were all there. the precious, chaotic rhythms of a family that once was. proof that there was a time when all was as it should be. proof, also, that time is gone, forever. and i'm natalie morales. and this is "dateline." case took us. >> one of the most extraordinary cases in lapd history. >> we are not in kansas any more, toto. >> as she walked away she gave me a big smile and i've relived that smile for years. >> reporter: and all that time the killer was hiding in plain sight. >> no indication she was ever spoken to? >> no. >> then a new detective took a look at an old lead.

>> he just said it's a match. >> a person no one would have ever suspected of murder. >> we were going to end this. >> was suddenly suspect number one. >> perfect murder. almost. hello. welcome to "dateline" she was. a new bride married just three months and she was found murdered. what happened to her remained a mystery for decades because police us thatfo theft mistaken killed during a break-in gone bad. they discovered it wasn't a murderd but a suspect whose trl led right to their own front door. here is josh mankiewicz with p "the smoking gun." >> february 1st, 2009, the detective arrived before dawn at

the los angeles police department's van nuys station. >> i was tired. i was tired. >> he had hosted a super bowl party the night before and the beer had flowed freely. >> that seemed to be a good day to have a cup of coffee and caught up on my reading. >> a couple of aspirin? >> maybe. >> reporter: he reached for a file sitting on his desk for months.hi of sherri rasmussen shot to death in her condo a few miles prosecute where he worked. >> up with of the worst most horrific crimet scenes i've se is this guy met a horrible ending. >> reporter: just asrr troublin sherri rasmussen was murdered a generation ago, february 1986, meaning the odds of catching her killer weref slim to none. >> memories fade. evidence has to be relocated.

so it's, obviously, a battle. >> reporter: uphill battle does not begin to describe it. the cold case the detective opened on that bleary-eyed monday morning would lead him on a w chase of a lifetime and sha the foundations of the lapd. dates back to 1986 and a battle for the truth by the parents of ah young bride. >> we miss her every day. >> reporter: those parents are nells and loretta rasmussen. >> doesn't make any difference what day it is. it's pain that is always there. there's no cure for. >> reporter: who. would want to kill sherri rasmussen? she was hard working, caring, and popular with her coworkers, trained as a nurse, sherri was director of critical care at a large local hospital. we are implementing the people difference program. >> it was a devastating day. she was 29 years old and just in

the prime of her career. >> reporter: ahthea kennedy was sherri's boss at the hospital and it originally hired her. >> we couldn't believe it, first of all. like how could someone do this? people crying. people upset. even the hospital was like a tomb, you know? so the loss was real pap panel. >> reporter: cher impsherri had married three months earlier to john ruetten. months after the wedding john found sherri sprawled dead. he was okayed. police determined this was a burglary turned violent. >> this was no accident. >> reporter:s yolanda mccleary

was a consultant to "dateline." >> multiple shots fired. shots fired at very close range. >> reporter: shecl has reviewed court records and media reports on this case. we returned withon her to the actual apartment where sherri was found murdered to try to understand what happened. police thinkun maybe the killer just walked in the open front door? >> they didn't find any forced entry d so, yes, they are assumg the frontye dorp was open and tt the killer just walked right in. >> reporter: right here where we are standinger is there some so kind of confrontation? >> yes. this appearsnf to be a struggle here. a not just a struggle but we also have shots fired at this point. we have one shot that clearly goes straight through this back slider and another shott that went through sherri and then back out through the slider also. >> reporter: so sherri isou now wounded and she tries to get back downstairs? >> that would be correct. she is bleeding profusely and very wounded and she gets down these steps and actually it

would appear she is trying to go out the door or make it to that alarm box where there is a panic button. at that point, we believe that sherri went down in this foy area due to the fact that you could see marks in this, as well as broken fingernails from her hands. >> reporter: so there is a tremendous fight going on? >> well, yes. the killer is actually dragging her back into this area and then the killeris takes a vase and hs her in the head with it, knocking herwi out, then grabs blanket, muzzles the gun and does a t contact shot into the victim. >> reporter: so that is an accusation? >> that would be correct. >> reporter: as for a motive? it seemed to be in plain sight. just a few feet from sherri's body. >> they found vcr and a disk player stacked one on top of the other in the frontn door. >> reporter: as if somebody was about to steal them? >> yeah, giving the indication this was a burglary or home invasion gone wrong. >> reporter: sherri's purse was

