>> yes. he looked at everything. i was even like, where was ted bundy at that time? >> we have to look under every stone, every pebble. >> they're talking about hundreds of names here. >> hundreds, thousands. >> she is driven. >> her tenacity is just remarkable. >> i knew i was going to find him. it was a competition between him and i. >> your heart is pounding like, oh, my gosh. this is real. >> i said, i found him. i know who killed helene. ♪ ♪ ♪ >> hello and welcome to "dateline". helene pruszynski lift by a simple philosophy, smile and make the best of everything. the budding journalist did just that as she started a college internship in radio. then helene was murdered. the investigation led detectives into the darkest corners of the criminal world, before a groundbreaking investigative tool helped bring the killer's secret to light. here's josh mankiewicz with "a promise to helene". >> 40 years is a long time. that's 40 winters here in colorado. and countless snowfalls. it was on a day like this that young woman disappeared. her name was helene and helene had a friend named kimberly. a friend who kept her word. you have any idea how many years you were signing up for when you made that promise? >> no. >> for those nearly four decades, kimberly kept her promise. 40 years looking at faces. 40 years meeting with detectives. 40 years retracing helene's steps. >> when i make a promise and make a commitment i follow through. >> helene never knew it but she had another friend. you never met helene. you feel like you know her? >> i do. i feel like i know her well. as well as i possibly could. >> shannon was three years old when helene disappeared. it wasn't until 2019 that she accepted a challenge. >> i had to win. i wanted to win for helene. helene pruszynski grew up as the baby daughter in a close knit family of five in hamilton, massachusetts. >> everybody that met her liked her company. >> janet was her older sister by nine years. but you didn't treat her as this annoying, younger sibling? you guys were pretty tight? >> not at all. she was my best buddy. she was a surprise, i think, to the family. and she just brought sunshine and life to our household. >> i met her my freshman year of high school. she was a sophomore. we both were part of a singing group called harmony and that's really where i got to know helene very well. >> she loved to sing? >> yes, she loved to perform. >> i'm involved with harmony, which is a musical group at the regional. >> helene spoke about her school life for a classmates local radio show. >> my philosophy on life? yeah, i have one. you should just, i don't know. be yourself and make the best of everything. and smile. >> smile? >> yeah, that's what i do all the time. >> there she is smiling along with kimberly in their musical group. also joining and, kimberly's older brother john. >> it was a real feeling of camaraderie, but also a dedication to excellence in our singing. >> he remembers the day camaraderie turned to something else. >> we started talking and for me it was an immediate spark. it was that kind of fluttery feeling that you have when you know you're talking to somebody that you realize you really like immediately. >> they were just in love. they were each other's first loves in high school, but very genuine. >> it didn't last beyond high school, but john and kimberly both kept in touch with helene after graduation. helene attended wheaton college in massachusetts where she sang in another group the whea-tones. there she is in the back row with the black dress on. one more thing, as much as she left her singing, helene had a another passion. journalism. what did you think what's going to happen to her? everywhere she headed? >> for great things. i saw helene the christmas of december of 1979 at church. she told me that she was going off to denver to do this internship to further interests in journalism. and she was very excited about it. >> helene arrived in january 1980 to begin that internship at a radio station in denver. a long way from home. fortunately, she had relatives nearby. your family didn't worry about her going off to colorado because she was not going to be alone and she was staying with your aunt and uncle. >> exactly. >> then came that day, january 16th. helene had barely been there two weeks when she grabbed the bus from the radio station around 6 pm to go back to her aunt and uncle's house. she'd made the commute before without a problem. that night, helene pruszynski never made it home. >> my parents called me and said they just gotten a call from my aunt and uncle and this was i think maybe 10:00 at night. >> what did you think that happened? >> we had no idea. this was so unlike helene. something had to be wrong. >> the next morning, the news, none of it good, made its way back to massachusetts. >> that was the first thing that came up, hamilton women have found murdered in