of the most precious people on the planet. that's all for this edition of "dateline." i'm craig melvin. thank you for watching. i'm craig melvin. >> i'm natalie morales. >> and this is "dateline." ♪ this is a tragedy on top of a tragedy now. >> it happened so quickly. their parents in the backyard spa. their mom in trouble. >> my dad just panicked. >> a sudden slip. a fatal fall. >> you're losing your mother. you're watching her go right in front of you. >> someone else was watching her too. a curious neighbor. >> it was scary. the look on his face was almost undescribable. >> what had she seen?

was this drowning really an accident? >> she's got a huge gash on her head. something like that is not consistent with just falling down. >> a husband and father is suddenly under suspicion. >> he's crying and we're crying. he said, they think i hurt mom. >> three daughters stand by their dad. and one prosecutor stands firm. >> he's holding his wife of almost three decades under the water. my job is to get justice for cristi hall. >> was it murder? ♪ hello and welcome to "dateline a young woman peers into her neighbor's yard and sees something for a few mysterious seconds, a man a woman and the moment it's unsettling. what she saw and what she did would set in motion a chain of events that would divide a

family and a jury. here is keith morrison. >> we know the truth. and we know everything that happened. >> how do we know what we know? >> emotionally unsatisfying not to have that answer. >> so it is. even if we've seen something or we think we have. and that's the question at the heart of the whole puzzle. is this woman right? >> i know what i saw. and i know the conclusion of my story. >> of course she does. of course she does. so why does this other woman think this? >> she doesn't know for sure what she saw. >> a question, we say, on which all the rest will turn. why don't we begin here. calimesa, california, riverside county. historic missions. sprawling suburbs creeping out to the rim of mountains around the eastern flank of los angeles. here is where chris and cristi

hall had come to live out their golden years, though they were far from old when it happened. just experienced, with life and each other. >> as far back as i can remember, it's always been chris and cristi. they were never thought of as separate. they were a unit. >> these are the three daughters. courtmy brianna and ashton. and all have heard scores of times the story of how their parents met. it was 1978, christie had gone to see a relative at the air force base in nearby san bernardino. by chance while she was there encountered a security guard who, to her, looked just like elvis. it was christopher hall. chris to her friends. >> apparently she was a little flirty at the gate. >> in short order, chris and christi got married. she was 17, he 20. and as the girls grew up, they said they never doubted for a single moment the powerful bond

of love. their parents with them and them with each other. >> they were probably closer with our parents than most children. their the parents that i hope to one day be. >> chris, her perfect mirror. >> my dad is a little more kick back, relax and quiet, but they're a perfect balance, i think. >> yes. >> for years chris hall was a police officer in san bernardino until he was shot in the line of duty. then he went off to become police chief in two small towns in idaho. then in 2005 anticipating an empty nest and eventual retirement, the halls bought this place back in calamasa. life in the spring of 2007 seemed to have hit a sweet spot and ashton and brianna remember their mother telling them. >> we were laying on the bed with her. she just started talking.

she was like, i am just -- i'm so happy that i have you girls and dad. >> it was one of those conversations that you don't have every day. >> still, there was work to be done. it was not a new house. it could use some remodeling. particularly the bathroom. courtney was still living with her parents as the work began. >> they're going to be doing the tile work and stuff. so we wouldn't have a shower for that day. >> so, shower out of commission, they decided to wake up early, put on their bathing suits and rinse off in the outdoor spa before the contractor arrived at 6:45 a.m. it was june 7th, 2007. chris got up first, turned on the spa to warm it up, then called brianna at her college dorm in san diego. >> here's your wake-up call, babe. get out and go on that run. >> back at the house, courtney dozed through her first wake-up. while chris and cristi made their way outside to the spa. just after 6:30, chris looked in on courtney again. second call.

