs of trouble. >> stomping out. carrie was upset. so how ya doing? enough pressure in here for ya? ugh. my sinuses are killing me. yeah...just wait 'til we hit ten thousand feet. i'm gonna take mucinex sinus-max. too late, we're about to take off. these dissolve fast. they're new liquid gels. and you're coming with me... wait, what?! you realize i have gold status? do i still get the miles? new mucinex sinus-max liquid gels. dissolves fast to unleash max strength medicine. start the relief. ditch the misery.

recently we've noticed some ads created by these two birds, inviting you to stay away from the streak free shine of windex. well dear windex users these ads are false. sfx: squeaks from window cleaning clean glass is better than dirty glass. don't stand for dirty. use windex. there's moving... and there's moving with move free ultra. it has triple-action support for your joints, cartilage and bones. and unlike the big osteo-bi flex pills, it's all in one tiny pill. move free ultra. get your move on. we were below the 88th southern parallel. we had traveled

my men driven nearly mad from starvation and frostbite. today we make history. >>bienvenidos! welcome to the south pole! if you're dora the explorer, you explore. it's what you do. >>what took you so long? if you want to save fifteen percent or more on car insurance, you switch to geico. it's what you do. >>you did it, yay! are you tired of hazardous glass made so clear by sfx: slide show windex that you don't even know it's there? sfx: slide show smudge it! with the new smudge stick even clear glass gets visibly smudged in a snap. sfx: smudge sounds against glass

music throughout unlike ordinary diapers, pampers to stay up to so your baby can sleep wishing you love, sleep and play.

grief can sneak in like a thief and steal your joy. >> that's what seemed to happen when carrie olson disappeared. grief gripped an entire community and didn't let go. >> everybody knew about it. it was the talk of the town. >> dennis harper is the founder of the quadcities missing person's network. >> whenever there was anything newsworthy, it was posted. it was in the news. it was on facebook. >> reporter: carrie's best friend amanda was a big part of that. >> on new year's day i did create a find carrie olson facebook page. and people were sharing it left and right. so her story was getting out. i even contacted dateline and >> reporter: when we posted carrie's story as part of dateline's online missing in america series, it reached 1.9 million people, and was shared 42,000 times. did you feel like that was something that could help? just getting it out on a national level? >> think it helped out a lot. >> reporter: thousands started to follow amanda's page. carrie's story united the quad

cities in a remarkable way. everyone wanted to help and everyone was hoping for a break in the case. but they were also on edge. did you just start to have worse and worse thoughts as you waited? >> i did. >> reporter: what are you told about what's going on with carrie? >> that she did not show up for work. the family was concerned. >> reporter: the family was so concerned they called the police. the case went to detectives rick voy and bill thomas of the davenport police department. they say carrie's live-in boyfriend justin told them he had no idea where she was. >> justin didn't have any answers. >> reporter: justin said he and carrie had a fight, she stormed out of the house and he hadn't seen her in two days. >> carrie was upset. >> what did she say to him? >> said somethin' to him about bein' stupid >> reporter: carrie's ex, tim mcvay, was in las vegas on vacation when he was told she was missing. he and carrie were still close friends and said he wanted to help and had an idea.

he talked to carrie's father >> tim told him, hey, she could be at my place. go over and look. there's a window open. you can crawl into the window >> dave went over there and >> yes. >> reporter: did he see anything? >> nope. >> reporter: no carrie at tim's. no carrie anywhere. and one thing left behind at her house was a sure sign something was terribly wrong, her beloved dog kolby. >> her everything was kolby. just like a little kid. and if she did go somewhere kolby was either with her, or she would make arrangements for kolby. there was -- she would never just leave. >> reporter: kolby being at home without carrie led detectives voy and thomas to a grim possibility. >> as detectives, do you have to consider that someone might have taken their own life? >> in a missing person's investigation, that's always a possibility. >> reporter: amanda gave that theory some weight.