denver, colorado. and then from there it was just horror and chaos. i went crazy. my son was 16 months old. i just grabbed my son and screamed and cried. i just couldn't believe it was happening. not to helene. >> that moment would launch a 40-year quest for justice to find helene's killer and learned what happened on that wintry night. >> detectives, family, and friends desperate for clues grasp at straws. who would want to harm helene? coming up. >> she gets off the bus and then she just disappears. >> she just disappeared. >> was it somebody that she worked without the radio station? could it be the boyfriend that she just broke up with in december? >> i thought i would be a suspect, actually. >> when "dateline" continues. knocks out symptoms from over 200 allergens. without knocking you out. feel the clarity and make today the most wonderful time of the year. live claritin clear. mom! i got the job! yeah, i feel like its all coming together. introducing the all-new 2024 chevy trax. with all the tech. here we go. we're going home monty. and all the room... for all of life's firsts. your first new car is here. the all-new chevy trax starting under $22,000. dupixent helps you du more with less asthma. and can help you breathe better in as little as 2 weeks. dupixent is an add-on treatment for specific types of moderate-to-severe asthma that's not or sudden breathing problems. dupixent can cause allergic reactions that can be severe. get help right away if you have rash, chest pain, worsening shortness of breath, tingling or numbness in your limbs. tell your doctor about new or worsening joint aches and pain, or a parasitic infection. don't change or stop asthma medicines, including steroids, without talking to your doctor. ask your specialist about dupixent. type 2 diabetes? 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>> douglas county was a completely rural community between colorado springs and denver. >> not a lot of homicides back then? >> maybe one every four years. >> investigators determined helene was last seen alive getting off that bus after work. >> from the bus driver, we knew that she got off that bus. from there -- >> and nobody got off with her? she didn't have any trouble on the bus? >> there was no indication from any witnesses there that she was in any distress or any one was following her. >> she gets off the bus and then she just disappears? >> she just disappeared. >> helene's body was found the next day in a field at nearly nine miles from that bus stop. she'd been stabbed nine times. an autopsy revealed she was also raped. what did you learn from the body, the scene, the autopsy? >> a number of her clothes were missing. she was wearing a mid sized winter jacket for colorado at that time, and a scarf. she was lying on her back. she had no defensive wounds but she had wounds on her knees and lower leg area. which would tell us that she had either crawled on her knees at some point into that rough area. the grass, based upon the injuries. >> and she didn't have defensive wounds suggesting she was not fighting her attacker? she was trying to go along with him, maybe to get him to let her go? >> correct. >> some of the forensics they shared with us let some of us to believe it wasn't a stranger. that it must be somebody that she knew. >> but she didn't know anybody there, did she? >> she didn't know anybody there, but she was working at a radio station. so, was it somebody that she worked with at the radio station? could it be somebody that she turned down for a date, or a ride, or something that got angry? >> helene's friend kimberly started thinking about the men in helene's life. the or mostly just friends, but she passed their names to investigators anyway. you're giving the detectives names of people and saying, you need to check out this guy and this guy, and this guy. >> yes. we said, could it be the boyfriend that she just broke up with in december? i looked at my brother, i said, john [laughs] could it be you? >> of course, john was helene's ex-boyfriend. as john worked through his own grief, it occurred to him, police might come knocking. >> i thought they would. i thought i would be a suspect, actually. but they never contacted me. >> that's because investigators quickly determined john was in massachusetts when the murder happened. back in colorado, investigators focused on what little evidence they had. different world of law enforcement back then. no surveillance cameras. no license plate readers. none of that. >> this was during the age of law enforcement where we still did not have dna. we did not have technology that would help us track where she was at. >> their old school police work did turn up something. a witness had seen a young man of medium build in his 20s or 30s. five foot nine, maybe five foot ten. he was standing by a car at the side of the road. it wasn't much. investigators wanted more from the