PRETORIA, South Africa — It came down to a question of improbabilities and a “great leap.” 
 
 On Monday, the fourth day of relentless cross-examination at his murder trial, Oscar Pistorius was taken back to the early hours of Feb. 14, 2013, when he shot his girlfriend, Reeva Steenkamp, 29, in what the prosecution says was an act of premeditated murder and the track star Mr. Pistorius, a double amputee, says was a mistake. 
 
 In close detail, the prosecutor, Gerrie Nel, had Mr. Pistorius, 27, relive the final intimate moments of Ms. Steenkamp’s life, as the athlete walked unsteadily on his stumps down an unlit passage from his darkened bedroom, a pistol in his right hand, and into a bathroom where he fired four rounds at the locked door of a toilet cubicle, believing, by his account, that at least one intruder was behind the door. 
 
 Then, Mr. Pistorius said, “I ran down the passage; I ran past my bed” to look for his girlfriend and call for help. 
 
 “When I realized that Reeva wasn’t on the bed, that was the first time I thought it might be Reeva in the bathroom,” Mr. Pistorius said. 
 
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 But, Mr. Nel said, the “first thing you would think is that you would check whether she left through the bedroom door” rather than assume she had been in the locked cubicle. 
 
 It required a “great leap” for Mr. Pistorius to go from believing that he had shot intruders to suspecting that he had opened fire on his girlfriend, said Mr. Nel, whose reputation as a pugnacious prosecutor has earned him the nickname pit bull. 
 
 “You see, Mr. Pistorius, this is one of the most crucial issues that makes your version so improbable,” Mr. Nel said, seeking to establish that the athlete’s evidence on the stand was, in the prosecutor’s words on Monday, “so improbable that it cannot possibly be true.” 
 
 The exchanges went to the core of a case that has drawn a global audience and transfixed many in South Africa as the hearings, which opened on March 3, focus in ever greater detail on the state of Mr. Pistorius’s mind in the early hours on Valentine’s Day 2013, when, the prosecution maintains, he killed Ms. Steenkamp in a jealous rage. 
 
 The spectacle of the trial also offered a stark counterpoint to the days of 2012 when Mr. Pistorius, a double amputee since infancy, not only triumphed at the Paralympic Games but also competed against able-bodied athletes at the London Olympics a month earlier, earning great adulation. On his return home, he and Ms. Steenkamp, a model and law graduate, were depicted as a gilded couple. 
 
 But that glittery trajectory of success and celebrity has collapsed. Headlines that once lauded Mr. Pistorius now focus on his increasing discomfort as a hard-nosed prosecutor sets out to paint a picture of inconsistency, improbability and mendacity. If convicted of premeditated murder, he would face a minimum prison term of 25 years. 
 
 Twice during Monday’s questioning, Mr. Pistorius broke down, as he has several times in the trial, his shoulders heaving as he sobbed. On other occasions, his voice quavered as he testified and, ashen-faced, he seemed on the brink of tears. 
 
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 But his displays of deepening distress drew only a sarcastic question from Mr. Nel, who asked, “You are not using your emotional state as an escape, are you?” 
 
 The prosecutor argued that forensic evidence linking the gunshots and Ms. Steenkamp’s wounds proved she had been standing in the cubicle facing the door when Mr. Pistorius opened fire. 
 
 “She was talking to you,” Mr. Nel said. “Why would she be there except if she was talking to you?” 
 
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 Mr. Pistorius said repeatedly that he had not known who was in the cubicle. “I didn’t fire to attack,” he said. “I didn’t have time to think.” 
 
 “You fired at Reeva,” Mr. Nel said bluntly. 
 
 “I did not fire at Reeva,” Mr. Pistorius said in a choked, strained voice, seeming overwhelmed. The court adjourned briefly to permit him to compose himself. But when the session resumed, Mr. Nel’s insistent questions did, too, despite objections from the defense that the prosecutor was repeatedly going over old ground. 
 