missing, as with her new bmw, an engagement gift from john. there was noge sign of the murd weapon t but detectives did recover two 38 caliber slugs and something else that caught the detective's tension. >> on the inside of sherri err left arm then found a bite mark and she swabbed that for a is a line va that could obtain to the killer. >> reporter: saliva that contained dna for anyone who bit sherri. remember, this was 1986, years before dna technology testing could arrive which could link a suspect to a w sample like this one so back then the dna wasn't much nahelp. but the swab was carefully packaged c and bundled with allf the other evidence. for now, detectives didn't have much elseec to work with. no eyewitnesses. no usable fingerprints. no cleare motive, except for

theory that this was a botched burglary. >> by the level of violence that occurred in this residence, the thorough was that it was a man or possibly two men that had entered the residence to do a burglary or home invasion that had not gone completely wrong, murders the victimet to cover u the crime and then fled. >> reporter: gone wrong because sherri somehow surprised them. theyur panicked. shot her. and then fled. the theory seemed to make sense, especially since sherri had no apparent enemies, certainly no one who want to kill her, or so they thought. coming up. >> we went to sherri's office and said if she couldn't have john, nobody could. >> reporter: when "dateline" continues. could. >> reporter: when "dateline" continues. wow, that's dialed in. i can still keep my eyes on the road. my truck doesn't have that. it offers an optional technology package with up to 15 different camera views. that's quality picture. it even offers one enhanced view

that makes your trailer appear invisible - to help you see what's behind you. oh, wow! which in this case happens to be the competition - since they don't offer the same amount of cameras as the silverado. literally in the rear-view. where they should be. ♪ thenot actors, people, who've got their eczema under control. with less eczema, you can show more skin. so roll up those sleeves. and help heal your skin from within with dupixent. dupixent is the first treatment of its kind that continuously treats moderate-to-severe eczema, or atopic dermatitis, even between flare ups. dupixent is a biologic, and not a cream or steroid. many people taking dupixent saw clear or almost clear skin. and, had significantly less itch. that's a difference you can feel. don't use if you're allergic to dupixent. serious allergic reactions can occur, including anaphylaxis, which is severe. tell your doctor about new or worsening eye problems,

such as eye pain or vision changes, or a parasitic infection. if you take asthma medicines, don't change or stop them without talking to your doctor. so help heal your skin from within, and talk to your eczema specialist about dupixent. pampers is here to help every parent love the changes a baby brings. [baby cries] pampers is the first and only diaper with air dry channels. they stay up to 3 times drier, so babies can sleep soundly...all night. pampers. with pronamel repair toothpaste, we can help actively repair enamel in its weakened state. it's innovative. my go to toothpaste is going to be pronamel repair.

♪ at progressive park! insurance themed fun ♪ my go to toothpaste children: yeah! announcer: ride the totally realistic traffic jam. ♪ beep, beep, beep, beep children: traffic jam! announcer: and the world's first never bump bumper cars. children: never bump! announcer: it's a real savings hootenanny with options that fit your budget. that's fun for the whole family. announcer: only at progressive par... maybe an insurance park was a bad idea. yeah. yep. skip to the good part with alka-seltzer plus. now with 25% more concentrated power. nothing works faster for powerful cold relief. oh, what a relief it is! so fast!

the year was 1986. crack was hitting los angeles and the city of angels had become a violent place. the murder rate would hit 831 killings that year. nearly three times the amount 30 years later in 2016 and the lapd was stretched very thin. >> this was a time where homicide was just booming in los angeles. >> reporter: miles corewin is a best selling author who has written several books with the lapd.

>> it's kind of a perfect storm of problems. he had the proliferation of high-powered weapons and crack cocaine hitting the streets and tremendous homicide rate and detectives are overwhelmed. >> reporter: in february of that year cops have their hands full with a heinous crime in the san fernando valley that was sprawling. 29-year-old sherri rasmussen had been brutally beaten and shot in her own home. no suspects and few clues. then a week later, a possible liter. former criminal variation yolanda mccleary was a consultant for nbc news. >> in the same vicinity, another woman was approached in her residence by two males at gun point, also involved a home invasion robbery situation, so police, early on, thought there was a possibility these two men might have something to do with the murder.

