Opposition Senator Leila de Lima on Sunday urged the National Bureau of Investigation (NBI) to investigate the recent killings involving three radio personalities who were reportedly murdered by snipers.

De Lima said the killings of radio block-timer Reynante "Rey" Cortes last July 22 and lawyer-radio hosts Hilda Mahinay-Sapie and her husband Muhaimen Mohammad Sapie last July 14 should prompt the National Bureau of Investigation (NBI) to take over investigations of sniper assassinations.

"It is alarming to hear two simultaneous reports that snipers killed these three radio personalities," De Lima said of the killings of the two victims in Davao and one in Cebu.

"Aside from their chilling effect on radio personalities and the media in general, the three consecutive murders tell us that other than the usual riding-in-tandem modus, snipers are now being used as assassins as well," she said.

Police are now looking into Cortes' work as a hard-hitting radio commentator as the possible motive in his murder, noting how he already survived an earlier attempt in his life.

Meanwhile, the Sapies, who were reportedly killed by a sniper in front of their residence in Davao on July 14, notably hosted a program where they gave free legal advice over 94.7 Power Radio Davao dxLL.

De Lima pointed out these killers should be easy to trace, since not just anyone can be a sniper as they are exclusively highly-skilled military or police personnel trained in the Armed Forces of the Philippines (AFP) and the Philippine National Police (PNP) special forces.

"All that one needs is a roster of all trained snipers of the AFP and PNP, both in the active service or retired, with focus on those with extensive combat experience and those dishonorably discharged from the service," she said.

The senator clarified, however, that her suggestion do not conclusively mean that the assassins are from the PNP or AFP, but rather "it is a place to start the investigations."

She said these cases should not be added to the PNP's list of unresolved crimes.

"Better yet, the NBI should take over the investigation of high-profile assassinations, whether involving snipers or riding-in-tandems," she stressed.

"It doesn't take rocket science to figure out that highly skilled and highly trained assets of the AFP and/or PNP are now being used in the lucrative EJK (extrajudicial killing) business, made profitable and ordinary under the Duterte regime," the detained lawmaker further said.