SPO4 Rogelio Tamayosa gave himself up to Superintendent Rodelio Jocson, San Juan police chief, but did not turn over his issued 9 mm automatic pistol, which he used in shooting Solomon Ebalo, 47, a engineer and Narciso Bautista, 40, a messenger at about 10:45 p.m.
Ebalo and Bautista, both of 29 de Augusto street in Barangay Salapan, sustained multiple gunshot wounds in the head and body and died on the spot.
Tamayosa claimed he acted in self defense.
Police said Ebalo and Bautista were having drinks inside their house that was adjacent to a house where Tamayosa and his friends were also engaged in a drinking session.
As the evening wore on, the drinking session of Tamayosas group turned boisterous. Ebalo instructed Bautista to confront the group and ask them to lower their voices.
Investigator PO3 Alric Macatuggal said Ebalo later heard Bautista engaged in a argument with Tamayosas group.
Macatuggal said Ebalo rushed to the aid of his friend, carrying a steel bar. He allegedly attacked the group of Tamayosa.
It was at this juncture when Tamayosa pulled out his service firearm and opened fire at Ebalo. The police chief then shot Bautista.
Tamayosa fled after the incident, but later surrendered to Jocson upon the intercession of his son.
The police chief admitted shooting to death Ebalo and Bautista.
Jocson said Tamayosa arrived in Metro Manila last week to bring money for his sons schooling.
He was visiting friends in Barangay Salapan when invited for a round of drinks, which he accepted.
Jocson ordered the filing of appropriate charges against Tamayosa, who is now detained at the San Juan municipal jail.