>> reporter: a composite sketch was released. the dna connected at the crime scene was useless, at least right now. police collected it any way. why? >> at crime scenes if you know is there possible evidence on anything you're not going to leave it behind so it was great forethought on their behalf actually to recover it. >> reporter: detectives scoured the condo and the entire complex. the only thing apparently stolen was from the garage, sherri's car, and that was recovered just a mile away from the crime scene with the keys still in it. the only other thing missing, sherri and her husband's marriage license. it seemed an odd thing to steal. cash, computers, and jewelry were not touched. but that wasn't the only thing that struck sherri's family and colleagues as strange. crime was especially violent for

a two-bit burglary. >> it just seemed a little like overkill. >> reporter: sherri's boss at the hospital, ahthea kennedy had to review sherri's autopsy report for insurance reasons and she was struck by what she saw. >> wow, she put up one heck of a fight, which wasn't real surprising because sherri was tall, athletic, and i'm sure wouldn't go down easily. >> reporter: the lapd theory back then was that there were two men robbing the house and so presumably sherri would have fought with two guys. does that sound like sherri. >> reporter:. >> that part didn't make sense to me because two men and two guns seemed weird. >> reporter: sherri wouldn't begin a fight with two guys who were armed? >> i wouldn't think so. >> reporter: what about with a woman? hawaii i think she would have

taken on a woman. >> we would really like to momeknow what happened. >> reporter: sherri's parents knew it it was a burglary. weeks before the burglary sherri had several strange encounters. one she dined at a restaurant and thought a woman was watching her. >> she said she has eyes that can see right through you. >> scary eyes. >> reporter: there was also a run-in at the hospital where sherri worked. >> she went to sherri's office and said that if she couldn't have john, nobody could. >> reporter: most terrifying, an encounter in sherri's own home and by now, she knew who the mystery woman was. >> she heard a noise and she looked up and there was john's ex-girlfriend. >> reporter: how did she get in the house? >> we have no idea. >> reporter: john's ex-girlfriend appeared to be stalking sherri, yet sherri never mentioned the woman's name

to her parents. instead, she told them not to worry. >> she told me, i want to see if i can't work this out myself. >> reporter: that conversation happened during a dinner celebrating sherri's 29th birthday. afterward, her parents should sherri to the airport. >> as she walked around, she turned and gave me a big smile and i've relived that smile for years. >> reporter: less than three weeks later, sherri rasmussen lay dead. the rasmussens insist that early in the investigation, they told the lead lapd detective about sherri's troubling encounters with john's ex-girlfriend. >> i told the detective not once, but probably 15 to 20 times and he said the trouble with you is you've been watching too much tv. coming up, old evidence offers new clues.

>> the suspect made it appear to look like a burglary. they staged it to mislead the investigation in 1986. she was executed. >> reporter: when "dateline" continues executed. . >> reporter: when "dateline"

years had passed and no arrests had been made in the brutal 1986 slaying of nurse and newlywed sherri rasmussen shot in her los angeles condo.

the trail kept getting colder. in 1993 sherri's parents would pay for the bite mark for dna but the blaped lapd declined. >> she said we don't have a suspect. if we had a suspect we would have something to match. >> reporter: so the case set for another decade. in 2004 the lapd was conducting cases on cold cases and one of them was the murder of sherri rasmuss rasmussen. it took two months to find that saliva sample buried in a refrigeration unit. the saliva was still inside and the dna was just enough to blow this case wide open. >> in that lab report, it indicated that the suspect that

had bitten sherri rasmussen during the struggle was a female. >> reporter: a woman, not two male burglaries as the original detectives had suspected all those years. but it would take a for you more years before investigators began to understand what that crucial dna test result meant. it was now 2009 and the case was cold once again. 23 years it sat with no apparent leads, no suspects, and no answers for the rasmussen family. then came that monday after the super bowl when detective jim nutall started peeking through that old case file and made a remarkable discovery. the dna test that had been conducted on that bite mark back in 2004. once the department realized a woman was involved, why did it take four years until you finally picked it up? what was the department doing in the interim? >> from what it appears,

