Police said Nelson Borja, 32, found the bodies of his wife, mother-in-law and daughter on the second floor of the house at 213 Yuan street, North Fairview.
The victims, who sustained several stab wounds in various parts of their bodies, were identified as Narcisa Elpedis, 60, her daughter Jona Borja, 32 and Juliana, who was seven months old.
Initial investigation revealed that Borjas wife took the baby to the house of her mother to borrow money, which her husband needed as placement fee to work abroad.
The mother left for the nearby subdivision at around 8 a.m.
The father said he later received a call at around 11 a.m., informing him that his his wife was killed at his mother-in-laws house. He rushed immediately to the house.
Investigators are eyeing robbery as a possible motive in the killing.
Initial investigation, however, showed there were no signs of forcible entry.
In Muntinlupa City, a 58-year-old businessman was killed while his 24-year-old son was seriously wounded after five armed men broke into their house last Wednesday night.
Senior Police Officer 1 Ricardo Gomez, officer-on-case, identified the victim as Tito Patdu, a resident of Estanislao street, Lakeview Homes, Barangay Putatan, Muntinlupa City.
Patdu sustained multiple gunshot wounds in the different parts of the body.
His son, Joey, who works at Muntinlupa City Hall, sustained a lone gunshot wound in the chest.
He is still under observation at the Muntinlupa Medical Center.
Initial investigation conducted by the police showed that the suspects barged in at around 8:30 p.m.
One of the suspects, upon seeing the elder Patdu, shot him several times in different parts of the body using a caliber .45 revolver.
Hearing the shots, Patdus son rushed to the living room and saw his father lying in a pool of blood.
The suspect also shot Joey in the chest, before fleeing the scene.
The two were rushed by neighbors to the Muntinlupa Medical Center.
Police Inspector Giovanni Martinez, head of Muntinlupa police Investigation and Intelligence Unit, said a witness, a tricycle driver, later appeared at the station.
The witness said he saw the suspects leaving the house of the victim, and when they saw him, poked a gun at him.
They then boarded his tricycle.
The tricycle driver dropped off the suspects near the Country Homes area in Barangay Putatan and fled on foot.
Gomez said the Patdus are a well-to-do family in the area, being engaged in the selling of metal drums.
The police are conducting a follow-up investigation on the case to track down the suspects. With Rhodina Villanueva