witness. >> investigators put that person under hypnosis and used a sketch artist to draw a rendition of the person that she saw standing next to a car on daniels park road, which would have been 100 yards or so from where the body was found. >> that works. putting somebody under hypnosis? >> here's the thing, i've been in this business for 40 years and i heard where it worked and they've heard where it didn't work. >> the result was this sketch. was it the killer? and would it lead anywhere? >> coming up -- >> they're known as serial killers. and according to law enforcement officials, there are at least 35 of them roaming the country now. >> a chilling new possibility. >> i was even like, where was ted bundy at that time? was he in colorado? >> a string of notorious killers on the loose. could one of them have committed this crime? >> you're being questioned in connection with the crime of homicide. >> these prolific serial killers, that certainly fit. >> that certainly fit. >> when "dateline" continues. 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[ cheers ] yeah! woho! running up and down that field looks tough. it's a pitch. get way more into what you're into >> in the weeks after helene when you stream on the xfinity 10g network. pruszynski's murder in 1980, police at last had a possible image of their suspect. except, it was leading them any closer to her killer. you start showing that sketch around and you put it up every place and nobody knows who that is? >> that is correct. no one came forward and said, oh, i know who that guy is. >> months went by and detectives just hit a dead end. >> it was clear that they had exhausted all of the leads by the wintertime of 1980, going into 81. the case had gone cold. >> for a victims family, there may be no greater frustration than having a loved one's case go cold. often someone needs to play the role of the tireless advocate. even at only 26, kimberly realized that and made her promise. which was? >> i saw helene's parents and i just promised them that i would not stop for as long as i was living in doing everything in my power to find helene's killer. >> everything to kimberly that constantly calling detectives, generating press coverage. anything to keep a laser focus on the case. >> i didn't want to see her parents or her sister, or her brother, have to not only deal with just day-to-day living. take some of that burden off of them and for them to feel good that somebody was still actively working on it and keeping that case alive. >> and then, in 1983, the case did seem to gain new life. throughout the 70s and early 80s, a number of serial killers had been grabbing headlines. >> we looked at every serial killer. i was even like, where was ted bundy at that time? was he in colorado? so, we even looked at every known serial killer that was active at that time to see if they could possibly have been in colorado. >> and then, there were these two men, henry lee lucas and otis tool. they were drifters. arrested and jailed in the early 80s. and began telling law enforcement something astonishing. how they had killed more than 200 women in a dizzying spree across the country. >> crime analysts there had painstakingly reported hundreds of details of dress, mode of travel and method of killing in the lucas, tool murder cases. >> that's dennis murphy reporting on it for nbc nightly news. >> they're known as serial killers and according to law enforcement officials, there are at least 35 of them roaming the country now. >> and these two admitted killers told police about one particular victim, in colorado. >> they confessed to committing the murder of helene pruszynski. what was unique about then is that detectives often thought that there might have been another person may be in the car waiting for whoever they took out into the field. that was one of the theories. >> so, these two guys who worked together, these powerful prolific serial killers, that certainly fit? >> it certainly fit. >> it's pretty seductive when a couple of serial killers who are on the hook for a lot of other murders confess to your murder, because it would close a lot of cases if you can link them to these guys. >> that's right. obviously they were like, this is awesome. we've got a confession. >> colorado investigators headed for texas to interview lucas themselves. >> you're being questioned in connection with a crime of homicide. >> the detectives showed him a map and asked him to pinpoint where he and tool picked up helene. >> we stopped her on the street and took her out of the car. and we took her all the way out to the country -- out there well, there's a bunch of rocks and stuff out there. she was stabbed to death and raped and covered up with, i think, a sheet and some plywood. >> then lucas added another detail. >> she was stabbed to death and shot once, i think, in the head -- >> who shot her? >> i shot her in the