Question: "Cold North Killers: Canadian Serial Murder" is a 2012 Canadian non-fiction book that documents the lives of sixty Canadian serial killers one of whom was a former what?
{'answer': 'Colonel in the Canadian Forces', 'supporting_facts': [['Cold North Killers: Canadian Serial Murder', 0], ['Cold North Killers: Canadian Serial Murder', 1], ['Russell Williams (criminal)', 0]]}