investigators may have followed the initial theory of this crime, that, in fact, it was a burglary. >> reporter: and that there was a woman involved in the burglary? >> that there was a woman involved in the burglary. looking back now in hindsight, it was an opportunity that may have slipped through our hands as an organization. >> reporter: but now nutall took a closer look at the crime scene photos and began to develop his own very different theory. remember, sherri rasmussen was shot at point blank range after a violent struggle and despite the stereo equipment stacked by the front door, very little was actually stolen. >> the suspect made it appear to look like a burglary. they staged it to mislead the investigation in 1986. she was executed. >> reporter: in other words, someone had wanted sherri rasmussen dead. so now nutall dug deeper through the file looking for names, female names. >> we had five women that would have had access to sherri and

perhaps at least some of them may have had a motive to harm her. three of them we eliminated almost immediately for insufficient motive. >> reporter: but there were still two names left. one of them was a coworker. >> a woman named debra that worked with sherri rasmussen in the hospital. this person of interest was later placed by sherri rasmussen in an official capacity and problems followed almost immediately after that. >> reporter: so there was bad blood wean them? >> there was a motive. >> reporter: debra had moved to northern california. nutall asked local law enforcement to watch her and secretly try to snag a sample of her dna for comparison testing. in the meantime, nutall learned more about the second woman. he contacted john ruetten, sherri's former husband and now living in san diego. >> john involved he had been involved in a dating relationship with stephanie

lazarus. >> reporter: that was the other name on the short list of suspects. nut consist all pressed ruetten for more on their relationship which had started when they were both students at ucla. they dated on and off until john got engaged to sherri. even though you're convinces the relationship that john had with stephanie lazarus overlapped with the relationship he had with his wife? >> we know from john that there was at least on one occasion where he was engaged that he was intimate with stephanie lazarus. there was a love triangle and stephanie lazarus had deep feelings for john ruetten and may have had a motive to harm sherri rasmussen. >> reporter: was sherri's killer a scorned lover or a jealous coworker? >> we had two women on the list who, in our opinion, had a motive to harm her. >> reporter: debra, the nurse, and stephanie lazarus? >> correct. >> reporter: a few weeks later

cops tracked down debra and secretly scooped up a sample of her trash which contained dna. it was sent to the crime lab in l.a. for analysis and 72 hours later, came an answer. >> she was not the donor of the dna profile from the bite. >> reporter: that left just one possible suspect, number five on the list, john ruetten's ex-girlfriend stephanie lazarus. nutall called the rasmussens. >> we came home and there was a message on our phone from a detective that they wanted to talk to us. i thought oh, yeah, right. i thought it was just another false hope. >> reporter: this is detective nutall? >> right. >> he said that they were opening the investigation. >> nells was upset with me. it was like detective where have you been for the last two decades. >> reporter: now nells rasmussen explained it all. how he told detectives back in 1986 that someone was stalking his daughter sherri, a woman

with crazy eyes, the ex-girlfriend of sherri's husband. nells had never known that the girlfriend's name was stephanie lazarus. but he did know something else about her. something very important and by this time, detective nutall knew it too. >> he was very cautious of what he said. but he said that we would be hearing more from him. >> reporter: nutall had ample reason to be cautious. because he learned that stephanie lazarus wore the same badge he did. >> we now have a los angeles police officer as a person of interest in a murder case. >> reporter: and you thought i've bitten off more than i can chew? >> toto, we are not in kansas any more. that changed everything. >> reporter: coming up, a top secret investigation, as detectives go after one of their own. >> we would never leave a paper trail of what we were doing. she worked our unit. >> reporter: when "dateline" continues. unit. >> reporter: when "dateline" continues.

saturdays happen. pain happens. aleve it. aleve is proven stronger and longer on pain than tylenol. when pain happens, aleve it. all day strong.

there's a company that's talked than me: jd power.people 448,134 to be exact. they answered 410 questions in 8 categories about vehicle quality. and when they were done, chevy earned more j.d. power quality awards across cars, trucks and suvs than any other brand over the last four years. so on behalf of chevrolet, i want to say "thank you, real people." you're welcome. we're gonna need a bigger room. that could allow hackers devices into your home.ys and like all doors, they're safer when locked. that's why you need xfinity xfi. with the xfi gateway, devices connected to your homes wifi are protected. which helps keep people outside from accessing your passwords, credit cards and cameras. and people inside from accidentally visiting sites that aren't secure.

