Question: who is the killer in season 1 of broadchurch
[{'answer': 'Joe', 'provenance': [{'wikipedia_id': '44452568', 'title': 'Broadchurch (series 1)', 'start_paragraph_id': 7, 'start_character': 306, 'end_paragraph_id': 7, 'end_character': 309, 'bleu_score': 1.0, 'section': 'Section::::Episodes.:Supplement content.\n'}]}]