 Why had Mr. Pistorius not warned the intruders that he was armed, he asked. “You were armed but you never said you were armed,” Mr. Nel said. 
 
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 Mr. Pistorius replied that he had not wanted them to know. 
 
 Why, then, had he fired, Mr. Nel asked. 
 
 Mr. Pistorius said he had heard a sound like “wood moving,” perhaps when a door was opened or a magazine rack inside the cubicle was moved. “I wasn’t thinking,” he said. “I was screaming to the person or persons to get out.” 
 
 “You never gave them the chance,” Mr. Nel responded. “You said to them to get out, then never gave them the chance to do it.” 
 
 “I fired in quick succession,” Mr. Pistorius said. “I discharged my firearm as quickly as I could.” 
 
 So “why did you only fire four rounds?” Mr. Nel asked. “Why not empty the magazine?” 
 
 Was it just by luck, then, that the gun was pointed at Ms. Steenkamp, Mr. Nel asked. 
 
 “How could that be lucky?” Mr. Pistorius asked, choking up. “She lost her life.” 
 
 “Mr. Pistorius, you are trying to get emotional again,” Mr. Nel said, suggesting that the court adjourn for lunch. ||||| Sky News has obtained pictures inside the house of paralympian Oscar Pistorius - including images of the bloody bathroom where he shot his lover, Reeva Steenkamp. 
 
 The pictures have emerged as allegations that police officers involved in the investigation are being questioned following the disappearance of one of the runner's watches from his house. 
 
 This is the first time the public has seen the actual room where the athlete's model girlfriend was killed. 
 
 The images show a panel missing from the toilet door - and two police markers below the handle which indicate bullet holes - low down. 
 
 It is likely the defence will argue this backs up the runner's claims that he was on his stumps and shooting - from low down - at what he thought was an intruder. 
 
 The pictures inside the house show a trail of blood from the bathroom 
 
 The athlete has always insisted he and Ms Steenkamp had had a quiet night in together at his house, which is in a secure compound in Pretoria. 
 
 He says he got up in the early hours to bring in a fan from the balcony. But when he went back into the bedroom again, in the pitch dark, he says he heard a noise. 
 
 He has already told the Pretoria Magistrates' Court during his previous bail application hearing in February that he immediately believed there was an intruder in the house. 
 
 He says he grabbed a gun that he kept for security purposes in the bedroom and ran seven metres or so down the passageway leading to the bathroom, without his prosthetic legs on. 
 
 The tape shows two bullet holes in the bathroom door 
 
 There he fired four shots into the toilet door, which was closed. He insists it was only when he went back into the bedroom and realised his girlfriend was not in bed that it dawned on him it was her in the toilet. 
 
 The couple had only been dating a few months when the shooting on Valentine's Day happened. But the world's best known paralympian insists he was deeply in love with Ms Steenkamp and her death was a horrible accident. 
 
 When the athlete last appeared in court, he said when he realised his mistake he did everything to save his lover, battering the toilet door with a cricket bat to get to her. 
 
 The pictures inside the house show a trail of blood from the bathroom as the paralympian carried Ms Steenkamp downstairs after shouting for help, with flecks of blood on the wall, on the sofa downstairs and on the landing. 
 
 Oscar Pistorius during his bail hearing 
 
 There is also an image of the gift that the model had wrapped up ready to give the athlete. Stuck on the top of it, is a card with just one word - Ozzy - her nickname for him. There is a container of heart-shaped sweets too. 
 
 But the prosecution believes a very different version to the one presented by Oscar Pistorius. 
 
 It maintains the athlete's girlfriend ran into the toilet after a row with the sportsman - and he deliberately targeted and shot her - having taken time to put on his prosthetic limbs beforehand. 
 
 This act, the prosecution maintained at the bail hearing, was tantamount to pre-meditation. 
 
 Reeva Steenkamp was shot dead on Valentine's Day 
 
 Other photographs show footprints in blood. The investigating policeman, Warrant Officer Hilton Botha, has already admitted he walked through the scene without wearing protective foot covers, potentially contaminating the evidence. 
 
