Philippine police on Wednesday said they used Facebook to help track down a computer technician accused of murdering nine people, three of them foreigners.
Police captured the suspect, Mark Dizon, 28, in San Fernando City north of Manila after his father, fearful that his son would be killed in a gunbattle, worked with authorities and arranged to meet him.
Witnesses initially identified Dizon as the murderer through his Facebook account, where police found out that a daughter of one of the victims was an ex-girlfriend.
"He had an account on Facebook and two witnesses positively identified him," Senior Superintendent Danilo Bautista, police chief of Angeles city where the murders took place, told AFP.
"We have an airtight case against him. I believe it is ironclad."
He said Dizon apparently closed his Facebook account after sensing police were on his heels, but two witnesses had already positively identified him using his profile picture.
The suspect tried to pull out a gun when police pounced on him Tuesday, but he was quickly subdued, Bautista said.
Dizon is suspected of killing American Albert Mitchell, 70, Briton James Porter, 51, and Canadian Geoffrey Bennun, 60, their three Filipina partners and three Filipino domestic helpers in separate attacks in Angeles this month.
All the men were retirees and lived in separate gated communities that are popular with foreigners in Angeles, which lies outside a former US airbase, Bautista said.
Angeles mayor Edgardo Pamintuan paraded a handcuffed Dizon before press photographers Wednesday and said murder charges had been filed against him.
The suspect stayed silent and tried to hide behind his police escort as he was led away, an AFP photographer said.
"Charges have already been filed against him. We have solid evidence to pin him down, including the items that he had stolen that were recovered," Pamintuan told AFP.
"We are happy that this was solved with the help of the citizenry and technology because he was identified quickly.
"I believe he knew what he was doing, because it was well-planned. It was good that we caught him because he would have struck again."
The good-looking Dizon allegedly befriended the victims first to gain their trust, so they allowed him to go into their homes freely on the pretense of fixing their computers, the police chief, Bautista said.
He then allegedly attacked them using a 9mm pistol, and robbed them of valuables including electronic gadgets which he then pawned.