Oscar Pistorius did n't consciously pull the trigger the night he shot and killed his girlfriend , the sprinter testified at his murder trial Tuesday . The Olympic and Paralympic athlete said he was `` overcome with a sense of terror and vulnerability '' before he shot through a closed bathroom door last year , fearing an intruder was inside . Defense attorney Barry Roux asked his client what he meant when he referred to the shooting as an `` accident . '' `` I mean the situation , and the situation as a whole , it was n't meant to be , '' Pistorius said . The double amputee said he was terrified when he heard the sound of the toilet door opening . `` I did n't think about pulling the trigger . As soon as I heard the noise , before I could think , I pulled the trigger , '' he said . The testimony came after the prosecution ended five days of grueling cross-examination , which has seen the athlete break down on several occasions . Valentine 's Day card . Pistorius cried and his voice trembled as prosecutor Gerrie Nel challenged his account of what happened the night he shot and killed his girlfriend , Reeva Steenkamp . Nel asked who should be blamed for shooting his girlfriend on Valentine 's Day 2013 . `` I 'm not sure , my lady , '' Pistorius said , directing his answer to the judge . He repeatedly said he feared for his life and thought there was an intruder in his bathroom . A day earlier , Pistorius testified , `` I blame myself for taking Reeva 's life . '' He became emotional as he described finding his girlfriend slumped over by a toilet after shooting her through a closed bathroom door . `` I was saying , 'Baby hold on . Jesus , please help me , ' `` he said Tuesday . Nel has accused Pistorius of `` tailoring '' his version of events to suit his story . He questioned Pistorius on details after the shooting that the athlete said he does n't remember , such as what exactly he did with the gun immediately afterward and who connected his cell phone to a charger in the kitchen . The prosecution contends that Pistorius shot Steenkamp intentionally after a heated argument , which Pistorius has repeatedly denied . The defense ended its re-examination of Pistorius by giving the court a piece of evidence : the Valentine 's Day card that Steenkamp wrote to Pistorius . Pistorius read the card aloud . `` Roses are red , violets are blue , '' he read , his voice cracking . `` I think today is a good day to tell you that I love you . '' Gripping trial . The defense called expert Roger Dixon as its next witness to take the stand at the Pretoria court . The forensic geologist was brought into the case to analyze the lighting conditions in Pistorius ' home , specifically the main bedroom and connected bathroom . The defense team will call 14 to 17 witnesses , Roux said when he opened his case . The trial is scheduled to continue until the middle of May . Judge Thokozile Masipa will decide the verdict in collaboration with two experts called assessors . South Africa does not have jury trials . The trial has gripped South Africa and millions of sports fans around the world who saw Pistorius as a symbol of triumph over physical adversity . His disabled lower legs were amputated when he was a baby , but he went on to achieve global fame as the `` Blade Runner , '' winning numerous Paralympic gold medals on the steel blades fitted to his prostheses . Only those in the courtroom saw Pistorius on the stand because he chose not to testify on camera . His testimony could be heard in an audio feed .
` ` Before I could react , I pulled the trigger , '' M ' says . He reads the Valentine 's Day card that his girlfriend had written for him . The prosecution is trying to prove Pistorius killed his girlfriend intentionally . The double agent says that he mistook Van Steenkamp for an intruder .