captions paid for by nbc-universal television i just know something horrible happened. >> she was a small time girl with big time dreams, and they were all coming true in vegas. a career at a casino and a fiance. then she vanished. >> i rememberoing to church every day and saying please, let us find her. >> daysbe later, police did. murdered. blood on her car. a struggle at her house. and clues from a camisole. what had happened? >> we capital rest until it is solved. >> her friends will not quit.

her parents will not stop. >> i am a pain and i am a nuisance, but i am a mother. >> can "dateline" investigators help? "lost in sin city." >> thanks for joining us, i'm ann curry. for years it has been a puzzle for police. a woman found a career and love in vegas. she seemed so happy. here is josh mankiewicz. >> las vegas. every year, the bright lights draw millions. some come looking for the promise of an easy fortune, or for the secrets that supposedly never leave here. and some people come to get lost. if you want to disappear in america, the shadows thrown by the bright lights can hide you.

and then there are those that don't want to disappear here, but they do anyway. people like teresa ensanaa. here one day, gone the next. >> she was going to make the big time. >> teresa's parents, joe and ann marie. >> do you ever worry about this little girl so far from home? >> me and my sister were very worried about her. >> sure i was worried. i also knew she was going to do good things. >> doing good things. it was a lesson teresa had learned well as the second of three children in a deeply religious, tightly knit family in niagara falls, new york. and from the earliest days of childhood, teresa's best friend was always her doting father. their love was deliciously obvious, spelled out in whipped cream and icing on the extravagant birthday cakes he made for her nearly every year of her life.

>> teresa loved it. she was, of course, my sweetheart. >> he was her friend. >> i was the disciplinarian. >> you were what, the co-conspirator? >> i was her enabler. okay? put it that way. >> no. >> the enabler fed teresa's love of beauty and fashion, giving daddy's little girl everything she could want and he could afford, and then more. >> she loved shopping and i think probably spent a lot of money buying clothes. >> teresa's friends from childhood. jennifer and grace. >> she never left her house without looking perfect. had the nicest clothes and always looked great. >> teresa bought many of the clothes herself, working several jobs as a teen, and beauty and fashion were put small facets of a much larger and meaningful life. >> she was friendly, loving,

kind, incredibly smart. >> an a student, she studied psychology in college, but was also an excellent dancer, and coupled with her size, she was barely five feet tall. that skill made her perfect for another of her passions. >> we tried out for the cheerleading team together. teresa felt so bad that she made the team and i didn't, she told me she wouldn't partake in the team. >> she was a loyal friend. volunteer to give up something like that. >> yes. she wasn't going to be a cheerleader because i couldn't be one. very loyal. >> after college, teresa returned to niagara falls and a post-graduate life of leisure. >> she was home and she was living with me, but she was going out at night, coming home real late, sleeping 'til noon. i says honey, it's not going to happen. you're going to do something. >> so teresa did. she packed her bags and headed for las vegas.

and along with her went melissa who grew up next door and remained the best of friends with teresa. >> we both fell in love with it as soon as we got there. so we immediately started on the job hunt when we got there. >> within days, teresa had a job in the electric city. not dancing on a chorus line, but working in sales at the rio. melissa soon found work at harrah's. they got a two bedroom apartment. teresa's parents came to visit. did she like it? >> she loved it. it was excitement. we says wow. >> i'll never forget it. teresa was so, so teresa, and here she is with a cigarette in her ear and starbuck's coffee, running down the hallway at the rio. i was like oh, my god, she was

so happy. >> her career was off and running and soon she metta guy, his name was jeff. he bought her a dog. they moved into this house together and got engaged, then he broke it off just before the wedding. teresa was crushed, but had moved on, reuniting with her best friends in the summer of 2004, standing up for her friend grace at her wedding. >> so many things, so many happy moments, so many things we've been through. >> we just really were happy to be all together, it was a good day. >> but a couple months after by the fall of 2004, vegas seemed to have lost some of its luster. teresa was thinking hard about moving back home to niagara falls, and maybe going to grad school. then the rio offered teresa a bigger job with better pay. >> it absolutely changed the course of her life.