then headed back to the spa. life's last normal moments. 6:37 a.m. >> i got up out of bed. i was putting on my robe. i heard this panicked, panicked scream from my dad yelling for me. i ran down the hallway to the back porch and i saw him just trying to pull out my mom out of the spa. >> emergency. >> it was she who dialled 911 as she and her father struggled to lift her mother out of the spa. >> it was the first moments of the worst day of our lives. >> is it possible for people to understand what it's like to be in that situation? >> i don't think so. to see just both your parents in the worst times that you've ever seen them. obviously my mom unconscious. and my dad just panicked and for

the first time in my life, seeing him just that way, not knowing what to do. >> because he was a cop, he was used to dealing with those kinds of things. >> he was a cop used to dealing with those kind of things with people that were not his wife. >> so courtney took charge. after calling 911, she started cpr on her mother with her father. emt and firefighter eric norwood was the first to respond. >> he just started, help my wife, oh, my god, help my wife, help my wife. >> chris hall was kneeling at his wife's side, more in the way than anything, and so hysterical it was hard for the emts to help. >> it took us a little bit to get him out of the way. >> he didn't want to leave her. he kept holding her hand, yelling her name. >> the paramedics worked on her for 20 minutes. no vital signs. none. >> no words to describe the fear and the anxiety. >> you're losing your mother and watching her go right in front of you. >> we tried to save her together. we just couldn't. >> the ambulance rushed her off

to the hospital where she was declared dead. she had drowned in the family spa. a private family tragedy. except -- maybe not so private after all. someone was watching. ♪ "dateline" returns after the break. for an entire month. ask your vet for more information. reported side effects include vomiting and itching. nexgard. the vet's #1 choice.

the moment you realize your family grew but your washer didn't. at lowe's we have appliances to fit your family's lifestyle. backed by our 30-day satisfaction guarantee. but it's tough to gete enough of their nutrients. new one a day with nature's medley is the only complete multivitamin with antioxidants from one total serving of fruits and veggies try new one a day with nature's medley. i love you, basement bathroom of solitude, but sometimes you stink. febreze air effects doesn't just mask, it cleans away odors. because the things you love can stink. you need to power your wellness. new emergen-c probiotics plus. purposeful probiotics to help boost your microbiome, plus vitamin c to support your natural immune defenses. new emergen-c probiotics plus.

emerge and see. new emergen-c probiotics plus. ♪ protect your pet with the #1 name in flea and tick protection. frontline plus. trusted by vets for nearly 20 years. ♪ >> on the morning of june 7, 2007, brianna hall was on the

road home from san diego, driving from college, to what, she didn't know. except that her elder sister courtmy had called and it sounded bad. >> she said there was an accident and you need to come home right away. >> it was courtney who eventually broke the news to ashton and brianna. their mother, their father's wife of close to 30 years, was dead. but neither courtney nor chris waited at the house to tell the sisters what happened or to comfort them. more did they linger ore the body at the hospital. they couldn't. because father and daughter were escorted to separate squad cars and driven to the police station to talk about the accident. what was that ride like? >> quiet. i remember crying the whole time. i couldn't comfort my father. he couldn't comfort me. we got to the station and they said that my dad would be a few more minutes. >> chris, so frenzied at the

scene, had calmed down by then. he was a cop among cops, after all, and he understand, he said, what was necessary to sort out what happened. >> i can't even start to imagine what you're going through, okay? just, you know, it's a death investigation and we have to do this, okay? >> happy to help, he said. whatever would get him back home to comfort his daughters as quickly as possible. >> we're all so close. >> chris told investigators what happened. how, as courtney slept, he and cristi were in the spa bathing. >> she got out, went in, went to the bathroom, got some more coffee, tried to wake up courtney. courtney didn't wake up, apparently. she came back out. >> as cristi returned to the spa, said chris, they passed each other on the patio. he went in the house, stopped by courtney's room to make sure she was awake, then went right back outside and saw his wife floating face down in the spa.

he called courtney then, he said, and they began a frantic effort to revive her. from what, a fall? must have been. >> in your gut, tell me what happened. >> i'm thinking she slipped in. she slipped or something. i don't know. that's the only thing i can think of. >> but chris apparently hadn't noticed the nasty three-inch laceration on cristi's head. and here suddenly, the point of the police interview is revealed. >> the gash she has on her head -- >> she's got a gash on her head? >> she's got a huge gash on her head, okay? something like that is not consistent with just falling down. >> not consistent with just falling down? why would the police think that? >> i mean, you've been around for a while. >> i know where you're going. and no. there's nothing -- >> why in fact was this ex-police-chief being questioned at all about the apparently disastrous accident that killed

