Question: who killed the family in season 4 of the killing
[{'answer': 'Kyle', 'provenance': [{'wikipedia_id': '41862975', 'title': 'The Killing (season 4)', 'start_paragraph_id': 28, 'start_character': 378, 'end_paragraph_id': 28, 'end_character': 382, 'bleu_score': 1.0, 'section': 'Section::::Development and production.:Casting.\n'}]}]