DAVAO CITY, Philippines — The police warned 14-year-old Bobby Alia that there would be consequences after he was accused of stealing a cellphone in November 2003, the boy’s mother said. A few days later he was dead, stabbed in the back with a butcher knife.

He was the third of Clarita Alia’s sons to die in Davao, the southern Philippines’ largest city, in killings that remain unsolved. A fourth was killed in 2007. All had been accused of crimes, all were stabbed and all, Ms. Alia said, had received similar warnings from the police.

For years, rights groups have called for an investigation into whether Davao’s mayor, Rodrigo Duterte — the tough-talking politician who next month will become president of the Philippines — was complicit in the killings of hundreds of people in Davao since the 1980s by what they describe as government-sanctioned death squads.  Continue reading…