and if someone trys we'll let you know. xfi advanced security. if it's connected, it's protected. call, click, or visit a store today.

i'm dara brown. democrats released transcripts from depositions of two key figures in the impeachment hearing when will testify publicly on tuesday. jennifer williams and tim morrison. both were on president's july 25th call with the ukraine president. >> president trump made unscheduled trip to walter reed medical center on saturday. the president said he was undergoing medically tests as part of his annual physical. now back to "dateline." ♪ welcome back to "dateline." i'm natalie morales. sherri rasmussen had been murdered in los angeles back in the 1980s. from the youl soutset her parend the investigators about several runs sherri with had her husband's ex. now a cold case detective was

focusing his attention on that very same woman who also happened to be a member of the lapd. here is josh man ko witnesskiew more of "the smoking gun." >> for two decades the lapd had two theories that she was killed by a botched burglary and science rewrote the script and this cold case suddenly was almost too hoted to hand to han. the prime suspect was a lapd detective stephanie lazarus. as jim newsall went through the murder book he found almost nothing on lazarus even though she was the ex-girlfriend of the husband of sherri rasmussen. there was only one notation in the criminology in 1986. a detective had written stephanie lazarus. p.o., police officer, as if her

name had come up but not as a suspect. no notes of any conversation with her? >> no paper trail. >> reporter: she seemed to be someone above suspicion. stephanie eileen lazarus had grown up in southern, california, a tom boy of sorts and loved sports. she attended ucla where she played basketball p.m. it was during her college days that she met and dated john ruetten, long before he and sherri got married. after graduating in 1982, lazarus surprised her family by joining the lapd. this when only a handful of women entered the force. >> i don't think i knew that she was applying. >> reporter: stephanie's brother steven. >> i was very proud of steph. i thought it was a cool thing. >> reporter: stephanie lazarus quickly rose through the ranks of lapd from patrol officer to detective and she was popular, friendly, and well-regarded. her assignments also included project d.a.r.e., a drug

prevention program aimed at kids and twice named detective of the year. later she worked at internal affairs investigating other officers accused of wrongdoing or corruption and then promoted to the lapd's art theft unit. her personal life was good, too. in 1996, lazarus got married to another lapd detective. together, they adopted a baby daughter. life both at home and on the job never seemed better. >> she was a happy person. she loved what she did for work. she loved her husband. loved their life. >> reporter: but in 2009 this high achieving cop became the focus of a homicide investigation. jim nutall and his team of three detectives had to be mindful that lazarus had many friends on the force, her husband worked at the same station as nutall did. >> we were going to work behind closed doors and work after hours. we would never leave a paper

trail of what we were doing. >> reporter: they even gave lazarus a code name -- number 5. and contrary to police procedure, they decided not to tell lapd headquarters that their new suspect was a fellow detective. you're doing that to protect her or to protect your investigation from her? >> dual purpose. it would protect the integrity of the investigation and if she was not involved, then nobody would mp knever know about it. >> reporter: four cops knowingly department rules to investigate one of their own. >> it was a difficult phase of her careers. she was one of us. she worked our unit. had worked side-by-side with the people around us. >> reporter: but nutall and his three fellow detectives didn't waiver. they methodically built a case by exhaustingly the original files and interviewing sherri's friends and family and it became clear to them that stephanie

lazarus had the means, the motive, the opportunity to kill sherry rasmussen. she seemed obsessed with john and jealous of his new wife. was she the came person was the scary eyes stalking sherri. >> reporter: sherri's purse and all of its contents stolen during the crime were recovered soon after the murder except for one item inside. >> the only thing to this day that was never recovered was john and sherri's marriage certificate. >> reporter: after three months of intense secretive investigation, nutall's team needed one last piece of evidence that would either clear detective lazarus or incriminate her. >> we needed a certisample of h dna. our variations were not cut out for undercover surveillance work. >> reporter: so nutall finally brought lapd's internal affairs detectives into the loop, hoping

they could close the deal by somehow secretly obtaining lazarus' dna. she was tailed for days, as undercover cops waited for her to leave some small piece of herself behind. finally at a retail store, it happened. lazarus ordered a soft drink and drank it. a traipse of her saliva was on the straw which she then tossed in the trash. it was more than enough for testing. two dna samples separated by two decades. 48 hours later, jim nutall got call from his supervisor. >> it was real simple. he just said, "it's a match." >> reporter: good feeling, bad feeling? >> surreal. that moment, that call, never forget it. >> reporter: but stephanie lazarus was still free and no klee after 23 years her department was on her tail for murder.

