In Germany, the case of a young Muslim refugee charged with the rape and murder of a teenage girl has captured media attention and rocked Germany’s Jewish community: The victim, 14-year-old Susanna Feldman, was Jewish. Missing since May 22, the girl’s body was found June 6 buried in a shallow grave near her hometown of Mainz. The case has rattled Germany, which is beset with worries about crime emanating from the large Muslim refugee population — many of whom are young, single men, frustrated and aimless. Before it appeared that anti-Semitism likely played no role in this crime, the...