Pistorius retches as he details moments before shooting

PRETORIA, April 8 (Reuters) - South African Olympic and Paralympic sprinter Oscar Pistorius retched on the witness stand on Tuesday as he described the moments leading up to the shooting of his girlfriend, Reeva Steenkamp, on Valentine's Day last year. During a morning of dramatic court testimony, Pistorius, who is accused of murdering Steenkamp, recounted how he heard a window sliding open in his bathroom in the middle of the night, convincing him an intruder was breaking in and that he needed to arm himself. "That's the moment that everything changed," he said, his voice tense with emotion. "I thought that there was a burglar that was gaining entry to my home." When post mortem pictures of Steenkamp's bloodstained body briefly flashed up on the courtroom television monitors, the 27-year-old athlete doubled over in the witness stand, retching into his cupped hands. Pistorius fired four rounds through the door, three of which hit Steenkamp, killing her almost instantly. He denies murder, saying he fired in the belief an intruder was behind the door. (Reporting by David Dolan; Editing Ed Cropley)