The call came over 911 at 2:16 a.m. on a cool October morning: a quick and brutal assault by two men that left a third twitching on the pavement. Minutes later, several police patrol cars arrived along with an ambulance, their lights harshly illuminating a usually quiet corner of Queens. The man, who carried no identification and could not communicate, was rushed to a nearby hospital with head trauma. Then the police left the scene, after making a quick and incorrect assessment that no crime had been committed. Roughly 12 hours later, after the man’s husband filed a missing-person report, detectives identified the patient with severe brain injuries as Louis Rispoli, a 62-year-old gay rights activist and mainstay of the close-knit community in Sunnyside, Queens.