the love of his life? and the answer was right next door. when chris and cristi hall took their outdoor bath that morning in june, someone was watching. her. >> i got up at 6:00. got my coffee. >> lindsay patterson was on leave from her i.t. job in the navy, visiting her mom who lives just over the backyard wall from the hall house. lindsay was inside, in the bathroom that faced away from the hall house and out onto the street, when she heard a noise. >> it was a horrible scream. it was just, something was wrong kind of scream. >> a woman's, she thought. she went outside to tell her mom. i said, did you hear that scream? she said, yeah, but i think it's just kids playing in the -- playing in the pool. >> kids, at six something in the morning? lindsay walked over to the six-foot brick wall between their yard and the halls'. she stepped on the planter, she said, and looked over the wall. >> at that point i saw a man

with his hand, one hand on top of a woman's head and one hand on her back, and she was face down in the water. >> like something was going on? >> yeah, that's what i assumed. >> that is, she thought she was looking at a sex act in progress. >> i don't know why it didn't seem right. but something made me want to look again. >> that's 90 seconds, she said, between her first and second looks. this time, she said, she only saw the man in the spa. >> he's leaning back, just relaxed in the hot tub. but i don't see her. he's got his elbows back, he's kind of looking around like nothing. >> where did the woman go? lindsay told her mom something seemed strange. >> she again tells me, lindsay, stop being nosy, don't worry about it. but it just didn't seem right. it wasn't enough time for her to have gotten out and gone inside the house.

>> so, said lindsay, she went to the wall again. her third and final look. >> at that point he was getting out of the jacuzzi. and he was in a very big rush. she's still nowhere to be seen. the look on his face was almost undescribable. it was almost as if he had just gone into another world. it was scary. >> it was instinct that told her something was wrong, said lindsay. so she called 911. >> 911, state your emergency. >> a woman was killed. >> now, hours and hours later, the detectives confronted chris with lindsay's story. why, they asked, didn't her story match his? >> so am i supposed to believe the witness is lying? >> i'm not going to say she's lying. she sounds like a truthful kid or whatever. but i don't know. i can't explain what she's saying she saw. >> so now that question we posed as we began.

did lindsay patterson really know what she saw? "dateline" returns after the break.

your mornings were made for better things than psoriatic arthritis. as you and your rheumatologist consider treatments, ask if xeljanz xr is right for you. xeljanz xr is a once-daily pill for psoriatic arthritis. taken with methotrexate or similar medicines, it can reduce joint pain, swelling, and significantly improve physical function. xeljanz xr can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections, lymphoma, and other cancers have happened. don't start xeljanz xr if you have an infection. tears in the stomach or intestines, low blood cell counts, and higher liver tests and cholesterol levels have happened. your doctor should perform blood tests before you start and while taking xeljanz xr, and monitor certain liver tests. tell your doctor if you were in a region where fungal infections are common, and if you have had tb, hepatitis b or c, or are prone to infections. xeljanz xr can reduce the symptoms

of psoriatic arthritis. don't let another morning go by without talking to your rheumatologist don't let another morning go by are you ready to take your then you need xfinity xfi.? a more powerful way to stay connected. it gives you super fast speeds for all your devices, provides the most wifi coverage for your home, and lets you control your network with the xfi app. it's the ultimate wifi experience. xfinity xfi, simple, easy, awesome.

♪ after his wife's drowning death in a backyard spa, police asked chris hall to explain what happened that morning. what chris did not know was that his neighbor had also talked to police.

and she told a very different story than the one chris was telling. here again is keith morrison. >> chris and cristi hall's three daughters clung together in grief and shock, all through the dismal evening hours of that worst of all days, june 7, 2007. waiting for their father to return from the police station. and they wondered, why was it taking so long? then the phone rang. and they had their answer. >> you know, broken-up words, and he's crying, and we're crying. that was when he said they think i hurt mom. i mean, he was very upset. >> but he didn't sound surprised when he said -- >> no, he was crying. he was crying. he was upset. >> very upset. >> but by the time police investigators were questioning chris, remember, they had heard from lindsay patterson. and at the station, chris' version of events in the spa differed in one crucial detail from what lindsay described

seeing that first time she peered over the wall and into the hall's backyard. >> that specifically, me holding her down in there, there's nothing that took place in that jacuzzi that would explain that. there was no sex. there was no -- i don't even think we had any contact while we were in the jacuzzi other than when i was getting her out. >> but investigators were getting a good look at cristi's body and saw wounds that to them suggested a struggle and more than one nasty blow to the head. so the police had to choose. which version, chris hall's or lindsay patterson's, was more likely the true story of what happened? tom dove is a senior investigator for the riverside d.a. >> i think they felt this was enough to say this was not an accidental drowning. it was purely much more suspicious than that. >> and so before the night was over, chris hall was arrested and charged with the murder of his wife.

