MANILA - As he bade goodbye to his slain son, Saldy Delos Santos could not help but question why it had to be his child.

Delos Santos, father of 17-year-old Kian Loyd who was killed in a police operation in Caloocan City last week, was in tears as he addressed hundreds of condoling friends and loved ones at the funeral mass for the boy at the Sta. Quiteria Church Saturday morning.

Delos Santos, who was unable to sleep on the final night of his son's wake, admitted he was still at a loss for words.

"Minsan natanong ko sa anak ko, bakit ikaw pa eh napakabait mo?" Delos Santos said in his eulogy.

He said he always depended on Kian to man their family's store in the morning before the boy went to school, and even in the evening when it's time to close shop.

"Mula alas-6 ng umaga, gumigising na ang anak ko, ilalatag 'yung paninda namin. Pagdating ng alas-12 [ng tanghali], ako naman ang papalit sa kanya. Bandang alas-7 [ng gabi] pag-uwi niyan, tutulong pa magligpit ng paninda. Paano mapapasok ang droga sa pamilya ko?" he said.

His son's shooting in an anti-drug operation on Aug. 16 has drawn heavy public condemnation as witness statements and forensic and video evidence indicate that he was executed.

Delos Santos said it is very hard for the family to accept that the child they raised to become a good citizen was just killed in an instant.

"Hindi ko na alam ang gagawin ko, pinaaaral ko ang anak ko para maging mabuting mamamayan ngunit sa isang saglit ay papatayin na lang," he said.

"Punong-puno ng pag-asa 'yung bata," he said referring to his 17-year-old son who wanted to be a police officer.

Ironically, it was the police who took Kian's life, accusing the teenager of resisting arrest and fighting back with a gun during an anti-drug operation.

"Hinuli nila 'yung anak ko, pinipilit nilang magturo ng bahay na may droga. Nagmamakaawa ang anak ko, wala ba silang puso?" he said sobbing

"Sana naririnig ng mga bumaril sa anak ko 'yun. Pero kung may puso pa sila, maraming simbahan, magsimba sila. Sa lahat ng mga pulis na nakapatay ng inosente, magsimba kayo, hindi pa huli para magbago," he added.

Delos Santos said he wishes that the cops who killed his son would not suffer the same fate because the pain is indescribable.

"Alam ko ama rin kayo... Alam ko kung gaano niyo kamahal ang una niyong anak na lalaki... Ganoon din ako," he said.

Delos Santos and his wife Lorenza tried to keep a straight face and stay strong during the final mass for their son.

But there were times when they suddenly burst into tears.

Their emotions poured out when they were asked to bless their dead son's body with holy water.

Kian was killed during a "One Time, Big Time" police operation in northern Metro Manila last week as police continued to enforce the Duterte administration's war on drugs.

Police alleged that they were forced to shoot Kian after the boy supposedly fired at them. But CCTV footage showed the teen being dragged by two men, supposedly police officers, before he was killed.

Two officers initially admitted it was them seen in the video dragging the boy, but one later denied this at a Senate hearing.

• READ: PNP-IAS: Cops' turnaround on CCTV clip of Kian's killing 'expected'

Autopsy results showed that the boy sustained fatal gunshot wounds to the head while he was already on the ground kneeling and turning away from the police.

• READ: PNP, PAO agree on autopsy: Kian already down when shot

Kian's death has sparked outrage against drug-related killings under the administration's war on drugs.

Members of various groups joined the funeral procession for the boy chanting, "Justice for Kian! Justice for all!"

Before proceeding to the church, Kian's funeral car stopped at the police station where the policemen tagged in his killing were assigned. The three officers were earlier relieved.

• LOOK: Caloocan police station 'undermanned' after Kian's slay