Four men arrested for possession of drugs in the Don Bosco neighborhood hid their faces from Berehulak’s lens. While in affluent neighborhoods, the police sometimes started with a polite knock on the door and then handed a pamphlet to a housekeeper outlining the repercussions of drug use. In poorer districts, the tactics were much harsher. The police grabbed teenage boys and men off the streets, ran background checks, and made mass arrests on the spot. Daniel Berehulak for The New York Times.