detectives wanted to speak to stephanie to elicit a statement, perhaps a confession, but they would have to do it without revealing how deeply implicated she was in sherri rasmussen murder so another secret plan was hatched. this time to get stephanie's side of the story and all of it would be captured on tape. >> stephanie lazarus is asked by fellow detectives to help in an interrogation, only to discover she is the suspect. coming up. when "dateline" continues. when "dateline" continues. e diamond almonds. oh, come on! sriracha? woo! don't fight your cravings. eat 'em. all the flavors you crave in a superfood. blue diamond almonds. crave victoriously. geico would like to take a moment to say thank you to our military service members at home and abroad for all their hard work and sacrifice. we all sleep easier knowing you're out there

keeping us safe. and on a personal note... sfx: jet engines ... i just needed to get that off my chest. thank you. geico: proudly supporting the military for over 75 years. what's the time? device: a dime is ten cents. severe cold or flu? take control with theraflu. powerful, soothing relief to defeat your worst cold and flu symptoms fast. device: (sneezes) theraflu. the power is in your hands.

steven could only imaginem 24hr to trenjoying a spicy taco.burn, now, his world explodes with flavor. nexium 24hr stops acid before it starts for all-day all-night protection. can you imagine 24-hours without heartburn? i'm a verizon engineer, and i'm part of the team building the most powerful 5g experience for america. it's 5g ultra wideband-- --for massive capacity-- --and ultra-fast speeds. almost 2 gigs here in minneapolis. that's 25 times faster than today's network in new york city. so people from midtown manhattan-- --to downtown denver-- --can experience what our 5g can deliver. (woman) and if verizon 5g can deliver performance like this in these places... it's pretty crazy. ...just imagine what it can do for you. ♪

june 5th, 2009 started routineli routinely enough for lapd detective stephanie lazarus. she took the train to union station in downtown l.a. reporting for her normal shift that morning at police headquarters in parker center. after arriving, stephanie was told to meet with two detectives, the man she didn't know from lapd's elite robbery homicide division to help them interrogate a suspect involving some stolen art work which was stephanie's beat as a detective. so lazarus went down to a secured area in the basement to meet with her two colleagues in a small interview room. because it's part of the jail, all cops who enter here are required to give up their guns.

unarmed and unsuspecting, lazarus didn't realize she was being recorded by an undercover camera. >> i don't know if you know my partner. >> hi. >> have a seat. >> that is when detectives revealed that this conversation wasn't about art. >> down john ruetten? >> john ruetten? john ruetten? >> you said you dated john. how long did you guys date? >> i mean, what? are you -- is this something -- i mean, you said i was going to interview somebody about art and now you're -- >> reporter: detective lazarus seemed uncomfortable and vague in her answers, especially when detectives asked about sherri rasmussen. >> you know, i may have talked to her. i -- it -- it sound -- i. >> you anged in hospital maybe. you may have talked to her in a hospital? >> yeah. yeah. i may have -- you know, i'm thinking back now.

you guys are bringing up all of these old memories. >> reporter: detectives turned up the heat. >> did you ever fight with her? >> you mean like fight? >> yeah. did you ever duke it out with her? >> no, i don't think so. >> reporter: you'd remember that, right? that would be a pretty -- >> yeah, i think so. >> reporter: most of us can remember without much difficulty the number of fist fights we have had over the course of our lives, but while detective lazarus, at one point, answers no, when asked if she repairs attacking sher ining sherri or attacked, at other points she can't rule. >> it doesn't sound familiar. i mean what are they saying? i fought with her so i -- i -- getting the jump of the leap? they are saying, i fought had her so i must have killed her? i mean, come on. >> reporter: after about 45 minutes, lazarus realized she was the prime suspect in sherri's murder. >> now you're accusing me of this? is that what -- is that what you're saying? >> we are trying to figure out what happened, stephanie.

