Mrs. Arroyo said the government "condemns the killing" of Arcillas and assured his family that police investigators will leave no stone unturned in identifying the killers.
The President issued the statement as the murder investigation shifted focus onto the possibility that it was triggered by alleged irregularities in the disbursement of campaign funds during the local elections last year.
Sources privy to the investigation said that before Arcillas was killed, the mayor called on the police Criminal Investigation and Detection Group (CIDG) in nearby Cabuyao town to investigate the disappearance of funds concerning their Lakas-Christian Muslim Democrats chapter.
The investigation over the funds could have triggered his detractors to liquidate the mayor, the source pointed out.
Officials, however, maintained the investigation is still looking into the possibility that communist New People’s Army (NPA) hitmen were behind the killing.
Arcillas, 63, had just finished officiating a mass wedding for 20 couples at the second floor of the city hall building when he was gunned down by at least three assailants.
One of his bodyguards, Police Officer 2 (PO2) Erwin Rivera, also died during the attack Tuesday.
Calabarzon police director Chief Superintendent Jesus Verzosa said another bodyguard identified as PO2 Nonoy Almendras was critically wounded.
Verzosa added investigators have noted Arcillas had been under threat by the NPA for the past three years.
Police said the manner of Arcilla’s assassination was similar to methods employed by NPA hitmen.
Investigators are also focusing on the statements of a witness claiming he saw a man believed to have sneaked in and hidden the murder weapons in the restroom of the building where Arcillas was gunned down.
The witness claimed he saw a man enter the city hall premises earlier in the morning.
Investigators recovered from the restroom near the crime scene a girdle and padding, apparently used to conceal the pistols used in Arcillas’ killing.
Police said the discovery of the undergarments supported earlier reports that a woman may also have been involved in the killing.
Investigators said they are also focusing on political motives and personal grudge. — With Rene Alviar