On the morning of Oct. 27, 2018, a gunman walked into the Tree of Life synagogue in Pittsburgh and killed 11 people who had gathered to worship, the deadliest antisemitic attack in the nation’s history. On Monday, more than four years later, the trial of the man accused of the massacre will begin with jury selection. The trial will take place in two phases, the first concerning guilt and the second on the penalty. As the facts surrounding the shooting are mostly undisputed, it will effectively be a monthslong tribunal about whether the defendant, Robert Bowers, 50, should be executed....