i was really, really upset because i wanted her to come back home, and i thought it was going to be the best thing for her. >> and going home might have been. staying in vegas clearly was not. because a month after her promotion on october 27th, 2004, teresa failed to report for work at the rio. she was gone for a day. then for another. so co-workers, including her childhood friend melissa went to her house. inside, no teresa. just her dog. and her keys. her cell phone. her purse. and her car. and on the car's bumper, an unmistakable spot of blood. >> i think at that point is when i became panic stricken and was like something is wrong. something is definitely wrong. >> where was teresa? what had happened?

and was she still alive? coming up, the investigation begins. police find more blood in the bathroom. >> not teresa's. >> not teresa's. >> what happened? >> she was like i have this feeling that somebody is in my house. n nhest wlosi "n tyci uein nts.♪ i like so many great pioneers nts.♪ before me, guided only by a dream. i'm embarking on a journey of epic proportion. i will travel, from sea to shining sea, through amber waves of grain, and i won't stop until i've helped every driver in america save hundreds on car insurance. well i'm out of the parking lot. that's a good start. geico, fifteen minutes could save you fifteen percent, or more on car insurance. recently tested stain treatments. they rated resolve laundry number one. beating shout.

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ten miles from the las vegas strip, concern and confusion suddenly ruled. for two days, 26-year-old theresa insana hadn't shown up at her job as a sales executive at the rio. back home in niagara falls, new york, her father with whom theresa spoke nearly every day hadn't been able to reach her. >> i am just calling and getting the message machine. >> she didn't call you back. >> didn't call me back. i says what the heck is happening. >> co-workers, including her friend, melissa madge, had gone to her house to check on her and found theresa's dog, cell phone, purse, and car. and that frightening spot of blood on the bumper of theresa's car. >> you've known her all your life, and you show up at her

house and she's gone, but all her stuff is still there. >> i think at that point i was in complete shock. you know, where was she? >> las vegas metro police responded and patrol quickly made a call that reached vegas homicide. a squad that included detective marty wildman and sergeant mike mcgrath was soon on the scene. >> we looked at the blood smear on the rear bumper of the car, then we said everybody out, we're taking this, started going through the house method cli. >> processing it as a homicide scene basically. >> it looked to detectives as if theresa had been attacked, and clues found throughout the house supported that. on the stairs, a footprint too large to be theresa's, and this. >> we saw a small little brass or metal ring. >> steps away in a half bath, detectives found a towel rack missing from a wall.

and two more spots of blood. one near the baseboard, another on the mirror. >> analysis of the two blood droplets from the same person? >> same person, full male profile. >> not theresa insana. >> not theresa insana. >> then there was the blood on the bumper of theresa's car. that would later out turn out to be theresa's blood, not an assailant's. detectives prepared themselves for what might be in the trunk. when it was opened, they found a bit more blood and mud. then inside the car, police found the driver's seat in an unusual position. >> the seat is pushed all the way to the back. >> she's barely five feet tall. >> she's a very small woman. >> based on this evidence, a theory was beginning to take shape, a theory that involved an attacker entering the home, possibly through the unlocked back door. possibly a struggle on the

stairs, a struggle that spilled into the half bathroom where a towel rack was torn from the wall, and where theresa's attacker lost blood. but no matter what exactly happened in the bathroom, detectives believed the struggle had ended with theresa's murder. then the loading of theresa's body into the trunk of her own car, the body's disposal somewhere, and then in a bizarre twist, the killer returning theresa's car to her own house. >> it is extremely unusual, is it not, for a killer to return to a crime scene like that? >> yes. >> usually people commit the crime and they want to get away. >> absolutely. you obviously have thorough knowledge of what she was doing, who was living there, and then the fact that you would be safe to come back. >> by removing the body buys him time. that's the time we believe that he can do all the things that he needed to do in the house. >> and what he apparently did in

the house was to start cleaning up, as evidenced by paper towels, trash bags, and spray bottles left inter east a's kitchen. >> how often are you at the scene of a homicide where the killer tried to clean up after himself or herself? >> it is not that often, and when it does occur, it is very bush league. >> this was different. >> this was different. it was methodical, it was slow. it was thorough. he spent a long time cleaning up. >> but who would know so much about theresa to know that no one would discover it if he took time to clean the house. and when had all of this occurred? detectives learned theresa was last seen at work at the rio on tuesday. two days before friends had gone looking for her. a good citizen, she had gone to vote at this church just a few blocks from her house about 5:30 p.m. then made some calls, speak to go her mom back in niagara falls