she said there was a sadness behind carrie's bubbly personality. >> i started thinking that maybe she committed suicide somewhere. >> did you think that carrie was capable of taking her own life? >> well, she seemed depressed at times. >> reporter: still, detectives needed to know more. they executed two search warrants, the first at the house carrie shared with her boyfried justin. >> the search warrant that we prepared for carrie's house included everything that justin owned and justin's vehicle. >> reporter: justin's truck was checked and photographed. and a sweep was made of the house. it was tidy. undisturbed. didn't look like a crime scene. another search was done at ex-boyfriend tim mcvay's house. >> we wanted to get into his residence and see was she there, was she not there. were there any clues that we needed to go on. >> reporter: detective tina noe executed the search on tim's home. >> we took lots of photographs. 'cause you never know what's gonna be important possibly later on. >> reporter: tim was in the

the house was a mess. random things were strewn everywhere; clothes, construction materials, rolls of carpeting. but nothing looked like a good lead. carrie's family was growing increasingly desperate. they wanted to do something. anything. when they reached out to dennis harker of the quad cities missing person's network. sadly, he knew just what to do. >> it's traumatic. i mean, it's just a crisis. and and it's overwhelming. >> reporter: his own son went missing just a few months earlier. >> you find yourself being tireless. you know, you can't sleep anyway, you might as well be doing something. >> reporter: dennis offered suggestions and organization to public. it was a remarkable effort. a reward was offered. a prayer vigil became a moment of peace, and faith. and, of course, there were endless searches. mississippi river, where his son's body had been found. >> the mississippi tends to collect a lot of people that go

missing. >> reporter: amanda was with dennis for one of his river searches. >> maybe she had drowned or been dumped in the river. so we started looking along the river. and i was lifting up everything and looking for her. >> i had to do something for her. because she would have done it for me. >> sarah paxton was searching, too. she remembers the frustration of trudging through a huge park covered with a fresh blanket of snow. >> every search, i felt smaller and smaller. and the world felt bigger and bigger. she was one of my closest friends. i loved her dearly. it just felt like a needle in a haystack. >> her friends and family would not stop looking or hoping. dozens of tips came in from strangers, well wishers, even psychics. it would be something much closer to home that would

finally lead to the first clue about what really happened. >> coming up -- >> had you ever heard anything about justin stalking carrie? >> she told me he would drive by her house. >> new questions about carrie's new boyfriend.

getting ready to end the >> reporter: the people of the quad cities were desperately searching for carrie olson. and law enforcement on both sides of the mississippi were doing their best pushing the investigation as hard as they could. for detective tina noe, solving the case became a mission. >> reporter: finding someone quickly is very important. >> it is very important. and it was bothering me. where is she? what could've happened to her? we need to find answers. >> in murder investigations, eight out of ten suspects and victim know each other. >> reporter: and that meant taking a harder look at carrie's boyfriend, justin mueller. detectives started by talking to carrie's family about him. >> we rely heavily on the information that families give us early on in an investigation. >> reporter: but carrie didn't

share details of her love life with her family. they didn't even know justin had moved in with her. it turns out the person carrie did confide in was her ex-boyfriend, tim mcvay. >> to me, it appeared that they were best buds. they talked daily. sometimes they would talk over 20 times a day via text. the main way of communicating was text messaging. >> reporter: tim drove straight to police headquarters when he flew back from las vegas, saying he wanted to help. >> i want to talk to you about carrie. >> absolutely. >> you know, that's why you're down here, right? >> anything you want to know. i don't know where she is. i don't know what she's doing. i very much want to know because i am concerned. >> reporter: it turned out tim also had a lot of concerns about justin, which he shared with the detectives. he said the problems started even before justin moved in to carrie's house. >> she called me out of the blue one afternoon freaking out because this guy justin that she

stalking her. >> reporter: it was something best friend amanda also worried about when carrie went missing. >> reporter: who did you think would wanna hurt her? >> i immediately thought justin. >> reporter: had you ever heard anything about justin stalking carrie? >> she had told me that he would drive by her house before he ended up moving in. he wanted to be with her so bad. >> reporter: and then there was justin's posttraumatic stress disorder. carrie had talked to her about it and she could relate. amanda's own military husband also struggled with ptsd. >> reporter: that could be a lot to handle, if you're not used to that and then you start dating a guy with ptsd.? >> it is a lot to handle. >> reporter: tim told police that carrie thought her relationship with justin had reached a tipping point. >> she goes yeah i can't do this anymore. i can't even keep pretending

to police that the problems in the relationship had escalated into that saturday morning fight. >> her and justin got in a fight. she didn't really want to go back and get into more. she wanted him to learn a lesson. >> reporter: and how did tim know about that fight? carrie had gone to his house after running out on justin in a huff and told him all about it. >> it sounds like she was getting ready to maybe end the relationship with justin. >> reporter: tim went on to tell police that he dropped carrie back home the next morning. >> i watched her go into the garage. her car and headed to the airport for his trip to las but when detectives spoke to justin, he said after carrie stormed out, she never came back home, and he hadn't seen her since. and that made a tip called in to police all the more intriguing. >> reporter: you all get a tip that there's a man looking for carrie in the milan area.