 Warrant Officer Botha was taken off the case after that emerged - as well as the news that he himself was facing seven counts of attempted murder. He has since retired from the police service. 
 
 Now, there are further allegations about the police conduct at the house. Two different sources have told Sky News that other officers are being investigated too after the disappearance of one of the athlete's watches from his house 
 
 The South African Police Service, when contacted by us, refused to comment. 
 
 But the latest allegations will only add to the impression that the initial investigation into the killing of Reeva Steenkamp was not entirely above reproach. ||||| PRETORIA, South Africa — It took just nine minutes on Tuesday for Oscar Pistorius’s defense lawyer to release him from anguished days and hours on the stand, and he did so with a last, loving message from the woman he is accused of murdering. 
 
 Invited to do so by his lawyer, Mr. Pistorius read out to the court in a halting voice the inscription in what the defense said was a Valentine’s card that the woman — his girlfriend, Reeva Steenkamp, 29 — had prepared for him shortly before he shot her in the early hours of Feb. 14, 2013. 
 
 The card was addressed to him by a nickname, “Ossie,” and included the lines, “Roses are reds, violets are blue.” Inside Ms. Steenkamp had written: “I think today is a good day to tell you that I love you.” 
 
 She had signed it with her name and “a smiley face,” Mr. Pistorius said. 
 
 On that note, his defense lawyer, Barry Roux, called time on almost seven full days in the stand, starting on April 7. They produced some of the trial’s Hollywood moments as the prosecutor, Gerrie Nel — whose pugnaciousness has earned him the nickname pit bull — sought to buttress the charge that Mr. Pistorius, a onetime Paralympic track champion, had committed premeditated murder. If convicted, the athlete would face a minimum prison term of 25 years. 
 
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 Even on Tuesday, the fifth morning of cross-examination, the combative Mr. Nel led the defendant back through the predawn hours when Mr. Pistorius, who had been an Olympic contender, loosed four hollow-point rounds into a locked bathroom door, and then began — by his account — to suspect that Ms. Steenkamp was inside. 
 
 In the wood-paneled courtroom here, Mr. Nel repeated his insistence that the athlete and his girlfriend, a model and law graduate, had argued and that Mr. Pistorius had fired at the door knowing she was standing on the other side of it talking to him. 
 
 Mr. Pistorius, 27, repeated that he had been aghast when he realized what he might have done. 
 
 Mr. Pistorius, whose legs were amputated at the knee in his infancy, said he had gone to find his prosthetic legs. He tried to shoulder the bathroom door open, he said, and then sought to kick it with his prosthetic legs. He grabbed a cricket bat to smash the door down, he said. 
 
 “I was crying out for the Lord to help me,” Mr. Pistorius said. “I was screaming for Reeva.” He added, “I was overcome with terror and despair.” 
 
 When the wood finally splintered, and he found her, “I checked if she was breathing, if she had a pulse,” he continued. “I heard her breathing and immediately tried to get her up and get her out of the toilet. I couldn’t pick her up, and I scuttled around with my legs.” 
 
 “I was crying. I was saying: ‘Baby, please hold on. Jesus, help me.’ ” 
 
 To the end, Mr. Nel maintained the derisive and dismissive tone with which he had pushed Mr. Pistorius into apparent contradictions, accusing him of lying, dissembling, changing his evidence and offering an improbable version of events. 
 
 “It’s got more and more improbable,” the prosecutor said Tuesday, shortly before he ended a cross-examination that frequently reduced Mr. Pistorius to tears and wails. 
 
 In a final summary of the prosecution’s case, Mr. Nel accused the athlete of fully intending to shoot and kill Ms. Steenkamp, his handgun loaded with Black Talon hollow-point ammunition. The couple had argued, the prosecutor said, and Ms. Steenkamp wanted to leave the house. “You were threatening her,” he said. 
 
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 In the face of Mr. Pistorius’s contention that the shooting of Ms. Steenkamp was a mistake, Mr. Nel barked at him: “So we shouldn’t blame you for having shot her. Who should we blame? Should we blame Reeva?” 
 
