The victim, PO1 Romeo Abenir, 34, of Cruz St., Barangay Parang and detailed at the Police Community Precinct 11 sustained nine bullet wounds in the body. He died on the spot.
His assailant, identifed only as Aldog, a caretaker of the Astig Farm in Barangay Parang, escaped after the incident.
Senior Superintendent Felipe Rojas Jr., Marikina City police chief, said Abenir was sharing some of his fighting cocks at the Astig Farm owned by Samer Padao, better known for his aliases Andy, Boy Tangkad and Boy Muslim.
During the past cockfights, Abenirs fighting cocks lost and the policeman suspected that Aldog, has not been religiously been doing his job.
At about 3:10 p.m. Wednesday, Abenir arrived at the farm and confronted Aldog, triggering a verbal tussle.
At the height of the heated argument, the suspect reportedly grabbed a caliber 9mm automatic pistol and emptied it on Abenir.
Nine empty shells, a deformed slug for a 9mm pistol and a live caliber .45 pistol ammunition were recovered at the crime scene.
Rojas said the suspect escaped taking with him the handgun.
He said the suspect could not have used Abenirs gun because it was locked in his locker in the nearby police station at the time of the incident.
Abenirs body was brought to the crime laboratory of the Philippine National Police (PNP) in Camp Crame for autopsy.
Rojas said they are investigating reports that a number of armed men were seen inside the farm in the past.
Rojas deputy Superintendent Romeo Abaring said that Aldog admitted shooting Abenir in a cellular phone chat with a fellow Muslim who is now coordinating with him for the safe surrender of Aldog.