>> yes. >> reporter: that deserved a close look because two days after she disappeared, her phone which hadn't been connecting to her cell network suddenly started pinging in the nearby town of milan. the man with the tip said the searcher was carrie's boyfriend. >> reporter: did you think it was tim at first? or did you think it was justin? >> justin. >> reporter: but justin had another story to tell. he said he wasn't in milan and insisted the fight with carrie was no big deal. that it was about something trivial. >> over some burnt eggs. >> reporter: and she had left that day, slammed the door and called him stupid? >> yes. >> reporter: justin insisted he never saw carrie again after that fight. and the morning tim said he dropped her at home and watched her go into the house. justin said that never happened. >> when one guy tells us, "i dropped her off here at 6:30 in the morning," and the other guy says, "she never came in the door." we know there's a problem.

a blowout with carrie, and an ex who gave her a shoulder to cry one. one of them was lying but which one? coming up, a caught on camera stunner. who is that using carrie's bank card? >> he is seen on video trying to get $400 out. >> and a song turns sinister. the karaoke moment no one could

>> it was sickening. man (sternly): where do you think you're going? mr. mucus: to work, with you. it's taco tuesday. man: you're not coming. i took mucinex to help get rid of my mucusy congestion. i'm good all day. [announcer:] mucinex keeps working. not 4, not 6, but 12 hours. let's end this they say when mr. clean saw all the different things his new smart phone does... ...it reminded him of his magic eraser. it's not just for marks on walls... it's tough on kitchen grease... and bathroom grime too. he's your... ...all around-tough-cleaner, mr. clean. (cell phone rings) where are you? well the squirrels are back in the attic. mom?

your dad won't call an exterminator... can i call you back, mom? he says it's personal this time... if you're a mom, you call at the worst time. it's what you do. if you want to save fifteen percent or more on car insurance, you switch to geico. it's what you do. where are you? it's very loud there. are you taking a zumba class? stress sweat. it can happen anytime to anyone. stress sweat is different than ordinary sweat, it smells worse. get 4 times the protection against stress sweat. with secret clinical strength invisible solid and clear gel. are you tired of hazardous glass made so clear by sfx: slide show windex that you don't even know it's there? sfx: slide show smudge it! with the new smudge stick even clear glass gets visibly smudged in a snap. sfx: smudge sounds against glass

carrie olson's boyfriend and ex-boyfriend had given conflicting stories about the day carrie went missing and now police were taking a close look at both of them. >> that's kind of a tough thing to have to figure out when you've got two potential suspects. >> one of these two individuals is not telling the truth.

detectives were trying to figure out which one, when they came across a significant clue. a trace on carrie's debit card led them to a gas station, where they looked at security camera video. it was chilling. there was carrie's car. her debit card was being used but there was no carrie. instead, the person using the card was tim mcvay. >> he's seen on video at the pump, trying to enter a number several times, you could tell, it's unsuccessful. >> reporter: tim also tried the card at a drive-thru atm at the mississippi valley credit union. but he had problems. >> that's carrie's bank. he is seen on video there three separate times, trying to get $400 out. >> reporter: the pin is not working? >> the pin is not working. >> reporter: why was tim driving carrie's car and using her debit card? tim told detective voy there was a simple explanation. even after they broke up, he and carrie always had each other's backs.

