Question: who is the killer in the book ordeal by innocence
[{'answer': 'Kirsten Lindstrom', 'provenance': [{'wikipedia_id': '2299915', 'title': 'Ordeal by Innocence', 'start_paragraph_id': 44, 'start_character': 374, 'end_paragraph_id': 44, 'end_character': 391, 'bleu_score': 1.0, 'section': 'Section::::Adaptations.:Television.\n'}]}]