head. >> at that moment, they had a problem. helene was stabbed, not shot. for detectives, this confession was starting to sound phony. they dug deeper, looking into lucas and tools long trail of arrest records. >> we could link them to other jurisdictions by other legal documents that could be authenticated. it would be impossible for them to be two places at one time. >> so, they weren't in colorado at the time helene was killed? >> they were not in colorado at the time she was killed. >> why would somebody confessed a murder they did not commit? what would be in it for them? >> they were becoming famous and they knew they were going to spend the rest of their lives in prison, if not on death row. >> so, why not be there as the most prolific serial killers in the country? >> exactly. >> as for any other serial killers on the prowl back then none could be placed in colorado at that time. ted bundy actually had spent time there in the late 70s, but he was behind bars in florida at the time of helene's murder. the serial killer leads had dried up. was that disappointing when that didn't pan out? >> that was disappointing because we knew at that point we were again back at point zero with nothing to work on. >> it wouldn't happen quickly, but overtime, this case would go from point zero to 100, with a young detective up for a challenge. >> coming up -- >> what i focus on when i'm working a case, what drives me the most is the victims. i wanted to speak for them. >> a new investigator and a bold new approach. >> you're talking about hundreds of names here. >> hundreds, thousands. having a competitive athlete most of my life, i think really it was a competition between him and i. i knew i was going to find him. i wanted to win for helene. >> when "dateline" continues. with nucala. nucala is a once-monthly add-on treatment for severe eosinophilic asthma that can mean less oral steroids. not for sudden breathing problems. allergic reactions can occur. get help right away for swelling of face, mouth, tongue, or trouble breathing. infections that can cause shingles have occurred. don't stop steroids unless told by your doctor. tell your doctor if you have a parasitic infection. may cause headache, injection site reactions, back pain, and fatigue. ask your asthma specialist about a nunormal with nucala. ♪ it's the most wonderful time of the year ♪ ♪ non-drowsy claritin knocks out symptoms from over 200 allergens. without knocking you out. feel the clarity and make today the most wonderful time of the year. live claritin clear. my mental health was much better, but i struggled with uncontrollable movements called td, tardive dyskinesia. td can be caused by some mental health meds. and it's unlikely to improve without treatment. i felt like my movements were in the spotlight. ingrezza is a prescription medicine to treat adults with td movements. ingrezza is different. it's the simple, once-daily treatment proven to reduce td that's #1 prescribed. people taking ingrezza can stay on their current dose of most mental health meds. ingrezza 80 mg is proven to reduce td movements in 7 out of 10 people. don't take ingrezza if you're allergic to any of its ingredients. ingrezza may cause serious side effects, including sleepiness. don't drive, operate heavy machinery, or do other dangerous activities until you know how ingrezza affects you. other serious side effects include potential heart rhythm problems and abnormal movements. it's nice people focus more on me. ask your doctor about #1 prescribed, once-daily ingrezza. learn how you could pay as little as zero dollars at ingrezza.com ♪ ingrezza ♪ >> i'm katie phang with the hours top stories. day two of uaw negotiations wrapped after 13,000 workers walked out good auto plans in three separate states. they're striking for higher and more equal pays at gm, ford, instant atlanta's. there was some movement on raises, but no agreement. biden hopes for a quote, win-win agreement. thousands remain without power during two tropical storm early. -- >> 70 mile aryl hour winds in eastern canada and parts of new england. >> welcome back to dateline. i'm andrea canning. helene brzezinski was found murdered in a field outside of denver. police pursued every lead including what's happened to be to false confessions from two notorious serial killers. decades would pass before a tireless young detective picked up the case, and set her sights on a promising you suspect, back to josh mankiewicz with a promise to helene. >> her murder had become the textbook example of a cold case. but in 1998 a ray of hope sprang up, it came from a somewhat newer textbook, the use of dna evidence had become a revolutionary tool in criminal investigations. they realized, there was dna from their suspect in evidence. >> there was body fluids on these pieces of material or swabs from the autopsy that had not been tested and so we were very excited at