about 6:30 p.m. >> what did she say in that conversation? >> she said mom, i'm tired and i'm going to have my macaroni and cheese and i'm going to rest and i'll talk to you tomorrow. >> but an hour later at 7:30 p.m., when theresa's cousin angela called, the phone went unanswered. >> so we had basically an hour window between the mother's phone call and angela trying to call her and not getting her. >> so there really wasn't an explanation other than she had already been attacked for why angela's phone calls weren't being answered. >> so police believe theresa insana was attacked between 6:30 and 7:30 tuesday evening. it was now thursday. her attacker had a nearly 48 hour head start. as word spread, theresa's best friends couldn't believe what they were hearing. >> i think at that moment, i just knew something horrible

happened. >> friends talked with police, hoping to provide clues inter east a's disappearance. investigators started reading her diary which was found in the house. and grace remembered something theresa had told her when grace was visiting six months prior. >> one morning we got up and were drinking coffee. she's like i can't put my finger on it, but sometimes, grace, i go to work and i'll come home and my dvd player will be on, or there will be a different station on the television than what i left it on. >> did she say anything was taken? >> nothing was taken. she was like i just have this feeling that somebody is in my house. >> do you know if she had her locks changed? >> i don't believe she did. >> detectives followed up every lead. canine units were called in. as police put it, the whole zip code was turned upside down. but experience told the detectives that any news they received about theresa was unlikely to be good news. >> we were just waiting for the

call. >> that someone found a body. >> yes. >> days dragged by. >> i remember going to church every day and saying please, let us find her. i don't know what i was hoping for, but i just wanted us to find her. >> and then nearly a week after detectives believe theresa insana was killed came the news police were waiting for. and theresa's family and friends were dreading. coming up, a painful discovery ends one mystery. but launches another. who could possibly be behind this? "dateline's" unsolved case squad with a dramatic theory

six days after theresa insana failed to show up for work at the rio in las vegas, her father joe was reciting catholic prayers, marking all saints day. >> i'll never forget it. i'm sitting there praying this litany of the saints, and i turned to ann marie, i said theresa is going to be found today because today she became a saint, too. >> and that very day, theresa's parents and her best friends received a call from las vegas metro homicide detective marty wildman. >> he called me and said grace, we have theresa. i know it's sad news, but we have her body, and i just didn't want you to suffer any more. >> it was just awful. most awful thing. >> theresa insana's body was found just three and a half miles from her home, near a golf course. her killer had wrapped her body in towels and blankets, carried

theresa down a steep, rocky embankment, and left her in a large culvert in standing water. an autopsy showed theresa insana had died by strangulation, and possibly had been sexually assaulted, although the medical examiner said the evidence was not conclusive. >> we thought that hey, maybe this is an act of anger by someone that was mad at theresa. was it staged. >> was somebody trying to make it look like a rape even though the point of it was something else? >> very good possibility. >> and with the discovery of theresa's body, three things were immediately clear to detectives. first, that tiny piece of metal found on the stairs of theresa's apartment, it was apparently torn from the camisole she was wearing at the time of her murder. secondly, the blankets around her body came from her home.

but police believe the rope and duct tape used to bind the body did not. it had been brought to the house by her killer. and finally, that blood in the bathroom matched a new spot of blood found on theresa's camisole. it also came, police believe, from the killer. >> we've got a bad guy and we've got a bad guy that left a print. >> this has to be left by the person that attacked theresa. >> absolutely. >> but whose blood was it? with the backlog at the vegas crime lab, dna test results were still months away. so in the first days after theresa's body was found, detectives begin to look at what they could learn from other evidence, like where her body was dumped, and whether they were looking for a killer or killers. how many people committed this crime? >> i believed just from our investigation it was a one person crime. where we found theresa makes that a little iffy, only because

