A man who has admitted to killing a transport network vehicle service (TNVS) driver was traced through Facebook, when he used his girlfriend's social media account, police said Monday.

Narc Delemios, arrested Tuesday, had sent surrender feelers to police prior to his arrest. He admitted killing "good samaritan" Grab driver Gerardo Maquidato.

National Capital Region Police Office Chief, Director Oscar Albayalde said Delemios was first identified through social media.

"Unang-una, na-identify siya through a Facebook account. Ginamit niya yung Facebook account nung kanyang girlfriend. Siya ang nagpa-book doon sa GRAB kaya na-identify siya," he said.

"Nagbigay siya ng surrender feelers through sa kanyang mother-in-law from Tarlac and then yung whereabouts niya naibigay din kaya may semblance ng voluntary surrender," added Director Roel Obusan of the Criminal Investigation and Detection Group (CIDG).

Obusan explained that Delemios had an existing warrant of arrest for murder committed in 2014 in Baclaran.

"Nagtago na siya from 2015 hanggang ngayon at nung nagawa niya yung krimen, tuloy-tuloy yung pagtatago niya," he explained.

Albayalde said robbery was initially the suspect's motive.

"Gusto niyang hold-up yung GRAB driver. Nag-scuffle sila kaya niya nabaril, based on investigation," Albayalde said.

For his part, Delemios apologized to the family of Gerardo Maquidato. He said he only wanted money but the victim resisted.

"Alam ko po na mahirap akong mapatawad ng pamilya. Di ko po alam na siya ay good samaritan. Humihingi po ako ng pasensiya pero mahirap po talagang maibalik," said Delemios.

Maquidato, according to the ride-hailing app, was recognized last year for giving a free ride to a sick passenger.

Maquidato's wife faced the suspect, and in tears asked why he did not give her husband a chance to live.

"Paano mo nagawa yun? Alam ko iniisip niya paano siya makawala sa iyon para makauwi sa amin. Bakit di mo pinagbigyan na mabuhay siya? Ang dami niyang panagrap sa mga anak namin, sa pamilya namin...bakit mo ginawa," she said.

PNP chief, Director General Ronaldo Dela Rosa said they now have an airtight case against the suspect.

"Rest assured the PNP will exert all effort to ensure the successful prosecution of this case to its logical conclusion," said Dela Rosa.