Question: where did the term serial killer come from
[{'answer': 'Robert Kenneth Ressler', 'provenance': [{'wikipedia_id': '1261856', 'title': 'Robert Ressler', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 22, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1261856', 'title': 'Robert Ressler', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 357, 'bleu_score': 0.9669306597086381, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10798516431507042556}, 'section': 'Section::::Abstract.'}]}]