the girls could stop waiting. he wasn't coming home. >> it was obviously a tragedy, losing our mother that day. but this is a tragedy on top of a tragedy now. >> because knowing our parents, it's the farthest thing from truth. >> and one that felt infected by some kind of madness, said the girls. cristi was the love of their father's life. the center of everything for him. how could he be accused of harming her? she was happy too, they said, as happy as she had ever been, they said, based on matt mother/daughter talk they had not long before she died. >> she kept reiterating how happy it was. >> it was kind of odd. me and brie will always cherish that. >> didn't think much of it at that, but that being the last time we actually saw her -- >> kind of burned into your memories. >> yeah. >> but right or wrong, the legal trigger had been pulled.

chris hall spent almost two months in jail, until his daughters received the payout from cristi's life insurance policy and used the money to meet his million-dollar bail. then he went home to what was meant to be his retirement retreat with the help of his daughters to prepare for a murder trial. >> it's very surprising to have a client in a murder case out on bail. but he was a special man. and this was a special situation. >> these are attorneys who would eventually defend him, although at first they only heard about the case. steve harmon and paul gretch. you've said two things. special man, special situation. >> i think both of us can say this is a man that we like and we know. we don't feel he could have done anything like this. >> chris hall and his daughters prepared for a trial which they hoped would make clear to everybody, the police, the neighbor, the world, that chris would not, could not, did not harm the love of his life. >> there was never, in 30 years of marriage, never one moment of

violence. there was no motive for this man to kill his wife. >> they had a look at neighbor lindsay patterson's eyewitness account and suggested it was not conclusive at all. it was tragically incomplete. >> she saw three snapshots. what is missed by everyone is the wife getting into the jacuzzi, slipping, falling into the jacuzzi, hitting her head, going unconscious, and drowning. >> see this sharp corner sticking out into the spa? hitting your head on this would certainly have opened a gash and knocked cristi out, said the attorney. >> she didn't see what was really happening during the times when she was not looking. >> that scream that made lindsay patterson look over the wall? lindsay, they pointed out, was in a bathroom that faced the street. she wasn't in the backyard when she said she heard it. could have been anybody. and courtney, near the spa, inside her own house, didn't

hear a thing. >> we don't think she was lying. we think she misinterpreted what she saw. >> lindsay concedes she didn't know what she was seeing in those glimpses that morning. >> something was wrong. >> yet you hadn't really seen anything. >> no. but i knew something was wrong. i don't know if in my brain i was putting things together. but from between the scream, the position that he was holding her, and then just not having enough time for her to have gone inside. >> it's like you've got three different snapshots. >> right. >> of something going on there. >> right. >> and had to kind of work out what this was. >> yeah. i wasn't thinking at that point, oh, this man just murdered his wife. >> but now, based largely on that account, chris hall would go on trial for murder. and it was a trial for his daughters, too. >> he loved her. they were each other's best friends. and this is just -- this is not fair to him because he truly

loved her more than -- more than anyone. >> and yet the prosecutor was going to try to prove that this family man and former cop murdered his wife. could it be done? >> "dateline" returns after the break. today... back pain can't win. now introducing aleve back and muscle pain. only aleve targets tough pain for up to 12 hours with just one pill. aleve back & muscle. all day strong. all day long. happiness is powerful flea and tick protection from nexgard. nexgard kills both fleas and ticks all month long. and it comes in an easy-to-give tasty chew. so you'll be happy you're keeping your dog protected with nexgard. no wonder it's the number one choice of vets for their dogs and yours. see your veterinarian for more information on flea and tick protection you and your dog will love. nexgard. the vet's #1 choice.

my mom washes the dishes... ...before she puts them in the dishwasher. so what does the dishwasher do? new cascade platinum does the work for you, prewashing and removing stuck-on foods, the first time. wow, that's clean! new cascade platinum. whenshe was pregnant,ter failed, in-laws were coming, a little bit of water, it really- it rocked our world. i had no idea the amount of damage that water could do. we called usaa. and they greeted me as they always do. sergeant baker, how are you? they were on it. it was unbelievable. having insurance is something everyone needs, but having usaa- now that's a privilege. we're the baker's and we're usaa members for life. usaa. get your insurance quote today. in testing our performance line, we go to at the lexus golden opportunity sales event. lease the 2018 is 300 and is 300 awd for these terms. experience amazing at your lexus dealer.