it was rough terrain. >> i believe that it was more than one person. i think that based upon where the body was found, 25 feet of rocks walking down. >> you would have to have some help. >> i would think, because we walked down there to view the body, and it was iffy walking down there with a notebook in our hand during the day, and this is the nighttime. >> and carrying a body. >> and carrying a body. >> theresa insana had been dead for nearly seven years when las vegas metro homicide granted unprecedented access to "dateline's" unsolved case squad, sharing information from the files of an open case with our experts. nbc news consultant dwayne stanton, retired homicide detective from washington, d.c. investigated chandra levy's murder. yolanda mcclaire ee, crime scene

investigator in vegas and model for the character on the hit series csi, and john lewen, los angeles district attorney specializing in cold case murders. >> how many people do you think committed this murder? >> i think where the body was located in the ravine with the rocks, i support two. >> i think it is one person committing the murder, and i agree clearly someone had help. >> what happened inside that house. >> one possibility. we know for a fact that theresa at some point was on the steps. i think what theresa attempted to do was clean herself inside the bathroom, away from her attacker or attackers. once inside the bathroom, there's a towel rack removed. you can see the bracket is missing as well. yolanda, i think the towel rack is on this wall. i go to grab you, you're holding

on to that towel rack, and then the towel rack possibly came out of the wall. the person that was behind her pulling on her. >> gets hit in the face. >> or in the head, wherever. >> thus causing blood splatter on the mirror and on the baseboard. >> and our team agrees. the elements of the crime, as well as moving theresa's body out of her home, using her car for transport, and returning to clean up the crime scene together strongly suggest this was no random murder by a stranger. had this person ever committed murder before? clearly some of the things they do show some sophistication. >> i don't think the person committed murders before. i think they watch a lot of murder movies and think they know how to do it. >> and unfortunately for them, they thought of things that were much more advance. let's move the car. let's make sure that we get the body out of the house. but they forget the basics. her purse and cell phone are sit

tlg. >> we know there's not another crime involved like robbery because nothing is missing in the house. nothing is missing other than theresa. >> it limits the pool of potential suspects. >> look at who has a grudge, who stands to benefit. >> who doesn't like her. >> who doesn't like her. >> coming up, police have a date with the ex. theresa's former fiance. >> did you have something to do with this? >> no. >> when "lost in sin city" continues. [ male announcer ] we asked real people if they'd help us with an experiment for febreze fabric refresher. they agreed. [ experimenter 1 ] relax, take some nice deep breaths. [ experimenter 2 ] what do you smell? lilac. clean. there's something that's really fresh. a little bit beach-y. like children's blankets. smells like home. [ experimenter 1 ] okay. take your blindfolds off. ♪ hello? [ male announcer ] and now new and improved febreze fabric refresher with up to two times the odor elimination so you can breathe happy, guaranteed.

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four days before theresa insana's body was found on that terrible monday morning in november, 2004, it was her co-workers from the rio who first went to her home to check on theresa, and then when they couldn't find her alerted police. among them, theresa's lifelong friend and former roommate, melissa madge. >> i couldn't wrap my mind around who would really want to hurt her. >> police asked you if she was involved in anything illegal. >> right, no. >> asked about boyfriends. >> they did. >> and in fact, theresa's former fiance was one of the co-workers who were the first to enter the home that day. his name is jeff fenton, and he

once lived in that house with theresa. but he also broke her heart just months earlier by breaking off their engagement right before the wedding. >> i want to do everything i can so that, you know, you guys know that i had nothing to do with this. >> one question by las vegas police, jeff fenton said he had played no part inter east a's murder. he said he tried not to touch anything in the house or garage where theresa's car was still parked. >> i said i don't -- i don't even want to open the trunk. i mean, the whole -- i was so completely freaked out. i mean, i was really scared that i was going to find something. >> police needed to know as much as possible about jeff, a man who seemed to be a bit of a mystery to most. a 30-year-old divorced market analyst for sees ars entertainment properties that included the rio. he and theresa were engaged two

