PRETORIA, South Africa -- Oscar Pistorius refused to look at a photo of his dead girlfriends bloody head wounds while testifying at his murder trial Wednesday as the prosecutor urged the star athlete to "take responsibility" for killing her. Puma Shoes Clearance Sale . "Its time that you look at it," chief prosecutor Gerrie Nel said, setting the stage for a rigorous first day of cross-examination of Pistorius, the double-amputee Olympian charged with premeditated murder for shooting Reeva Steenkamp three times through a toilet door at his home. "I remember," Pistorius said of Steenkamps bloodied head, becoming distraught and then crying as he turned away from the gruesome image of the injuries he inflicted that were displayed next to him in a packed courtroom in South Africas capital. Nel said Steenkamps head "exploded" when it was struck by one of four hollow-point bullets that Pistorius fired through the door on Feb. 14, 2013 with his 9 mm pistol. The showing of the photograph on TV screens in the courtroom caused gasps among spectators, who included Steenkamps mother, June. The police photo showed a side view of the dead model and reality TV stars head, with a mass of blood and human tissue on the back and upper parts. Her eyes were closed. "I will not look at a picture where Im tormented by what I saw and felt that night," Pistorius said. "As I picked Reeva up, my fingers touched her head. I remember. I dont have to look at a picture, I was there." Pistorius, 27, says he shot Steenkamp in the pre-dawn hours on Valentines Day -- in the head, arm and hip -- by mistake thinking she was a dangerous intruder behind the door in his bathroom about to come out and attack him. Prosecutors charge he killed the 29-year-old intentionally, and Nel aggressively questioned Pistorius for the first time. "You killed her," Nel said. "You shot and killed her," and he asked Pistorius to say it. Pistorius would not, saying merely: "I did." Pistorius faces a possible prison term of 25 years to life if convicted of premeditated murder. Nel also showed a video, first broadcast by Sky News days before the trial started, of the celebrated athlete firing a gun at a watermelon at a shooting range. On the video, Pistorius can be heard saying the melon was "softer than brains" after it explodes when the bullet hits it, and calling the powerful .50-calibre handgun he was using a "zombie stopper." Referring to the watermelon, Nel said to Pistorius: "You know the same happened to Reevas head. It exploded." Defence lawyer Barry Roux objected to the gun video being shown, saying it was inadmissible character evidence and amounted to a legal "ambush" of the defence. After the dramatic start, prosecutor Nel also started to poke holes in details of Pistorius version of the events of the fatal night. The champion runner said that his claim in a court document a year ago that he went out onto a balcony at his home before the shooting was incorrect. Pistorius said he went to the edge of the balcony but not outside. The discrepancy could be significant because Pistorius says he heard a noise in the bathroom that alerted him to a possible intruder, which would have been harder if he was out on the balcony. Nel tried to pin down Pistorius on whether he meant to fire into the toilet cubicle door at a perceived intruder, or whether his gun discharged accidentally. Pistorius said he didnt intend to shoot "anyone" and that he fired "before thinking" because he thought his life was in danger, prompting Nel to accuse him of weighing the legal implications of the question before answering. The dogged prosecutor implied that Pistorius, who grew more agitated, was becoming emotional because he was faced with a difficult question. The judge noted that Pistorius had been emotional throughout the trial. Pistorius told his questioner that he was trying to be careful with his answers because the stakes were high. "My life is on the line," he said. Nel retorted: "Reeva doesnt have a life anymore because of what youve done." And Nel tried to dismantle a sympathetic image of Pistorius that the defence had sought to build up in three days of testimony, asking the athlete to explicitly acknowledge that he killed Steenkamp. "I made a mistake," Pistorius said. "What was your mistake?" Nel shot back. Pistorius then said he "took Reevas life." Nel also questioned the defences portrayal of Pistorius as a good role model. The prosecution depicts him as an angry hothead with a gun obsession. The prosecutor asked Pistorius if people looked up to him as a sporting hero, if he would hide anything and if he lived by Christian principles. "Im here to tell the truth, Im here to tell the truth as much as I can remember," Pistorius said. He also said: "Im human. I have sins." Discount Puma Shoes Sale . The NFL announced Friday that the Texans sixth-year veteran offensive lineman will replace Philadelphia Eagles tackle Jason Peters in the Jan. Puma Shoes Wholesale China . They wanna make t-shirts about it and sell them at our next hockey game..DB: Wow, they want to make t-shirts? That sounds pretty amazing.MS: Yeah, I was also on the Top 10, I was number 1 today, so that was pretty cool. http://www.cheappuma.net/ . Trailing 2-1 from the first leg, Fiorentina levelled on aggregate in the 14th minute when Joaquin Sanchez Rodriguez headed back a long ball from David Pizarro and Pasqual smashed home an angled volley.We hear from James Taylor and Michael Holding as well as the captains after England wrapped up victory over Sri Lanka in the first Investec Test. Taylor discusses how players pass the time during rain delays, his disappointment at having been forced to retire just as he was establishing himself in the England side and how he is enjoying the chance to join the big names in the Sky Sports commentary team for the day.Click here to download the latest Sky Cricket Podcast. He also talks about his upcoming surgery, fielding at short leg and playing rugby against Jonny Bairstow.Meanwhile, on the pitch England completed a comprehensive win by an innings and 88 runs with James Anderson taking another five-for to end with match figures of 10-45.Afterwards, both captains - Alastair Cook and Angelo Mathews - as well as man of the match Bairstow, gave their reaction.. Cheap Puma Shoes Wholesale. . Sky Sports Cricket Podcast - 21st May As well as that, Michael Holding explains why Englands bowlers should be given the credit rather than the Sri Lankan batsmen being blamed for their low scores at Headingley and sees promise in Kusal Mendis.The former West Indies fast bowler also ponders how England will try to replace Ben Stokes if the all-rounder is ruled out of the second Test at Durham.Watch the second Investec Test between England and Sri Lanka, at Chester-le-Street, from 10am, Friday, Sky Sports 2. Or watch from £6.99 without a contract, on NOW TV. Also See: Jimmy takes 10 in innings win WATCH: Story of D3 Scorecard As it happened ' ' '