A 65-year-old woman was found dead on a kitchen floor in Muizenberg, Cape Town, early on Saturday.
Also found outside the home in Uitsig Road, Marina Da Gama, was a 71-year-old man, who had been shot in the stomach.
The woman had been stabbed.
Police spokesperson Colonel Andrè Traut said it is too soon to speculate over what happened, and police are investigating the matter.
ER24 spokesperson Ross Campbell said the woman had suffered knife wounds to her head and back.
The man was found lying outside the house in a critical condition and needed advanced life support.