months after they started to date in 2002. shocking to many of her friends and family members. >> jeff seem like a good guy to you? >> i believed at first he was quite a nice, wonderful man, who she wanted. he asked for my blessing. i gave it to him. >> but those closest to the couple saw something odd in jeff. he seemed to be constantly under the weather. >> he came for a week, and he had -- every day he had an ailment. god's going to strike me dead. >> he always complained a lot of headaches and that he was stressed and he had suffered panic attacks a couple of times. he stayed around home a lot. >> and theresa who had been very social would stay around to take care of him. >> she isn't going to go out socially if her fiance is homesick. >> jeff and theresa were engaged

for a year. then five weeks before it was set to go, he called it off. >> he came to her one sunday morning and said i can't do this and theresa was very taken aback and completely devastated at that time. >> theresa was heartbroken, as evidenced by this entry in her diary. >> i have never felt so crushed in all of my life. my life is in uproar. i still wish this is all a horrible dream and one day i'll wake up and everything will be okay. i have no real answers, nothing to go on, just my new white dress hanging in the closet for me to stare at and wonder. >> i think she was just so sad, and you know, that was when she shared that maybe there were signs she should have seen before. >> what did she say the signs were? >> she said there was a girl's name on her caller id, someone she worked with, and i think she -- there was some thought there that maybe there was something going on. >> and apparently there was. shortly after jeff fenton broke up with theresa, he began dating

that very woman whose name had been found on the caller id. another co-worker at the rio named melissa ball. >> theresa ever express how uncomfortable it was to work with both her ex-boyfriend and her sort of romantic rival in the same office? >> it wasn't an easy situation for her. every day she had to go into work and see the man that broke her heart, and then have to look at melissa. she always would say to me i'm trying to be a better person and not allow it to bother me. >> and as the months passed, jeff and theresa were at least civil to one another. one weekend two weeks before the murder jeff agreed to take care of theresa's dog, and he slept over at her house when theresa had to work overnight at the hotel. but on the day police believe theresa was murdered, she did tell her friends something that made investigators pay close attention. >> she had come to my office that day and we were chatting, and she had mentioned that she

had exchanged some words with jeff, like i confronted him, you know, and i said this to him, and that was really it. >> what was the argument about? >> i honestly don't really recall. i just sort of tried to be the supporting friend and say don't worry about him, just ignore him, just move on with your day. >> did you have something to do with this? >> no, no. >> when he was questioned by police, jeff said that tiff never actually happened. >> you had a fight on monday? >> no. >> no verbal argument where another co-worker says, oh, they had an argument on monday? >> no. >> no argument monday. >> there was another reason detectives were suspicious. theresa's body had been found just two miles from jeff fenton's apartment. but police soon learned he had an air tight alibi. that evening jeff and his new girlfriend were buying a car, and police believe they were at

the car dealership during the exact hour when theresa was murdered. >> this whole process, it just seems so unreal to me. >> still, detectives thought jeff fenton, the man who had panic attacks and was described as highly stressed didn't seamstressed at all by the murder of his former fiance. >> it's just really upsetting. >> well, here's the thing that i don't understand. i mean, i get upset, i'm upset, okay? you, right now to me, don't appear upset. you're like this, flat line. okay? and you're saying, watch me. i'm really upset. you know. why is that that i'm get that long from you as just nothing is bothering you? >> i just don't think i've been able to process everything

that's happened. >> one possible reason for jeff fenton's flat affect? he was taking anxiety medication. another? he had just lost his former fiancee', and was confused by all of the questions, because he was not involved in her murder. still, police kept looking at those close to theresa as they searched for answers. coming up. >> there's no way in hell he would ever hurt that woman. >> the new girlfriend makes an entrance and a dramatic exit. >> how many people have you seen get up in the middle of a polygraph and run out of the room. >> it is unusual to do what she did. >> what wilol tve chease unsolv squad make of this when "dateline" continues. experts from a leading consumer publication

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november, 2004. theresa insana came home to resin niagara falls, new york. her friends and family were living with equal measures of agony and bewillederment. who had killed theresa, and why? >> theresa was such a good person. she didn't do anything bad to anybody. there would be no reason to kill her. >> and as their grief settled in, theresa's former fiancee', jeff fenton, was being questioned about the murder.

