In the wintry darkness 23 years ago on a back street in Williamsburg, Brooklyn, a jewelry thief fleeing a botched robbery panicked and shot a Hasidic rabbi in the head. Four days later, the rabbi, Chaskel Werzberger, an Auschwitz survivor, died of his wounds. Even in the New York City of 1990, as homicides crested at 2,245, the murder stirred grief and outrage. The “Slain Rabbi” was front-page tabloid news. Mayor David N. Dinkins traveled to Williamsburg’s Satmar enclave to sit in mourning and to offer a $10,000 reward.