On May 14, five days after voters in the Philippines chose Davao Mayor Rodrigo Duterte as their next president, two masked gunmen cruised this southern city's suburbs on a motorbike, looking for their kill.

Gil Gabrillo, 47, a drug user, was returning from a cockfight when the gunmen approached. One of them pumped four bullets into Gabrillo's head and body, killing the small-time trader of goods instantly. Then the motorbike roared off.

The murder made no headlines in Davao, where Duterte's loud approval for hundreds of execution-style killings of drug users and criminals over nearly two decades helped propel him to the highest office of a crime-weary land.