Another three people were still at large and police have launched a manhunt for them, said Lt-Colonel Lungelo Dlamini.
Police seized stolen goods including three firearms, a laptop, camera, binoculars and cellphones.
On Thursday night, Charles Hen Derson, 61, and his wife were ambushed by a group of men who assaulted them with knives and firearms.
The couple were tied up while the robbers ransacked their house.
The wife managed to untie herself in the early hours of Friday and went to find her husband. He had already died.
The wife is in hospital in a serious but stable condition.
The three are due to appear in the Krugersdorp Magistrate’s Court on Monday.
Dlamini said police believe the gang could be connected to other serious crimes committed in the Krugersdorp area.