 “No, my lady,” Mr. Pistorius said, addressing the judge, Thokozile Masipa, as is the courtroom practice in South Africa, where there are no jury trials under a system of law dating to the first arrival of Dutch settlers in the 17th century. 
 
 “Should we blame the government?” Mr. Nel asked with heavy sarcasm. “You must blame somebody.” 
 
 “I believed there was someone coming out to attack me,” Mr. Pistorius said. In the courtroom, a grisly police photograph from the crime scene showed the toilet with blood smeared on the bowl and a pool of blood on the floor. 
 
 At the start of the session on Tuesday, Mr. Nel asked Judge Masipa to postpone the hearings until May 5, starting with an unspecified date later this week when many South Africans wind down for a four-day Easter weekend break. Judge Masipa said she would rule on the request on Wednesday. 
 
 The cross-examination has left the defense reeling, and Mr. Roux set about rebuilding his case with the Valentine’s card — an image of a loving couple to counter the nightmare visions conjured by the prosecution of a raging Mr. Pistorius stomping around his darkened, upscale home, brandishing a cocked and loaded handgun as Ms. Steenkamp screamed in terror. 
 
 Mr. Roux then is likely to construct a painstaking defense, with a series of witnesses seeking to rebut Mr. Nel’s accusations. Ultimately, Mr. Pistorius is the only witness to what happened — and that is what has made the credibility of his version of events so important. “You are the only person who can give us a version of what happened,” Mr. Nel said on Tuesday. 
 
 First, though, Mr. Roux sought on Tuesday to re-establish his client’s most basic argument: that the killing had been a dreadful accident. After Mr. Nel ended his cross-examination, Mr. Roux rose briefly to re-examine. 
 
 “Could you explain to the court, if you talk about an accident, can you explain what you meant by that?” Mr. Roux said. 
 
 “It wasn’t meant to be,” Mr. Pistorius replied.
– It's day two of Oscar Pistorius on the witness stand, and if you're wondering, yes, he did once again reportedly vomit in court at the sight of photos of Reeva Steenkamp's body. Yesterday's session was adjourned early due to the athlete feeling "exhausted," but today doesn't seem to be shaping up to be much easier. In this morning's testimony, Pistorius walks the court through some troubling texts (they were sent on a "bad day," he says) and read out loud more mundane and loving ones, while crying. "I miss you more than anything," Steenkamp wrote on one occasion. "I replied with smiley faces and kisses," he says. One word getting a good deal of attention: "besotted." That's how Pistorius described his attraction to Steenkamp from the get-go; "I think I was maybe more into her than she was at times with me,” he said, per the New York Times. After the lengthy text-reading session, Pistorius started to walk the court through the events of Feb. 13 and 14. He says he put on his pajamas around 7pm, after having dinner with Steenkamp. She did yoga on the bedroom floor; he called a cousin and discussed cars. They both went to the bathroom, then went to bed. "Reeva was sitting up and I was lying with my head on her stomach." The two also exchange Valentine's Day gifts, but he didn't open his that night. He ultimately unwrapped his—four framed photos of the couple—on Steenkamp's birthday in August, reports the Telegraph. The fateful moment, as he tells it: "I heard the window opening in the bathroom. That is the moment that everything changed. I thought a burglar was gaining entry into my home. The first thing that ran through my mind was that I needed to protect Reeva and myself." He says as he moved toward the noise he screamed at the intruders and "shouted for Reeva to get on the floor. ... Just before I got to the bathroom heard a door slam. It could only have been the toilet door. It confirmed that there was a person or people inside the bathroom at that time." Court was then adjourned for lunch. The BBC expects him to be cross-examined this afternoon. One other notable moment from the morning: His lawyer had Pistorius remove his prosthetic legs. The Telegraph describes it as "a poignant demonstration of ... his vulnerability on his stumps to lodge in the judge's mind as she listened to his description of events."