friends. she is the kind of friend if she called me i would drop whatever i was doing to go help her out. shirt off my back kind of thing. >> reporter: tim said that's why he had taken care of carrie when she came to his house after storming out on justin. and it also wasn't unusual that she lent him her car and debit card, he said. >> she gave me her debit card she said go to the mississippi atm and get out $400 then go and top off the gas tank, whatever it takes to fill it up. >> reporter: tim said carrie had also promised to drive him to the airport in minnesota that sunday. but then she changed her mind at the last minute. >> she says just take my car and drive yourself up there drop me off at home. >> according to tim, he and takes carrie back to her residence. >> reporter: and when they pulled up to the house, tim said carrie told him she didn't care how justin might react to her doing him a favor. >> she was saying i am going to walk in the door. and say i let tim borrow my car

to get himself up to the airport. you need to shape up, ship out. >> reporter: detective voy questioned tim's version of events, saying security camera video from the genesis health clinic next to carrie's house did not show him dropping her off at home. >> explain to me then the video cameras on the side of the genesis where you dropped her off, it does not show you there. >> it has to show that the car was there. >> reporter: tim didn't realize it but detective voy was testing him. there was actually no video camera at the clinic. tim stuck to his story insisting he dropped off carrie. >> you're not in the video, and justin said, "she never came in that house." he's home. >> i don't know. >> she didn't walk into the garage and then walk away. >> i'm thinking justin's probably not being very truthful with you. >> reporter: it was clear one of them wasn't telling the truth and it was time to find out

>> reporter: did you ask tim to >> did. a polygraph? >> did. >> reporter: but when justin and tim took those lie detector and then they both went back to their lives. still, detectives kept an eye on them, hoping one might slip. >> reporter: one night later that winter, tim mcvay, the karaoke king of the quad cities, was back singing in front of a crowd. he sang, "i used to love her," by guns n' roses. i used to love her yeah but i had to kill her >> reporter: a woman at the bar, who was aware of the case, knew mcvay was a suspect. shocked by his performance, she said she shot this video to document it then gave it to detective noe. >> he says, "i used to love her, but i had to kill her. and i put her six feet under." tim knew what he was doing.

that song? it was sickening. >> reporter: but that song was played frequently at the bar, and detective noe knew that tim's performance didn't prove anything. so with no physical evidence connecting tim to carrie's disappearance, there was nothing she could do. the investigation had hit a wall. >> it was a mystery. we felt something just wasn't right. something was going on and we needed to figure this out. fast. >> reporter: carrie was still missing winter was settling in and it would be a long one. coming up, this brand new clue. this tattoo. >> i e-mailed amanda. it was a definite match. >> police are poised for a major break in the case. >> a huge piece to our puzzle. >> when "dateline" continues. here in the city, parking is hard to find. seems like everyone drives.

and those who do should switch to geico because you could save hundreds on car insurance. ah, perfect. valet parking. here's the keys. and, uh, go easy on my ride, mate. hm, wouldn't mind some of that beef wellington... to see how much you could save on car insurance, go to geico.com. ah! (car alarm sounds) it's ok! degree gave women a motion-activated wristband to understand how much they move,... and created degree with motionsense. the world's first antiperspirant activated by movement, it has unique microcapsules that break with friction to release bursts of freshness all day.

motionsense. protection to keep you moving. degree. it won't let you down. so how ya doing? enough pressure in here for ya? ugh. my sinuses are killing me. yeah...just wait 'til we hit ten thousand feet. i'm gonna take mucinex sinus-max. too late, we're about to take off. these dissolve fast. they're new liquid gels. and you're coming with me... wait, what?! you realize i have gold status? do i still get the miles? new mucinex sinus-max liquid gels. dissolves fast to unleash max strength medicine. start the relief. ditch the misery. let's end this. recently we've noticed some ads created by these two birds,

inviting you to stay away from the streak free shine of windex. well dear windex users these ads are false. sfx: squeaks from window cleaning clean glass is better than dirty glass. don't stand for dirty. use windex. olay regenerist renews from within, plumping surface cells for a dramatic transformation without the need for fillers your concert tee might show your age... your skin never will. olay regenerist. olay. ageless. check this out, bro. what's that, broheim?