that time because we had an abundance of dna evidence available to us. >> evidence that had been preserved even though you weren't testing for dna back then, no one was? >> no one was and to this day i give the credit to the colorado bureau of investigation crime scene techs that collected that evidence, had no idea what was going to be into the future but they collected it, they properly stored it and properly packaged it to where in 1998 we could open it up and scientists would say oh, that is perfect, let's use it. >> investigators were able to put that dna kit into the fbi's database of criminal profiles, known as codis. that is a huge lucky break. >> very huge. >> except, it doesn't match anybody in codis. >> doesn't match to anyone. >> spurlock in his team were disappointed and so was kimberly, but always mindful of the promise they had made. kimberly wasn't about to let the case freeze up again. >> i would jump on it and shake the trees and i was never met poorly, i was always met with welcome arms by the colorado detectives. >> she was key in connecting us to other people that we felt was very important to the case. >> in 2004, kimberly was arranging a reunion concert of there singing group harmony, to celebrate helene's birthday. when she had an idea. >> i said, it is time, we need to get this solved, let's fly out on the anniversary of helene's murder and retrace her steps in realtime. >> i mean, you know the detectives have done that before, probably right after the murder and a bunch of times since, what did you think you were gonna get out of it that they hadn't done? >> create a media stir in the news hoping that the killer would see us, we would know that there are eyes still on the case, make a lot of noise. >> four high school friends of a young woman murdered 26 years ago say there is still hope that their friends killer will be found. the plan worked, they made all the local news casts. >> 30 of us decided to band together to do whatever we could to make sure that this case is reopened and solved. >> they also set up a website about the case hoping the killer might click on it and reveal his internet address. >> that was our hope was just to get the worm to crawl out from under the rock. >> that didn't happen, the worm stayed hidden? >> he did. >> in 2009 her brother died, then her mom and dad followed in 2012. sister janet was the only one left. you've settled into this life where you don't know. >> right, it was heartbreaking. >> by june 2019, helene had been dead almost 40 years. the coldest of colorado cases. that's when a new detective shannon janssen was assigned to the case. >> what i focus on when i'm working a case, what drives me the most is the victims. >> jensen had been a competitive rower at berkley before she enrolled in the police academy and joined law enforcement, she got to know howling through all the pictures and information in the case filed. she was hoping to get to know someone else. >> what do you know about your unknown suspect, you know it's a man, you know he's between the ages of -- >> we don't know his age. we know that the witness said that he was in his early 20s, but ultimately nobody else saw him. >> detective jensen decided the key to all of this was the dna profile. she decided to consult with a genealogist, and upload the suspects profile into a website called gedmatch a site used to track them relatives. >> they allow law enforcement upload kits or dna, that dna is matched with other kids who opt in who want to assist law enforcement. >> so jensen started looking for any people with dna similar to that of the suspect. this is not just a matter of plugging jumbles of code into a computer, it's the equivalent of old fashion shoe leather detective work, but for the 21st century. that's because a similar dna profiles just another lead that needs running down. so instead of knocking on doors, jensen was picking up the phone. >> interesting, thank you for returning my call. >> asking for cooperation from possible distant matches. you're this disembodied voice on the phone saying tell me about one of your relatives who might be a murderer, and i need you to help me and give me some personal information. >> yes. >> would they be willing to share their entire family history on the chance they were related to a murderer? it's a big ask. >> and i would contact these matches and they would give me their family trees and any family history so we could fill and safer adoptions or unknown pregnancies. >> you're talking about hundreds of names here. >> hundreds, thousands. the people who spoke to me all said hey, if this is somebody in my family that did this, they should be arrested for the crime. there should be justice for this young victim. >> what's that like for you knowing your sort of pursuing this, this cipher? >> haven't been a competitive athlete most of my life, really it was a competition between