...ancestrydna can pinpoint where your ancestors are from... ...and the paths they took, to a new home. could their journey inspire yours? order your kit at ancestrydna.com.

this is the hour's top stories. rudy giuliani is accusing michael cohen of violating attorney/client privilege by discussing his exchanges with trump. giuliani waived privilege when he talked about cohen's recordings of trump. john lewis is recovering. he fell ill on a flight to atlanta. he is expected to be released later today. now, back to "dateline." ♪ welcome back. i'm craig melvin. chris hall was charged in the

drowning death of his wife cristi. hall's daughters stood by him, proclaiming his innocence. would anything change their minds about their dad? here again is keith morrison. >> this is a hard-charging man, ex-member in good standing of the san francisco d.a.'s office, now senior deputy d.a. in riverside. that takes skill, persuasive power. he would need them in the murder case against the former police chief and family man, chris hall. >> mr. hall on the surface looks like a loving family man. he looks like a good father. he is somebody that had the support of his family. >> so he did. but he wasn't buying the loving father and family man bit. no. when he heard about chris hall's very obvious grief, the wailing that went on after the so-called accident, the phrase that crossed his mind was it's an act. >> i think it was a wonderful

performance by the defendant of acting like a bereaved husband, but when you look at his actions, how little he did to help his wife. >> who tried harder to save cristi? not chris, said the prosecutor, but his daughter. >> she called 911. she helped him get the body out of the spa. he had no interest in truly helping his wife. >> a matter of opinion, of course. but prosecutor strunsky poked around in chris hall's past as a policeman. and what did he find? >> this man had an uncanny ability to fabricate stories. >> seven years earlier, while hall was chief of police in cascade, idaho, he was charged with and convicted of misuse of public money, embezzled $19,000, spent ten months in jail. a white collar crime, hardly murder. but what struck the prosecutor is that he says hall tried to

cover it up. to plan a fraud, to lie about it, not just lie about it, but lie about it effectively. >> i think that was very telling about who we were dealing with. >> suddenly the prosecutor's prospects were looking better. at the trial, strunsky made lindsay patterson his star witness, of course. it was her story, after all, that got the whole thing started. but almost as important, he called the riverside county medical examiner who testified that those lacerations in cristi's could not in his opinion have been the result of a single accidental fall. and the m.e. argued the particular type of bruising on cristi's face and body was the hallmark of a homicide. >> the totality of injuries were not consistent with somebody slipping and falling and then a rescue attempt. >> and there was a clump of hair in the bottom of the spa, still entwine with a broken plastic hair clip. that, said the prosecutor, could have only come from a violent struggle. >> when you lose that amount of hair, it's not explained by any

kind of fall. >> there were minor hiccups in the case. lindsay patterson, for example, was a little inconsistent about how long she looked over the backyard wall that first time she saw something going on. was it just a few seconds? or as long as a minute? but either way, said the prosecutor, lindsay was sure she saw physical contact. that was the important thing. >> he was given the opportunity to explain any physical contact that could in any way reasonably explain what lindsay patterson saw. in other words, were they washing each other, were they involved in a sex act? was there anything she could have misinterpreted? and at the end of the day, you're not just stuck with the fact that lindsay patterson made a mistake. you have to actually believe that lindsay patterson really hallucinated about everything she saw. >> and what made lindsay's story all the more convincing, said prosecutor strunsky, was she told it before finding out what happened to cristi. she dialled 911 a full minute

and a half before anyone from the hall house did. before lindsay had any idea how it would end. here is what the jury heard her say in that call. >> and i saw him put her underwater and hold her there. >> and she was still on the phone with 911 when chris hall came outside and found his wife's body floating in the spa and called out for courtney. investigator tom dove. >> i heard it best described during the trial as a cosmic coincidence that someone could see something that they perceived to be more than just some kind of kinky action in a jacuzzi in the morning, and then that actually turn out to be true, that a woman was actually drowned in that spa. that is not a coincidence. that is what she saw. >> the prosecution's theory? somehow, sitting in that spa that morning, chris was overcome by some private fury, who knows what.

