Eleven terrifying hours left Jeffrey R. Cohen grappling with a range of emotions for the better part of a year. It brings him to tears, recalling the way Colleyville and the larger North Texas community — spanning across religious and political affiliations — responded in the days after Jan. 15, when he and three others were held hostage in their synagogue, Congregation Beth Israel. Less often, he’s angry, mostly toward the circumstances that allowed his hate-filled and unstable captor, 44-year-old Malik Faisal Akram, to get his hands on a gun. But he also feels compassion, and some regret, that the...