>> well, i was -- you know, i'm just saying. you know? i need to get a lawyer? you're confuaccusing me. >> reporter: moments later it came to an end as it must have felt uncomfortable as all of them. >> i know you guys have had to do your job and i guess i have to contact somebody. >> that's fair. >> i mean, because i know how this stuffed works. >> reporter: and then stephanie lazarus was read the same words she, herself, had read to hundreds of suspects over the years. >> stephanie, you know you have the right to remain silent? do you understand? >> yes. >> reporter: and for just a moment, you can see the handcuffed placed on her by her fellow officers. >> i'm like in shock. i'm totally in shock. >> reporter: word of lazarus' arrest traveled fast to tucson, arizona where deduct nutall was standing by to deliver the news to the rasmussen family. tell me what you said. >> you were right, folks. you folks were right and i

apologize that it took us over two decades to give them that closure. >> reporter: you feel better? >> the most gratifying moment of my career. >> i was extremely happy. i said, i feel like i knew it all along. >> reporter: back in l.a., the lazarus family also got the news. >> well, it was numbing. >> reporter: i'm guessing one of the things you said or thought was, they got it wrong somehow. this is a mistake. >> absolutely. >> reporter: some error has been made here? >> yes. it will be cleared up by the end of the day, yeah. >> reporter: it didn't happen? >> didn't happen. >> reporter: stephanie lazarus didn't go home that day after her arrest. bail was set at $10 million. much higher than most murder cases. the judge considered her a flight risk, citing the strong case against her. and for the lapd?

it was a bittersweet day. a 23-year-old cold case they believed had finally been cracked, but the prime suspect worked right beside them. for the rasmussen family stephanie's arrest brought back their memory of the original lapd. >> i think she was a police officer so they figured they would cover this one up. >> reporter: the family hired a prominent l.a. attorney john taylor who filed a lawsuit against detective lazarus and also the lapd claiming the department deliberately ignored crews that pointed to a fellow officer. >> the earlier missteps of lapd weren't missteps. they were intentional conduct, intentional ignoring of evidence, and intentional dereliction of duties, beyond yu bei just being sloppy or lazy joot fact they didn't close the case

and they didn't listen to the family, those two things are not evidence of a cover-up. >> it wasn't that they didn't close the case. they didn't do anything to create a case. >> reporter: he says that in 1986, the detectives were protecting stephanie lazarus. >> they actively covered up the identity of the person who committed this crime. >> reporter: the rasmussen's lawsuit alleging a cover-up was dismissed in 2011. charlie beck was then the lapd chief and he spoke with us about the case. >> i can accept somebody that is unable to solve a crime that is solvable. i cannot accept somebody that covers up a crime or covers up an individual involved in a crime and i have no -- absolutely no indication that is what happened here. >> reporter: there is intoing to suggest they deliberately looked away and stephanie or not a road they didn't want to go down? >> i think a lack of -- not an act to exclude stephanie.

>> reporter: in february of 2012, nearly 26 years to the days since sherri rasmussen murder, stephanie lazarus would have her day in court. a chance to clear her name and reputation and to show that dna isn't always right and that the los angeles police department had it all work. coming up, about the lapd have it wrong? >> john was -- and stephanie went to tell sherri, look, you guys are getting married, i'm telling him not to call me. >> we, the jury, in the above entitled action, find the defendant stephanie irene lazarus -- >> when "dateline" continues! ws and especially med d savers. select a medicare part d plan

with walgreens as your preferred pharmacy and get co-pays for as low as zero dollars and 100 rewards points on prescriptions. isn't saving great? save smartly on med d. walgreens. trusted since 1901. pets. ♪ [ gasps ] they see everything we do. whoo! [ screaming ] and they never say a thing. [ sighs ] well, i feel better. that's why progressive covers them in your auto policy at no extra charge. [ crying ] he only needed a spare. keeping you and your secret keepers safe.

skip to the good part with healka-seltzer plus.re. now with 25% more concentrated power. nothing works faster for powerful cold relief. oh, what a relief it is! so fast!

