Mayor Leon Arcillas succumbed to multiple gunshot wounds while being treated at a hospital in nearby Biñan town while one of his bodyguards, Special Action Force (SAF) Police Officer 2 (PO2) Ariel Rivera, was also killed in the attack.
Another bodyguard, identified as PO2 Nonoy Almendras, was critically wounded, police said.
Philippine National Police (PNP) chief Director General Arturo Lomibao ordered a massive hunt for the killers, who fled on foot after shooting Arcillas and his bodyguards as they walked down a second-floor hallway in the Sta. Rosa city hall.
Visiting the crime scene, Lomibao ordered the immediate relief of city police chief Superintendent Joselito Vera Cruz for laxity in securing Arcillas.
Lomibao also ordered the investigation of the seven policemen who were assigned as security escorts of the slain mayor.
Lomibao noted Vera Cruz had apparently failed to order an immediate police response to the scene.
Arcillas, 63, had just finished officiating a mass wedding for 20 couples on the second floor of the newly constructed Municipal Trial Court (MTC) when he was gunned down.
The mayor was walking along the hallway with his police escorts in tow when he was attacked by the gunmen.
Several witnesses claimed seeing the gunmen attacking simultaneously.
One of the gunmen approached and shot Arcillas at close range while two others ambushed the police escorts from behind.
Officials said one of Arcillas’ police escorts fired back at the assailants, but they escaped by quickly blending in with the crowd.
It was unclear how many were involved in the attack but Arcillas’ secretary, Sony Cerdena, quoted witnesses as saying there were at least three assailants, one of them a woman.
One of Arcillas’ civilian bodyguards, Daniel Bantatua, claimed the attack caught them completely off guard.
Bantatua gathered that the gunmen were in their early 20s and armed with caliber .45 automatic pistols.
Police investigators later released the sketches of the gunmen.
Investigators also recovered from one of the comfort rooms near the crime scene a girdle and padding which was apparently used to conceal the handguns used in the killings.
Lomibao said the discovery of the underwear supported earlier reports that a woman was involved in the killing.
Calabarzon police director Chief Superintendent Jesus Versoza, for his part, immediately formed a task force to investigate the killing of Arcillas.
Interior Secretary Angelo Reyes likewise said all possible angles in the killing must be pursued.
Reyes condemned the assassination as a "dastardly act of treachery that would not go unpunished."
"I am hereby directing the Philippine National Police to utilize all of its resources to bring to the bar of justice the perpetrators of this treacherous killing of a public official," Reyes said.
Police said the incident was the second assassination attempt on Arcillas in the past three years.
On July 7, 2003, an unidentified man shot at Arcillas during the induction of homeowners’ association officials in Barangay Tagapo of the city. The town mayor survived the attack, which was never solved.
Versoza said investigators are focusing on three possibilities — political motive, personal grudge or a threat from the New People’s Army.
Cause-oriented groups had suspected Arcillas of being behind the killing of Mely Carbajal, the leader of a militant group, in the city in August 2004.
Some urban groups also slammed Arcillas for ordering the demolition of squatter shanties in the city last year.
"We are also eyeing if there’s any connection on the demolition order of Mayor Arcillas in Pulong Sta. Cruz in Sta. Rosa," one police investigator said.
SAF director Chief Superintendent Marcelino Franco claimed Arcillas had sought police protection after receiving death threats from the NPA who were apparently angered by the death of a labor group member during a police-aided demolition of illegal structures in the city.
"He (Arcillas) sustained gunshots to the head and body," said police investigator Victoriano Perya. "The style of the attack is similar to those carried out before by the NPA."
The NPA, the armed wing of the Communist Party of the Philippines, has assassinated public officials in the past.
Police said Arcillas had been warned of an alleged NPA attempt to assassinate him.
Two weeks ago, the Sangguniang Panlunsod slammed Arcillas for his failure to update the salaries of some local government employees, including the vice mayor.
Arcillas was an in-law (balae) of former national police chief Cesar Nazareno. His daughter Arlene, a member of the city council, is married to Nazareno’s son. — With Rene Alviar, Arnell Ozaeta, Ed Amoroso, AFP