i switched to geico and got more. more savings on car insurance? yeah bro-fessor, and more. like renters insurance. more ways to save. nice, bro-tato chip. that's not all, bro-tein shake. geico has motorcycle and rv insurance, too. oh, that's a lot more. oh yeah, i'm all about more, teddy brosevelt. geico. expect great savings and a whole lot more. >> reporter: april 5th, 2014. warm weather, finally, after a merciless midwestern winter. melting snow led to a terrible discovery. >> a body had been found in minnesota that was similar to carrie's description. >> reporter: it was found unclothed, in a wooded area off

a country road in the town of hastings, 300 miles from where carrie olson went missing. police circulated a possible identifying image, the dead woman's tattoo. >> i e-mailed amanda, and i said, "i hate to say it, but that's her tattoo, isn't it?" >> i had one picture of her tattoo. and i sat and compared it to the drawing on that news report. >> reporter: what is that moment like, when you look at the photograph of your friend and the photograph of the tattoo in the news report? >> i was completely empty. i called my mom and dad and i said, "there's a definite match for carrie in hastings, minnesota." >> this is where carrie olson's body was found on saturday night. >> we had mixed emotions, obviously. we wanted to find her but then finding out, you know, what had

happened -- it was rough. it was a rough time for the whole community. >> i just sat there. i cried. i lost a confidante. i lost someone i could laugh with. i lost -- i lost a very good friend. >> reporter: the funeral was at st. paul's church in davenport. >> she got to come back home again. >> reporter: it was a day to lay carrie to rest and remember a beautiful life. but there were still so many unanswered questions. >> now we need to find out why. we need to find out what happened. >> reporter: first step, an autopsy. but it couldn't answer the key question for detectives. >> the doctor that did the autopsy called it homicide by unspecified means. >> reporter: no cause of death? >> no cause of death.

"come on. there's got to be a cause of death? >> it's rare. but we had seen the photos of the scene, and you can tell that she didn't walk up there and just fall over dead, that her body was placed there. >> reporter: but the autopsy did offer a possible clue. >> the doctor had found a chunk of carpet in her hair. we remembered from january's search warrant that tim had beige carpet rolls in his house. >> reporter: but they also knew that carrie worked in a store that sold carpeting, so it might not mean anything. still, the carpet in carrie's hair and the carpet in tim mcvay's house were sent to the lab for analysis. how long did it take you to get your answer? >> it takes a while. it doesn't come back after the commercial break like on tv. >> reporter: while detectives waited for results, they explored the most tantalizing clue they had received, and it didn't come from carrie's body. it came from where she was

>> we knew that's where tim parked his car before he went to the airport. >> reporter: when tim mcvay flew from minneapolis to las vegas the same weekend carrie disappeared, it turns out he left carrie's car in hastings. why? that's where his girlfriend at the time lived. pretty big coincidence. >> yeah. that's what we call a clue. >> reporter: but detectives needed more. they had to tie mcvay to the very spot where carrie's body was found. they did have one long-shot clue. just a few feet from carrie's body, investigators discovered this $4 price tag. a google search showed the tag was for a kids' shovel sold at the discount chain big lots. detective thomas found a big lots store in lacrosse, wisconsin, where that kind of shovel was bought on the samame day mcvay drove to minnesota. lacrosse is about two-thirds of the way between the quad cities and hastings. but the store's security cameras were broken -- no video.

so how could detectives tie mcvay to this purchase? they decided to work backwards. >> inside a tobacco outlet, he is seen on video. >> reporter: mcvay had told police that before driving to minnesota and the airport that cigar at this tobacco outlet in so, you knew exactly what time tim had been here -- >> exactly. going? >> correct. >> reporter: the big lots in lacrosse is a three and a half hour drive up highway 61 from the tobacco outlet. and it turns out, the shovel was purchased exactly three and a half hours after mcvay bought that cigar. >> that was huge for us. you leave the tobacco outlet, which is the exact amount of time to get to la crosse, wisconsin. >> reporter: but detectives still needed something more concrete to connect mcvay to the purchase of the shovel. >> so then we asked for the actual sales receipt. >> reporter: on the receipt was not only the shovel but a black

>> a black bag. >> reporter: a desage brand travel bag. it cost only $10, but it was the big payoff police had been looking for. >> we found it in the garage at tim's parents' house. that was a huge piece to our puzzle. >> reporter: so on july 18th, 2014, three and a half months after carrie's body was found and 7 months after she went missing, tina noe and the other two detectives went to a construction site where mcvay was working. >> tim was up on a ladder. and i said, "we have a warrant for first-degree murder for you and concealing a homicide." >> reporter: tina also brought along her signature accessory -- pink handcuffs. >> reporter: you chose to cuff him with your hot pink cuffs? >> yes. >> reporter: how did it feel seeing him in pink handcuffs? >> good. >> reporter: was it an extra little jab? >> yes.