welcome back. there was a lot at stake at the murder trial of lapd detective stephanie lazarus who stood accused of murdering sherri rasmussen. the prosecution believed the dna evidence was their smoking gun. but the defense said it was tainted. what would the jury believe? here is josh mankiewicz with the conclusion of "the smoking gun." >> reporter: it took 26 years to get here. a generation of false leads, missed opportunities. a family's frustration. a police department's nightmare. february 6th, 2012, the people versus stephanie lazarus finally began in a courtroom in downtown los angeles. the prosecution laid out a clear case of how stephanie lazarus

was deeply in with john ruetten and was devastated when he became engaged to sherri and sh then executed her and covering it up by staging a burglary. linda doyle of the associated press covered the trial. >> the opening statement was quite dramatic by the attorney and he came up with a theme which was the case was about a bite, a bullet, a gun barrel, and a broken heart. and that kind of resonated in the courtroom. >> reporter: the jury saw journals police seized from stephanie's home detailing how upset she was when she learned john was engaged to someone else. stephanie's date book was also introduced which mentioned locksmithing books, that could explain why there was no forced entry to the condo. and on the day of the murder, then patrol officer lazarus happened to be off duty. the ammunition used in the

shooting was the same type issued by the lapd said prosecutors and was the same caliber of lazarus' off-duty weapon, a .38 revolver she reported stolen two weeks after the murder. the real smoking gun was the bite mark dna found at the crime scene. >> dna was definitely the centerpiece of this case. this shows she was there. without the dna, they could not have placed her at the condo. >> reporter: and the statistics were staggering. 1.7 sextillion to one chance that the dna belonged to someone other than stephanie lazarus. the defense attorney aggressively attacked that dna evidence and insisted it was mishandled and improperly stored and sealed which compromised the sample. >> the vile was protruding, rather than being inside the envelope and sealed in order to protect the integrity of the

evidence. you can't rely on the scientific results. >> reporter: overland said hair, blood, fingerprints found at the crime scene did not come from lazarus. the shots that were fired? he insisted several other types of guns besides stephanie that could have fired those bullets. as for motive? the defense argued there was no evidence that stephanie lazarus was object sessessed with sherr husband john. >> john was still calling her and stephanie went to tell sherri, look, you guys are getting married, i'm telling him not to call me. >> reporter: after five weeks, it was up to the jury. loretta and nells rasmussen had waited a long longer than that. the two of you feel confident? >> as confident as you can be with a jury. you never know what is jury is

going to do. >> we the jury in the above entitled action find stephanie irene rasmussen military of the murder of sherri rasmussen and find the murder was of the first-degree. >> reporter: the day the rasmussen family thought would never come, finally did. as their attorney john taylor explained. >> the family is overwhelmingly relieved that, again, their suspicions and today's verdict reflects and confirms the identity of the person who killed their daughter and the intent with which she did it. it's a tremendous relief. >> reporter: for the lazarus family, their wife, daughter, sister, and once decorated detective, was now a convicted killer. >> we really did not expect this result with the state of the evidence and the way mr. overland presented the case, so it's devastating.

>> reporter: for the lapd, a case was final solved but with painful side effects. >> i'm very pleased but it's bittersweet and i'm thrilled that the conclusion has been reached and that some form of justice has been brought to a family that has grieved for far too long. we would much rather this not be a los angeles police detective for sure. i've known stephanie for laf years. this is a tragedy on a bunch of levels. this is not something that we are proud of in that we had a los angeles police detective involved here. >> reporter: stephanie lazarus was sentenced to 27 years to life in prison appear as for that wrongful denial civil lawsuit that sherri rasmussen's parents filed against lazarus, they were awarded $10 million and so end theed the case of a detective finally caught by her very own department. she almost got away with it. >> the perfect murder. almost committed the perfect murder. >> reporter: and who better to do that than a police officer?

>> than a police officer. >> that's all for this edition of "dateline." i'm natalie morales. thanks for watching. i'm natalie morales. thanks for watching. >> nuclear terrorism. >> why was he killed? we follow the tale of a dark conspiracy. >> are you threatened for your life? >> we'll meet and confront the u prime suspect -- did you put polonium in the tea? >> -- and now is the dge