PRETORIA (AFP) - The prosecution on Wednesday derided a forensic expert hired by Paralympian Oscar Pistorius, accusing him of being unqualified to testify and rubbishing his account of the circumstances of his girlfriend Reeva Steenkamp's death.
State prosecutor Gerrie Nel sought to prove that forensic geologist Roger Dixon was out of his depth when he was testifying about bruises on Ms Steenkamp's body and other key elements of the crime scene.
Mr Dixon, a university professor, told the court about the sound made by Pistorius's cricket bat hitting his toilet door, visibility in the star sprinter's bedroom and blood splatter. Under intense pressure from Mr Nel, Mr Dixon described himself as a "layman", a phrase the prosecutor seized on.
"You see Mr Dixon how irresponsible it is to try and be an expert on an area that you're not," said Mr Nel.
Pistorius' defence team has tried to prove that neighbours who testified to hearing "bloodcurdling screams" followed by gunshots were mistaken.
If proven correct, the neighbours' account could punch a hole in Pistorius' claim that he did not know Ms Steenkamp was in the toilet.
The defence team - with the help of Mr Dixon - has tried to show that the noises were in fact Pistorius bashing a cricket bat against his toilet door after realising he mistakenly killed the model.
"Are you a sound expert, sir?" asked Mr Nel. "Have you received training in decibels and sound?" Not specifically, said Mr Dixon.
He also testified that Pistorius' bedroom was so dark that the athlete could not have seen whether Ms Steenkamp was in bed. When Mr Nel asked the geologist about how he analysed the visibility in the bedroom at night, Mr Dixon said: "The instruments I used there were my eyes."
"Are you a blood splatter expert?" said Mr Nel. "I have received no training in blood splatter analysis," said Mr Dixon, a former employee of the South African Police Service.
Pistorius' lawyer Barry Roux is expected to call up to 17 witnesses to bolster the athlete's story that he shot his girlfriend by mistake, believing she was an intruder breaking into his upmarket home in a gated Pretoria community.
The Paralympic gold medallist has pleaded not guilty to intentionally killing the 29-year-old model and law graduate. He has also pleaded not guilty to three other charges connected with the reckless discharge of a firearm and the illegal possession of ammunition.
He stepped down from the witness stand on Tuesday, after a gruelling cross-examination at the hands of Mr Nel. Legal experts said Pistorius, who was evasive and argumentative on the stand, did himself more harm than good.
"I think it's a desperate man," said Mr William Booth, a criminal lawyer based in Cape Town. "The more questions you ask somebody like Oscar, it could actually get worse."
Earlier, the judge overseeing the trial granted an adjournment from Thursday afternoon until May 5, citing scheduling concerns raised on behalf of the state. The prosecution, with the backing of the defence, had asked for a delay because an assistant prosecutor is involved on another case and other members of the legal team had planned holidays.