DNA expert Luthando Tiya testified on Thursday in the trial of Mortimer Saunders, the man who has admitted to the shocking killing and sexual assault of three-year-old Courtney Pieters.
Tiya went into detail regarding the presumptive DNA testing that had taken place, and explained the processes followed to prevent contamination of DNA samples.
Tiya said there was a full profile match between the DNA profile found on Courtney Pieters’ top and Saunders’ DNA profile.
Tiya then went on to explain that while the second right-thigh swab tested positive for semen, the DNA was too minute to visualise a full DNA profile.
Defence advocate Mornay Calitz objected to this evidence, saying this result was not disclosed to the defence.
Earlier, the court had heard from forensic toxicologist Jacobus van Zyl, who explained how he found carbaryl in samples from Courtney Pieters’ stomach, blood and bile.
Carbaryl is a pesticide commonly used to kill insects such as ants, ticks and spiders.
In a plea explanation, Saunders admitted to feeding the child ant poison before assaulting her.
Van Zyl said he found 0.8 milligrammes a litre of poison in the child’s blood, which is more than a lethal dose for an adult.
He added he was surprised to find carbaryl in Pieters’ blood because most pesticides usually metabolised very quickly and moved into the urine.
Van Zyl said the finding told him the deceased had been exposed to a high dose of poison and death occurred quickly, in which case metabolism stopped.
Because the three-year-old’s body was only found nine days after her death, Van Zyl said there was no telling how much poison she had been given.
The matter will resume on Tuesday, June 12. Saunders remains in custody.