him and i. i knew i was gonna find him, i wanted to win for helene. >> and by the fall of 2019, detective jensen seemed to be making progress. after speaking with contacts through the database and building those family trees, she had found a woman whose dna was so close to that of the killer she might be a first cousin. there was just one problem. >> that first cousin didn't really know her family, the family wasn't close. >> would there be any way to fill out that possibly critical family tree? the cousin put jensen in touch with another cousin. when you talk to that woman you think this is it, we're getting close? >> yeah, i knew, this is it, i'm on the right track, i'm gonna figure out who he is real soon. >> coming up. >> she's like, i know who did it, i'm like did what's? she's like, i know who the killer is for helene. >> the beer mug that just might seal this case. >> i was convinced, very quickly, by their determination. >> i mean the how the heart is pounding like oh my god, this is real, this is the guy. >> when dateline continues. long lasting relief in a scent free, gentle mist. flonase all good. also, try our allergy headache and nighttime pills. ♪ i gotta good feeling about this, yeah ♪ flonase all good. ♪ i'm with it ♪ ♪ i gotta good feeling about this ♪ ♪ yeah, ♪ ♪ so let's get it ♪ ♪ i'm feeling good vibes ♪ dupixent helps you du more with less asthma. and can help you breathe better in as little as 2 weeks. dupixent is an add-on treatment for specific types of moderate-to-severe asthma that's not for sudden breathing problems. dupixent can cause allergic reactions that can be severe. get help right away if you have rash, chest pain, worsening shortness of breath, tingling or numbness in your limbs. tell your doctor about new or worsening joint aches and pain, or a parasitic infection. don't change or stop asthma medicines, including steroids, without talking to your doctor. ask your specialist about dupixent. as someone living with type 2 diabetes, i want to keep it real and talk about some risks. with type 2 diabetes you have up to 4 times greater risk of stroke, heart attack, or death. even at your a1c goal, you're still at risk ...which if ignored could bring you here... ...may put you in one of those... ...or even worse. too much? that's the point. get real about your risks and do something about it. talk to your health care provider about ways to lower your risk of stroke, heart attack, or death. learn more at getrealaboutdiabetes.com [coughing] when caroline has a cough she takes robitussin. so, she can have those one on ones again. hey jim! hey! can we talk about your yoga breaks? sure. get fast, powerful cough relief with robitussin, and find your voice. ♪ robitussin ♪ >> kimberly had spent years determined to help solve her friend helene's murder, and she was nothing if not resolute. that said, fate tends to keep its own schedule. kimberly, with a husband and kids learned that in 2010. >> my oldest one went off to college, right the same week that my husband died, his dad and my younger one was 15 and fell into a deep depression. i didn't know how the price until he went off to college at northwestern university an end up taking his own life. >> it was a one two punch that would've crushed a lot of people. despite that, kimberly never lost sight of her friend helene. >> certainly no one would blame you for saying i still want to solve helene's murder, i still want to help to police, but that's on the backburner, now i have all of the things to deal with. >> that's when i became obsessed with dateline episodes because every tiny thing that i could pick up on on an episode i would immediately call douglas county or the colorado bureau of investigation and say did you think of this, did you look at that? >> at her desk in colorado, shannon jensen was asking questions of her own with a computer screen and a telephone as her tools. and she had tracked down a promising lead. she spoke with someone whose dna profile was close enough to that of the killer, that they were likely cousins. that cousin told jensen about two men who had been estranged from her family for years. >> there were two brothers and essentially i had to look at both of them. >> and as she started digging something stood out about one of the brothers. >> out comes the criminal history for curtis allen white. >> he was convicted of rape in the late 70s. >> he served times for right before he was parole to dulles county. >> douglass county colorado where she was murdered. it all fit. he was how older at that point? >> 21 when he was paroled here. >> same age as helene. >> yes. >> it was time to tell the tenant then boss of the cold case unit. >> i come around the corner i see her and she says i know who did it, i said did what? she says i know who the killer is for helene, and i'm like no you don't. >> he knew all about the investigative dead ends in this case, he