Philippine President Rodrigo Duterte gestures with a fist bump during his visit to the Philippine Army’s Camp Mateo Capinpin at Tanay township, Rizal province east of Manila, Philippines on Wednesday, Aug. 24, 2016. MANILA, Philippines — A Philippine opposition senator and leading critic of President Rodrigo Duterte’s deadly anti-drug crackdown was arrested Friday on drug charges but professed her innocence and vowed she would not be intimidated by a leader she called a “serial killer.”