Philippine police tracked down a suspect in a series of grisly robberies and killings with the help of his Facebook account, officials said Tuesday.

Mark Dizon, a 28-year-old computer technician, did not resist when arrested Tuesday while talking with his father in a public square in northern San Fernando city, police Senior Supt. Danilo Bautista said.

He is accused of killing nine people, including six Filipinos, an American, a Canadian and a Briton, in three different robberies at hotels and homes this month in Angeles city.

The area, near the former U.S.-run Clark Air Force Base some 80 kilometres northwest of Manila, is home to many retired expatriates.

Dizon, who is from a well-off family and according to police had a fascination with guns, was Facebook friends with the daughter of one of the victims. A friend of her family showed his photo on the popular social networking site to witnesses to help identify him, police said.

Murder charges will soon be filed against Dizon, who denied involvement in the killings, Bautista said. The string of deadly robberies started July 12, when Canadian Geoffrey Alan Bennun, 60, and his Filipino girlfriend were shot to death after a robber broke into their hotel room.

In the latest killing last week, a gunman killed American Albert Mitchell, a 70-year-old veteran of the U.S. Air Force, along with his Filipino wife, Janet, 53, and three Filipino staff inside their Angeles home, Bautista said.

The fleeing gunman was seen by a village guard and a motorcycle taxi driver, who later described him to investigators, according to police.

After hearing descriptions of the suspect, a family friend of the Mitchells looked up Dizon's Facebook page — the Mitchells' daughter was one of his friends on the site. He showed the Facebook profile photo to the witnesses, who identified him as the man fleeing they saw, Bautista said.