>> it's obviously something that i had nothing to do with. >> also questioned was fenton's new girlfriend, melissa ball. she was 23 and worked with jeff and theresa at the rio. >> i mean, i don't want to scare you or anything, but your name has come up as just a person that we need to talk to. >> first melissa ball confirmed jeff's alibi, saying they were both at that car dealership the evening theresa was murdered. >> he was with me all day tuesday and tuesday night. he was with his little sister and me wednesday night. and there's no way in hell he would ever hurt that woman. >> but melissa ball also admitted to police that she did not exactly favor jeff's decision just two weeks before the murder to sleep over at theresa's house, to watch the dog while theresa stayed at work. >> it upset me because in their

relationship she made him feel guilty for a lot of stuff, and i felt like that's what she was doing again. >> i think the fact that jeff came over and watched the dog and stayed and slept at theresa's house was definitely upsetting to melissa. >> even though she is not there at the time. >> i mean, that's what she's told. >> you think maybe she thought theresa is there? >> or she's using excuse to get jeff back in the picture, stay at the house, here is the key. >> still a tie between jeff and theresa that we believe melissa didn't want. >> especially thought detectives a new girlfriend who lerpd a few days before she was pregnant with his child. detectives thought melissa ball had reason to worry. after all, jeff's first marriage ended in divorce. he left theresa weeks before their wedding. and now melissa was pregnant and wanted to get married.

what woman wouldn't worry? but when melissa talked to police, they felt her demeanor was not that of someone that was shocked by the apparently random and senseless killing of a co-worker. >> did you and this theresa have some sort of argument or words exchanged on monday at work? never? >> never. >> here is a woman she sees every day at work, and she's unconcerned at all. >> generally people are pretty upset. >> yes. i mean, you can't imagine the amount of people from the rio that were calling, wondering if it was someone stalking her at the hotel, and she had none of that. >> she wasn't worried about that. >> she wasn't worried about anything. >> four months later, jeff and melissa would return to vegas homicide for polygraph tests. although the tests are not add miscible in court and don't prove someone committed a crime, here are the findings. when asked if they caused

theresa's death and if they knew theresa was dead before her body was found, the examiner found both jeff and melissa showed deception. but just as interesting was what melissa did toward the end of the test. >> she got upset and grabbed her stuff and she was crying and was out of there. >> how many people have you seen get up in the middle of a polygraph and run out of the room? >> most people stay. it is unusual to do what she did. >> tell me if i'm wrong, but generally innocent people want to stay and answer every question. >> they want to clear up all facets. >> whatever to convince you i didn't do it. >> melissa at one point seemed to sympathies with theresa having been jilted by jeff. >> i know how i reacted when an old boyfriend broke up with me after a couple months, and i couldn't imagine what she was going through, so i let her go through it. >> our team was also interested

in how at another point melissa referred to theresa not by name, but as that woman. >> there's no way in hell he would ever hurt that woman. >> this is somebody who worked with theresa and obviously they are both romantic rivals at points in time for jeff's affection. >> saying okay, she doesn't like her, doesn't mean she killed her. >> what's fascinating, you don't say that woman. it shows a level of detachment, and to me of anger and hostility that we would think might have existed while she was living, but this woman was brutally murdered. >> and still exists. >> and that's your response. >> people do react in different ways to polygraphs and to news as stunning as that of a murder. and for jeff, it's what happened after the interview that got our team's attention. >> there's a point during jeff's

interview with police where they leave the room, and jeff is sitting there like this. >> i love it. >> what's that say to you. >> what it says is oh, my gosh. >> what have i gotten myself into. >> it is classic. >> it is the first sense of emotion out of him. >> 45 minutes, 50 minutes, nothing. >> that's not necessarily a sign of guilt. >> maybe what he's concerned about is he's saying you know what, i didn't commit this murder, but the more i'm hearing, i got a terrible feeling who might be involved. >> right. coming up. a new development from the crime lab. will it mean a new theory about the case? >> could this be a murder for hire? >> absolutely could be. >> very well could be. >> a crucial piece of the puzzle. when "lost in sin city" do i look like someone who is at risk for heart disease ? well, guess what ? i am.

