BERLIN—A German court on Monday convicted a right-wing extremist of murder and attempted murder and sentenced him to life in prison for his attack on a synagogue last year on Yom Kippur, Judaism’s holiest day. He killed two people after he failed to gain entry to the building. The Oct. 9, 2019, attack is considered one of the worst anti-Semitic assaults in Germany’s post-war history. The 28-year-old defendant, Stephan Balliet, posted a screed against Jews before trying to shoot his way into the synagogue in the eastern city of Halle while broadcasting the attack live on a popular gaming site. Judges at the Naumburg state court, which met in the state capital of Magdeburg for security and capacity reasons, on Monday found him “seriously culpable,” news agency dpa reported. That means he will be effectively barred from early release after 15 years, which is typical for people in Germany given …