This, as communist rebels reportedly owned up to the killing. A spokesman was said to have told a Manila radio station that the attack was meant as a punishment "for crimes against farmers and for being usurers."
But Senior Superintendent Arturo Lomibao, regional police director, said they were still verifying the claim of the supposed communist spokesman.
He said that besides the communist angle, the attack could also be politically motivated.
Even Hernaez’s widow, Estrella, expressed doubts on whether communist rebels had a hand in the killing. Their lawyer-son, Neil, shared the same sentiment.
Mrs. Hernaez, her husband’s vice mayoral running mate, said they have not received any death threats or letters from the New People’s Army (NPA).
Luis Jalandoni, head of the National Democratic Front’s peace panel, told radio station dzMM that they will conduct their own investigation into reports that the communist rebels were behind Hernaez’s killing.
Lomibao, meanwhile, revealed that Hernaez’s killing was captured on video by an unnamed balikbayan. The footage, he said, is being reviewed by investigators.
Singson, in a radio interview, said he was personally offering the reward for the immediate solution of the murder and for the sake of peace and order in the province.
"We should not be afraid. Let’s unite to solve this problem so that justice will prevail," the governor said.
Lomibao said many residents witnessed the killing but nobody has come forward to give information for fear of reprisal.
Hernaez was shot dead with caliber .45 and 9 mm pistols while delivering a speech in a fiesta celebration in Barangay Namatican, Sta. Lucia town. The barangay is said to be a rebel stronghold.
Also killed were the mayor’s brother Rodolfo and two police bodyguards, PO2 Robert Naungayan and PO3 William Agpalo.
Mrs. Hernaez, who was present during the attack, said the gunmen were unfamiliar to the villagers and could possibly be hired assassins employed by their political rivals.
Hernaez was seeking his third and last term as Sta. Lucia mayor under Singson’s Lakas-NUCD-Bileg party against Vice Mayor Romulo Garcia of the Liberal Party-People Power Coalition.
Police investigators said Hernaez succumbed to four gunshot wounds in the cheek and chest.
The attack, they said, was well-planned and executed "Sparrow style," referring to the NPA hit squad.
About 10 armed men were reportedly spread around the crime scene and executed the attack. They divested the two slain policemen of their M-14 rifle and caliber .38 pistol.  With Myds Supnad and Nestor Etolle