An elderly couple in Sitio Kimamaon, Kimaya in Jasaan town was found dead inside their home on Wednesday.
Victorio Ipulan, 72, sustained 2 stab wounds while his wife Adelaida, 68, was stabbed 5 times in different parts of the body.
Emricko Tabequero, son-in-law of the victims, suspected that the couple could have been dead since Monday since no one saw them leave their house that day.
"Our initial motive is robbery because some disclosed to us that the couple has savings from their rice field, corn field they also have a sari-sari store," said Chief Inspector Rogelio Labor Jr.
The family, however, could not confirm if the couple lost their money after the incident but said it is possible because they are earning from their farm.
Police are securing sworn statements against "persons of interest" in the incident.