Was broken. Did the killer have a key . The question always was, how did the person get into the house . A decade later, in a state 1500 miles away, detectives finally found their answer. We got a dna hit. Reporter and more questions. We knew there was more to this story than just some guy coming from colorado to commit a murder and go back home again. Reporter did someone closer to home want her dead . Youre 99 sure that he had something to do with it, but theres no smoking gun. So many secrets still to be revealed. I know more about this than ive said. Reporter and one more killer still on the run. He knew what was in that house. He knew what he was doing. Doesnt get any worse than that. Reporter im lester holt and this is dateline. Heres Dennis Murphy with indiscretion. Reporter she was a bubbly woman in her early 20s just looking for a clean break. Heidi bernadzikowski, a baltimore pool league ace had, in recent years, endured some tough times. But now the shots were starting the drop. A steady job as a receptionist. A boyfriend she could take to meet the parents. Talk, even, of a Summer Wedding in las vegas. And then it was game over for heidi just like that. Someone had made their way into her rowhouse on a thursday night in april back in the year 2000 and killed her in most brutal fashion. Baltimore county 911. My girlfriends been murdered. What happened . Was she shot or no. Shes cut. Her throat, her throats cut. Any parent opens a door, 6 00 a. M. , theres two cops standing there, you know thats not good. Reporter it was a murder case that wasnt going to be solved in a few hours, or a few weeks, or even a dozen years. The heidi Murder Investigation would go stone cold until one day in a matter of hours really everything became clear. And how strange and terrifying it all turned out to be. When donna and walter bernadzikowski met at a church social, talk of a family even preceded the engagement ring. He used to scare the girls away by saying he wanted 12 children. And i said, well, i always thought i wanted to have 12 children. He says, oh, my god. Reporter they didnt have 12, but this devout Roman Catholic couple did raise their five in a baltimore, maryland suburb. High heidi, the only girl in a sea of brothers. When i hear that, i think poor heidi. Yep, yep. Reporter growing up with all those boys. Well, and we had friends that used to say to us, oh, she must be treated like a princess. And i said, are you kidding me . She had to be just about tough as they were. And she kept them in their place too, i mean. She wasnt treated like she was a Little Princess thats for sure. Reporter heidi grew up to be a happy, outgoing, athletic girl, surrounded by friends. It was a noisy, loving family with strict rules. Everyone at the table for dinner. Mass on sunday and no back talk. Heidis brothers frank and harold. Reporter true that your mom was known to wash out a potty mouth with a bar of soap . Or was that a metaphor . I got it. True. Reporter did you . True. Yeah. They were very strict. Definitely had a bar of soap from time to time. Reporter as she grew into her late teens heidi started to bristle under her parents strict house rules. By 19, she, the next to youngest, became the first to leave the family nest. But the grass wasnt greener. Right away, reality offered up a deadbeat roommate; and a succession of lowpaying jobs that evaporated like the morning dew. And yet she could always count on her girlfriends to buoy her up. And it was one night with her bffs shooting pool, she caught the eye of a guy holding a cue stick. It was Stephen Cooke. They were shooting against one another. And he noticed heidi in the bar. Reporter kim is Stephen Cookes sister. The first night they actually went home together. And three days later, they moved in together. Reporter fast. So its pretty reporter fast romance. It was really fast. Really fast. Reporter stephen was five years older than heidi. His sister says he could be quiet and shy but always wanted to be around heidi. They did everything together. I dont think they that they really did much without each other. Reporter in 1998, stephen and heidi moved to this rental townhouse in dundalk, maryland. Stephens dad steve sr. Says after living together for nearly two years, the couple was talking about taking the next step. Was it your understanding steve, they were going to get hitched . Yes, in vegas and every time i talked to them that was the their plans. It never changed. He loved her. Reporter the timing seemed good. Heidi had just gotten a promotion at the Insurance Company where she worked. She was finally a 9 00 to 5 00er after years of temping. She was just Getting Started or getting settled into a in each when things happened. Reporter strange things that rattled heidi. In april of that year, it appeared someone was trying to break into their townhouse there was chipping around a lock on their basement door. Looked like the doors had been monkeyed with . Yes. Reporter not long after that discovery of mischief on the locks, a stranger knocked at the front door one night saying he was forming a neighborhood block watch. He scared heidi so much that she told friends. And described the stranger as africanamerican with a tattoo. Stephen demanded new locks and keys from the townhouse management. They were installed on april 19th, 2000. The very next evening was when it happened. Are you sending somebody . Yes, i am. Just send somebody. Im going to. Just stay with me okay . Reporter an officer dispatched to their home saw heidi on the living room floor. Her boyfriend leaned up against the wall, cradling her, and crying uncontrollably. It appeared shed been strangled, her throat so severely slashed her blood had dripped through into the basement. And there was Something Else something mansonesque, scrawled on the wall in red lipstick above heidis body was the number one. Reporter when we come back a possible suspect. Im thinking, maybe, you know, this is our guy. Butcher. Heidis killed with a knife. And youll get there. 