us. >> mcvay, come on up. >> reporter: tim mcvay pleaded not guilty. he was denied bail and put in the county jail. that's where "dateline" found him for his first television interview. >> i did not kill carrie. and i did not dump her body. >> reporter: tim said the wrong guy was behind bars, pointing to the fight carrie told him that she and justin had that saturday morning. >> reporter: did she say what the fight was over? >> romantic issues. i guess that'd be the best way to put it. >> reporter: of a sexual nature? >> that was my impression, yes. >> reporter: and then what happened after that? >> there was some throwing. a couple of things had gotten broken. there was a little bit of a physical altercation between the two of them. >> reporter: tim said the last time he saw carrie was when he drove her back to her house, just before he went to the airport. >> she was walking into the garage at her house -- alive, happy, as well as could be. >> reporter: tim said he still loved carrie, even though they'd

but how could he explain the seemingly damning lyric -- "i used to love her but i had to kill her" -- that he sang at the karaoke bar while she was still missing? maybe not the best choice of song given -- >> oh, i agree with that. actually, i -- i told >> reporter: -- what was going on -- >> i told my brother-in-law -- he was with me that night. i said, "why didn't you slap me when i put that song in? that's kind of a bonehead move." just -- but it had nothing to do with carrie. it was nothing to do with anything. it was just a song. it was more than a song. a killer. prove that in court. tim mcvay was about to stand trial for murder. >> a show down in court. one boyfriend accused and another on the stand. >> she stormed out of the door.

>> what really happe >> reporter: tim mcvay's murder trial started in june of 2015. there was no jury. judge michael meersman would decide. mcvay's defense attorneys believed they held the winning hand. >> he had passed the polygraph. so we thought this could be the truly innocent accused here. >> prosecutor john mcgehee knew he was facing a tough test. >> you had no cause of death. you had no weapon. you had no ironclad forensic evidence. >> i did feel that it could be an uphill battle. it was going to be a real challenge. >> as the trial began mcgehee presented the prosecution's theory as to how tim did it. even though there was no official explanation for how carrie died, the state presented something called burking -- a method of suffocation designed

someone's chest and covering their nose and mouth. to support that scenario, the state called one of mcvay's ex-girlfriends, cati smiddy. >> are you a little bit nervous today? >> yes, i am. >> why are you nervous? >> i'm scared of him. >> reporter: cati described an incident one night in 2013. she said she was startled awake by mcvay sitting on her chest. >> i couldn't breathe, he had cut off my air, i couldn't -- he was, he's a big man and i'm not a very large woman i couldn't, i couldn't inhale. >> you moved out after that? >> reporter: the evidence in prosecutor mcgehee's case was largely circumstantial, but he still felt it was strong. he believed mcvay was the last one to talk to carrie. he had her car, used her debit card, and her body was found parked her car at his girlfriend's house. and the prosecution had the test

found in carrie's hair. they matched that rolled-up carpet in mcvay's house. >> how does a piece of carpet get lodged in someone's hair and remain in her hair? her head must've been on tim mcvay's floor at the time of her death. >> reporter: the prosecutors also used mcvay's internet searches to show how he was constantly checking the website of the newspaper in the distant town where carrie's body was found. >> he knew that he had concealed her body in hastings. so he started accessing the hastings "star-gazette" in january, wanting to know the headlines when her body would be discovered. he accessed that website 100 times. that is an action of a guilty man. >> what were you looking for? you don't live in hastings. it's kind of a long ways away. >> a newspaper's a newspaper. but i'm not going to answer any questions about that. >> reporter: and why not? >> all i can say is a newspaper's a newspaper.

i don't have any other comments about that. >> just interested in hastings? >> move on to your next question. >> reporter: finally, prosecutors called to the stand carrie's boyfriend -- justin mueller. he testified about the last time he saw carrie. >> did you say good-bye? >> i didn't really have a chance to say good-bye. the way she left. i tried to say good-bye, yes. >> reporter: justin acknowledged that she was upset with him. >> the way she stormed out of the door, and i thought maybe i upset her in maybe some minor way or, cause i wasn't paying attention to her somehow. >> reporter: as the hours of carrie's unexplained absence and silence grew, so did justin's concern and his texts. prosecutors had him read them in court -- >> "baby, come home. i love you." "i'm sorry for whatever i did. i love you. kolby and i miss you." "is everything okay? i gave kolby his pill." >> did you get a response? >> no.

