Father Brown S01 E06 The Mirror of the Magistrate

Brilliant but controversial conservative jurist Sir Arthur Travers is found murdered by gunshot in his estate garden. As he was murdered outdoors, the police are unable to explain how an indoor mirror in his house came to be shattered. Osric Orm, a Fabian Socialist known for his radical views, is charged, but Father Brown instinctively believes him innocent and sets out to find the real killer.