Judges, defense lawyers and former colleagues say Acting Justice Danny Chun—the state court system’s first Korean-American judge—is fair, has a sharp knowledge of the law and keeps an even keel on the bench.

But the 54-year-old judge will be scrutinized as never before when he pronounces sentence on Peter Liang, a former New York City police officer who was convicted of manslaughter in the fatal shooting of an innocent black man during the patrol of a Brooklyn public housing development.