“I pleaded not guilty because what I am accused of did not happen,” said Pistorius.
Prosecutor Gerrie Nel had asked him how he selected his plea when he appeared in court last year after shooting Steenkamp dead in his toilet on Valentine’s Day.
Pistorius said he thought there was an intruder in the bathroom when he fired four quick shots from his firearm.
The State alleges they had argued and that her death was premeditated.
Pistorius said he did, however, believe that the bloodied scene at his house in Pretoria was tampered with and that his counsel would present witnesses to testify to this.
Nel defined the word tampering twice for him at his request “It is ‘you change something on the scene with the intention to let it look different’.”
Pistorius said according to his legal counsel there had been tampering, disturbance and contamination of the scene.
People were in the house without protective clothing, Steenkamp’s iPhone had been moved, according to police photographs taken of the scene, a fan had been unplugged, curtains had been opened and discs had been moved.
He said anything that was changed would bother a person involved in such a serious case.
A detective who was among the first on the scene, Warrant Officer Hilton Botha, was removed from the case and has since resigned from the police.