8:10. were you starting to get worried then? >> yes. >> reporter: although there was no evidence presented about mcvay's motive for murder, in closing arguments the prosecutors offered their theory -- he killed carrie in a twisted fit of rage, because he demanded her car to get to the airport and she'd said no. >> we see it all the time that people are murdered for sometimes the smallest little things. and you're just surprised that another human being can do this to another human being. but that's what happened. >> reporter: mcvay's attorneys -- aaron dyer, dan dalton and john ruud -- argued that the prosecution's theory of motive was preposterous. >> the idea that he could kill her and take her car to just get a ride to minnesota, i think is laughable. >> they didn't have a cause of death, so how do you point the finger at somebody?

produce any witnesses of their own. instead, they aggressively challenged the state's witnesses, like that former girlfriend. the defense tried to show mcvay was more playful than violent. >> you said when i finally did get him off me, he said he was just playing around, but you didn't find it funny? >> yes. >> he wasn't striking you, right? >> no, he wasn't striking me, he's never struck me. >> reporter: defense attorneys also attacked detective bill thomas, who traced that kid's shovel to a big lots store in wisconsin. >> you have no videos of that transaction, right? >> no. >> you have no receipts with tim's name on any of them for that date, right? >> no, it's paid by cash. >> reporter: the defense confronted justin mueller. police had said he was spotted in the town where carrie's phone last pinged, but he wouldn't admit it. >> you remember being in the milan area at all during that week? >> no. >> his phone records put his phone, at the very least, in milan. another person indicated to the police that he was seen in

milan. >> reporter: what do you make of that? >> i think it's a huge hole in the prosecution's case. >> reporter: the defense also challenged the state's evidence -- like the carpet fibers found in carrie's hair that investigators said matched the carpeting in mcvay's house. >> she worked in a carpet store. so just because it happened to be in her hair certainly doesn't indicate anyone intentionally killed anybody. >> reporter: they even challenged the idea that a crime had been committed at all. >> how did she get there? we don't know. how did she die? we don't know. it's one of the biggest mysteries that not even sherlock holmes, i don't think, could solve. >> reporter: tim mcvay declined to take the stand in his own defense, but he maintains that kids, not the violent thug described in court. >> i'm just not that kind of person. >> you were accused by cati smiddy though of -- >> well, that was a lie. >> reporter: -- >> that was a lie. >> reporter: did you kill carrie? >> i did not. >> reporter: there's a lot of

coincidences -- >> there are. >> reporter: -- going on. terrible -- >> there are. coincidences for you. >> i agree, yeah. >> reporter: what do you say to those people watching who just maybe don't believe you right now? >> all i can say is what i know. i know that i did not kill carrie. she was a beautiful person, a wonderful friend, a lover, a confidante. she was -- she meant the world to me. >> it's been the end of a long trial. >> reporter: after more than two weeks of testimony and argument, judge meersman was ready to give his verdict. >> timothy mcvay, i'm finding you guilty of count one murder, count two concealment of a homicidal death. >> i jumped out of my seat. i was so excited and happy. >> reporter: tim mcvay was stoic, showing no emotion. and three months later, he was just as stoic when the judge sentenced him to 45 years in prison. >> i believe you killed her. and the saddest part is, you

money. >> reporter: for justin mueller, the cloud of suspicion finally lifted. for carrie's family and friends, the verdict meant justice and bittersweet relief. >> i just bowed my head and started crying. and it felt just like this huge weight was gone. >> reporter: but justice for carrie still couldn't explain the why. >> if it was over a ride to minnesota, a car, and money, it's not a very good why. >> reporter: what will you miss most about carrie? she's not there, pulling in that driveway, honking, you know, announcing that she's here. she had a heart of gold. she was there for everybody. >> she had a lot of hope for her future.