128 of 151 DNA tests ‘flawed’

The first defence witness in the trial of axe murder accused Henri van Breda, pictured, took the stand for a second day yesterday in the Western Cape High Court, where she testified that most of the DNA samples analysed by the South African Police Service forensic laboratory were “technically invalid”.

DNA expert Dr Antonel Olckers told the court she received analysis of 151 DNA samples out of 216 from the crime scene. She had found that of the 151, a total of 128 were invalid. Only 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.

Earlier in the trial, state witness and chief forensic analyst Lieutenant-Colonel Sharlene Otto testified that “no unknown DNA” had been found at the Van Breda home in the luxury security estate, De Zalze, in Stellenbosch.

Henri van Breda, 22, is on trial for the axe murders of his mother, Teresa, father, Martin and brother Rudi in January 2015.

He also faces a charge of attempted murder after his sister Marli, who was 16 at the time, survived the attack. She suffered severe brain injuries.

Van Breda has claimed that an intruder with an axe and knife, wearing dark clothing, a balaclava and gloves was behind the murders. In his plea explanation, he said he recalled “the angry voices of more than one person, somewhere else in the house ... it sounded like the persons were speaking Afrikaans”.

He has pleaded not guilty to all the charges against him.

On Monday, Olckers told the court samples from the same case shouldn’t follow each other on a laboratory work list, yet this had happened with 116 samples, raising the chance of cross-contamination. 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. – ANA