Sign up for the Slatest to get the most insightful analysis, criticism, and advice out there, delivered to your inbox daily. Rumeysa Ozturk, a Ph.D. student on a student visa at Tufts University, was walking down a street in Somerville, Massachusetts, on Tuesday night to meet friends to break her Ramadan fast when a man in a dark hoodie and baseball cap crossed the street toward her. Chilling surveillance footage shows the moment he approaches: “Excuse me, ma’am,” he says politely, his tone disarming. Ozturk hesitates and tries to sidestep him. Another man in plainclothes appears across the street. One...