Question: how do owen and riggs know each other
[{'answer': 'had been friends', 'provenance': [{'wikipedia_id': '50811211', 'title': 'Nathan Riggs', 'start_paragraph_id': 3, 'start_character': 186, 'end_paragraph_id': 3, 'end_character': 202, 'bleu_score': 1.0, 'section': 'Section::::Storylines.\n'}]}, {'provenance': [{'wikipedia_id': '50811211', 'title': 'Nathan Riggs', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 719, 'bleu_score': 0.9643025203494101, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1450809715242082054}, 'section': 'Section::::Storylines.\n'}]}]