the hidden violence, is what strunsky called it. and then killed his spouse when he thought nobody was looking. >> chris hall ambushed his wife, grabbed her by the hair, slammed her head twice into the concrete edge. he's holding his wife of almost three decades under the water, showing absolutely no mercy, no remorse. an absolute desire to end her life at that point. >> and then the piece de resistance. >> he then gets out of the spa, walks into the house where his plan is to wake his 22-year-old daughter, who he can use as an alibi witness. >> one little quibble. why? in fact, as convinced as he was of hall's guilt, strunsky conceded the why was a problem. he didn't legally have to know, he said. but he just didn't. there it was. >> it's emotionally unsatisfying not to have that answer, not to

know the entire narrative of what happened. >> but you would want to know why this guy, married to this woman for almost 30 years, apparently happily, would suddenly turn on her and drown her in the pool. >> right. and i'm not sure we got the answers to that specific question. >> kind of an important question, isn't it? >> it's an important question, and a question that we ask in all spousal homicides. >> so, proof enough or reasonable doubt? almost three years after cristi hall's death, a riverside jury would have to decide. >> "dateline" returns after the break.

♪ happiness is powerful flea and tick protection from nexgard. nexgard kills both fleas and ticks all month long.

and it comes in an easy-to-give tasty chew. so you'll be happy you're keeping your dog protected with nexgard. no wonder it's the number one choice of vets for their dogs and yours. see your veterinarian for more information on flea and tick protection you and your dog will love. nexgard. the vet's #1 choice. but i am a simple farmer.bas! my life is here... [telephone ring] ahoy-hoy. alexander graham bell here...

no, no, my number is one, you must want two! two, i say!! like my father before... [telephone ring] like my father before... ahoy-hoy! as long as people talk too loudly on the phone, you can count on geico saving folks money. fifteen minutes could save you fifteen percent or more on car insurance. withwhat sore back?sk... what bum knee? advil is relief that's fast strength that lasts you'll ask... what pain? with advil

♪ chris hall's daughters sat through every miserable minute of their dad's trial for murder here at the courthouse in riverside, california. their review of the prosecutor's port trait of their father, it was a lie, they said. >> it was hurtful for us to hear someone to say he knows our parents better than we do and knows our father is a sociopath and that we're blind to it and he knows that there was hidden violent in our parent's marriage and we just didn't see it. you're basically telling us that we didn't know our whole lives we're alive. >> to top it off, there's no proof of that. >> chris hall had never been violent, argue the defense, had no motive, no reason to suddenly turn on his wife.

it had to be a freak accident. so, said the defense, lindsay patterson didn't really know what she saw. in fact, if she really witnessed chris hall drowning his wife, why then didn't she claim to see cristi's body in the spa when she looked again? it didn't make sense. but the highlight was the daughters' testimony, emotional, quite powerful. it put prosecutor strunsky in a strange position, at odds with the victim's own family. they were so clear, if we had any inkling he had done this, we would have done something, we would have said so, we would have seen it. >> and i think that's what they truly believe in their hearts. this weighs on my greatly. but my job is to get justice for cristi hall. >> now it was up to a jury to decide, after six days of testimony, two days of deliberation, they couldn't. it was a deadlock. the judge declared a mistrial.

chris hall walked out of court with his family free, but not quite in the clear. and nothing at all like a victory for the hall daughters. what was it like to get that hung jury? what did you think then? >> that was tragic. >> that was devastating to us. >> you expected a not guilty verdict? >> oh, yes. not a doubt. >> deputy d.a. burke strunsky was disappointed too. he was also determined to retry the case. but first he sent his investigator on a mission to explore the life and marriage of chris hall. and what do you know. in idaho, where hall had been a disgraced police chief, the investigator uncovered a startling accusation. >> chris was a great, great con man. >> former los angeles police officer jerry winkel is a county commissioner up in idaho now. but once upon a time he was chris hall's friend, that is, before a night of poker and booze when he said paul made a

disturbing revelation, that he had shot himself in the leg when he was a cop in order to get medical retirement benefits. >> chris had been drinking beer. he came out and told me that he had shot himself. >> but there was more. d.a. investigator tom dove had discovered a secret, not in chris' past, but in cristi's. >> there had been infidelity in the marriage in the past, six years prior. while chris hall was in custody in idaho. >> her affair was relatively brief, years earlier. but she had been in phone contact with the man just days before she died. had chris found out? impossible to know. but when investigator dove talked to cristi's co-workers at the clinic where she was an x-ray technician, several said they noticed a sudden change in her usually vibrant personality.