had seen plenty of them over the years. >> i said how do you know you do and she understood the dna, she understood the genealogy, i didn't, so she had to explain it. while then there's still a little bit of doubt, you know, do i go upstairs, don't i? so i did. >> both of them made their walk upstairs to face the sheriff. >> and they said we believe we got it, this is the guy. >> you had been on the business end of a few other this is the guy kind of conversations where it didn't pan out? >> i was. >> detective jensen laid out her case, two brothers, only one in colorado at the time of the murder, and there was another thing. as jensen dug through white's criminal history, she discovered and old mugshot from 1998, remember that initial witness sketch drawn with the help of a hypnotist? you get the booking photo from 1998 in florida and it looks like the sketch, doesn't it? >> it looks like one of the sketches. pretty remarkably. >> those two, you could lay them over each other, it was the mustache, the hair, the eyes. it was so eerily positive. >> the sheriff was sold. >> i was convinced, very quickly, by their determination and i think also their confidence in what they had learned through this genealogy that this is the one we need to go after. >> the heart is pounding like, oh my god, this is real, this is the guy. >> they needed to find curtis white and track him to florida, where he had been living under a new name, james curtis clinton. >> he became james curtis clanton and went on with his life, got married, had a child, built a career for himself and just went on with his life as if nothing happened. >> and stayed out of trouble? >> yeah, pretty much. >> douglas county detectives went to florida to watch him. >> he's living in a trailer on somebody's property. we see his van he had a white van with a shark on the side of it, we knew that was his van, we see it, okay, we have his house. we have the van. >> when you're down there and you're surveilling this guy, the first time you see him you're thinking, that's helene's murderer right there, getting into his. truck >> yes. >> they surveilled a newly minted mr. clanton as he drove to a local bar to grab a beer. then, investigators asked the bars owner to save those mugs. >> he grabbed impotent in backs for us and met us at the back door and met us at the backdoor. >> three beer mugs? >> yes. >> the detectives brought the mugs back to colorado. >> do you say to the dna lab, this is it, step on it? >> they knew. colorado bureau of investigations they have been working on this case since 1980. >> everyone waited until finally shannon jensen got the call. >> the lab techs said hey, it's a match. one of them had your suspects dna sample on it, and it matched the semen that was left on the coat. >> what is that like? >> i don't even know if i can describe what it is like. it is extremely rewarding. >> and then, the bad news. the statute of limitation had expired on the rape, meaning clanton could admit to that with no consequence, and then, deny the murder. to make their case stronger detectives needed to get clanton to talk with them, so he and his team came up with a strategy. >> the plan was to go talk to mr. clanton and see if we can get him to come down voluntarily to talk to us and slow play into why we're really there. a technique we used is the social security number had been used in a large identity theft case. >> the officers wore body cameras. >> would you mind voluntarily coming down to the sheriff's office here in union county just to talk in a video recorded interview for a few minutes? >> after four decades, what would he have to say? >> coming up. >> have you ever lived on business in colorado? >> i lived in colorado many, many, many years ago. >> detectives on the hunt for answers. >> we do care about a young woman in colorado in 1980. and we want to, we want to show you a picture of her and see if you recognize her. >> would helene get justice at last? >> i lost it. i really freaked out. >> i just was paralyzed. i couldn't even breathe. >> when dateline continues. before advil. advil targets pain at the source of inflammation. when pain comes for you, come back fast with advil liqui-gels. -what even is this? -don't touch my things. gross. janice, when you bundle your home or renters with your auto, progressive provides 24/7 protection for almost everything you own. -but do you really need... -my weighted hoop? it's for my snatched waist. that's my dog chaise lounger. foot treadmill. that's my tuesday chalice. purse that says purse. hyperbaric oxygen therapy chamber. i can't live without oxygen. solid gold coffee machine. -lake making kit. -really? 