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because of a backlog of cases, it took more than a year after theresa insana's murder for word to come back from the crime lab to vegas homicide. the dna from that blood found inter east a's bathroom, and on the clothes she was wearing at the time of the murder did not come from her former fiance, jeff fenton. it also didn't come from the woman that a month after theresa's death became his wife, melissa ball. >> when you got the dna back, were you surprised? >> i don't think surprised. we thought it was a possibility it wouldn't be him. it made us lean towards more that melissa was calling the shots and jeff might have found

out after the fact. >> do you believe jeff fenton has something to do with it? >> i do. >> that's not his blood at the scene. >> he knows something and his new wife knows something and we just need to find that one person that they know or somebody else knows. >> maybe he's not involved. >> it's a possibility. just the actions and interviews, we have a hard time really swallowing that, that he's not involved. >> it may well be that neither jeff nor melissa had any involvement. and to this day, neither has been charged with any crime. through his attorney, jeff fenton denied repeated requests for an on camera interview. and melissa ball fenton didn't respond to "dateline's" requests for comment. >> one thing we know, there's no prosecutable case now against jeff or melissa. they had an alibi and somebody else's dna is at the crime scene and on the victim's body. >> there's not enough probable cause at this juncture.

>> you have a very interesting case with a lot of evidence that points certain ways and then a giant missing piece. >> i completely buy there was some tension between melissa, jeff, theresa. there's a big jump from that to murder. >> been on enough homicide cases, josh, there's no good reason for any of them. >> i think the mistake people sometimes make is when they try to look at motive as being always reasonable, always apparent, always clear. it's not. >> could this be a murder for hire? >> absolutely. >> absolutely could be. >> very well could be. >> most obvious scenario here is this is somebody that either knew her or was employed by somebody who knew her, and wanted her dead. >> what's it going to take to solve this murder? >> going to take probably a dna hit on this profile or somebody actually starts talking. >> i think dwayne will tell you as a homicide investigator, you want to be good, you want to be

thorough. sometimes your best friend isn't hard work, it's luck. >> luck. someone coming forward with information, someone making a mistake. >> detectives have run the dna through the national database. no matches yet. but detectives are still waiting. >> you guys fantasize about the moment you'll be able to call the insana family and say we made an arrest? >> that will be a tremendous day. it would be a day that i hope is before i retire. >> we'll get what we call a full loaf. that means a full confession out of this guy. he'll have no reason that his blood should have been there. he'll confess. we just need to know who he is. >> for now, it is ann marie insana who faithfully places the calls, refusing to let her daughter's murder be forgotten. >> how often do you talk to police? >> every couple weeks. and i am a pain, and i am a nuisance, but i am a mother. i don't know if it's going to

happen in my lifetime or joe's, but i believe it will happen. >> high school graduation. >> theresa's friends, too, live for the day when an answer will come. and until then, they'll remain as loyal to her memory as she always was to them. >> we know that it's not in our hands at this point, it's in god's hands to bring this person to justice. but i will never give up, and i truly believe in my heart of hearts that this case will be solved. >> but for theresa's best friend, her father, no matter when those answers come, there will always remain a hole in his heart that can never be stitched up. >> god, she was my lifeline. i loved her so much. i love her now. i feel her essence and presence was so strong, she's still with us today. but i can't talk to her, i can't

hold her, i can't kiss her. that's what saddens me the most. >> that's all for now. i'm ann curry. for all of us at nbc news, thank i'm ann curry. for all of us at nbc news, thank you for joining us. wwc.w.taovimco vita c captions paid for by nbc-universal television this sunday, a special broadcast from new york. the president's diplomacy. the palestinians push for statehood with the united nations. they are ungrateful. the united states commitment to israel's security is unbreakable. >> there are new fears of violence for any peace talks twin israelis and palestinians. >> it is time to change our policy of appeasement toward the palestinians to strengthen our ties with the nation of israel.

>> this morning, i speak with israeli prime minister benjamin netanyahu. how will he manage this during the historic era. then theebate at home. the economy and taxes. is the president's plan fairness or warfare? what will it mean for jobs. joining me, mayor of new york, michael bloomberg. finally, we kick off education nation. what big ideas are driving reform in public schools? what role should the federal government play? what should our students know to go through this economy. now president of the university of miami, donna shalala. ormer press secretary of president reagan, bill ben net. chairman and