Pienaar was convicted of murdering his parents, Herman Snr (58) and Christine (49), at their Valhalla home on 27 February 2014.
Pienaar shot both his parents in their heads after an argument. He had been drinking and using illegal narcotics, including CAT and cannabis, at the time.
He had also been diagnosed with bipolar and hyperactivity disorders two years prior.
During the trial, Pienaar said his father had sworn and accused him of not wanting to work.
He also claimed he wanted to kill himself but changed his mind and decided to shoot his father instead.
His mother then heard the shot and ran inside the house.
Pienaar shot her in the head too.
