Cape Town - Musician Arno Carstens' defence team will not call any witnesses in his drunken driving trial, the Cape Town Magistrate's Court heard on Wednesday.
His lawyer Milton de la Harpe told magistrate Nadia Banwari the defence was closing its case. No witnesses would be called because the defence felt the charges against the former Springbok Nude Girls' frontman had not been proven, he said.
The trial was postponed until July 24 for closing arguments and possible judgment.
Carstens has pleaded not guilty to a charge of drunk driving, alternatively driving with a blood-alcohol level of 0.20 percent. The 0.20 percent level came from the State's analysis. The legal limit is 0.05 percent.
He was arrested in central Cape Town in December 2010 when a traffic officer noticed his black Mercedes-Benz swerving.
De la Harpe has attacked the State's case from all angles. In previous appearances, he sought to cast doubt on the level of care taken when his client's blood was initially drawn and when it was analysed later.
He criticised the conduct of nurse Sheila Newman, who testified she dabbed Carstens' arm with cotton wool dipped in clean water before inserting the needle to draw his blood.
De la Harpe said this went against instructions in a pamphlet of the blood testing kit, which recommended that a non-alcoholic antiseptic be used to clean the needle site.
He questioned her method of mixing the blood with sodium fluoride, to prevent bacteria from forming.
Newman testified to tilting the tube only two or three times, but the testing kit recommended the tube be tilted 10 times.
“I've been taking blood since 2006, and I've never got a complaint from the lab saying the blood was not mixed well,” she said at the time.
When De la Harpe cross-examined laboratory analyst Pakami Pati, he revealed he would call for Carstens' acquittal during closing arguments on the grounds that her analysis of his blood was unreliable.
“I will say that, due to careless practices in the laboratory, some of the blood used in a previous test contaminated my client's blood,” he said.
He repeatedly argued that there was a huge chance for the blood sample to be contaminated by bacteria or other micro-organisms.
The State called in a scientific expert to conduct an independent analysis of Carstens' blood by looking at the raw data.
Expert witness Tim Laurens, head of forensic toxicology at the University of Pretoria, concluded that his analysis matched the State's.
De la Harpe put it to Laurens that forensic medical literature proved Carstens' behaviour during and after his arrest was not that of a man whose blood alcohol level was 0.20 percent.
He stated that Carstens should have suffered speech impediment, muscle impairment and memory loss at the time of his arrest, but instead had no such behaviour.
On Wednesday, he questioned Laurens' credibility. He said Laurens was not qualified to testify about microbiology because he was registered as a chemical scientist and not a microbiologist with the SA Council for Natural Scientific Professions (SACNASP).
Laurens replied that there were many grey areas in science.
“Science is a multi-disciplinary thing and there is a great overlap. Biochemistry is also chemistry and in my opinion I am very much qualified to testify on the formation of ethanol from glucose.”
Laurens said, however, that he had never created the impression he was an expert in microbiology.
Carstens, always dressed in a smart suit, has seemed frustrated with the slow pace of the trial. During his appearances in the dock he has fidgeted and run his hand through his hair, during periods of repetitive or technical questioning.