Wade died three days after being admitted to Steve Biko Academic Hospital in April 2009 after receiving brain injuries, broken ribs, and bruises all over his body
In June 2012, both pleaded not guilty to charges of physically harming and murdering their two-month-old baby son and abusing another child. The trial continues.
Police arrived at the premises after Engelbrecht contacted his brother, who then contacted the authorities. Engelbrecht later drove into a truck, killing himself.
He is further alleged to have shot dead her 19-year-old son Conrad, who was lured to the house and had pleaded for his life.
Kotze faces 17 charges, including rape, murder, conspiracy to rape, kidnapping and assault with intent to cause grievous bodily harm.
The case is continuing. Kotze and his co-accused were refused bail.
The 61-year-old man is thought to have been angry that Innus wanted to search for his biological family, Beeld newspaper reported. He was arrested with the gun still in his hand.