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>> i lived in colorado many, many, many years ago. >> okay, well that's helpful. when was that, approximately? >> 79, 80. >> that was important, clanton was now on tape saying that he had been in colorado when helene was killed. it was time to change the subject. >> we do care about a young woman in colorado in 1980. we want to show you a picture of her, and see if he recognized her. >> no, sir. and i think i want an attorney now. you're accusing me of something else, i know. >> clanton stopped speaking with investigators. it didn't matter, his dna spoke for itself. >> we do have a warrant for your arrest. >> for what? >> first degree murder and kidnapping? >> you've got the wrong guy. >> we actually have your dna in her and on her. >> later that day janet pruszynski looked down and saw a colorado number on her phone. it was sheriff tony spurlock. >> he said we want to tell you that we found the murderer and so i lost it, they were saying -- i really, really freaked out, the realization that after 40 years there would be justice served and it was just hard to comprehend. >> because it's a relief but it's also reliving? >> exactly. >> lieutenant tommy barrella began escorting clanton back to colorado, as they spoke, the detective began gaining his trust. you're building a report with this guy. >> kind of, yeah. i'm just a personable guy. >> their suspect had clammed up in that interview room, then, suddenly seemed to have a change of heart. he wants to talk? >> he wants to talk and they want to talk, my gosh, you have to let them talk. >> as they drove to the airport, tommy barrella grab his iphone and pressed record. my name is lieutenant tommy barrella and jim advised me that he'd like to talk about the crimes that he is being accused of. >> he told tommy barrella that he wasn't surprised when detectives asked them about helene. >> because i knew that was gonna come up and get me one day. >> why was it gonna come up and get you? >> i killed the girl they're accusing me of killing. >> in that moment, i was like holy crap, it pinched me, he just admitted it >> he lay down the details of that cold evening, how he had seen helene coming out of the bus and forced her into his car. >> i put my arm around her and had a knife in my hand and showed to her. >> did she say anything? >> she said i'll go. >> helene, he said, was cooperative which explained her laugh of defensive wounds on her body. he confirmed that he raped and stabbed her multiple times, then left are in that snowy field. >> the fact that she was alive and on that bus was the only reason that he kidnapped, raped and murdered her. and >> he's gonna pay for that? >> yes. >> and clanton had one more thing to say. he claimed his life of crime could have been much worse, he said it wasn't. because something about helene had haunted him. >> you know, i got a conscience. and in my mind, i had actually took the step over to become a serial killer with helene. >> right. >> and i couldn't because of who she was and so -- i'm a serial killer of one. >> kimberly, who had made so many calls trying to keep the case alive, now received a call herself. >> i couldn't even breathe i wasn't jumping for joy, it wasn't crying, it was just pure shock. i just was paralyzed. >> after 40 years, the end came quickly, there was no trial, james clanton pleaded guilty to helene's murder, many of her friends and family traveled to colorado in july 2020 to speak remotely at his sentence hearing. >> she was never forgotten, her spirit never died. >> mr. clanton i sentence you to a sentence in the department of corrections for the rest of your natural life. >> and then they had a reunion of sorts, with some of the many investigators who had worked helene's case over the years. >> it was amazing to sit across the table from the mall and just soak in who helene pruszynski was in their minds. >> when we last spoke, janet said she still thinks about her baby sister every day. >> you're doing okay? you have grandchildren now? >> two grandchildren, yes. one of them was born on helene 's birthday, my granddaughter. >> what do you tell them about her? >> we have pictures of helene in the house, she's only five so i haven't said too much yet, but she will know a lot about helene. >> you finally have justice for helene and her family, all the victims that were left behind -- >> it's why you got into police work, isn't it? >> it is. >> after a 40 year crusade for answers, it was the truth that connected to women. the detective who took on a quest, and the friend who never forgot. >> helene needed to be heard. she needed people to know what happened to her. so she's not alone anymore. >> that's all for this edition of dateline. i'm andrea canning, thank you for watching. >> we begin this hour with breaking news in texas, where republicans in the state senate failed to hold one of their own accountable, voting to acquit attorney general ken paxton in his impeachment trial. this is once again a story of gop leaders prioritizing loyalty to the party over all else. impeachment articles accused paxton of misconduct,