The Mystique of David James Thompson

If what he is saying is the truth and he is holding Lucy while she's being hit with the axe, he is a participant in her homicide. It really does come down to this last statement related to this unknown white male. The thing with David James Thompson is that he had an alibi. He was at work for other men, cooperated the alibi. We don't know anything about him except he is a white guy who would have known about the space inside the house.