200 feet at a time. The corolla. Toyota. Lets go places. Mcdonalds is getting together a mix of fun new flavors this summer. With the new oreo frappe and the new real lemonades from mccafe. Brandon thinks hellmanns is heaven in a jar. Thats because our ingredients come from. Farmers committed to responsibly sourced oils. Blended with ingredients like cagefree eggs. Mmm. Heaven. Real ingredients. Thats how were working to bring out the best. What if getting ready was this easy . Now teethwhitening is with the colgate optic white toothbrush plus whitening pen just brush, whiten, and go no waiting. No rinsing. It deeply whitens for whiter teeth in 2 days. Optic white toothbrush plus whitening pen. Brush. Whiten. Go. Ava and i needed a little vacay. But we needed to watch our spending. Meaning i needed to watch nikki. Shes the spender. Im the saver. So, mobile banking from td bank helps me keep track. For both of us. She was just browsing. We gotta go. Im ava. Im nikki. And we bank human at td bank. What . Reporter a female Police Officer was the first on the awful scene. Shes seeing Stephen Cooke, holding heidi up against the wall. Hes got her wrapped in his arms. Reporter Stephen Cooke, Heidi Bernadzikowskis livein boyfriend of nearly two years, told the arriving officer that he came home that night only to find an apparently lifeless heidi in their living room. Nevertheless, he tried cpr. At 8 58 p. M. , hed called 911. Are you sending somebody . Yes, sir, theyre on their way, sir, okay . I want you to stay with me. No, no, i cant stay with you. I gotta go with her. Reporter Baltimore County homicide detectives al meyer and gary childs arrived later that night. It appeared to them heidi had been strangled. It was obvious her throat had been deeply cut with something sharpedged, probably a knife. When you get to a scene like that, detective, does it speak to you . Does it explain itself at all what happened here . Well, it was kind of an odd scene. The living room of the house was no Real Furniture to speak of. Up on the wall to the left of where heidis body was, was a number one written on the wall. So found that obviously to be odd. Shes number one and get ready cause because right, yeah. Here comes trouble, huh . Exactly. Reporter those first few hours left investigators wondering was this the first signature of a budding serial killer . Was there going to be a number two . Or was it Something Else . The house was tossed, yeah, ransacked. Youve got a potential motive of burglary. And youve got the other motive on the wall of a serial murderer. Reporter 20 miles away walter and Donna Bernadzikowski got a knock on the door at their severna park, maryland home. It was the police. And he says, you have a daughter heidi and, yes. You know, and i said, you know, whats the matter . You know, shes been in an accident . What you know, whats going on . And he said, heidis dead. It it was quite a shock, and i just started like pinching myself. Ive got to wake up from this dream. This has gotta be a dream. I think our whole world just changed. Reporter a short time later, stephens sister, kim, got a knock too. I remember running into the bathroom and getting sick. And i was kind of i couldnt i couldnt do anything. Reporter heidis boyfriend stephen, meanwhile, had been down at a Police Station the whole time being interviewed. Officers snapped this picture. His clothes bloodied he from trying to perform cpr and then cradling heidis bleeding body. Now, how much did you know about him or the victim by that point . Really a lot. Not a lot. We just knew they were in a relationship. The relationship was good. Reporter husbands and boyfriends are always persons of interest, but homicide investigators say stephen was cooperative. He told them how after his shift ended at a local lowes, he picked up heidi from her job in the car they shared, a 1994 red honda civic. It was 5 45 pm, he thought, when he dropped her off at their home. It was, he said, the last time he saw her alive. The detectives put together a timeline for the boyfriend whod run a bunch of errands after dropping heidi off. A stop at the atm, followed by a haircut, an oil change at a jiffy lube and then a swing by home depot for a plumbing piece needed to repair his sisters sink that night. He had time stamped receipts for virtually everything and turned them over to the police. Hes got a very solid alibi for his whereabouts from the time he left work until he picks up the phone and calls 911 . He does. But you still have to take into account, you know, it doesnt take long to do what had been done. You know, shes strangled and her throat is slit. You know, that could happen in a matter of seconds. Reporter after about six hours of police questioning, stephen went home. His sister remembers him being a wreck. I could certainly tell my brother was just a mess. He was devastated. I could see in his face that he was just looking attitude at him he had been crying. Reporter in the days that followed, al meyer and other investigators felt a serial killer unlikely the robbery gone bad theory too because there were no signs of a forced entry. But dna was found under heidis fingernails fingernails presumeably from her killer. Their hopes were soon dashed however when the sample turned out to be virtually useless. You had a mixture of dna from the victim and you had a mixture of the dna from the suspect. And the technology in those times was that you couldnt separate it. Reporter but detective meyer did have one suspect he was very interested in finding. That suspicious neighborhood block watch person. The dark skinned man with a tattoo whod scared heidi at her front door. And one person of interest was a local butcher. Reporter Terry Gilliam worked with stephens sister at a safeway just miles from heidis house. Im thinking, okay. Hes african american. Im thinking, maybe, you know, maybe this is our guy. Butcher, heidis killed with a knife. Reporter investigators theorized a connection through stephens sister. Theyre looking for somebody that comes to the