Chris Jooste and his wife Katrien, who were both in their sixties, were shot dead while delivering stock to a spaza shop in Soshanguve.
Jooste was shot in the stomach while on his way back to his bakkie.
His wife was shot in the chest when she tried to defend herself by spraying pepper spray on her attackers.
She managed to phone her daughter after they were shot. The couple died while on their way to hospital.
Their attackers got away with R3.50 in cash and a toy gun.
Judge Lettie Malopa found Victor Mbuyseni Simango, Solomon Solly Selekane and Collen Peter Molapo — all in their 20s — guilty of the November 2011 murders.
They were also convicted on a charge of robbery with aggravating circumstances and illegal possession of firearms and ammunition.
Simango was in addition convicted of robbing the same couple of R500 in cash while they were delivering stock in Soshanguve 16 days earlier.
A fourth accused, Nkomo Romeo Mathebula, is still being sought by the police after escaping from custody at the Ga-Rankuwa Magistrate’s Court earlier this year.
Malopa rejected the three accused’s protestations of innocence to the cold-blooded murders as lies and fabrications.
She said all of them had known what was going to happen and conspired to rob the Joostes.
She accepted the evidence of an accomplice, Gift Tuuba, who had acted as the getaway driver in Selekane’s blue bakkie that day.
Tuuba testified for the State in exchange for possible indemnity from prosecution.
He testified that Simango had given him instructions to the scene and had told him to move the bakkie nearer to the scene after the other three left the bakkie and they heard shots.
Tuuba had acted as getaway driver after the three shooters jumped into the bakkie.
Selekane denied that he had been involved in the shooting, but said he had seen Mathebula shooting “the white man” and Molapo shooting the woman.
When he asked them why they had shot the couple, Molapo said the woman had sprayed him with pepper spray.
Three witnesses who saw the incident testified that they had seen three men approaching the couple and shooting them before fleeing in a blue bakkie.
The trial was postponed to February 10 for sentencing proceedings.