one co-worker offered them more. >> she told us that she was contemplating a divorce. >> if true, and it was only an if, it might well persuade a jury. prosecutor strunsky also needed to explain why lindsay patterson saw or didn't see. why didn't she see cristi's drowned body when she peeked over the wall a second time? >> we were not able to explain to the jury why she didn't see cristi at that point, and i think that allowed the defense to make the argument that cristi hall was inside. >> the prosecution hired a water expert to do a recreation of the hall spa. andrea has been assisting law enforcement with drowning investigations for 20 years. she got in the spa. >> from the center of the pool and towards where lindsay was standing, anywhere i was laying, you could not be seen from lindsay's viewpoint. so once i sank below the surface

and hit that bottom, you could not see me at all from lindsay's viewpoint. >> and now the prosecutor was ready. in may 2011, one year after the first jury deadlocked, burke strunsky went back to court armed with new evidence for a brand-new panel of hall's peers. jurors heard medical experts testify about the injuries to cristi's head and once again heard lindsay's 911 call. >> i saw him put her under water. >> cristi's co-workers testified for the prosecution. and jerry winkel travelled from idaho to tell jurors what he thought of chris hall. >> i was ashamed to admit he was once a police officer. >> if the prosecution had upped its game between the two years of trial, so had the defense. that's when well-known attorneys steve harmon and paul gretch entered the scene and came out swinging. that story about cristi's affair, for example? there's a shadow hanging over all of this stuff.

a very human sort of shadow, which is that she was having a little affair, right, had a boyfriend. >> yes. if the husband knew about it. but the wife never, ever mentions it and tells the husband. no one tells the husband. >> quite right, said the judge. and because there was no evidence that chris knew about his wife's affair, he ruled it out of the trial. the story about hall shooting himself for retirement benefits? >> that was just absolutely a lie. that's wrong. there was never, never any evidence or indication or not even a moment's breath that he shot himself. >> anyway, the story was prejudicial, said the judge, so he threw that out too. as for what lindsay patterson says she saw, chris hall holding his wife's head underwater, the defense had prepared its own visual demonstration, had taken pictures from her angle at the wall to show that it could look like two people were touching in

the spa even if they weren't. >> this is what she described seeing in her testimony. but on the close-up, what do you notice? >> they're not touching but they're in position where they could be. >> but that's different than actually touching. >> again, the hall daughters were there every minute. their father's enduring champions. and this time, more family members came to court. two of cristi's own siblings testified for chris. >> and said the same thing. we have not a doubt in our minds that this was not a moment of violence. this was not a murder. the victim's own sister and own brother. that's an amazing thing to see. >> perhaps it was. but listen to this. the defense had one more very significant witness. a witness who oozed credibility. the sitting medical examiner for neighboring san bernardino county, who stuck his neck way out to disagree publicly, in a

court of law, with the medical examiner from riverside. >> he found this to be an accidental death, not a homicide. >> this was not some ordinary hired gun. this was a public official who said straight out that cristi's head injuries could and perhaps should be explained by an accidental fall. he didn't rule out homicide? >> he didn't rule out homicide. but he said the preponderance of the evidence was towards an accidental drowning. border, if cristi had slipped and fell four or five blocks over, the pathologist in that county would never have filed criminal charges. an accident of geography. >> so now a second jury would sort through these two sets of allegations, these two opposing realities. and decide whether chris hall would turn and embrace home and

his loving daughters a pair of handcuffs and a life in prison. suburb -- "dateline" returns after the break. ♪ go your own way copd tries to say, "go this way." i say, "i'll go my own way, with anoro." ♪ go your own way once-daily anoro contains two medicines called bronchodilators that work together to significantly improve lung function all day and all night. anoro is not for asthma. it contains a type of medicine that increases risk of death in people with asthma. the risk is unknown in copd. anoro won't replace rescue inhalers for sudden symptoms and should not be used more than once a day. tell your doctor if you have a heart condition, high blood pressure, glaucoma, prostate, bladder, or urinary problems. these may worsen with anoro. call your doctor if you have worsened breathing, chest pain, mouth or tongue swelling, problems urinating, vision changes, or eye pain while taking anoro.

