what has happened. he has to live with the weight of it. >> i set over and i cried. >> an in-depth look at the story that stunned the world. murder and the blade runner. >> olympic runner, oscar pistorius, is charged with the murder of his girlfriend. >> you realize she is not coming back and it hits you. >> you can't deny that reeva was killed by himself, at his house. >> what everybody will be watching for is whether he can prove he intended to kill? >> i did not kill reeva. >> you want to believe him, you really, really, really want to believe him. hello, and welcome to "dateline." reeva and oscar pistorius were a dazzling couple . she was a brilliant model, he was an athlete famous for defying the odds. their futures glowed with promise, then, reeva was gunned down. as police investigated, a chilling question transfixed the world, was her death an accident, or it was south africa's national hero a murderer? >> here is keith morrison with the rise and fall of oscar pistorius. such a time it was, like a different world looking back at this now. this was london. the year was 2012, and olympic history was about to be made. the moment was electrifying. in 45.44 seconds, a south african double amputee running on carbon fiber legs was transformed from global nobody, to international superstar, with a superhero nickname, the blade runner. he was oscar pistorius . >> he was just this amazing, amazing icon.>> and in south africa, he was adored. not just as a remarkable athlete, but as a man of apparently flawless character, modest, good manners, and a man of little words. resistant. i meant was almost wealthy, and certainly a list for a glorious eight months. and then, [ sound of gunfire ] four bullets at close range through a closed door. a woman was dead, and the mist of the blade runner was blown away. it was number 3:20 a.m. on february 14th, 2013, valentine's day. when police arrived at oscar's house, he told them a harrowing story. >> oscar pistorius, according to him, has suffered death threats, has been a victim of serious and violent crimes. >> the dark side of fame, he says, which is why he always kept a distal handy. karen covered the story for south africa's 24 hour news channel. >> he worked around with a nine millimeter gun with him all the time. >> that night, oscar was in his room, the gun at his bedside table when he suddenly is startled awake. he grabbed his gun, he said, got out of bed, without putting on his prosthetic legs, and went looking for the source of the noise. >> walked over to the bathroom, screams at this person he believes to be an intruder, get out of my house, get out of my house, and opens fire. >> right through the bathroom door. >> and then, he told the police he went back in the bed, sleeping with his new girlfriend, 29-year-old model and aspiring attorney named reeva steenkamp. that is when oscar said , he made a horrible discovery, reeva was not in bed . >> and it immediately dawns on him that she could be the person in the bathroom. he puts on his prosthetic limbs and tries to break down the door. he then picks up a cricket bat, which he also keeps in his room for protection against burglars or intruders, or whatever, bashes down the door with a cricket bat. >> inside, he says, he found reeva bleeding. >> she is slumped over, but she is still alive. he picks her up in his arms, carried her downstairs and she still breathing. >> she'd been struck by three bullets and by the time the police arrived, she was dead. oscar sobbed as he told the story. >> he did not mean to kill her. it was a horrible accident. and to quote his words, he is mortified to have taken the life of the person so loved by some of the people. >> detectives collected evidence, the bullet riddled door, the cricket bat, they found security camera video showing reeva arriving at oscar's gated subdivision at 6:00 p.m., followed 10 minutes later by oscar. on the coffee table, they found a valentine's day gift and card from reeva to ozzie, as she liked to call him. it was all such a terrible, tragic mistake, says oscar. but, too little details did not seem right. they found reeva's cell phone in the bathroom. why would she take that in there in the middle of the night, and more importantly, why was reeva dressed as if preparing to leave when she was shot? an accident, oh no, said detectives. this was no accident. >> double amputee olympic runner oscar pistorius was charged overnight with the valentine's day murder of his girlfriend . >> it was like an explosion, a huge nationwide shock. oscar pistorius charged with murder , how is it possible? a true hero, their international star in court like a common criminal, pleading to be released on bail. >> he walked into the dock and he was shaking. his entire body was shaking. he was overcome, sobbing, struggling to breathe. it did seem to be, because it was over three days, i don't think it would be physically possible for a human being to fake that over that length of time. >> was he telling the truth? was reeva steenkamp the victim of a terrible accident, and he of a miscarriage of justice ? millions hoped so, because if oscar was lying, there olympic hero must have been hiding a very dark side, indeed. coming up, the oscar pistorius that the public did not see. >> oscar walked up to him and just started screaming, off with him. >> fights, threats, and the fast crowd when "dateline" continues. continues. discover caplyta. unlike some medicines that only treat bipolar i, caplyta is proven to deliver significant symptom relief from both bipolar i & ii depression. and in clinical trials, movement disorders and weight gain were not common. caplyta can cause serious side effects. call your doctor about sudden mood changes, behaviors, or suicidal thoughts right away. anti-depressants may increase these risks in young adults. elderly dementia patients have increased risk of death or stroke. caplyta is not approved for dementia-related psychosis. report fever, confusion, or stiff muscles, which may be life threatening, or uncontrolled