Cape Town - A witness for the defence in the trial of triple murder accused Henri van Breda admitted in the Western Cape High Court on Monday that she has never been employed in a forensic laboratory.
DNA expert, Dr Antonel Olckers, faced gruelling cross-examination from senior state prosecutor Susan Galloway who attempted to show the court that her experience consisted of mostly "administrative and academic positions".
Olckers was hired by Van Breda's defence team to test the validity of DNA evidence presented by state witness and chief forensic analyst at the police's forensic laboratory, Lieutenant Colonel Sharlene Otto.
Van Breda, 22, faces three charges of murder, one of attempted murder and one of defeating the ends of justice for the January 2015 axe attacks on his family at their luxury home in Stellenbosch.
He has pleaded not guilty to all the charges.
Instead, he claims that after a fight with an axe-wielding intruder who was also armed with a knife, the man had escaped. Otto, however, who analysed 216 samples from the crime scene, testified that "no unknown DNA" had been found.
Last week, Olckers told the court that she received analysis of 151 DNA samples out of the 216 taken from the crime scene. She found that of the 151, a total of 128 were invalid. She said just 23 samples could be considered valid.
Olckers said standard operating procedures had not been followed and a breakdown in three processes in particular invalidated the analysis.
She told the court that samples from the same case shouldn’t follow each other on a laboratory work list, yet this had happened with 116 samples in this case, raising the chance of cross-contamination.
Furthermore, she said there were 32 DNA samples where the expiration date of Hemastix, used in presumptive testing for blood, was not indicated. She testified that it cannot be used once expired.
Triple murder accused Henri van Breda. Picture: Catherine Rice / ANA
On Monday, Olckers confirmed that she had revised her report and had only completed and handed it to the court on October 6, after the state's DNA experts and blood spatter expert had taken the stand.
"I sent it to counsel and some verification took place. I sent the revised report on 6 October. This is the summary, the scope had changed over time".
She said the scope had narrowed as "we had to focus on aspects that were most scientifically pertinent".
Judge Siraj Desai was visibly irritated that her report had been compiled after key testimony from state witnesses, saying: "It would be really helpful if you produced your report before you could be clouded by the evidence and what counsel told you".
Desai dismissed objections from defence lawyer Matthys Combrink.
The trial continues.