The heartless trio was allegedly part of a gang of about 12 men who attacked two couples at the park in Kensington Gauteng .
The accused have been charged with murder, rape and robbery.
Judge Papi Masopa has found Admore Ndlovu, Thabo Nkala and Mduduzi Mathibela Lawrence guilty on all charges.
Masopa says the trio failed to convince the court beyond reasonable doubt that they did not commit the crimes.
The judge went on to say the convicted murderers worked together with a common purpose to execute their crimes.
The two women who were raped and widowed broke down in court as Judge Masopa handed down his judgment, they were comforted by friends and relatives.
On 17 October 2015 the two couples were walking through Rhodes Park when they were approached by a gang of about 12 men.
Police say the gang tied the husbands up and threw them in a dam, where they drowned.
One of the women was gang raped while the other managed to escape.
The court is now due to hear argument in mitigation of sentence.