The Central Visayas Police Office said that out of the 12 suspects, 4 were already arrested.
Danny Tancinco and Ronnie Herebias were caught last July 31 at Badian, Cebu while Jojo Ogatis and Oto Anadon were caught last August 3 at Mabato, Ayungon, police said.
Eight other suspects remain at large.
Police said they are now working on the facial composites of the suspects so the public could help locate the 8 remaining NPA members said to be responsible for the torture and death of the four policemen.
4 pulis patay sa pananambang sa Negros Oriental
The suspects are supposed spotters and the lookouts for the NPA.