Antonio Liongson, NBI director for Central Luzon, refused to identify them pending the formal filing of charges this week.
The families of the three victims Arnold Mendoza, Henry Marin and Alexander Lising, all residents of Barangay Pendan here sought the NBIs help after witnesses claimed they were shot at close range and did not die in a shootout as the police claimed.
Liongson said they are filing criminal and administrative charges against the prosecutor who allegedly covered up the case to support the police claim of a shootout.
The NBI has gathered the testimonies of witnesses and crime laboratory findings which reportedly showed that the victims gunshot wounds had powder elements, indicating they were shot at close range.
Police claimed the victims were shot while attempting to flee aboard a Honda TMX tricycle along the Magalang Road in Barangay Pulung Maragul here.
A local businessman had complained that the victims, who allegedly claimed to be members of the Maralitang Hukbo ng Bayan, were extorting money from him for supposed "revolutionary taxes."
Acting on the complaint, police set up an entrapment and pursued the victims after receiving an envelope containing P2,500 from the trader.
The victims were reported to have demanded from the businessman an additional P100,000 which they were supposed to pick up later.
Learning about the alleged shootout, newsmen rushed to the scene but found the victims bodies lying next to each other away from the tricycle where they were supposed to have been shot.
There were signs that the victims were tied up when they were gunned down.