Seems to me like some police departments are essentially farming drug dealers.
I suppose that’s why Duterte let’s his cops assassinate anyone they or their higher ups don’t like, under the pretense of hunting evil drug dealers. It’s a neat way of silencing individuals who are witnesses to crimes committed by said cops. Individuals, like for example a sister of a previously slain drug dealer, who knows about all the dirty dealings the cops forced on their brother before killing him, e.g because he wanted to get out.
Once everyone is afraid you can protect and serve with impunity.