A teenager last week allegedly succeeded in killing his father in Rockville, Soweto, after having failed several times in the past.
The 17-year-old allegedly stabbed Phinda Thabethe 14 times after his father had asked him why he had taken so long to return from the shop, said the deceased's wife Makie Thabethe.
Thabethe was a teacher at Crestview Primary in Alberton.
One of two friends with whom the deceased was having tea said Thabethe had quarrelled with his son inside the house and then joined them outside.
He entered the house again and a short while latter they heard him screaming.
The friend said he rushed into the house and found his son stabbing his father repeatedly. The friend, who asked not to be named, said he disarmed the boy and called the police and ambulance.
Thabethe was certified dead on the scene.
The boy ran away but returned with his mother. Police at the scene arrested him.
Thabethe's brother, Umziwakhe Thabethe, said the family was in shock.
"What happened is a shame," Thabethe said. "My mother, who is always in and out of hospital, is taking it very hard."
The deceased's wife said she had moved out of the family home because of problems with her son but had recently returned "to help my husband deal with him".
She said her son had in the past tried to set his father alight with petrol, but luckily he was saved by the neighbours.
"He misbehaved at school and at home. He used drugs. Now I am scared of going back to my house," she said.
Captain Mpande Khoza of Moroka police said the teenager would appear in court soon.