Question: who killed katie in the movie mystic river
[{'answer': 'Dave', 'provenance': [{'wikipedia_id': '460052', 'title': 'Mystic River (film)', 'start_paragraph_id': 4, 'start_character': 43, 'end_paragraph_id': 4, 'end_character': 47, 'bleu_score': 1.0, 'section': 'Section::::Plot.\n'}]}, {'provenance': [{'wikipedia_id': '460052', 'title': 'Mystic River (film)', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 725, 'bleu_score': 0.937648651979853, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14624939877916021566}, 'section': 'Section::::Plot.\n'}]}]