Authorities will look into criminal records of Pasay City Councillor Borbie Rivera after he was killed outside SM Southmall in Las Pinas last Saturday.

Chief Superintendent Tomas Apolinario, director of the Southern Police District, in a radio interview said a possible motive of Rivera's death is related to his murder case last 2014.

Apolinario said threats against the councilor's life started after his case was dismissed.

"He was arrested that time. That's why he was detained for more or less one year and one year and a half. That's the first lead we are looking because after he was detained and eventually the case was dismissed. After that case, that's when attempt to kill him started," he said.

They are also looking into political rivalry, business, and personal grudge as possible motives.

Rivera was shot at door number 4 near the parking area of SM Southmall around 8:30 pm.

Las Pinas City police director Marion Balonglong, in another radio interview, said Rivera was brought to Asian Hospital and Medical Center but was pronounced dead on arrival.

He suffered gunshot wounds in the head and body.

Balonglong said unidentified suspects approached Rivera and shot him. On board a motorcycle, they fled towards unknown direction after colleagues of Rivera retaliated.

Apolinario said Rivera's son was the one who tried to follow the suspects.

He said, based on their initial report, around three to four suspects were involved.

He said they will check the CCTV footage in the area for more evidence.

He added a joint investigation is being conducted by Las Pinas City Police Station and Pasay City Police Station.

SM Southmall management, in a statement at its Facebook page,. said they returned to normal operations after authorities declared that it's safe to re-open the establishment.

"The mall is back to normal operations. A joint investigation with the PNP is currently ongoing," SM said. Ella Dionisio/DMS