DNA experts’ showdown: Otto vs Olckers in the Van Breda trial

10 October 2017 - 15:06 By Tanya Farber
Lieutenant Colonel Sharlene Otto at the trial of Henri van Breda on 10 October 2017.
Lieutenant Colonel Sharlene Otto at the trial of Henri van Breda on 10 October 2017.
Image: Ruvan Boshoff

Both are highly experienced DNA experts‚ and both have delved deeply into the Van Breda triple axe murder trial on a molecular level - quite literally.

Lieutenant-Colonel Sharlene Otto is a chief DNA analyst for SAPS and spent hours upon hours in the witness box in Cape Town High Court being cross-examined by Henri Van Breda's defence counsel who seemed painted in a corner when highly damning evidence against him came to light last month.

Van Breda is accused of murdering his father Martin‚ mother Teresa and brother Rudi. In addition he has been charged with the attempted murder of his sister Marli.

This week in court‚ the defence lashed back with their own DNA expert‚ Dr Antonel Olckers‚ who started and heads up DNAbiotec and who spent the first two days of this week discrediting the work of the SAPS laboratory.

Otto said:

  1. The DNA of Teresa and Rudi were found on nail scrapings taken from the accused.
  2. Their DNA was also found on the blood stains on his shorts.
  3. In all 216 samples that were tested‚ enough DNA was present to get an accurate result. The majority of the samples were done with “good quality DNA which we did not struggle to get”‚ she said.
  4. Yes‚ 39 had been loaded with “less than optimal” amounts of DNA. However‚ “less than optimal” did not mean they were invalid and‚ on the contrary‚ “all results obtained were reliable and valid”. She said that the Standard Operating Procedures stated a recommended amount as a guideline for what was optimal‚ but did not mean that anything that fell short of that would not give a result.
  5. She said the Standard Operating Procedures which the defence claimed were violated were being misrepresented.
  6. No‚ the SAPS lab is not accredited - but not for a lack of trying. She has been there 24 years and is still waiting to be audited so they can get their accreditation.

Olckers said:

  1. In the case of 39 (of 216) samples‚ less than 1ng of DNA was available and therefore the results should not be seen as valid.
  2. Personnel at the laboratory had erred in allowing samples from the Van Breda family to follow one another on the work list when they should rather be separated to prevent cross-contamination. There has been no suggestion yet in court that such cross-contamination had occurred‚ but according to Olckers‚ it indicated a contravention of the Standard Operating Procedures.
  3. The lab's lack of accreditation means that "no standardised independent audit" of the lab has been done.
  4. Where Teresa and Rudi's DNA is said to be in a mixture with that of Henri's own DNA‚ it is possible that only Rudi and Henri's DNA would have been detected if a different analysis kit was used.
  5. Nobody can confirm if the substances used in some of the analysis kits had expired or not.

The case has been adjourned to Monday.