muscle movements which may be permanent. common side effects include sleepiness, dizziness, nausea, and dry mouth. these aren't all the side effects. in the darkness of bipolar i & ii depression, caplyta can help you let in the lyte. ask your doctor about caplyta. find savings and support at caplyta.com. (coughing) next! stuck at the dmv, and i think i'm late on my car insurance. good thing the general gives you a break with flexible payment options. let's get you a break while you wait. what is this place? this is our dmvip. vending machine charcuterie? is that guy getting a painted license? wait until the driving test. now that's a park job! for a great low rate, go with the general. norman, bad news... for a great low rate, i never graduated from med school. what? -but the good news is... xfinity mobile just got even better! now, you can automatically connect to wifi speeds up to a gig on the go. plus, buy one unlimited line and get one free for a year. i gotta get this deal... i know... faster wifi and savings? ...i don't want to miss that. that's amazing doc. mobile savings are calling. visit xfinitymobile.com to learn more. doc? keith morrison: it was like grief, in a way, first, shock, then here in south africa, denial, it was like grief in a way. first, shock, and here in south africa, denial as they are blade runner set at the dock, charged with murder. reeva steenkamp, a young woman just beginning to make a name for herself for fighting for domestic reviews-- abuse had been killed by her girlfriend-- boyfriend. all were trying to hang on to the fact that her death was a nightmarish accident, nothing more. >> this was a very conflicting narrative, because you want to believe him. you really, really, really want to believe him. >> it was a common desire. he must have thought he was firing at a burglar. >> the support has been overwhelming from all across the world. >> pete, oscar's manager, spoke to us two weeks after the shooting. >> it's support for him having lost someone really dear and close to him. >> then, then the questions, could they believe it, really? who was he, anyway? nbc's mary carillo was there with him when you beyond south africa even knew his name. >> is my face turning green? lol next >> he was happy, apparently all the time. >> you never have terrible days? >> not really. >> oscar was born without key bones in his feet and lower legs . his parents could have opted for years of reconstructive surgery, but instead decided to have oscar's lower legs amputated when he was 11 months old. it was a good decision in the end, says, oscar. >> i believe i've said some things in my life have changed, my personality come in a positive way, due to having a disability. >> as nbc cameras followed oscar around south africa in the weeks leading up to the 2012 olympics, he seemed grounded, humbled. he'd joined charities. this one dedicated to helping landmine victims. >> i've been very lucky to be involved in two projects in mozambique in the past where we have been able to get funding to make them prosthetic legs. >> i really had exalted this guy. i really thought that he was a game changer. >> "new york times" reporter michael scovel of spent a few weeks with oscar back then and he too was impressed. >> in oscar's home, there is almost an entire shelf of mandela biographies. oscar reads them. he's a smart guy. he is a literate person. >> just before those triumphant olympics, scovel witnessed a disturbance in oscar's life, he broke up with his longtime girlfriend, samantha taylor. here is a selfie of the two of them during happier times. olympics came first, he told samantha. >> he was too focused, too intent on this goal, and he did not feel it was something he could routinely break it off with her. >> after the olympics, oscar flew to the seychelles to film an episode of the south african so-called "top building." his accomplice on the show was samantha taylor, his old girlfriend, the one he broke up with before the olympics. certainly looks here as if oscar had patched things up with her now. >> it makes my life easier, spending time with someone-- you're very caring. >> your both blushing. [ laughter ] >> at home, of course, oscar was an item wherever he went. when he ordered a brand-new mclaren sports car, it was noticed, like everything he did was noticed. oscar clearly enjoyed the attention and began to spend more time with new friends. the solid coaches who raised him taught him humility, gave way to piles like billionaire financier clifton vandeberg, seen here on his reality tv show, "clifton shores" and there was nightclub owner and former ex-convict, kenny. >> i was a gangster! if you are out of it, it is easy to say that. >> kenny loved oscar, loved showing him off to a new cast of characters, not all of them home necessarily had oscar's best interest at heart. >> is that world at all dangerous for a newbie to become involved in? are there sharks out there? >> yes, everywhere there are sharks. >> many, he said, behind the wheels of fast and fancy cars. >> there's lamborghinis, porsches, there is mclarens, rose versus, trying to make very flashy. >> oscar loved speed of all kinds, fast people, fast cars. here at the local formula one race track, he met a fast crowd too. they'd rent the whole place for their private parties and races in the clubhouse. here, oscar met the kind of people he would have never met had he not been oscar pistorius . here, he met the people who pulled a thread from the carefully woven fabric of his life. in particular, his new friend, quinton brandenburg. oscar allegedly accused quinton of having an affair with samantha taylor, during the olympics that is, after oscar first broke it off with samantha. >> oscar walton, just started swearing at him, going, off with him. i'm running for my country. >> d.c. south african soccer star, mark batchelor. he told us quinton ever denied dating samantha taylor and he was so upset by oscar's outburst, he asked bachelor to speak with him. >> he was shaken up. oscar, what's going