door, did you ever go to heidis door and knock on the door . No. Saying youre from the Block Watch Association . No. Actually, i dont even know where heidi lived at. No, never knocked on her door. Reporter but the cops wouldnt just accept the butchers denials and be done with him. There were other reasons to dig deeper, including his work time card. A time was changed on one specific day. Its the day of the murder, one of his times is handwritten in. So the so the only day of the month . Everything else matches. Exactly. Now i have him not being able to account for himself the day of the murder. Reporter and there was Something Else heidi herself had said the suspicious block watch person had a tattoo on his left arm. Do you have a tattoo on your arm . Yes, i do. On your left arm . Yes. Terry, let me ask you now did you kill heidi . Definitely not. Reporter officials werent done yet with the butcher and heidis boyfriend Stephen Cooke remained a suspect too despite his receiptheavy alibi. A lot of time starts to go by. Doesnt it . Too much. Reporter at first months go by. Then years. More than a decade. No arrests. But there would be one advantage to the passage of time breakthroughs in dna technology. And that finally gave police a suspect. Who was shocked everyone. Reporter coming up its always the husband or the boyfriend, right . Apparently not in this case. The headline here is Stephen Cooke is not the guy . Right. Imagine she wont have to remember passwords. Or obsess about security. Shell log in with her smile. Hell have his very own personal assistant. And this guy wont just surf the web. Hell touch it. Scribble on it. And share it. Because these kids will grow up with windows 10. Get started today. Windows 10. A more human way to do. There are no medals won for earning a living. Its just what you do for family. But its hard to build a future if you cant see past today. Thats why walmart is investing in the most important part of our company our people. Because a raise in pay, raises us all. With the pain and swelling of my moderate to severe rheumatoid arthritis. Ordinary objects often seemed. Intimidating. Doing something simple. Meant enduring a lot of pain. If ra is changing your view of everyday things orencia may help. Orencia works differently by targeting a source of ra early in the inflammation process. For many, orencia provides longterm relief of ra symptoms. Its helped new ra patients and those not helped enough by other treatments. Do not take orencia with another biologic medicine for ra due to an increased risk of serious infection. Serious side effects can occur including fatal infections. Cases of lymphoma and lung cancer have been reported. Tell your doctor if youre prone to or have any infection like an open sore, the flu or a history of copd a chronic lung disease. Orencia may worsen your copd. If youre not getting the relief you need. Ask your doctor about orencia. Orencia. See your ra in a different way. Reporter as the years rolled by, the Heidi Bernadzikowski murder case got colder and colder. Detective al meyer was frustrated. He was promoted out of homicide but he never forgot the case. Even when he was in another unit, he would come back up to the homicide unit and go through the file. Never got squirreled away, huh . No, no. Never. Yeah, he never he never let it go. Reporter heidis grieving family was trying to get on with their lives, remembering her on her birthday by eating her favorite shrimp alfredo, but family events were hardly the same. You couldnt fully enjoy these special occasions because youre always painfully aware that you had an empty chair. You got an empty chair, that she should be there and shes not there. Reporter heidis boyfriend Stephen Cooke was trying to move on with his life as well. He married, had a child, and landed a steady job with veterans affairs. Hes got a normal life for the first time in a long while, huh . He does. Things are looking pretty good for him. Reporter then, in 2011, 11 years after heidis murder, meyer rejoined the homicide unit and once again cracked the file. This time, he and veteran Baltimore County detective gary childs got an idea. Technology had progressed and we knew now that theres a possibility that heidis fingernails macon taken some physical evidence. So whats the thought, lets run it again, see what happens . Yeah. The thought was to resubmit. Reporter to their surprise, the criminal database spit out a match. We got a dna hit. I couldnt believe it. Reporter but the hit wasnt for anyone in heidis known circle, even in her geography. It was a name completely off the radar from a state over 1500 miles away. They tell me its this guy, Alexander Bennett, from colorado. Colorado . And im, like, wow, thats not good. Im hoping its going to be somebody from baltimore, somebody that would be local. Did that name mean anything in heidis circle, Alexander Bennett from colorado . Never heard of him before. Absolutely not. No. Reporter baffled detectives started the dig. They called the colorado authorities and learned bennett was an unlikely suspected killer. In his early years, he showed promise as an opera singer. Performing recitals and winning a scholarship to the prestigious Manhattan School of music. After moving back to colorado though, hed gotten into some smalltime trouble. But then he did something just plain crazy. Hes a pretty talented guy, but he had some issues with the people he hung with and one of these issues was with a friend named grant lewis. Reporter in 2003, bennett and grant lewis had been arrested in a doozy of a scheme. Theyd called 911 and said that a friend of bennetts wanted to bomb the courthouse. But they went further, building a real bomb and planting it in his house. The bomb squad was dispatched and that friend hauled down to the station for an interview. Theyre grilling him pretty hard because thats kind of a serious crime. One of the detectives ultimately lets him listen to the 911 call and he recognizes grant lewis voice. So its not all muffled or disguised or no.