What makes the murder of Sonya and his son Frank Anthony Gregorio unique wasn't the sharp wailing of grieving relatives. It was the "relative non-reaction" of the young girl in the background, Philippe Jose Hernandez wrote in his Inquirer column Monday.

"Any human being with an ounce of humanity, of sensitivity, regardless of age, will be moved when headshots are fired and when people fall to the ground lifeless," the Philippine Daily Inquirer quoted a line in Hernandez' column.

Sonya, 52 and his son Frank Gregorio, 25 - who were both shot in the head point-blank in front of their house by an off-duty Philippine police officer - were laid to rest Sunday, two days after Christmas in what should have been a happy occasion for the family.

Rose (not her real name), 14, broke down in tears as the caskets of her brother and mother were opened during the funeral rites. "I'll never see you again... it's too painful, I can't bear this," Rose said.

More than a thousand people lined the streets during the burial at the Paniqui Garden of Angels Memorial Park in Barangay Salomague. They wore black and white shirts with the word "justice" emblazoned across the chest.

The suspect - Senior Master Sgt. Jonel Nuezca - remained in police custody pending a court decision. He is facing double murder charges.

A cellphone video of the murder went viral on social media, sparking outrage from the public who had called for the government to institute immediate reforms in the police force that has been involved in a wave of controversies this year.

When she was killed, Sonya was holding on tightly to her son to keep him from being taken away by Nuezca - who wanted to arrest him for causing alarm from an improvised pipe bomb he made and other family disputes - at the height of their altercation.