on? >> but, said, bachelor, when he phoned oscar-- >> what's the problem, you got a problem with me, i'm not scared of you. i said, you are out of your league. he said, >> i will break your [ bleep ] legs. i do not think anything of it. >> batchelor, by the way, had a checkered past himself, so he said, he knew the signs of a man losing his balance, hanging out with the wrong people . >> i know the crowd they were with and oscar got sucked in there. i was thinking, it became too much too quickly for him. >> there was a final breakup with samantha. friends say, she complained oscar was not pleasant at all. samantha's mother says she was afraid for her daughter's safety, but the public knew none of that. as far as his fans were concerned, oscar was on top of the world. so, when oscar pistorius walked the red carpet in november 2012 at the national sports awards show with this woman on his arm, the entire country wanted to know, who is she? coming up. >> reeva had a brilliant mind. she was smart, funny, all of those things, but she was brilliant. >> oscar and reeva's new romance into an old lane. authorities wonder could jealousy be a motive in this shooting, when "dateline" continues. line" continues. 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(♪♪) hey dave, don't knock it 'til you smell it. new gain relax flings. keith morrison: in police reports of the shooting, she is described as the victim. in police reports of the shooting, she is described as the victim. but according to her friends, that is altogether the wrong word to describe reeva steenkamp. reeva's brief journey to her tragic end began with a last- minute phone call to the most sought after celebrity in south africa. >> hi, i am oscar pistorius, and he needed a date at the last minute , so if you could just throw your stuff together and come and be my date. >> reeva was 29 when she lit up the red carpet at the south africa sports awards ceremony in november 2012. reeva had looks, no question there. according to her friends, that might have been the least of her attributes. >> reeva had a brilliant mind here she was smart, funny, and all of those things, but she was brilliant. >> gina myers was reeva's roommate, which may be understating their relationship. reeva actually lived with her and her parents. hoping to save money. also being far from home, she missed her family and it was comforting to be a part of somebody else's . >> she often told me how grateful she was for her upbringing. her family was very down to earth, the salt of the earth. they were very humble, and we were exactly, the exactly the same. >> reeva grew up on the small farm, tough enough to come back from the serious fall of a horse, she broke her back, spent eight months in the hospital and have to learn to walk all over again. she attended a devout and diverse catholic school, saint dominic's, where students are taught to be of service to the poor. by the time she entered the prelaw program at nelson mandela metropolitan university, reeva was primed to make a difference to be a part of the new south africa. but then, a relationship with a man, her first serious boyfriend, turned abusive, frightening, destroyed her self- confidence. >> she had spoken about having a previously abusive relationship. >> after a graduation to break free, riva-- reeva moved to the big city, johannesburg. lauren me hoover met reeva soon after she arrived in town and the two fell in love. >> how long did you go out together? >> four and half years. >> during which, reeva became determined to do something about the kind of domestic violence she expressed at the hands of that first boyfriend. warren encouraged her. shared her outlook and sensibilities. in one of life's weird twist, mark batchelor new reeva back then too . before then, reeva wanted to live out a fantasy. she had dabbled in modeling as a teenager and decided to give it another try before going on to law school. >> she was looking for what was going to take her places. >> reeva's career took off. she appeared in ads, commercials, videos, like this one from the men's magazine, " fhm." >> did she get a big head? >> no. >> she wanted for the first time in her life to be on her own. >> i was very busy, she was very busy. sometimes, you need a break. >> by then, reeva was speaking out publicly about domestic violence . she only knew oscar the way everybody knew oscar, as the electrifying blade runner in the olympic games. and then, pure coincidence, really, four months later the car dealer from whom oscar ordered that mclaren showed him a picture of reeva, suggested he might want to take her to the sports awards . it was like they were made for each other, both disciplined, hard-working, well read, hoping to put their fame to use for the betterment of others, oscar for landmine victims, and reeva, for victims of domestic violence. >> did you ever meet oscar? >> i did, yes. he seemed like a gentleman. >> and like a gentleman, warren graciously accepted his role of reeva's x and would occasionally meet her at a cafe to talk about old times. one of those passing encounters would forever be replayed in warren's mind. >> what did she tell you she was up to? >> she seemed like she was happy. >> perfectly innocent, says warren. but did oscar think so? mark batchelor had seen, he said, how jealous oscar could be about his former girlfriend, samantha. he told us reeva's friends believed oscar now felt the same way about her. >> there was talk about jealousy. she was protecting her ex, warren. >> was oscar jealous of warren, we don't know. but we do know this, that little coffee date warren had with reeva was on february 12, 2013, 36 hours before oscar killed her. coming up, prosecutors lay out the case. iphones, bulletholes, reeva's close, neighbors' stories. >> what everyone will be watching for his mother you can prove he intended to kill her. >> we would not have charged him if we did not believe so. >> when "dateline" continues. but this is my story. 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