ask your doctor about anoro. ♪ go your own way get your first prescription free at anoro.com. get your first prescription free happiness is powerful flea and tick protection from nexgard. nexgard kills both fleas and ticks all month long. and it comes in an easy-to-give tasty chew. so you'll be happy you're keeping your dog protected with nexgard. no wonder it's the number one choice of vets for their dogs and yours. see your veterinarian for more information on flea and tick protection you and your dog will love. nexgard. the vet's #1 choice.

i've been making blades here at gillette for 20 years. there's a lot of innovation that goes into making america's #1 shave. precision machinery and high-quality materials from around the world. nobody else even comes close. now starting at $7.99. gillette. the best a man can get.

welcome back. chris hall's first trial ended in a deadlocked jury. but with new evidence presented by both sides during his retrial, the jury was able to reach a verdict. now, with the conclusion to our

story, here is keith morrison. >> may, 2011. for the second time, 12 men and women of riverside county, california, filed out of the courtroom, a second jury, to make a life decision about chris hall. did he murder his wife? which of the medical examiners should they believe? whose account of the defendant's character and, perhaps most important, what did lindsay patterson see when she peeked three times into the halls' back yard. >> do you ever have those sort of little dark moments of the soul where you think, i may have misinterpreted, misremembered -- >> it's something i've thought about every day, whether i misinterpreted, whether i think i saw something that wasn't there. i didn't see everything. >> yeah. >> but i saw what i saw. and i know the conclusion of my story. i know it. i know it. right here. i know it.

>> of course, chris hall's daughters say they know the truth too, real thing. in their hearts. >> i think that we were the three most critical jurors in that courtroom. believe me, if we had heard anything or had any inkling that our father could have done this, as much as it would hurt and as much as we love our father, we would want that justice for our mother. >> the jurors deliberated two days and then broke for the long weekend. it was memorial day. halls' daughters felt good. >> things can only go so wrong for so long before something actually has to go right for us. >> we just did a lot of talking

about the future and this, you know, being over, this being finished and honestly i was concerned about dad and how he was finally going to be able to grieve for the loss of his wife. >> then it was tuesday, 8:45 in the morning. the jury gathered. and minutes later, a signal. they were ready. chris hall and his daughters rushed to court. and in the end it was very quick. guilty of first degree murder. their father would not be coming home. probably ever. >> he was being cuffed. and potentially put away for life. and yeah, it hurts, and we are angry about that. >> you can still hear those daughters. >> i can. >> thinking you unfairly convicting their father. >> absolutely. it weighs on me. but at the same time, i know who i am dealing with when it comes to chris hall. in fact, he is the one that's stolen their mother from them. >> it had been a peculiar fact of this case that the victims' and defendants' families stood

solidly together against the prosecution. but what nunn knew was the truth was more complicated. after the verdict at chris hall's sentencing, a letter was introduced from one of chris hall's brother, billy carlton, who until now had said not one public word about the case. we would like to ask his honor for the maximum sentence, wrote billy. the pain that my family has suffered through this tragedy is unforgivable. >> i didn't want to hurt the girls. i had to say what was on my mind. >> there was a deep divide in the family, said billy. some of the relatives believed chris was innocent but he and he said others including cristi's uncle steve mundy urged on the prosecutor silently. >> half the family was convinced he was innocent and half was convinced he wasn't. that's hard to do when you have a big family and you all have to be together once in a while. >> when it involves a member as loved as cristi was. >> exactly.

>> does that explain why this kind of group of people in the family decided to just let justice take its course? >> we talked about it quite a bit. >> i think so. >> you've got to know when to show up sometimes and when not to show up, just to keep what's left together of the family as together as you can have it. >> thank you so much for coming. >> when it was over, hall convicted and sentenced to 25 years to life, some of cristi's relatives met with prosecutor strunsky and thanked him. >> thank you for putting him away because he is a murderer. >> and the hall daughters, having lost their beloved mother, fought to save a father they adored. >> it's a devastating reality, it really is. especially for a family that, you know, to say that we were close is an understatement, you know? to go from that to being not

able to be there with each other. it's -- it's the biggest heartbreak that anyone can ever experience, i think. that's all for this edition of "dateline." i'm craig melvin. thank you for watching. good morning. i'm dara brown in new york. it is 7:00 in the east, 4:00 out west. here is what's happening. new threats from president trump's lawyer who says former trump attorney michael cohen needs to keep quiet. taking care of business, why a court ruling threatens to blow the lid off president trump's financials. >> we need to know, whether the president in conducting business around the united states and around the world is