On Oct. 9, 2019, a gunman tried to enter a synagogue full of Jewish worshippers in the German city of Halle. The door was locked. Instead, he shot two bystanders who happened to be nearby. This attempted massacre was a wake-up call that right-wing extremism is on the rise in Germany. On Tuesday, our colleagues with the PBS program Frontline will air the documentary “Germany’s Neo-Nazis & The Far Right.” Evan Williams is the film’s reporter, producer and director.